MORPHOLOGY AND GENESIS OP SOME SOILS CONTAINING PRAGIPANS IN NORTHERN MICHIGAN By N ic o la o s John Ya.ssoglou AN ABSTRACT S u b m itte d to th e School o f G rad u ate S tu d ie s o f M ic h ig a n S ta te U n i v e r s i t y o f A g r ic u lt u r e and A p p lie d S cien ce in p a r t i a l f u l f i l l m e n t o f th e re q u ire m e n ts fo r th e d eg ree o f DOCTOR OP PHILOSOPHY D epartm ent o f S o il S cie n c e 1959 Approved N ic o la o s John Y asso g lo u ABSTRACT The m orphology and g e n e s is o f th r e e s o i l p r o f i l e s t i v e o f th e M cB rid e, r e p r e s e n ta ­ I s a b e l l a and N e s te r s e r ie s w ere i n v e s t ig a t e d . Th ese th r e e s e r ie s c o n s t i t u t e a 1 1 thosequence o f w e ll d r a in e d , b is e - q u s l p o d z o ls o f N o rth M ic h ig a n form ed on c a lc a re o u s sandy loam , c la y loam, and c la y loam t i l l , sandy r e s p e c tiv e ly . S o ils o f th e above lith o s e q u e n c e f r e q u e n t ly c o n ta in fr a g ip a n s , h o r iz o n s , w hich a re r e v e r s i b l y in d u r a t e d when d ry and f r i a b l e o r f ir m when w e t. FT ag ip an s a re form ed i n th e e l u v i a l They have h ig h b u lk d e n s i t ie s , r e s tr ic t zone o f th e lo w e r sequura. and lo w w a te r p e r m e a b i l i t i e s . They th e r o o t g ro w th o f p l a n t s . C h e m ic a l, p h y s ic a l, m in e r a lo g ic a l and m ic ro s c o p ic a l d e te rm in a ^ t i o n s showed t h a t th e n e c e s s a ry c o n d itio n s f o r th e in d u r a t io n o f th e f r a g ip a n w ere th e c lo s e p a c k in g o f th e sand and c o a rs e s i l t g r a in s an 55optimum" c la y c o n te n t. o f n o n -e x p a n d in g m in e r a ls The c ls y o f th e f r a g ip a n c o n s is ts m a in ly (illite , c h lo r ite , k a o lin ite ). s o l i d b r id g e s h o ld in g to g e th e r th e sand g r a in s . h a v e a c e m e n tin g r o l e , and as i t It form s F ree a lu m in a may a ls o shows a s m a ll in c re a s e i n th e f r a g ip a n . The im p o r ta n t p r o p e r t ie s o f th e fr a g ip a n have been d e ve lo p e d g e n e t ic a lly . The c lo s e p a c k in g o f th e g r a in s , th e lo s s o f th e non­ e x p a n d in g c l ^ r and th e re a rra n g e m e n t o f th e m a t r ix su b stan c e s r e s u l t in a s i g n i f i c a n t r e d u c t io n o f th e volume o f th e fr a g ip a n fo r m a tio n o f v e r t i c a l c ra c k s i n R e s u lts o f X - r a y , ses showed t h a t i l l i t e and i n th e t h i s p a r t o f th e p r o f i l e . H T .A ., s p e c ific and i n t e r s t r a t i f i e d s u rfa c e and t o t a l K a n a ly c la y s a re b e in g d r a s t i c a l l y N ic o la o s John Y asso g lo u w e a th e re d n e a r th e s u r fa c e o f th e s o i l . m o r illo n ite and v e r m i c u l it e D is c r e te m in e r a ls o f m ont- a re b e in g form ed t h e r e . The p rim a ry m in e r a ls w h ich showed s i g n i f i c a n t w e a th e rin g ares c a lc ite , h o rn b le n d e , o liv in e and e p id o te . The w e a th e rin g o f both th e c la y and p r im a ry m in e r a ls d e c re a s e s w ith in c r e a s in g d epth from th e s u r fa c e . F ilm s o f a n is o t r o p ic th e th in h o r iz o n . s e c tio n s o f a l l ( w e l l o r ie n t e d ) c la y have been seen in th e h o r iz o n s o f th e lo w e r sequa e xc e p t th e C The number and th e th ic k n e s s o f th e f i l m s , how ever, w ith d e p th and re a c h a maximum in in c re a s e th e Bt h o r iz o n . The P o d z o l sequa a re c h a r a c t e r iz e d by a h ig h s t a t e o f p h y s ic a l, b io lo g ic a l, and c h e m ic a l a c t i v i t y , w h ile th e G ray-B row n P o d z o lic a r e c h a r a c t e r iz e d by h ig h p h y s ic a l a c t i v i t y . g ic a l a c t iv it ie s p o d z o l sequa. in th e l a t t e r sequa The c h e m ic a l and b io lo ­ sequa seem to be lo w e r th a n in th e MORPHOLOGY AND GENESIS OF SOME SOILS CONTAINING FRAGIPANS IN NORTHERN MICHIGAN By N ic o la o s John Y asso g lo u A THESIS S u b m itte d to th e School o f G rad u ate S tu d ie s o f M ic h ig a n S ta te U n i v e r s i t y o f A g r ic u lt u r e and A p p lie d S c ie n c e i n p a r t i a l f u l f i l l m e n t o f th e re q u ire m e n ts f o r th e d e g ree o f DOCTOR OF PHILOSOPHY D epartm ent o f S o il S cie n c e 1959 ProQuest Number: 10008536 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. uest ProQuest 10008536 Published by ProQuest LLC (2016). Copyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code Microform Edition © ProQuest LLC. ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106- 1346 ACKNOWLEDGMENT The a u th o r w ish e s to e x p re s s h i s s in c e r e g r a t i t u d e W h ite s id e f o r h i s i n t e r e s t to D r. E. P . and g u id a n c e th ro u g h o u t th e c o u rs e o f t h i s s tu d y . Also he w ould l i k e D r. B. T. S a n d e fu r, D r. to th a n k D r. R. A.E. L. Cook, E ric k s o n and D r. D r. T. D. S te v e n s , M. M. M o rtla n d fo r s e r v in g as members o f h i s g u id a n c e c o m m itte e . The a u th o r i s in d e b te d to Dr. T. H. Wu f o r h is s u g g e s tio n s on s o i l h a rd n e s s m easurem ents and to Mr. K enneth M e t t e r t and Mr. S h e tro n o f th e O s c e o la County S o il S urvey P a r t y f o r t h e i r in s am p lin g th e p r o f i l e s . S tephen a s s is ta n c e IN MEMORY OF SOPHIA CHXOROU whose w i l l e n a b le d two g e n e ra tio n s o f G re e k f o r e s t e r s advanced s tu d ie s i n to p u rs u e t h e i r f o r e ig n c o u n tr ie s TABLE OF CONTENTS Page In tr o d u c tio n LITERATURE REVIEW........... ........................................................................................................ 1 A. G e n e ra l v ie w s on P o d z o ls .................................................................................... 1 B. P o d z o ls o f M ic h ig a n ................................................................. . .......................... 5 C. S o ils w ith f r a g ip a n h o r i z o n s . . . . . . . . ........................................................... 8 F IE L D S TU D IE S ............................................................................................................................. 15 I. G e n e ra l e n v iro n m e n t.............................................................................................. 15 1. C lim a t e ................................................................................................................. 15 2. G eo logy.......................................... 16 3. II. V e g e ta tio n . ...................... . ......................... S o i l s . . . . . . ................................. 17 D e s c r ip t io n s ............................................................................................................. METHODS OF ANALYSIS................................ I. 2. II. 25 33 DETERMINATION OF PHYSICAL PROPERTIES. 1. 16 ...................................... 33 W ater p e r m e a b i l i t y ...................................................................................... 33 P o re s iz e d i s t r i b u t i o n .................................................................... 33 B u lk d e n s it y ...................................................................... . ................... 34 H a rd n e ss ............... . ...................................... 3. M e c h a n ic a l a n a l y s i s . . . . . ............. 4. A i r d r y w a t e r .................................................................................................. 34 36 37 CHEMICAL ANALYSES................................................................................................... 37 1. O rg a n ic c a rb o n .......................................... 37 2. p H . . . . ........................................ 38 3. Loss i n 38 4. D e te r m in a tio n o f th e r e l a t i v e d i s t r i b u t i o n o f th e a l k a l i s o lu b le s i l i c a in th e s o i l p r o f i l e s ........................... s o l u t i o n ......................... 38 5. III. D e te r m in a tio n o f th e r e l a t i v e d i s t r i b u t i o n o f s o lu b le a lu m in a i n th e s o i l p r o f i l e s .......................................... 41 MIN.ERAIOGICAL ANALYSES...................................................................................... 43 1. X » ra y d e te r m in a tio n s o f c la y m in e r a ls ........................................ 43 2. D i f f e r e n t i a l th e rm a l a n a ly s is o f c la y m in e r a ls ...................... 4 4 3. T o ta l s p e c ific 4. T o t a l p o ta s s iu m i n c l a y .......................................................................... 45 5. M in e r a l a n a ly s is o f th e f i n e s u rfa c e o f c la y s ....................................................... 44 sand.................................................. 46 THIN SECTIONS OF SOILS..................................................................................... 47 RESULTS.............................................................................................................................................. 49 IV . 1. P h y s ic a l p r o p e r t i e s ................................................................................... 49 2. M e c h a n ic a l A n a ly s is .................................................................................... 51 3. C hem ical P r o p e r t i e s .................................................................................... 54 4. X -r a y d e te r m in a tio n o f c la y m in e r a ls ................................... 5. D i f f e r e n t i a l Therm al A n alyses o f C la y ......................................... 64 6. T o t a l S p e c if ic S u rfa c e and K C o n te n t o f C la y s ..................... 65 7. Summary on C la y A n a ly s e s ........................................................................ 66 8. M in e r a l A n a ly s e s o f F in e Sand............................................................ 70 9. D e s c r ip tio n o f T h in S e c tio n s .............................................................. GENERALDISCUSSION 1 . Changes AND EVALUATION OF THERESULTS............................................. due to 59 76 97 s o i l f o r m a t io n ........................................................................ 97 ( a ) U n if o r m it y o f th e p r o f i l e s ................................................................... 97 ( b ) Changes i n p h y s ic a l p r o p e r t i e s ......................................................... 98 ( c ) Changes i n m in e r a lo g y .................................................................................101 1. P r im a r y m in e r a l chang es ............................................ 101 2. C la y m in e r a l chang es............................................ 103 ( d ) C hem ical c h an g es ........................................................................................... 106 2. Ib r m a tio n o f th e f r a g i p a n 3. C la s s ific a tio n SUMMARY - . .......... . ...................................................... 107 and h o r iz o n n o m e n c la tu re CONCLUSIONS, . ...............................114 .................................................................................................. 119 BIBLIOGRAPHY................... 122 APPENDIX X -r a y d i f f r a c t i o n p a t t e r n s o f c l a y . . . . . . . . . . . ............................ 1 D .T .A . p a t t e r n s o f c l a y ............................. 15 M ic ro p h o to g ra p h s ................... 18 L IS T OF TABLES Page 1. P h y s ic a l P r o p e r t i e s .................................................................................................. 52 la . P e r c e n t A i r Dry M o is tu r e ...................... . .................................................... 53 2. M e c h a n ic a l A n a ly s e s ............... . ............................................................................... 55 3. $ o f P in e Sand i n 4. P e r c e n t o f 5 - 2 m icrons s i l t 5. th e T o t a l Sand F r a c t io n ............................................. in th e t o t a l s i l t fr a c tio n C hem ical P r o p e r t i e s . . . . . . . . . ............... . ................ 58 60 6. T o t a l K c o n te n t and t o t a l s p e c i f i c 7. P e r c e n t o f h eavy m in e r a ls i n 8. P e r c e n t fre q u e n c y i n th e heavy f r a c t i o n o f f i n e sand................ 72 9. P e r c e n t fre q u e n c y i n th e l i g h t sand................ 75 Volume o c c u p ie d by one gram o f f i n e s a n d -s iz e d q u a r ts ................ 98 10. s u rfa c e o f th e c l a y . . . . . . 58 th e f i n e sand........................................ fr a c tio n o f fin e 67 67 INTRODUCTION T h in g s can be c l a s s i f i e d a c c o rd in g to t h e i r p r o p e r t ie s e m p i r i c a l l y on th e b a s is o f o b s e r v a tio n s and e x p e r ie n c e , ic a lly on th e b a s is o f law s w hich e x p la in e it h e r or s c ie n tif­ and p r e d i c t when, w here, how and why th e s e p r o p e r t i e s d e v e lo p . S o il c l a s s i f i c a t i o n has as i t s w hich w i l l s o il e tc . e n a b le us to e s tim a te th e s u i t a b i l i t y f o r s p e c i f i c p u rp o s e s , T h is s u ita b ility aim th e developm ent o f schemes, such as A g r i c u l t u r e , o r p o te n tia l, how ever, and p o t e n t i a l o f each F o re s try , E n g in e e rin g depends on th e p ro p e r­ t i e s o f th e s o i l . S o i l g e n e s is t r i e s e n a b le u s to d e v e lo p and fo r m u la te la w s , to e s tim a te o r p r e d i c t th e p r o p e r t ie s o f each s o i l , th e m a g n itu d e o f each o f th e s o i l Jenny (3 1 ) is fo rm in g f a c t o r s , when as proposed by known. Each s o i l g e n e s is p ro b le m , s p e c ific which w i l l th e re fo re , is d e s ig n e d to answer q u e s tio n s and c o n t r ib u t e to th e fo r m u la tio n o f th e law s o f s o il c la s s ific a tio n . The p r e s e n t i n v e s t i g a t i o n has as i t s p u rp o se to stu d y th e p r o p e r tie s and g e n e s is o f th e s o i ls o f N o rth e rn M ic h ig a n h a v in g fr a g ip a n s i n r e l a t i o n fa c to rs in th is to th e e x i s t i n g m ag n itu d e s o f th e s o i l a re a . F ra g ip a n s a re s o i l h o r iz o n s , when th e y a r e d ry and s l i g h t l y a re m o is t. w hich a r e r e v e r s ib l y in d u r a te d c o h e s iv e o r f ir m bu t f r a g i l e They d e c re a s e th e w a te r p e r m e a b ilit y o f th e s e r io u s d e fo rm a tio n s by s o i l fo rm in g in th e r o o t system o f e r o s io n th e y a r e d i f f i c u l t to p lo w . tn e p la n t s . when th e y s o il end cause When exposed When s tr o n g ly d e ve lo p e d 2 th e y seem to re d u ce th e p h y s io lo g ic a l depth o f th e s o i l . It is im p o r ta n t to p e d o lo g y , how th e s e s o i l s a r e fo rm ed , a g r i c u l t u r e and f o r e s t r y to know what causes th e in d u r a t io n o f th e fr a g ip e n e and how th e y c o u ld be d e s tro y e d i n o r d e r to d e ve lo p b e t t e r p h y s ic a l c o n d it io n s f o r th e g ro w th o f p l a n t s . To answer th e s e q u e s tio n s , th e p r o f i l e s , by d e t a i l e d s tu d i es. s in c e fie ld , zero th e changes w hich h ave o c c u rre d i n tim e o f s o i l c h e m ic a l, p h y s ic a l, fo r m a tio n , have been e v a lu a te d r a in e r a lo g ic a l and m ic r o s c o p ic a l REVIEW OF LITERATURE A. G e n e ra l v ie w s on P o d zo ls A g r e a t number o f works on p o d z o ls have been p u b lis h e d , S p re n g e l (1 8 3 7 ) J o ffe , d e s c rib e d what we know now as p o d zo l s o i l s . i n h i s P e d o lo g y , a f t e r re v ie w in g th e c l a s s i c a l w orks and h y p o th e s e s c o n c e rn in g th e g e n e s is , th e m orphology and th e c h e m ic a l p r o p e r t i e s o f th e p o d z o ls o f th e w o rld , p r o file s s in c e and c i t i n g two t y p i c a l p o d z o l on th e c o a s t a l p l a i n o f New J e rs e y , makes th e f o llo w in g gen­ e r a l s ta te m e n t; " I n g e n e r a l, th e p ro c es s o f p o d z o liz a t io n d e p le t io n o f th e a l k a l i so from th e h o r iz o n . The reason f o r th e d i f f e r e n c e i s a d s o r p tio n c a p a c it y . On p a r e n t m a t e r i a l r i c h i n tio n , d i s t r i b u t i o n o f th e bases in w h e th e r r i c h o r po o r i n th e p r o f i l e . e n te r in t o th e p r o f i l e to bases, th e to th e d i f f e r e n ­ The ty p e o f v e g e ta ­ bases, may a ls o be a f a c t o r . “ W ith th e d e p le t io n o f b ases, p a r tic le s due to th e h o r iz o n and hence a h ig h e r r e t u r n o f th e s e th ro u g h th e v e g e t a t io n c o n t r ib u t e s tia l th e and a l k a l i n e e a r t h bases from th e A^ and more h ig h e r o r g a n ic m a tte r c o n te n t o f th e c a t io n r e s u lts in c ir c u la tio n , th e s e s q u io x id e s and th e c la y move downwards and a ccu m u late in form th e B h o r iz o n and g iv e i t s c h a r a c te r is tic s . The a b s o r p t iv e power o f th e c la y causes th e r e t e n t i o n o f some a l k a l i n e e a r th bases which i n tu r n enhance th e p r e c i p i t a t i o n o f th e s e s q u i- o x id e s ." ¥ a r b u t (4 0 ) in c lu d e d th e p o d z o ls i n h i s P e d a lf e r s . to him , a t y p i c a l p o d zo l p r o f i l e o f o n ly p a r t i a l l y c o n s is ts o f a r e la tiv e ly A cc o rd in g th ic k la y e r decomposed o r g a n ic d e b r is , u n d e r la in by a g ra y 4 l a y e r o f m in e r a l s o i l . T h is l a y e r ra n g e s i n f i l m up to more th a n one f o o t . o r t s t e in o r o rte rd e , and i t is brown, The g ra y la y e r w hich i s h e a v ie r i n to p . is u n d e r la id by th e t e x t u r e th a n th e g ra y l a y e r d a rk brown o r c o ffe e brown i n c o lo r . s tr o n g e r a t th e to p o f t h i s l a y e r and i t s Sometimes i t th ic k n e s s from a mere i s cem ented in t o te x tu re is The c o lo r i s a ls o f i n e r . a h ard p an w hich i s h a rd e s t n e a r th e The o r t s t e i n i s u n d e r la id by th e p a r e n t m a t e r i a l , a g r a d a t io n fro m one i n t o has a r e l a t i v e l y and a l k a l i n e th e o t h e r . but th e r e i s C h e m ic a lly th e g ra y (A ) h o riz o n lo w amount o f i r o n and a lu m in a and o f t e n o f a l k a l i e s e a rth s , and a h ig h p e rc e n ta g e o f s i l i c a - (B ) h o r iz o n c o n ta in s a r e l a t i v e l y The o r t s t e i n h ig h p e rc e n ta g e o f a lu m in a , o x id e and o r g a n ic m a t t e r , and a lo w e r p e rc e n ta g e o f s i l i c a . h o r iz o n i s a lu m in a , lo w e r i n ir o n , th e p a r e n t m a t e r i a l and h ig h e r i n a lk a lie s and a l k a l i n e e a r th s than in d ic a t e d and a lu m in a were c a r r i e d down from th e A h o r iz o n i n c o l l o i ­ d a l fo rm a lo n g w ith c o l l o i d a l o rg a n ic m a tte r and d e p o s ite d i n h o r iz o n . The A s ilic a . M arb u t p o in te d o u t t h a t p re v io u s i n v e s t i g a t i o n s th a t i r o n ir o n The p r e c i p i t a t i o n o f th e c o llo i d s in th e B th e B h o r iz o n r e s u l t e d m a in ly fro m c o l l o i d a l r e a c t io n s c o n t r o l le d by th e c o m p o s itio n o f th e s o lu t io n and th e c o n c e n tr a tio n o f th e c o l l o i d a l th e i r o n i s removed e n t i r e l y from th e s o i l s u sp e n s io n . Some o f th ro u g h d r a in w a te r. S o ils w hich h ave d e v e lo p e d u n d e r th e in f lu e n c e o f a r e l a t i v e l y weak podzo Li z a tio n a r e , tr u e p o d z o ls . a c c o rd in g to M a rb u t, p o d z o iic s o i l s but n o t These s o i l s have c o a r s e r te x tu r e d A h o riz o n s and f i n e r t e x t u r e d B h o riz o n s w hich d i f f e r from th e o r t s t e i n o f th e t r u e p o d zo ls i n h a v in g no h ig h e r o rg a n ic m a tte r th a n th e A h o r iz o n and n o t b e in g 5 i n d u r a t e d as a r u l e . B. M cCool, e ra l P o d zo ls o f M ic h ig a n V e a tc h and Spurway ( 4 5 ) have g iv e n th e f o llo w in g gen­ d e s c r ip t io n o f a p o d z o li z o liz e d s o i l from th e n o r th e r n p a r t o f M ic h ig a n : 1. T h in humus s o i l . 2. Gray p o d z o li zed h o r iz o n ( 3 - 2 4 3. Brown h o r iz o n in c h ) . (d a r k c o f f e e "brown to l i g h t and d u l l y e l l o w ) : th ic k n e s s 4 i n . l e a t h e r c o lo r to 4 f e e t ; h o r iz o n o f a c id c o n c e n tr a tio n . 4. H o riz o n showing i r o n o x id e c o l o r a t io n ; te n t: 5. g r a d a t io n to h ig h e s t c la y con­ s u b s tra tu m . S u b s tratu m . V ea tc h ( 5 9 ) s e p a ra te d th e P o d zo l re g io n o f M ic h ig a n s o i l s th e G ray-B row n P o d z o lic r e g io n by a l i n e which fo llo w s th e a p p ro x im a te s o u th e rn l i m i t o f th e n a t iv e w h ite p in e and beech v e g e t a t io n . e s t a b lis h e d a t r a n s i t i o n a l from He a ls o zone betw een th e P odzol re g io n o f th e n o r th e r n p a r t o f M ic h ig a n and th e G ray-Brown P o d z o iic re g io n o f th e s o u th e rn p a r t o f th e s t a t e . V e a tc h and M i l i a r b is e q u a p r o f i l e s , (6 0 ) re c o g n iz e d i n M ic n ig a n th e so c a l l e d w hich c o n s is t o f more than one zone o f e l u v i a t i o n and more th a n one zone o f i l l u v i a t i o n . G ard n er and W h ite s id e (2 1 ) P o d z o l-G ra y Brown P o d z o iic th e s e p r o f i l e s s tu d ie d b is e q u a p r o f i l e s o f th e tr a n s it io n a re a . T h e ir s tu d ie s c o n s is t o f a P o d zo l u p p e r seouum u n d e r la in showed th a t by th e A2 6 and Bg o r sequum, o f a Or ay- Bro wn P o d z o iic p r o f i l e . s o ils th e P o d z o l sequum i s G ray-B ro w n P o d z o iic tru e . sequum, In th e s a n d ie r much more s tr o n g ly d e v e lo p e d th a n th e w h ile i n th e f i n e r s o i ls th e re v e rs e i s The a u th o rs c o n c lu d e d th a t a l l h o riz o n s a re g e n e tic and a re t h e r e s u l t o f e i t h e r s im u lta n e o u s developm ent o r o f th e developm ent o f a younger P odzol p r o f i l e P o d z o iic in th e Ag h o r iz o n o f an o l d e r G ray-B row n s o il. Cann and W h ite s id e (1 2 ) in v e s t ig a t e d G ray-B ro w n P o d z o iic i n t e r g r a d e th e g e n e s is o f a P o d zo l s o il p r o f i l e . w e ig h t and g a in i n volum e ta k e s p la c e l a r g e l y th e p r o f i l e They found t h a t lo s s i n i n th e P o d zo l sequum o f and a m arked in c r e a s e o f o rg a n ic m a t e r ia l i n th e P odzol B and a s l i g h t in c r e a s e o f o rg a n ic m a tte r and c o n s id e r a b le c la y i n th e G ray Brown P o d z o iic B. Both h o r iz o n s , th e re fo re , a re i l l u v i a l bu t th e p r i n c i p a l c o n s t it u e n t a ccu m u lated i s o rg a n ic m a tte r i n and s i l i c a t e c l a v i n th e G ray-B row n P o d z o iic B. t h a t th e developm ent o f th e bisequum i s cesses i n v o lv in g p o s itio n th e P odzol B The a u th o rs c o n c lu d e d a r e s u l t o f s im u lta n e o u s p ro ­ th e movement o f d i f f e r e n t c o n s t it u e n t s and t h e i r de­ i n d i f f e r e n t p a r ts o f th e solum. V eatch (6 1 ), i n h is book " S o ils th e f o llo w in g and Land o f M ic h ig a n " , g iv e s d e s c r ip t io n o f th e most c o m p lete p r o f i l e i n M ic h ig an p o s s ib le u n d e r th e n a t u r a l environm ents "1. S u rfa c e h o r iz o n o f o rg a n ic a c c u m u la tio n i n c lu d in g th e m a t e r i a l commonly d e s ig n a te d humus. 2. Maximum e lu v ia t io n s u s u a lly l i g h t g r a y is h , o r b le a c h e d , in c o h e r e n t o r f r i a b l e . 3. H o riz o n o f secondary i l l u v i a t i o n ; y e llo w ; commonly brown o r c o l l o i d a l m a tte r m o s tly o r g a n ic and i r o n o x id e s ; 7 h ig h e r aluminum s i l i c a t e th a n i n 4. No. 5. lo w e r l i x i v i a t e d a lig h te r c o n te n t th a n i n No. 2 hut le s s o r b la n c h e d h o r iz o n ; y e llo w is h becoming shade w it h depth and i n g le i-lik e , g ra y m o tt le d , extrem e d e ve lo p m e n t, o r c o n ta in in g c o n c r e tio n s and p a r t i a l c e m e n ta tio n by i r o n o x id e s . 5. 6. A ife r r ic h o r iz o n ; maximum c o n te n t o f c la y and maximum c o lo r in g from f e r r i c o x id e s . T r a n s i t i o n a l h o r iz o n o f w e a tn e rin g betw een solum and u n a lt e r e d p a r e n t m a t e r i a l , s l i g h t a c c u m u la tio n o f c a r ­ b o n a te s . 7. U nw eathered p a r e n t m a t e r i a l . " V eatch s t a t e s , how ever, f o l l o w th e above p a t t e r n . Gray P o d zo l w hich i s th a t n o t a l l th e "n o rm al" P odzol s o i l , v e r y weak o r a b s e n t, m a te r ia ls ) and T u rk (4 3 ) M ic h ig a n P o d zo l p r o f i l e s . some P o d z o l p r o f i l e s is th e Brown P o d zo l w hich e l u v i a l g ra y s u rfa c e h o r iz o n and th e Gray P o d zo l c la y s i n w hich o r t e r d e h o r iz o n i s M a te is k i M ic h ig a n He d e s c rib e s v a r i a t i o n s o f P o d zo ls as th e d e v e lo p s an o r t e r d e brown h o r iz o n but i t s is th e p r o f i l e s i n (d e v e lo p e d on c la y v e ry weak o r a b s e n t. s tu d ie d th e heavy m in e r a ls o f some They c oncluded t h a t th e brown B h o r iz o n o f th e r e s u l t o f th e d e co m p o s itio n o f a r e l a t i v e ­ l y h ig h o r i g i n a l c o n te n t o f opaque and fe rro m a g n e s ia n m in e r a ls . The l e a s t r e s i s t a n t m in e r a l was found to be th e d a rk g re e n h o rn b le n d e . The a u th o rs c o n s id e re d o r g a n ic m a tte r as an e f f e c t i v e in w e a th e rin g agent th e B h o r iz o n s . B a ile y , m a te ria ls W h ite s id e and E ric k s o n ( 2 ) as a f a c t o r i n s tu d ie d th e r o l e o f g l a c i a l th e m orphology and g e n e s is o f 23 s o il s e r ie s o f M ic h ig a n . They fou n d th a t th e s o la in c r e a s e i n th ic k n e s s e xcep t when th e p a r e n t ro c k c o n ta in e d more th a n 12 % a c id s o lu b le m a t e r i a l s . The p e r c e n ta g e o f in c r e a s e in c la y c o n te n ts r e l a t i v e p a r e n t ro c k s i s s m a ll e x c e p t i n th e v e ry to t h a t in sandy m a t e r i a l s , th e where most o f th e c la y m ig h t be p e d o g e n e tic i n o r i g i n . M cKenzie (4 6 ) s tu d ie d th e re d o x p o t e n t i a l s i n th e d i f f e r e n t h o r iz o n s o f th e K alkaska-S augatuck-R oscom m on s o i l c a te n a i n M ic h ig a n . He found t h a t i n th e w e ll d ra in e d K a lk a s k a , lo w e s t o x i d a t io n p o t e n t i a l o f a l l th e A h o r iz o n had th e th e h o r iz o n s , h o r iz o n s had th e h ig h e s t o x id a t io n p o t e n t i a l i n is o la te d w h ile th e B i r and C th e p r o f i l e . fro m th e B ir m icro o rg a n is m s a b le to o x i d iz e fe r r o u s i r o n . C. C a r lis le lic a tio n s S o ils w ith fr a g ip a n h o riz o n s (1 4 ) h as summarized i n h i s P h .D . r e g a r d in g r e v e r s ib l y in d u r a te d th e s is s o i l h o r iz o n s . s e v e ra l pub­ These in v e s ­ t i g a t i o n s need n o t be re m e n tio n e d i n th e p re s e n t l i t e r a t u r e C a r lis le M a rd in i s lu s ia is b elo ng to s tu d ie d th e M a rd in and V o lu s ia s o i l a p o o r ly d r a in e d Low-Humic G-ley s o i l s e r ie s . as P o d z o l. Vo­ Both s e r ie s th e Bat h - Ma r d i n - Pr e emo nd - Vo lu s i a - Chippewa s o i l c a te n a , g la c ia l t i l l . M a rd in shows a t y p i c a l p o d z o l sequum to th e p o d z o l B h o r iz o n i s h o r iz o n 3 -6 in c h e s t h i c k , c o lo r o f t h i s h o r iz o n i s y e llo w is h re v ie w . s e r ie s o f New Y o rk . a m o d e ra te ly w e ll d r a in e d s e r ie s c l a s s i f i e d th e y h a ve been d e v e lo p e d on s i l t y ly in g He a ls o brown m o tt le s . loam t e x t u r e and a w e a k ly The u p p e r solum o f a depth o f 15 in c h e s . U nder­ a l i g h t e r c o lo re d and c o a rs e r t e x tu r e d which C a r l i s l e names an A^p h o r iz o n . r i g h t y e llo w is h brown ( 2 . 5 Y 6/ 4 It and has a c o a rs e s i l t The 5 Y w i t h loam o r v e r y f i n e Sandy to m o d e ra te ly d e v e lo p e d f i n e and medium y p la ty s tru c tu re , The Af % and sometimes a v e ry weak: medium b lo c k y s t r u c t u r e . h o r iz o n i s fr ia b le The pH ran g es from 5 . 0 a g e n e tic on e, to s lig h t ly to 5 . 5 . because o f i t s f ir m C a r lis le and b r i t t l e assumes t h a t when d ry . t h i s h o r iz o n is c o n s ta n t th ic k n e s s and c o n s ta n t depth fro m th e s u r fa c e o f th e s o i l w i t h i n a g iv e n k in d o f p r o f i l e . bases h i s in assum ption on th e f a c t th a t t h i s h o r iz o n i s th e sane p o s i t i o n Below th e th r e e fe e t th ic k , T h is h o r iz o n i s fir m k! ^ i® th e fr a g ip a n o r v e ry f i r m , in t o h o r iz o n , com pacted and has an o l i v e 1 1 /2 in c h e s w ide and 5 0 -6 0 g ra y s i l t a brown c o l o r . a c ro s s ) in ch es lo n g . p o ly g o n a l p a t t e r n . It is v e ry The pan i s by v e r t i c a l g ra y s tre a k s On a h o r i z o n t a l p la n e These s tr e a k s a re f i l l e d and p o o rly d ra in e o h o r iz o n 3 - 4 In c h e s t h ic k u n d e r la in by A/ w ith ^ V o lu s ia s o i l s have an A^ and B / h o riz o n s s im i l a r to W ardin but more s tr o n g ly g le y e d . C a r lis le advances th e h y p o th e s is t h a t formed from a com pact, an in c r e a s e o f th e w a te r p e r m e a b ilit y r e s u lt e d i n th e developm ent o f an e l u v i a l w a te r movement, and i n k *2 th e d e p o s it io n o f s i l t y form ed d u rin g d ry w e a th e r. above th e pan is h o r iz o n th ro u g h l a t e r a l m a t e r ia ls i n C o n tin u ed d e p o s itio n r e s u lte d b u lk d e n s it y and low p e r m e a b ilit y tn e i n t e r a c t i o n th e above s o i l s were s lo w ly p e rm ea b le and c a lc a re o u s ground m o ra in e . Ey means o f p h y s ic a l w e a th e r in g , p r o file about loam . The im p e r f e c t ly th o s e in w hich i s dense and s lo w ly p e rm ea b le to w a te r. v e ry l a r g e p rism s th e s tr e a k s form alw ays lo c a te d to o th e r h o riz o n s o f th e p r o f i l e . when m o is t and h a rd to e x tre m e ly h a rd when d r y . d iv id e d 1 /4 - r e la tiv e He a ls o o f th e pan. in th e c ra c k s tn e h ig h Tne c h a r a c te r o f th e a r e s u l t o f th e w ater c o n d itio n s produced by o f th e pan and to p o g ra p h y . D e g ra d a tio n o f th e pan 10 in M a rd in s o i l s is due to a c c e le r a te d lo s s o f c la y from p a r t s o f th e pan exposed to a c id s o lu t io n moving downwards from th e P o d zo l h o r i ­ zons . C a r lis le , b r ittle Knox and Grossman ( I S ) d e s c rib e d fr a g ip a n s s u b s o il h o r iz o n s t h a t appear to be in d u r a te d when dry but not in d u r a te d when m o is t. They c o n s id e r them as g e n e tic h o riz o n s below an A=B h o r iz o n sequences (s e o u a ) c h a r a c t e r i s t i c Brown P o d z o iic o r A c id Brown E a r th s , s o ils Flumic G ley s o i l s . fin e sandy loam o r s i l t loam fr a g ip a n s have a weak, s tru c tu re s ilt te x tu re . te x tu r e d pans. te n d in g tow ard a m assive c o n d it io n . p a t t e r n on a h o r i z o n t a l p la n e . pans a re s i m i l a r to B rew er ( 8 ) , Brown s o i l s c i n i t y o f M a d rid , w hich i s a s s o c ia te d s u b a n g u le r b lo c ky s t r u c t u r e o u t lin e d th a t form p o ly g o n a l C la y loam and s i l t y c la y loam f r a g i ­ in h i s R e p o rt o f O verseas v i s i t , i n C a l i f o r n i a i n th e U n ite d S p a in . d e s c rib e s Non- S ta te s and i n th e v i ­ These s o ils h ave a w e ll d e v e lo p e d Ag h o r iz o n v e ry h a rd and b r i t t l e when d ry and f r i a b l e The a u th o r s t a t e s t h a t th e h a rd n es s o f t h i s h o r iz o n i s w ith th e d i s t r i b u t i o n o f p a r t i c l e s o f s i l t sand w hich form w h ite , c o a tin g s f ir m e r and th e ones o f in t e r m e d ia t e t e x t u r e . s t r u c t u r e le s s , when m o is t . The a u th o rs s t a t e P in e sanaj'- loam and loam fr a g ip a n s have a v e ry c o a rs e p r is m a tic m a te r ia l, te x tu r e s Loamy sand and sandy t h i c k p l a t y o r weak, by v e r t i c a l p la n e s o f g r a y is h s i l t y calcic and as components o f Low- loam fr a g ip a n s a r e t h i c k e r , h a rd e r when dry th a n th e c o a rs e r found o f F o a z o ls , They a re found in m a t e r ia ls o f v a r io u s b u t t h e i r c h a r a c t e r i s t i c s v e r y w ith t h e i r th a t 1? isa , and v e ry b le ac h e d c o a tin g s on th e c o a r s e r g r a in s . a r e seen th ro u g h a (.■ DX) hand le n s . th e N o n - c a ll c Brown s o i ls o f C a l i f o r n i a fin e These Brew er p o in ts o u t th a t and Spain a re morpho lo g i c a l l y 11 s im ila r to s tr o n g ly d io r ite s d iffe r e n tia te d s o ils form ed on g r a n i t e s , and ro cks o f s i m i l a r c o m p o s itio n , g ra n o - in th e S o u th ern T a b le la n d s o f New South W ales, A u s t r a l i a . W in te rs and Simonson (6 7 ) i n th e p r o f i l e th a t is d e s c rib e th e fr a g ip a n as a h o r iz o n s lo w ly p e rm e a b le , d ry and m o d e ra te ly f r i a b l e to f r i a b l e as th e p re d o m in a n t t e x t u r a l c la s s . when m o is t. They a is o S ilt h a rd when loam i s c i t e d s t a t e t h a t v e ry f i n e sandy loam , s ilty f r a g ip a n s . Change o f c o n s is te n c e w ith change i n m o is tu re c o n te n t i s a s tr ik in g c la y compact o r dense, loam and c la y loam a re common te x tu r e s o f f e a t u r e o f f r a g ip a n s . lumps from fr a g ip a n s , when p la c e d in w a te r a f t e r e v id e n c e t h a t th e la y e r s occur in th e s la k in g o f a i r d r y in g , a re not cem ented by s i l i c a , is an even though th e y re g io n s where r e le a s e o f la r g e amounts o f c o l l o i d a l s i l i c a can be e x p e c te d . If would d e s tro y i t s c em e n tin g pow er. its They suggest th a t th e cem en tin g agent w ere th e s i l i c a g e l ,d r y i n g c e m e n tin g p r o p e r t i e s u n le s s i t The s i l i c a g e l would n o t re g a in were d is s o lv e d and r e p r e c i p i t a t e d , w hich w ould n o t o c c u r as th e s o i l was r e w e tte d . Knox (3 6 ) M. Y . s tu d ie d fo u r fr a g ip a n h o r iz o n s M ic r o s c o p ic a l e x a m in a tio n showed th a t from Orange C ounty, sand g r a in s a re p a r t i a l l y c o a te d and bonded t o g e th e r w ith y e llo w is h brown b rid g e s o f f i n e ma^te r ia l. These b r id g e s c o n s is t o f c r y s t a l s o f f i n e c la y h e ld to g e th e r by a f i n e r c r y s t a l l i n e m a t r ix . d iffr a c tio n e x a m in a tio n s r e v e a le d th a t h o ld s th e sand and s i l t p a r tic le s s y n th e s is e x p e rim e n ts d e s ig n e d to m a te r ia ls as hydrous i r o n c la y showed t h a t i l l i t e s ilt and c o a rs e O p tic a l and X -r a y th e f i n e - g r a i n e d m a t e r ia l to g e th e r was i l l i t e . S ta b ility w hich and stu d y th e r o le o f p o s s ib le bonding and aluminum o x id e s , was r e s p o n s ib le c o llo id a l s ilic a , f o r a m a jo r p a r t o f th e and 12 s tre n g th o f ty p ic a l s ilic a th a t is f r a g ip a n s , a r e in v o lv e d i n and t h a t both i l l i t e and c o l l o i d a l th e s tr e n g th o f an e xtrem e pan. th e e f f e c t iv e n e s s o f i l l i t e due to h ig h b u lk d e n s it y , Knox assumes as b in d in g m a t e r i a l i n th e f r a g ip a n la c k o f e f f e c t i v e s tru c tu re , and s p e c ia l d i s t r i b u t i o n o f c la y . Grossman and M. G. C lin e h o ris o n s o f New Y ork S t a t e . (l) s ilt The a u th o rs t r i e d r ig id ity sandy loams and c o a rs e loam s, ©nd p a r t i c l e shaped by hand in to mm. in d ia m e te r . p e r a t u r e o f 420 c . to and ( 2 ) fe ll in to medium to f i n e d e te rm in e th e r e la t i o n s h i p s betw een s iz e d i s t r i b u t i o n . Fragm ents o f fr a g ip a n were rough c y lin d e r s a p p ro x im a te ly 40 mm. lo n g and 25 These c y lin d e r s were d r ie d f o r 48 hours a t a tem­ A f t e r d ry in g , th e c y lin d e r s ends i n p l a s t e r o f p a r i s an a x i a l s t r e s s - s tu d ie d tw e n ty -fo u r fr a g ip a n The t e x t u r e o f th e s e h o riz o n s two g ro u p s : loam s. (2 3 ) were encased from both end th e y were cru sh e d by slow a p p lic a t io n o f The maximum s tr e s s w ith s to o d p e r u n i t o f c r o s s -s e c - tio n a i a re a was found to be h ig h ly c o r r e la t e d w ith p e r c e n t o f t o t a l c la y . The d a ta d id n o t j u s t i f y c la y as a bonding a g e n t. th e p r i n c i p l e e q u a lly Grossman and C lin e c oncluded bonding a g e n t, e ffe c tiv e any s p e c ia l r o l e o f th e u l t r a - f i n e t h a t v e ry f i n e th a t c la y was sand and s i l t mav be as a m a t r ix w it h in w hich such c la y bonds o c c u r, t h a t c la y can a ls o be r e s p o n s ib le f o r weakness o f th e pan due to developm ent o f s t r u c t u r e , depending upon i t s Anderson and W h ite ( 1 ) w ea th e re d s o i ls o f These h o r iz o n s a re found im m e d ia te ly below th e m ain p a r t o f th e B h o r i zon o r th e mum c la y a c c u m u la tio n . p r o file In a d d it io n to w hich d id n o t have a fr a g ip a n , th e amount and d i s t r i b u t i o n . s tu d ie d th r e e h ig h ly s o u th e rn In d ia n a , h a v in g fr a g ip a n h o r iz o n s . and zone o f m axi­ th e fr a g ip a n p r o f i l e s , a fo u rth b u t was form ed from s i m i l a r 13 p a re n t m a te r ia l, pH v a lu e f o r was s tu d ie d f o r c o m p aris o n . th e p r o f i l e R e s u lts showed a h ig h e r w hich d id n o t have a f r a g ip a n . The a u th o rs re a c h e d th r e e c o n c lu s io n s r e g a r d in g th e fra g ip a n s o f th e m o d e ra te ly w e ll d r a in e d Hosmer s i l t loam s o i l : (a ) The c la y o f th e s e h o r iz o n s i s lo w e r in m o n t m o r illo n it e compared to a s i m i l a r s o i l p r o f i l e f r a g ip a n . (b ) O nly a s m a ll amount o f th e m o n t r r o r r illo n it e o f th e s e h o r iz o n s i s c a p a b le o f e xp an sio n u n d e r norm al c o n d itio n s . c o n s is t o f s o i l p a r t i c l e s Grossman e t a l th a t w ith o u t a (c ) They w hich a re w eakly cem entea by i r o n o x id e s . (^’4 ) found in th e Hosmer s e r ie s o f I l l i n o i s fr a g ip a n and b is e q u a i n a tu r e in c re a s e w ith d e c re a s in g lo e s s t h i c k ” ness and w ith l a t i t u d e from n o rth to s o u th . The h o r iz o n they name as f r a g ip a n I s lo c a te d below th e (B ^g) h o riz o n o f maximum c la y i l l u v i a - tio n and i t has an in t e r m e d ia t e m ic r o s tr u c tu r e betw een th e r i c h i n c la y f ilm s m icro s tr u e tu r e o f and th e u n a lt e r e d m icro s t r u c t u r e o f th e C i h o r iz o n . F itz p a tr ic k (1 9 ) suggests th a t in d u r a te d la y e r s o f c e r t a in S c o t t is h and N orw egian s o i ls have been form ed by p e r m a fr o s t. He l i s t s s e v e r a l m a cro s c o p ic c h a r a c t e r is t i c s o f th e s e h o r iz o n s as o c c u rre n c e , to p o g ra p h y , d u r a tio n , d ra in a g e , s tru c tu re , th ic k n e s s , which a r e v e ry s im i l a r to d e p th , com paction and i n ­ th e c h a r a c t e r is t i c s o f th e f r a g i - pans d e s c rib e d by Am erican a u th o rs ana found i n s o i ls o f M ic h ig a n d u r in g t h i s i n v e s t i g a t i o n . F itz p a tr ic k a te d la y e r p r e v io u s were p roduced under p e r i g l a c i a l tim e s , c o n d itio n s e x is tin g in and th ro u g h th e f o llo w in g mechanism: "A t f i r s t o e p th . su g g ests t h a t s t r u c t u r a l fe a tu r e s o f th e in d u r ­ summer th a w in g would ta k e p la c e to S ucceeding tu n d r a c o n d itio n s w ith a c o n s id e r a b le the accompanying v e g e ta tio n 14 and l i t t e r w ould p r o v id e i n s u l a t i o n which would cause a s te a d j' re d u c ­ t i o n o f th e dep th o f th a w in g . ta k e p la c e s lo w ly , f r o s t ta b le . The r e d u c tio n i n depth o f th a w in g would a llo w in g th e g ra d u a l hut s te a d y r i s e i n T h is g r a d u a l upward movement o f th e p e rm a fro s t t a b l e w ould p roduce a m arked developm ent o f a l t e r n a t i n g ic e th e perm a­ and th e s o i l w hich w ould account f o r s t r u c t u r e o f th e in d u r a te d l a y e r , la m in a e o f c le a r th e w e ll d e ve lo p e d la m in a r e s p e c ia lly at its u p p e r s u r fa c e . The p re s e n c e o f c o n tin u o u s v e g e t a t iv e c o v e r would te n d to cause th e d e p th o f th aw in g to be f a i r l y T h is s u g g e s tio n is u n ifo r m i n based on e x a m in a tio n s o f th e p e rm a n e n tly fr o z e n s u b s o ils o f S p itz b e r g e n , la r any l o c a l i t y . " which re v e a le d a macro s t r u c t u r e to th e one o f th e in d u r a te d l a y e r o f th e S c o ttis h s t r u c t u r e o f th e p e rm a fro s t l a y e r , was p re s e rv e d a f t e r a g ra d u a l w hich c o n ta in e d th a w in g . s o ils . s im i­ The bands o f c le a r i c e , F i t z p a t r i c k was a D le to p ro ­ duce v e s i c u la r p o re s by f r e e z in g a mass o f s o i l p u d o le d w ith ta p w a te r and w ith i c e c o ld w a te r s a t u r a t e d w ith carb o n d io x id e . o f th e 002 in The p resen ce th e w a te r in c re a s e d th e number and the s iz e o f th e p o re s . 15 FIELD STUDIES F i e l d s t u d i e s h ave been made m a in ly on s o i l s M ic h ig a n . i n Osceola County, A few s o i l s o f n e ig h b o r in g Lake County have a ls o been s tu d ie d d u rin g t h is i n v e s t i g a t i o n . d u r in g t h r e e The f i e l d summer p e r i o d s o f d e t a i l e d s o i l s t u d i e s were c o m p lete d s u r v e y in g , i n 1956, 1957 and 1 9 5 8 . I. O s c e o la County i s s u la , and f a i l s (I) e n tire ly G en era l environm ent lo c a te d in th e n o r t h e r n p a r t o f l o v e r P e n in ­ w i t h i n th e Podzol Region o f M ic h ig a n . C lim a te . The c l i m a t e o f M ic h ig a n i s f l u e n c e d by th e p re s e n c e o f th e G re a t Lakes. th e c l i m a t e a lte rn a te s I n th e i n t e r i o r between c o n t i n e n t a l and sem im arine, on th e d i r e c t i o n and t h e f o r c e o f th e w ind. no w in d , the c o n t i n e n t a l c l i m a t e p r e v a i l s , Lakes tr a n s f o r m the c l i m a t e i n t o When t n e r e i s c lim a te . s e m im a rin e . Narrow b e l t s th e y e a r . the c l e a r i n M ic h ig a n i s fa irly The r e l a t i v e h u m i d i t y i s h ig h i n th e summer. S o ils The number o f c lo u d y days i s days, but c l e a r depending little or w e ll a lo ng the s tu d ie d i n t h i s a r e s u b j e c t e d to tn e c i m t i . n e n t a l - s e m i i r a r i n e P re c ip ita tio n c o u n tie s but s tr o n g winds from the shores o f th e G re a t Lakes have m a rin e c l i m a t e s . in v e s tig a tio n s ig n ific a n tly type o f d is trib u te d th e w i n t e r about e qual th rough and m oderate i n to th e number o f days a r e more f r e q u e n t d u r in g th e summer m o n th s . f o l l o w i n g a r e some m e t e o r o l o g i c a l d a t a from Reed C i t y , County, ta k e n from th e Yearbook of A g ric u ltu re , 194 1 , p. O s c e o la 9 i4 -» c .4 . in ­ 16 T e m p e ra tu re Average P r e c i p i t a t i o n i n in c h e s J a n u a r y a v e ra g e 1 8 .7 ° ? W in te r 4 .4 4 J u ly 6 9 .2 ° F S p rin g 7 .4 1 a v e ra g e Maximum i0 2 0 p Summer 9 .4 5 Minimum -4 2 0 p P a ll 8 .4 3 Annual 2 9 .7 3 Len g th o f Growing Season 125 days. (2 ) Geolojgy. M ic h ig a n was e n t i r e l y co ve re d by i c e d u r i n g r e c e n t g l a c i a l p e r i o d s and, la rg e ly th e s u r f a c e forms a r e t h e r e s u l t o f t h e ty p e and t h i c k n e s s o f th e g l a c i a l d e p o s it s . O s c e o la County i s South P e n i n s u l a . l o c a t e d i n th e N o r th e r n H ig h la n d o f th e The a l t i t u d e 1200 f e e t to 1400 f e e t . c e o l a and o f the s i t e s tiv e ly th e re fo re , above t h e sea l e v e l ranges from about The p h y s io g ra p h y o f th e b ig g e s t p a r t o f Os­ s tu d ie d in Lake County a re m o r a i n i c . A re la r* s m a ll a r e a c o n s i s t s o f g l a c i a l and outwash c h a n n e ls . (3 ) V e g e ta tio n . The p re d o m in a n t woodland v e g e t a t i o n o f th e a r e a a t p r e s e n t c o n s i s t s o f n o r t h e r n hardwoods, in g s p e c ie s : cana, sheets L . ), E h rh .), M ic h x .), Sugar m aple Basswood ( T i l i a (A c e r saccharuin, a m e ric a n a , Hemlock (T s u g a canadensi s, L .), L .), i n c l u d i n g th e f o l l o w ­ M a rs h ), Elm (Ulmus a n e r i - Beech (Fagus g r a n d i f o l i a , Aspen (P o p u lu s tre rn u lo id e s , and s c a t t e r e d i f n i t e p i n e (F in u s s tr o b u s , L .) The p r e s e n t c o m p o s itio n and d i s t r i b u t i o n o f th e v e g e t a t i o n has r e s u l t e d from th e e x t e n s i v e lu m b e r in g and subsequent b u rn in g d u r in g th e l a s t q u a r t e r o f th e 1 9 t h c e n t u r y . The o r i g i n a l v e g e t a t i o n b e fo r e t h e lu m b e r in g was, a c c o r d in g to V ea tc h ( 5 9 ) , o f a h a r d w o o d - c o n if e r 17 ty p e , c o n s i s t i n g o f th e hardwoods m entioned above, p l u s Bed p i n e nus r e s i n o s a , A it) and W hite p i n e (P in u s s tr o b u s , L .) • ( P i— The p in e s used to form p u r e o r m ixed w i t h hardwoods s ta n d s . O p in io n s c o n c e r n in g the c li m a x v e g e t a t i o n a r e d i v id e d i n t o g ro u p s . One c o n s id e r s p in e -h e m lo c k and th e o t h e r c o n s i d e r s hem lock- d eciduous f o r e s t as a c li m a x . s o ils The l a t t e r group c o n s id e r s p i n e on sandy as an edaph ic c li m a x o r post c li m a x . F o tzg e r (5 4 ) s ta te s th a t p o lle n p r o f i l e s in d ic a te th a t p in e i s a p o s t c l i m a x and T s u g a -b ro a d le a v e d g e n e ra a r e th e c li m a x . file s , tio n , two a c c o r d in g to P o t z g e r , c lim a tic flu c tu a tio n s a lso show t h a t , P o lle n p ro ­ s in c e th e l a s t g l a c i a ­ from c e n t r a l I n d i a n a to th e Upper P e n in ­ s u l a o f M ic h ig a n were n o t s u f f i c i e n t to cause g r e a t changes i n t h e fo re s t cover. th e i c e He assumes t h a t P i c e a g l a u c a c o n s t i t u t e d a b e l t between f r o n t and th e deciduous f o r e s t to t h e south i n th e i n t e r i o r o f In d ia n a . When P inus crowded i n , P i c e a s t a r t e d b e in g r e p la c e d by d e c id ­ uous s p e c ie s a s s o c i a t e d w i t h Tsuga and s u b s e q u e n tly P in u s s t a r t e d to d e c lin e . II. The o b j e c t o f and g e n e s is o f c e r t a i n S o i ls t h i s i n v e s t i g a t i o n was to s tu d y the morphology s o ils i n N o r th e r n M ic h ig a n c o n t a i n i n g f r a g i p a n h o r i zons, ^ a g i p a n s have been d e f i n e d i n th e U. zons, ric h i n sand and s i l t , b u t lo o s e o r f i r m when w e t. ti n u o u s v e s i c u l a r p o re s i n in th e lo w e r p a r t . S. as compact s o i l h o r i ­ and which a re h a r d and b r i t t l e They have a p l a t y t h e i r upper p a r t, T h e i r u p p e r boundary i s when d ry s t r u c t u r e and d is c o n ­ and a massive s t r u c t u r e s h a r p ly d e f i n e d , w h i l e th e IB l o w e r boundary i s u s u a l l y d i f f u s e . T h e i r common c h a r a c t e r i s t i c fe re n tia te s is They hav^ r e l a t i v e l y l i g h t th e r e v e r s i b l e in d u ra tio n , c o lo rs . which d i f ­ them from o t h e r n o n - r e v e r s i b l e pans. Guy Smith g i v e s th e f o l l o w i n g d e f i n i t i o n o f f r a g i p a n i n th e 5 t h A p p r o x im a tio n ; "A fra g ip a n i s a loamy s u b s u rfa c e h o r i z o n , u s u a l l y u n d e r l y i n g a B, v e r y lo w i n o r g a n ic m a t t e r , t h e solum above, c o n s is te n c e , w it h h ig h b u l k d e n s i t y r e l a t i v e s e e m in g ly cemented when dry, to h a v in g h a r d o r v e r y h a r d but when m o is t m oderate o r weak b r i t t l e n e s s (te n d e n c y f o r a ped to r u p t u r e sudd e n ly r a t h e r than u n d e rg o in g d e fo r m a tio n as i n ­ c r e a s in g p r e s s u r e i s p e rm e a b le to w a t e r , a p p lie d ). It F ra g ip a n s a r e u s u a l l y found w i t h a b ru p t o r c l e a r u p p e r h o r i z o n b o u n d a rie s a t su rfa ce , from 15 to 40 in c h e s below th e o r i ­ v a r y from a few in c h e s to s e v e r a l f e e t i n have g r a d u a l o r d i f f u s e lo w e r b o u n d a r ie s . ro o ts e x c e p t f o r th e b le a c h e d c r a c k s . b oth i n s lo w ly o r v e ry s lo w ly and u s u a l l y has o c c a s io n a l o r f r e q u e n t b leached c r a c k s fo r m in g p o ly g o n s . g in a l i s m o t t le d , t h ic k n e s s and They a r e n e a r l y f r e e o f C la y s k in s a r e s c a rc e to common th e p o l y g o n a l c r a c k s and i n th e i n t e r i o r s o f the p e d s . H It has been r e p e a t e d l y obs erv e d i n th e f i e l d th a t s o ils o f N o r t h e r n M ic h ig a n , which have f r a g i p a n h o r i z o n s , sequences o f s o i l s form ed from g l a c i a l d r i f t s o f loamy sand, loam , sandy c l a y loam, pronounced f r a g i p a n s , c l a y loam, however, and sandy c l a y t e x t u r e s . a re found i n p r o f i l e s sandy loam o r sandy c l a y loam p a r e n t m a t e r i a l s . c l a y loam and f i n e r t e x t u r e d p a r e n t m a t e r i a l s , s tro n g ly d e ve lo p e d i n d e ep ly le a c h e d p r o f i l e s in c h e s fro m t h e s u r f a c e ) . b e long to th e l i t h o sandy The most d e ve lo p e d on I n th e case o f sandy t h e f r a g i p a n s a r e more (lim y h o rizo n s below 40 The weakest f r a g i p a n s a r e found on c l a y 15 loam p a r e n t m a t e r i a l . loam p a r e n t m a t e r i a l s were n o t common and s i l t loams were absent i n t h e a r e a s t u d i e d and th e s e t e x t u r e s were n o t s tu d ie d , a lt h o u g h i t is e v i d e n t i n o t h e r p a r t s o f M ic h ig a n t h a t f r a g i ­ pans form i n loam and s i l t loam m a t e r i a l s , to o . F r a g ip a n h o r i e o n s were r e c o g n iz e d i n w e ll as i n i m p e r f e c t l y d r a in e d s o i l s . w e l l d r a in e d s o i l s as The i m p e r f e c t l y d r a in e d s o i l s were n o t dry enough to r e v e a l th e e x tre m e hardness o f t h e i r pan, t h e p h y s i c a l p r o p e r t i e s o f th e pan were c onsp icuous. f r a g i p a n s a r e found i n p ro file s in th is lith o s e q u e n c e , c le a rly s o i l s w i t h b is e q u a p r o f i l e s area. th e u p p e r Podzol sequum i s v e r y w eakly de ve lo p e d , S o ils zonal w h ile formed on sandy loam and f i n e r p a r e n t do n ot d e v e lo p o r s t e i n i n o r t e r d e o r B h ir h o riz o n , the a r e a s t u d i e d , on heavy members o f t h e l i t h o s e q u e n c e . a lm o s t a lw a y s p r e s e n t , b ut they do form o f which th e c o l o r ra n g es from t h e m oderate ora nge y e l l o w to th e d a r k r e d d is h brown. but i t s The l i g h t c o l o r e d B h i r forms The e l u v i a l g ra v A2 h o r i z o n i s th ic k n e s s is q u ite v a ria b le , r a n g in g from one in c h up to f i v e o r s i x i n c h e s . As a g e n e r a l r u l e , t h e f r a g i p a n h o r i z o n d e ve lo p s i n th e second zone o f th e p r o f i l e , o f th e s o i l s it is j u s t below t h e P odzol B h o r i z o n . a c o n tin u o u s h o r i z o n , p r o f i l e s h a v in g m u l t i p l e fin e r which a re th e d e veloped P odzol u pper sequa a r e found on loamy sand and sandy m a te ria ls e lu v ia l Most o f th e I n th e case o f th e f i n e s t members o f th e loam p a r e n t m a t e r i a l s . u s u a lly but te x tu ra l bands, but i n In zone, th e w h i l e th e c o a r s e r show any c e m e n ta tio n . th e case o f w e l l developed f r a g i p a n s , be d i v i d e d i n t o sand and loamy sand th e f r a g i p a n develops i n t e x t u r e d bands below th e second e l u v i a l l a y e r s betw een th e bands do not I n most th re e in d iv id u a l la y e rs : u pper, t h e cemented zone can m id d le , and l o w e r . 20 The u p p e r l a y e r c o n s t i t u t e s a t r a n s i t i o n a l l a y e r between th e F o a z o l B h i r and t h e f r a g i p a n . l o w e r boundary i s i s coarse, p la ty I t s up p e r boundary i s s h a rp ly d e fin e d . r a t h e r d i f f u s e but i t s Both b o u n d a rie s a r e i r r e g u l a r . and v e s i c u l a r i n s t r u c t u r e and weakly cemented, th e B h i r u s u a l l y has a weak crumb s t r u c t u r e and i t th is la y e r, duc in g a d a r k e r c o l o r th a n t h a t o f th e l a y e r below . w e ll d is tr ib u te d in th is la y e r. o rig in a lly s i m i l a r to th e h o r i z o n below, by p r o c e s s e s r e s p o n s i b l e qunm. Its It seems t h a t and t h a t i t la y e r. and i t Its has been a f f e c t e d se- and v e s i c u l a r s t r u c ­ i s much denser and h a r d e r than th e o v e r l y i n g t r a n s i t i o n a l t e x t u r e u s u a l l y i s c o a r s e r th a n th e B h i r and th e imme­ d ia t e ly u n d e rly in g h o riz o n . k in d o f i l l u v i a t i o n . 10 YR 5 / 2 , t h i s l a y e r was ranges between one and two in c h e s . The m id d le h o r i z o n has a d i s t i n c t p l a t y tu re , pro­ The r o o t s a r e f o r th e development o f the u p p e r Podzol th ic k n e s s u s u a lly w h ile i s n o t cemented. Some o r g a n i c m a t t e r and s e s q u io x id e s p r e c i p i t a t e i n fa irly It 10 YR 6/ i , There i s no m a c ro s c o p ic a l e v id e n c e o f any The u s u a l c o l o r s o f t h i s l a y e r 10 YR 6/ 2 , 10 YR ?/ 2 , are: and 10 YR 7 / 3 . (m o is t) T h is h o r i ­ zon c o n t a i n s a few b lo c k s r i c h e r i n c l a y than the r e s t o f th e h o r i z o n . These f i n e r t e x t u r e d b lo c k s h a ve a r e d d is h brown c o l o r i n th e g r a y i s h c o l o r o f t h e b u l k o f th e h o r i z o n . depends on th e amount o f c l a y p r e s e n t , e l u v i a t i o n o f each one o f them. 10 YR 5/ 4 , 5 t r 5 / 3( is q u ite v a r ia b le , l o n g e s t d im e n s io n . 5 YR 4/ 3 , c o n t r a s t to The c o l o r o f th e b lo c k s which v a r i e s w it h t h e d e g re e o f The most common c o l o r s observed a r e and 7 . 5 YR 4 / 4 . The 8i 2e Qf the b lo c k s but th e y g e n e r a l l y a r e l e s s than one in c h i n t h e i r Depending on th e degree o f e l u v i a t i o n o f th e c l a y , some o f th e b lo c k s a r e c o n s i d e r a b l y h a r d e r and o t h e r s much s o f t e r th a n t h e r e s t o f th e h o r i z o n . U s u a l l y th e g r a y e r t h e i r c o lo r, th e h a r d e r 21 th e y a r e . The b lo c k s a r e more abundant and r e l a t i v e l y d e ve lo p e d on th e f i n e r te x tu re d m a te ria ls in s o fte r in th e l i t h o s e q u e n c e , t h e h a r d e s t o f them have been found i n s o ils p arent m a te ria ls . th e upper boundary i s As m e n tio n e d above, s o ils but formed from loamy sand i r r e g u l a r as th e P o d z o l sequum exten d s as tongues i n t o sharp and th e f r a g i p a n . The depth to t h e u p p e r boundary v a r i e s i n most cases from 10-22 i n c h e s . The d e e p e s t pans a r e u s u a l l y th e l i thosecfuence. found i n th e c o a r s e r t e x t u r e d members o f I n many cases a s h ea th o f s i l t y m a t e r i a l has been found around th e p e b b le s i n th e s e p r o f i l e s . been found by F itz p a tric k o f th is la y e r ra n g e s from 5 to 12 in c h e s . found on c o a r s e r s o i l s . (1 9 ) i n perm afro st h o riz o n s . t h ic k n e s s i s but a Tap r o o t s o f a l f a l f a have been obs erv e d which a p p a r e n t l y had d i f f i c u l t i e s in p e n e tra tin g course f o l l o w i n g c r a c k s . th is la y e r v a r ie s in The h i g h e s t The th ic k n e s s Root b ra n c h in g i s r a r e i n t h i s l a y p r , few ta p r o o t s go th ro u g h i t . ta k e a zig za g S i m i l a r f o r m a tio n s have d i f f e r e n t p la c e s , th e pan, f o r th e y The degree o f c e m e n ta tio n o f and i t seems to depend on the amount o f c l a y p r e s e n t . The lo w e r l a y e r o f the pan i s h a r d e r and a l i t t l e t u r e i s m a s s iv e , r ic h e r in c la y a ls o v e r y dense but c o n s i d e r a b ly th a n th e m id d le l a y e r . but sometimes when p ressed i t Its b re ak s i n t o s tru c ­ c o a rs e p l a t y o r s u b a n g u la r and a n g u la r b lo c k y fra g m e n ts . The v e s i c u l a r d i s ­ c o n tin u o u s p o r e s a re c o n s i d e r a b l y l e s s abundant i n t h i s p a ^ t o f the pan. and i r r e g u l a r . is I t s u p p e r boundary i s c l e a r a ls o c l e a r i n most cases but is very i r r e g u l a r , illu v ia l in zone. sometimes i t The lo w e r boundary i s g ra d u a l, w i t h many tongues e x te n d in g i n t o and g e n e r a l l y th e u n d e r l y i n g The t h i c k n e s s o f t h i s l a y e r v a r i e s c o n s i d e r a b l y even th e same s o i l , m a in ly because o f th e tongues and th e i r r e g u l a r i t y 22 o f th e lo w e r ‘boundary; it u s u a lly ranges "between 5 and 15 in c h e s , F i n e r t e x t u r e d "blocks a r e more abundant i n t h i s l a y e r m id d le one, except in bu t th e y u s u a l l y loamy sand s o i l s , h ig h e r c la y co n te n t, are s o fte r 10 YR 5 / 2 i n which th e y may be h a r d e r . th e c o l o r o f th e lo w e r l a y e r i s h o riz o n e it h e r , and 7 . 5 5 / p. Due to a little the more Common c o lo r s a r e ; There i s no r o o t b ra n c h in g i n th is and t a p r o o t s have z ig z a g shapes. I n many s o i l s and e s p e c i a l l y i n th o s e formed on sandy c l a y loams and c l a y loam s, a t r a n s i t i o n a l l a y e r i s d e ve lo p e d between the pan and th e second zone o f i l l u v i a t i o n . illu v ia l th e than th e b u lk o f th e l a y ^ r , p i n k i s h th a n th e c o l o r o f t h e m id d le l a y e r . (m o is t) than i n T h is t r a n s i t i o n a l l a y e r i s and re s e m b le s th e u n d e r l y i n g B^. h o r i z o n , fo r t h e most p a r t , b ut i n c e r t a i n p l a c e s and e s p e c i a l l y on th e edges o f t h e s t r u c t u r a l u n its , it i s g ra y is h in c o lo r, p e r tie s in th e s e p l a c e s has a medium, shows e l u v i a t i o n a re s i m i l a r to and g e n e r a l l y i t s pro­ th e p r o p e r t i e s o f th e pan. It s u b a n g u la r b lo c k y s t r u c t u r e . Most o f th e f r a g i p a n p r o f i l e s s t u d i e d have s e v e r a l w e d g e - l i k e c r a c k s e x t e n d in g from t h e top o f t h e pan down to the t r a n s i t l o n a l i l l u ­ v ia l h o riz o n . in S ilt th e s e c r a c k s . b a lls I n c e r t a i n p a r t s o f th e c r a c k s , form by d e p o s i t i o n . s o il m a te ria ls o f g ra v ity . to and c l a y have been d e p o s it e d by p e r c o l a t i n g w a te r fa llin g In p i t s The c r a c k s c o n t a i n , a ls o , dug 5 - 6 f e e t w id e , p l a n t ro o ts and the c r a c k s have n o t been found c r i b e d by C a r l i s l e (14) The c r a c k s , th e ir v e r tic a l o rie n ta tio n , te rn a l c la y or c la y down from th e P odzol sequum un d e r th e i n f l u e n c e form r e g u l a r p o l y g o n a l p a t t e r n on a h o r i z o n t a l due to s ilty in s o i l s o f Hew Y o rk , d r a in a g e o f th e s o i l , s u rfa ce , as des­ and by o t h e r w o rk e rs . c o n t r i b u t e to th e i n ­ which o t h e r w i s e would have been i m p e r f e c t , 23 because o f t h e lo w w a t e r p e r m e a b i l i t y o f th e f r a g i p a n . v e rtic a l cracks, h o riz o n ta l p la n e -lik e pan o f many s o i l s . c ra c k s have been found i n They a r e 0 . 5 - ones can be as wide as 2 o r 3 in c h e s . 2 mm. w id e, w h i le t h e v e r t i c a l The c ra c k s have a w h i t e c o l o r when examined u n d e r th e b i n o c u l a r m icros c ope , fille d th e These c r a c k s c o n t r i b u t e to th e p l a t i n e s s o f th e s t r u c t u r e o f th e pan. end, Besides th e a r e found to be w ith s i l t . The pan o f the i m p e r f e c t l y d r a in e d s o i l s has s i m i l a r p h y s i c a l p r o p e r t i e s to th o s e o f t h e w e l l b e in g wet f o r lo n g e r p e r i o d s , d u r i n g th e y e a r d r a in e d s o i l s , re v e a ls i t s but i t hardness f o r i s m o ttle d , and s h o r t e r p e r io d s than th e pans i n th e w e l l d r a in e d s o i l s . The f r a g i p a n o f M ic h ig a n s o i l s i s compact, has a h ig h bulk d e n s ity , e x h ib its a r e v e r s ib le in d u ra tio n , in i t s m a c r o s c o p ic a l c h a r a c t e r i s t i c s th e U. S. tiv e ly h ig h and abroad, as c i t e d i n but i t the l i t e r a t u r e r e v ie w . The r e l a ­ n ot l i m i t e d o n ly extends down to th e t r a n s i t i o n a l i l l u v i e l h o r i ­ zon and even to th e Bt h o r i z o n . The b u lk d e n s it y o f th e s o i l below f r a g i p a n d e cre a se s w ith d e p th . Below t h e t r a n s i t i o n a l h o r i z o n i s o r B t, which i s th e h o r i z o n r i c h e s t o r r e d d i s h brown c o l o r . in g s s im ila r to those d e s c r ib e d e ls e w h e re i n bu lk d e n s i t y o f many s o i l s o f M ic h ig a n i s to t h e f r a g i p a n , th e and g e n e r a l l y i s the second i l i u v i a l h o r i z o n in c la y . I t u s u a l l y has a brown T h e re a r e numerous and conspicuous c l a y c o a t ­ a lo n g t h e ro o t c h a n n e ls and on th e s u r fa c e s o f s t r u c t u r a l u n i t s . The s t r u c t u r e i s u s u a l l y medium s u b a n g u la r blo c ky but sometimes i t a n g u la r b lo c k y . There i s a f a i r r o o t b ra n c h in g i n b r a n c h in g and c l a y c o a t i n g s a r e also tio n a l i l i u v i a l h o riz o n . found i n th is h o riz o n . th e o v e r l y i n g is Root tra n s i­ The t h i c k n e s s o f th e Bt ranges between 12 24 ana 25 i n c h e s . is Coarse s h l s nave u s u a l l y no e v id e n c e o f c e m e n ta tio n i n t h i c k e r Bt h o r i z o n s . t h is h o rizo n , except a s l i g h t one i n t h e cas e o f loamy sand and some sandy loam m a t e r i a l s c o l o r s o f th e Bt a r e 5 YR 4 / 4 , 5 YR 4 / 3 t The Bt h o r i z o n i s u n d e r l a i d zon which i s a c a lc a re o u s g r i t t y o f li m e and to c la y , the r e l a t i v e l y 5 YR 3/ 4 , 5 YR 6/ 3f and 7 . 5 YR 4 / 4 . g la c ia l d rift. low amount o f i r o n Due to th e pre se n c e a s s o c i a t e d w it h th e Common c o lo r s a r e : 7.5 yR 6/ 4 , 7 . 5 YR 5 / 4 , 5 YR 5 / 3> 5 vp 3 / 4 . a r e no c l a y c o a t in g s i n d ia te ly Common m o ist by th e p a r e n t m a t e r i a l o r C h o r i ­ th e C h o r i z o n has l i g h t e r c o l o r than th e B t. (m o is t) below th e B t. There There th e C h o r i z o n e xcept i n a t h i n l a y e r imme­ The C h o r i z o n i s g e n e r a l l y n o t so compact, th e o v e r l y i n g l a y e r s and r o o t s show a f a i r These f r a g i p a n p r o f i l e s as amount o f b ra n c h in g . a r e u s u a l l y m o d e r a te ly a c id from the s u r f a c e down to th e lo w e r boundary o f th e Bt h o r i z o n . Since f r a g i p a n s quences o f s o i l and s in c e w e l l a r e found i n M ic h ig a n m o s tly i n th e l i t h o s e ­ formed i n loamy sand to c l a y loam p r im a r y m a t e r i a l s , d r a in e d members o f th e c a te n a s which f a i l above l i t h o s e q u e n c e s , fre q u e n tly w i t h i n th e form w e l l developed f r a g i p a n s , which a r e a p p a r e n t l y cemented f o r lo n g e r p e r io d s a n n u a lly th a n i m p e r f e c t l y d r a in e d fra g ip a n s , it was decided f o r th e p r e s e n t i n v e s t i g a t i o n . th e above l i t h o s e q u e n c e , fo r r e p r e s e n t a t i v e s o f th e s e Three w e l l d ra in e d Podzol p r o f i l e s o f h a v in g w e l l expressed f r a g i p a n s were s e l e c t e d s tu d y . The p r o f i l e s s o il to s e l e c t s e le c te d fo r th is study belong to th e f o l l o w i n g s e rie s : (1 ) McBride formed i n sandy loam p a r e n t m a t e r i a l (2) I s a b e l l a form ed i n sandy c l a y loam to sandy c l a y p a r e n t mat e r i a l (3 ) W ester formed on c l a y loan"! to s i l t y c l a y loam p a r e n t mat e r i a l f o l l o w i n g a r e d e s c r i p t i o n s of' t h e t h r e e p r o f i l e s te e n s u b je c te d to d e t a i l e d I. fie ld and l a b o r a t o r y which have s tu d ie s : McBride sandy loam lo c a tio n : NW 1 / 4 , SB 1 / 4 , T 20 N, R 11 W, S e c tio n 23, Lake County, 100 f e e t e a s t o f th e ro a d across from the farm house. V e g e ta tio n : Sugar maple, D ra in a g e : w e ll Slope: 8# E ast P h y s io g r a p h y : B o l l i n g g l a c i a l m oraine H o riz o n Depth D e s c rip tio n 0 -1 " Leaf l i t t e r A0 ia l. 40 y e a r s o l d stand d r a in e d It and p a r t i a l l y decomposed o r g a n ic m a te r­ c o n ta in s many f i b r o u s Dark g r a y i s h y e l l o w i s h brown (1C YR Ai coarse, sandy loam; r i c h in w e ll i n t e r m i x e d o r g a n ic m a t e r i a l , fib ro u s ro o ts ; pH. A2 ro o ts . 3-5 " 5 .4 ; m oderate, 3 /2 m o is t); decomposed and h e a v i l y m a tte d w ith medium, crumb; fria b le ; boundary- a b r u p t. L i g h t brow nish g ra y - g r a y i s h y e l l o w i s h brown (1C YR 5 /1 is m o is t); loamy sand; th e number o f f i b r o u s s m a l l e r th a n i n Ao» A i; numerous c h a n n e ls , ro o ts ro o t and worm h o l e s , and d i f f e r e n t passages a r e f i l l e d w ith da rk m a t e r i a l s C o lo r names used are ISCG-NBS names. from Ao &hd A i; weak, medium, 26 s u b a n g u la r 'blocky, B h ir fria b le ; pH 5 . 2 ; boundary a b r u p t . 5 -1 7 *’ M o d e ra te y e l l o w i s h brown (1 0 YR 4/4 m o i s t ) ; sand; ric h i n r o o t s o f v a r i o u s s iz e s ; s u b a n g u la r b lo c k y ; fria b le ; pH 5 . 3 ; weak, few r o o t s ; and medium, v e s ic u la r, m o d e ra te , suban g u la r b lo c k y ; w ea k ly cemented when dry; medium, boundary c l e a r . Bm ( t r a n s . ) 1 7 - 1 9 ” M oderate y e l l o w i s h brown (1 0 YR 3 / 4 m o i s t ) ; sand; loamy th ic k , loarry p la ty f r i a b l e when wet, c o n ta in s s m a ll lumps which re se m b le th e h o r i z o n below; pH 5 . 6 ; boundary c l e a r , irre g u la r. jA2Jm 1 9 - 2 4 ” L i g h t y e l l o w i s h brown (1 0 YR ? / 4 m o i s t ) ; f i b r o u s r o o t s a re p r a c t i c a l l y a b s e n t, lo a n y sand; a v e r y few t a p r o o t s go through t h i s h o r i z o n w i t h o u t b ra n c h in g ; v e s ic u la r, dry, s tr o n g , fria b le when w et; w ith m a t e r i a l s v e rtic a l very th ic k , p la ty ; i n d u r a t e d when a few worm h o le s cure f i l l e d from o v e r l y i n g h o r i z o n s ; c r a c k s c o n t a in s i l t and c l a y wedge-shaped d e p o s it s ; 0 .5 - 2.0 mm. wide h o r i z o n t a l p l a n e - l i k e c r a c k s f i l l e d w ith s i l t ; compact; pH 5 . 8 ; boundary c l e a r , irre g u ­ la r . 2 4-35 ” L i g h t g r a y i s h brown ( 7 . 5 YR 3 / 2 m o is t) g re ates t p a rt, m o is t) lumps, fo r i t s b u t c o n t a i n s m oderate brown (5 YR 4 / 3 which e re f i n e r i n t e x t u r e than th e r e s t o f the h o r i z o n and i n c r e a s e i n number and s i z e w i t h d e p th , sandy loam; b re a k s i n t o s tr o n g , massive but when p r e s s e d , very t h i c k , p l a t y s u b a n g u la r b lo c k y fra g m e n ts ; and medium, i n d u r a t e d when d ry , it 27 fria b le when wet; v e r t i c a l and h o r i z o n t a l c ra c k s same as i n t h e o v e r l y i n g h o r i z o n ; root d is t r ib u t io n a ls o (th is is same as above; est o f a l l v e r y compact; th e h o r i z o n s o f th e p r o f i l e ) ; th e h a rd ­ pH 5 . 6 ; boundary c l e a r and i r r e g u l a r . Bt 35-53" M ode ra te brown ( 5 YR 3 / 4 m o i s t ) ; loam; s tro n g , very firm , medium, a n g u la r b lo c k y ; somewhat compact; b ut n o t in d u r a t e d ; coarse, sandy c l a y when m o is t i s r i c h i n c l a y c o a t in g s r o o t s a r e abundant; pH 5 . 2 ; bound­ a r y c l e a r and wavy. 1= 53" C L i g h t g r a y i s h r e d d i s h brown - sandy loam; m o d e ra te , medium, b lo c k y ; no c l a y c o a t in g s ; ro o ts f a i r l y m o is t , s u b a n g u la r f i r m but n o t com­ abundant; pH 7 . 8 ; c a lc a re o u s . I s a b e l l a sandy loam SW 1 / 4 , L o c a tio n : NE 1 / 4 , O s c e o la County, V e g e ta tio n : Sugar m aple, D r a in a g e : W e ll d r a in e d S lo p e : 1 6 # West P h y s io g ra p h y : G l a c i a l m o ra in e . H o r iz o n Depth D e s c rip tio n 0- 1 " Leaf l i t t e r Ao brown (5 YR 5 /3 m o is t); p act; II. lig h t NW 1 / 4 , S e c tio n 3 1 , T 19 N, R 9 W, M ic h ig a n . elm, beech, and p a r t i a l l y and w h ite p i n e decomposed o r g a n ic m ater- i al • Al •3 f t Dark g r a y i s h y e l l o w i s h brown (1 0 YR 2 / 1 m o i s t ) ; sandy loam; weak, medium, crumb; fria b le ; r ic h in fib ro u s ro o ts and w e l l decomposed and i n t e r m ix e d o rg a n ic m a tte r; A2 3 -5 " pH 4 . 7 ; boundary a b r u p t . L i g h t g r a y i s h y e l l o w i s h brown (10 YE 6 / 2 m o i s t ) ; coarse, a b le ; sandy loam; weak, fin e , fe w er r o o t s th a n i n A^; i t and o t h e r l a r g e po re s f i l l e d th e A l; B h ir 5 -1 1 ” pH 4 . 7 ; fin e , fri­ c o n t a i n s r o o t h o le s w ith d a rk m a t e r i a l from boundary a b r u p t. M oderate brown (5 YE 3 / 3 , weak, crumb; m o is t , 4 / 3 m o is t); sub an g u la r b lo c k y ; m o is t , o f v a r i o u s s iz e s a re abundant; pH 4 . 6 ; sandy loam; fria b le ; ro o ts boundary c l e a r and i r r e g u l a r . Btq ( t r a n s . ) 1 1 - 1 3 ” G ra y is h y e l l o w i s h brown to moderate y e l l o w i s h brown (10 YR 3 / 3 , m o d e rate, th ic k , weakly cemented, pH 4 . 6 ; &2m 13=21" 4 / 3 m o is t ) p la ty loamy sand; v e s i c u l a r , and medium, m o d e ra te ly compacted; - (1 0 YR 3/1 m o i s t ) ; w ith l i g h t g r a y i s h y e l l o w i s h brown fin e r t e x t u r e d m oderate y e l l o w i s h brown (10 YE 3 /4 m o is t ) v e s ic u la r, w e d g e - li k e 2 1-34 ” medium p l a t y ; when m o is t , 'lumps; loamy sand; i n d u r a t e d when i t s t r o n g l y compacted; and v e r t i c a l c ra c k s and o l d ro o t h o le s s ilt have f a l l e n A3m s tr o n g , dry and f r i a b l e c o n ta in few r o o t s ; boundary sharp and i r r e g u l a r . L i g h t brownish g ra y is a n g u la r b lo c k y ; and c l a y d e p o s it s and m a t e r i a l s down from u p p e r h o r iz o n s ; ro o t d is tri­ b u t i o n v e r y s p ars e ; pH 4 . 9 ; boundary a b r u p t. L i g h t g r a y i s h brown ( 7 . 5 YR 3 / 2 m o is t ) te x tu re d l i g h t brown (5 YE 3/3 moi s t ) th a t w ith lumps; fin e r sandy 29 loam; m a ss ive , m o d e rate, "but when p r e s s e d , medium, d u r a te d when d ry , file ), it b re ak s i n t o s u b a n g u la r b lo c k y fra g m e n ts ; (th e h a rd es t h o riz o n in in ­ th e p r o ­ s t r o n g l y compacted; c ra c k s and r o o t h o le s same as i n th e h o r i z o n above; pH 5 . 0 ; boundary d i f ­ fu s e and i r r e g u l a r . A & B 34-42" M oderate brown ( 7 . 5 YR 4/4 m o i s t ) , f o r t h e most p a r t ; sandy c l a y sandy c l a y loam, loam but sm all p o r ­ t i o n s a r e y e l l o w i s h g r a y (1 0 YR ^ / l m o is t ) and have loamy sand t e x t u r e ; m oist firm , weak, medium, m o d e ra te ly compact, s u b a n g u la r b lo c k y ; the v e r t i c a l cracks stop i n t h i s h o r iz o n and c o n ta in g r a y i s h sandy ma­ te ria ls a lo n g w ith s i l t and c l a y d e p o s it s ; t h e r e a re numerous c l a y c o a t in g s a lo n g the r o o t h o l e s and o t h e r c h a n n e ls ; pH 4 . 8 ; B t* 42-55" f i n e f i b r o u s r o o t s a r e abundant; boundary a b ru p t and i r r e g u l a r . M oderate brown ( 7 . 5 YR 4/4 m o i s t ) ; weak, medium b lo c k y ; m o is t, sandy c l a y v e ry f i r m , loam; n o t compact; r i c h i n m oderate brown (5 YR 4 / 3 m o i s t ) c la y c o a t ­ in g s a lo n g th e r o o t h o le s and p la n e s o f weakness; ro o ts a re abundant; pH 5 . 3 ; boundary c l e a r and wavy. C 4 -5 6 L i g h t brown ( 7 . 5 5 / 4 m o i s t ) ; sandy c l a y loam; weak, * Between th e Bt and C h o r iz o n s have been found 1 -3 in c h e s t h i c k p o c k e ts o f s i l t y m a t e r i a l s which have no g e n e t i c r e l a t i o n s w i t h th e h o r i z o n s , but th e y a r e g e o l o g ic d e p o s it io n s fr e q u e n t i n th e g l a c i a l depo s i t s . medium, s u b an g u la r b lo c k y ; c l a y c o a t in g s ; III. few r o o t s ; f i r m but n o t compact; pH 7 . 9 , no c a lc a re o u s . H e s t e r sandy loam lo c a tio n ; Sff 1 / 4 , SW 1 / 4 , O s c e o la County, V e g e ta tio n : Sugar maple, SE 1 / 4 , S e c tio n 3 6, T I S N, R 10 M ic h ig a n . aspen, b irc h , ash, basswood and few firs . D ra in a g e ; W ell d r a in e d Slope: 2^ East P h y s io g r a p h y : M oraine H o r i zon Ao Depth D e s c rip tio n 0- 1" Leaf l i t t e r and p a r t i a l l y abundant f i b r o u s r o o t s ; Ai 1 -5 " 5 - 9 11 boundary a b r u p t and wavy. Dark g r a y i s h y e l l o w i s h brown (1 0 YR * V 2 m o i s t ) ; sandy loam; m oderate, A ^ /B h ir decomposed o r g a n ic m a t t e r ; medium, crumb; ric h in w e ll te r; m a tte d w i t h 5 .4 ; boundary a b ru p t and smooth. m o is t, fria b le ; decomposed and i n t e r m i x e d o r g a n ic mat­ fib r o u s and la r g e r ro o ts ; pH C r a y i s h y e l l o w i s h brown (10 YR 5 / 2 m o i s t ) , but i n c e r t a i n spots a weak, moderate y e l l o w i s h brown (10 YR 4 / 4 m o i s t ) o r t e r d e has d e ve lo p e d ; erate, sandy loam; mod­ medium, p ia t.y ana s u b a n g u la r blocky; r o o t s o f v a r i o u s s i z e s a re abundant; h o le s are f i l l e d boundary ab ru p t w ith m a te ria ls and i r r e g u l a r . n o t d e ve lo p e d w e l l fria b le , r o o t and worm from the A i; pH 5 . 2 ; The Aii and B h i r are enough to be d i s t i n g u i s h e d as 31 in d iv id u a l h o rizo n s , A2m 9 -1 6" G r a y is h y e l l o w i s h brown (1 0 YR 5 / 2 rn o is t) w ith f i n e r t e x t u r e d m oderate brown ( 7 . 5 YR 4/4 m o is t ) lumps 1 / 4 - 6" i n d ia m e te r ; sandy loam; v e s i c u l a r , ir o d e ra te , th ic k , p la ty , w it h some v e r t i c a l c r a c k s and h o r i z o n ­ t a l p l a n e s o f weakness; cemented when d r y , when m o i s t ; it (fflnen d ry , is fria b le th e h a r d e s t h o r i z o n i n th e p r o f i l e . ) very few unbranched ro o ts p e n e tra te t h i s h o rizo n ; s ilt and c la y d e p o s it s a r e p r e s e n t i n th e c r a c k s and t h e r e a re a few c l a y c o a t in g s a lo n g r o o t c h a n n e ls ; pH 5 . 4 ; A & B 1 6 -2 7 " M oderate brown boundary c l e a r and i r r e g u l a r . YR 4/4 m o i s t ) (7 .5 f o r th e most p a r t and g r a y i s h y e l l o w i s h brown (10 YR 5 / 2 m o i s t ) i n some e l u v i a l s p o ts ; c l a y loam, in th e i l i u v i a l p a rts and sandy loam i n th e e l u v i a l p a r t s ; dium, s u b a n g u la r b lo c k y ; tre m e ly firm ; m ode rate, me­ dry cemented o r m o is t e x ­ m o d e r a te ly compact; th e v e r t i c a l c r a c k s end i n t h i s h o r i z o n and c o n t a i n sand s i l t and c l a y d e p o s it s ; th e re i s a fa ir r o o t b ra n c h in g ; c l a y c o a t in g s a r e abundant a lo ng th e r o o t c h a n n e ls ; pH 5 . 0 ; Bt 27-48" boundary c l e a r and i r r e g u l a r , M ode ra te brown ( 5 YR 4/4 m o i s t ) ; dium, c la y ; s t r o n g , me­ s u b a n g u la r b lo c k y ; m o is t very f i r m , compact; r o o t s a r e abundant; m o d e r a te ly numerous c l a y c o a t i n g s a lo n g the r o o t c h a n n e ls and on the s u r f a c e s o f the s tru c tu ra l u n its ; pH 5 . 0 ; boundary c l e a r and wavy. 32 C 48-55" M oderate brown (5 YH 4/3 m o i s t ) ; c la y loam c o n t a i n i n g lim e s t o n e ; m oderate, m o is t v e r y f i r m ; c l a y loam to sondy f i n e g r a v e l s o f decomposing medium, s u b a n g u la r b lo c k y ; ro o ts are f a i r l y c o a tin g s in i t s upper p a r t; abundant; pH 7 . 5 ; few c l a y boundary a b ru p t and wavy. D 4= 65" M ode ra te brown ( 7 . 5 YH 4/4 m o is t) c a l c a r e o u s ; c o a rs e sandy loam ; n o t compact. Kem arks; The morphology o f th e d e s c r ib e d and o t h e r s i m i l a r p r o f i l e s s uggests t h a t p o d z o l i z a t i o n has d i s i n t e g r a t e d the upper p a r t o f th e fra g ip a n . The p re s e n c e o f th e f i n e r t e x t u r e d lumps i n th e f r a g i p a n and th e e x is te n c e o f a t r a n s i t i o n a l e l u v i a l - i l l u v i a l fra g ip a n , th a t show t h a t at le a s t l a y e r j u s t below the t h e pan had been i n th e p a s t r i c h e r i n c l a y , some o f i t s p ro p e rtie s v e lo p e d g e n e t i c a l Bt h o r i z o n s . and end f e a t u r e s a r e p r e v i o u s l y de­ The f i n e r lumps can be c o n s id e r e d as r e l i c s o f th e p a r e n t m a t e r i a l . The dependence o f th e hardness o f the pan and o f i t s t e x t u r e d lumps on ohe c l a y c o n te n t ro le fin e r suggests t h a t c l a y p l a y s a c e r t a i n as a b in d in g a g e n t. The t r a n s i t i o n a l was not w e l l e l u v i a l - i l i u v i a l h o r i z o n o f the McBride s o i l d e f i n e d and, t h e r e f o r e , in sam pling, it was s p l i t between t h e lo w e r h o r i z o n o f th e pan and th e u n d e r l y i n g second i l i u v i a l h o r i ­ zon. The symbol B h i r used h e r e does n o t im p ly o u t s t a n d i n g accumula­ tio n o f iro n S o il and o r g a n i c m a t t e r c a u s in g c e m e n ta tio n as s t a t e d i n Survey Manual. th e 33 METHODS OF ANALYSIS S tu d ie s o f th e p h y s ic a l, o f each h o r i z o n were c o n d u c te d i n and amount o f changes i n c h e m ic a l and m i n e r a l o g i e s ! p r o p e r t i e s th e l a b o r a t o r y to d e te r m in e th e k i n d th e c o u rs e o f s o i l g e n e s is o f th e t h r e e se­ le c te d p r o file s . S i x u n d i s t u r b e d c o re samples and a t h r e e to f o u r pound bag sample were ta k e n from each o f the h o r i z o n s c h ap ter. sample, d e s c r ib e d i n th e p r e v i o u s The bag samples were p a r t s o f a b ig g e r and th o r o u g h ly mixed r e p r e s e n t a t i v e o f each h o r i z o n , Methods f o l l o w e d i n th e l a b o r a t o r y d e t e r m in a t i o n s a r e : I. 1. DETFBMJ NAT 10 N OF PHYSICAL PHOPEHTIES W ater p e r m e a b i l i t y , p o re s i z e d i s t r i b u t i o n , ana b u lk den- s i ty were d e te r m in e d on s i x r e p l i c a t e c o r e samples from each h o r i z o n , a c c o r d in g to Uhland and O 'N e a l ( 5 8 ) methods. W ater p e r m e a b i l i ty was d e te r m in e d by a p p l y i n g 100 c c . o f d i s ­ tille d w a t e r on top o f th e w a t e r s a t u r a t e d c o i e s , tim e which e la p s e d u n t i l d ra in e d . and r e c o r d i n g the w a te r on top o f th e c o r e was c o m p le t e ly In t h e c a s e o f c o re s w i t h slow p e r m e a b i l i t y , the volume o f w a t e r p a ss e d th ro u g h th e c o r e i n two h o u rs was e s t im a t e d by m easuring t h e volume o f t h e w a t e r which re m a in e d on th e top o f th e c o re at tim e and s u b s t r u c t i n g i t fro m 100 m l. th at No c o n s t a n t head o f w a te r was used. P o re s i z e d i s t r i b u t i o n . Water s a t u r a t e d c o re s were w eighed 34 and p l a c e d on 60 cm, t e n s i o n t a t t l e s . ta in e d , A f t e r c o n s t a n t w e ig h t was ob­ t h e samples w ere oven d r i e d a t 1 05 ° C. u n t i l w e ig h t was re a c h e d . a new c o n s ta n t The w e ig h t lo s s e s i n grams on th e t e n s io n t a b l e and i n t h e oven d i v i d e d by th e volume o f th e c o re s th e p e r cen t n o n - c a p i ll a r y and c a p i l l a r y p o r o s i t y (3 4 7 m l . ) rep resen t re s p e c tiv e ly . B u lk d e n s i t y was d e te rm in e d by d i v i d i n g t h e oven dry w e ig h t o f the s o i l sample by t h e volume o f th e c o r e . H a rd n e s s . f r a g i p a n s by r e c o r d i n g ly c y lin d ric a l Grossman and C l i n e (2 3 ) measured hardness o f th e c r u s h i n g p r e s s u r e a p p l i e d on dry and rough­ a rtific ia lly molded c y l i n d e r s o f s o i l m a t e r i a l s . They e x p r e s s e d t h e i r r e s u l t s i n terms o f a c r u s h in g number which was r e ­ la te d to t h e f o r c e a p p l i e d and the s i z e (cro ss s e c tio n ) o f the c y l i n ­ ders. S in ce c r u s h in g v a lu e s a r e s c i e n t i f i c a l l y m e t r i c a l l y p e r f e c t b o d ie s a r e b e in g t e s t e d , method c o u ld n o t be s u c c e s s f u l l y used i n it is e x tre m e ly d i f f i c u l t p le s w ith o u t d e s tro y in g more d i f f i c u l t it to was f e l t the p r e s e n t th a t s tu d y , to p r e p a r e g e o m e t r i c a l l y p e r f e c t th e ir n a tu ra l s tru c tu re . th is because s o il sam­ The problem i s s till i n th e c as e o f f r a g i p a n h o r i z o n s because o f t h e i r b r i t ­ t l e n e s s and t h e i r numerous p la n e s o f weakness. fo re , sound o n l y when geo­ It was d e c id e d , th e re ­ to u s e th e r e l a t i v e r e s i s t a n c e o f th e u n d i s t u r b e d c o res o f s o i l th e v e r t i c a l p e n e t r a t i o n o f a 9 0° m e t a l l i c cone as a measure o f the s o i l hardness. A d is a d v a n ta g e o f t h i s method i s in te rfa c e s o ils . tu re , which may m o d ify th e r e s u l t s Factors in f lu e n c in g adherence on the soi 1 - m e t a l e s p e c ia lly in fin e te x ^ u i ed th e m a g n itu d e o f th e adherence a r e : s t r u c t u r e , ty p e o f c l a y minerals p r e s e n t , o r g a n ic m a t t e r , te x ­ and 35 w ater c o n te n t. In the c a s e o f th e p r o f i l e s s tu d ie d , how ever, d i f f e r e n c e s i n h a rd n e s s o f th e t e s t e d h o r iz o n s were so g r e a t th e th a t th e i n f l u e n c e o f a d herence c o u l d be d i s r e g a r d e d . A n o th er p ro b le m i n m easuring h a rd n es s was the p r o p e r w a te r c o n t e n t o f t h e samples a t th e tim e o f measurement. F r a g ip a n s have been d e f i n e d as h o r i z o n s i n d u r a t e d when dry but n o t i n d u r a t e d when m o is t. It has been o b s e rv e d , how ever, t h a t deeper and f i n e r h o r i z o n s , n o t h a v i n g th e axjpearance and th e p r o p e r t i e s o f f r a g i p a n , e x tr e m e h a rd n es s when th e y are a i r d r i e d . bo th i n ly th e f i e l d and i n th e l a b o r a t o r y , m a i n t a i n t h e i r h a rd n e s s i f c ity , It e x h i b i t an has a ls o been o b s erv e d , t h a t m o is t t h e i r w a te r c o n te n t fra g ip a n s p a r t i a l ­ i s below f i e l d capa­ w h i l e o t h e r h o r i z o n s become e i t h e r f r i a b l e o r p l a s t i c . The w a te r c o n t e n t a t one atmosphere t e n s io n was found to be s a tis fa c to ry f o r th e s e measurements. The two h a r d e s t c o re samples from each o f th e t e s t e d h o r iz o n s were w a t e r s a t u r a t e d and p l a c e d i n p r e s s u r e c o o k e rs , s u b j e c t e d to one atm osphere p r e s s u r e u n t i l re a c h e d e q u i l i b r i u m (c o n s ta n t w e ig h t). cone f o r 1.5 cm. i n t o where th e y were t h e i r w ater c o n te n t had 'The f o r c e r e q u i r e d to push th e th e u n d i s t u r b e d s o i l o f the c o re was measured by means o f an u n c o n fin e d com pression a p p a r a tu s . The v e i y h a r d cores o f t h e A3m h o r i z o n s were t e s t e d by means o f a T i n i u s O ls e n h y d r a u l i c press. Th re e measurements were made on each base o f th e c o r e s . The a v e ra g e Cone P e n e t r a t i o n R e s is t a n c e f o r each h o r i z o n was c a l c u l a t e d by u s i n g the f o r m u l a s u g g e s te d by Capper and Cassie ( 1 3 ) : CFH = (fT z - Vwp2 JF (F2 - P i )2 w here CPU - cone p e n e t r a t i o n r e s i s t a n c e Wi = w e ig h t o f th e cone i n ^ 2 - a p p l i e d l o a d i n Kgms. Pi s p e n e t r a t i o n i n cm. ?2 = f i n a l p e n e t r a t i o n due th e cone ( 1 . 5 3. ly Kgras. due to t h e w e ig h t to th e o f th e cone lo a d a p p l i e d p lu s t h e w e ig h t o f c m .) M e c h a n ic a l A n a ly s e s : w i t h a wooden r o l l i n g p i n to a v o id f r a c t u r i n g p r i m a r y p a r t i c l e s , and t h e m a t e r i a l p a s s in g th ro u g h a p e r t i e s o f t h e h u lk sam ples. 2 by d i g e s t i o n w i t h 50 m l. . sere ‘Lr s t c u i c- s ' f the 25 gms. o f m o d e ra te ly f i n e t e x t u r e d s o i l samples and 50 gms. o f sandy s o i l was d e s t r o y e d t y o v e r n i g h t The h u lk samples were c rushed l i g h t ­ samples were used. d i g e s t i o n w i t h 200 ml. O rganic m a t t e r o f 10$ H2O2 , f o l l o w e d o f 3 0 $ H2O2 on a 90° C. h o t p l a t e u n t i l t i o n c e a s e d and t h e excess o f H2O2 was e v a p o r a te d . reac­ Samples o f Al h o r i ­ zons r i c h i n o r g a n i c m a t t e r were r e p e a t e d l y d i g e s t e d w it h 1 0$ and 3 0 $ H202 u n t i l th e y were n o t r e a c t i v e w ith H202. C a rb o n a te s and e xc h a n g e ab le Ca^ t h e sam ples w i t h 300 c c . c a lc a re o u s KC1 u n t i l samples o f io n s were removed by washing o f 1$ ECl s o l u t i o n i n Buchner th e C h o r i z o n s were r e p e a t e d l y a c o n s t a n t pH o f 3 . 5 - fu n n e l s . The t i t r a t e d w i t h 1$ 4 . 0 was o b t a i n e d . The c h l o r i d e s were th e n removed by w ashing w it h d i s t i l l e d w a te r u n t i l AgN03 produced no w h ite p r e c i p i t a t e w ith The samples were th e n t i t r a t e d to pH 8 . 5 w ith 0 .1 th e l e a c h a t e s . NaOH and w er- sand was s e p a r a t e d from th e s i l t mesh s i e v e . medium, fin e , shaken o v e r n i g h t . A f t e r s h ak in g , the and c la y by s i e v i n g through a 300 The sands were oven d r i e d and then s e p a r a te d i n t o c o a r s e , and v e r y fin e f r a c t i o n s by m e c h a n ic a l sh ak in g f o r 15 or m in u te s i n a n e s t o f s ie v e s , A 1000 m l. w a te r susp e n s io n was made from th e l e s s than 5 0 fuL and th e amounts o f 5 0 - 2 0 , and f i n a l l y 20-5, these s e p a r a te s were weighed. fra c tio n 5-2 and l e s s than 2 m icron s o i l sepa­ r a t e s were d e te r m in e d "by th e p i p e t t e method as d e s c r ib e d by F i l m e r and A le x a n d e r (3 5 ). C o r r e c t i o n s f o r the NaOH added i n each sample were made. The r e s u l t s o f oven d r y , th e m e c h a n ic a l a n a ly s e s were c a l c u l a t e d on an o rg a n ic m a tte r f r e e and c a r b o n a te fr e e and H s a tu ra te d b a s is . Hygroscopic w a te r. 10 gms. o f a i r dry s o il were weighed, oven d rie d fo r f o u r hours and weighed a g a i n . The lo s s i n w e ig h t e xp ressed as a p e r c e n t o f the oven dry w e ig h t o f th e s o i l r e p r e s e n t s the p e r c e n t o f h y g r o s c o p ic w a t e r . II. C H M C A L ANALYSES The samples were c ru s h e d by a wooden r o l l i n g p i n th ro u g h a 1 mm. 1. tra in s o il s ie v e . O rg a n ic C a rb o n . The d ry combustion method o f th e carbon was f o l l o w e d as d e s c r i b e d by P i p e r were mixed w i t h 0 . 2 5 o f carbon (5 1 ). f r e e ground q u a r t z i n a p o r c e l a i n boat and were i g n i t e d i n a t 9 5 0 ° C. w i t h a c o n s t a n t f l o w o f P u r i f i e d c arbon d i o x id e was absorbed i n and w eig h e d . th e a s c a r i t e tube Car “Donates o f th e C h o r i z o n s were decomposed p r e v i o u s to com b u stio n by s u l f u r o u s a c i d . o f o rg a n ic 1 - 3 gms. o f oven dry gms. o f manganese d i o x i d e and about 2 gms. t h e com bustion tube o f th e t r a i n oxygen. and passed R e s u lt s were c a l c u l a t e d as p e r c e n t c a rb o n on an oven dry 1 mm. c a r Donate c o n t a i n i n g b a s i s . 2. 25 c c . o f b ra te pH meas u r e m e n ts . d is tille d fo r h a lf i n a 100 m l, w ater an n o u r . 25 gms. o f a i r d ry s o i l were m ixed w i t h b e a k e r and a llo w e d to e q u i l i - Measurements were made by u s i n g a Beckman z e r o m a t ic pH m e te r . h, lo s s i n s o lu tio n . 10 gms. o f oven d r i e d s o i l was p la c e d i n 4 0 0 m l. p re w e ig h e d b e a k e rs and d i g e s t e d w i t h 10-1> and 30% o f H^Ok as d e s c r ib e d i n th e method o f m e c n a n ic a l a n a l y s i s . A fte r tn e o r g a n ic m a t t e r was d i g e s t e d , t h e samples were oven d r i e d and weighed w it h th e b eakers. \% rin g , 100 m i. o f HC1 were th e n added ana, a f t e r adequate s t i r ­ th e suspension was f i l t e r e d Buchner f u n n e l s . beakers, c u la te d The s o i l was f i n a l l y oven d r i e d and w eighed. by s u b t r a c t i n g t i o n w i t h H2O2 . The lo s s i n D e t e r m in a t i o n o f th e r e l a t i v e s ilic a in th e y a r e r e l a t e d th e y a r e i n the a c id s o l u t i o n was c a l ­ from th e t o t a l lo s s th e lo s s due to th e d ig e s ­ d i s t r i b u t i o n o f th e a l k a l i th e s o i l p r o f i l e s . Amorphous o r ” f r e e s ilic a " were measured to d e te r m in e w h e th e r to t h e fo r m a t i o n and i n d u r a t i o n o f the f r a g i p a n s , c e rta in ir r e v e r s ib ly amorphous s i l i c a c o n t e n t its t r a n s f e r r e d back, i n t o The r e s u l t s were e xp ressed on oven dry b a s i s . 4. s o lu b le and washed f r e e o f c h l o r i d e s i n in in d u ra te d hardpans. as A h ig h r e l a t i v e the f r a g i p a n could p o s s i b l y c o n t r i b u t e to c e m e n t a t io n . Methods f o r e x t r a c t i n g " f r e e e x t r a c t a n t s - commonly O.bhhSaOH. w i t h pH. Sawney The s o l u b i l i t y s ilic a " from th e s o i l use a l k a l i The s o l u b i l i t y o f s i l i c a in c r e a s e s of s ilic a a ls o i n c r e a s e s w it h te m p e r a tu r e . and. Jackson ( 55 ) removed amorphous s i l i c a c l a y s by b o i l i n g s o lv e n ts , and a lu m in a from th e samples w i t h s 5 hUaOH f o r fo u r houi s . how ever, t a k e s i l i c a in^ o s o lu tio n from s i l i c a t e s Hot a lt -.e li and o u a r t t , 39 to o . The amount o f s i l i c a p a s s in g i n t o s o l u t i o n i n c r e a s e s w i t h de­ c r e a s i n g s i z e o f th e m i n e r a l s . S in c e o n l y r e l a t i v e mined i n th is s tu d y , o f c ry s ta llin e it s ilic a , amounts o f f r e e s i l i c a were to he d e t e r ­ was d e c id e d , in order to b o i l th e s o i l to m in im iz e samples w it h the s o l u t i o n . 5NNaOH f o r o n ly 15 m in u te s . The f o l l o w i n g a dapted g r a v i m e t r i c method was f o l l o w e d f o r th e d e te rm in a tio n o f th e e x t r a c te d s i l i c a : I m p l i c a t e 5 gm. ers. s o i l samples were p u t i n 400 m i. n i c k e l beak­ 50 m l. O.SNNaDH were added and th e suspension was b o i l e d f o r 15 m in u te s on a h o t p l a t e . A fte r b o ilin g th e s o l u t i o n was f i l t e r e d in to 100 r n l. n i c k e l c r u c i b l e s 2 - 4 tim e s u n t i l no s o i l p a r t i c l e was l e f t th e s o lu t io n . were u s ed . No. 4 .2 "Whatman f i l t e r A f t e r each f i l t r a t i o n , th o r o u g h ly s p la tte rin g - to dryness - A lk a li d ro o w is e u n d e r th e s l i g h t l y th e l i d s and th e 70% r a is e d fu r n a c e f o r h a l f th e to p , to p e rc h lo ric lid s . a c id t h i s way o x i ­ th e c o v e r s were (KCIC 4 ) were added When e f f e r v e s c e n c e cea s ed, s id e s o f th e c r u c i b l e s were washed down w ith a m i n i - mar,. o f w a t e r and the c r u c i b l e s , o ra te d an e l e c t r i c s o l u b le o r g a n ic m a t t e r was i n and 15 m l. o f was s lo w ly c a r e was ta k en to a v o id any The c r u c i b l e s were then c o o le d f o r 15 m in u te s , p l a c e d on them, fu n n e ls and t h e f i l t e r p a p er were The c l e a r f i l t r a t e th e r e s i d u e was i g n i t e d i n an hour a t 5 0 0 ° C. of the s o i l washed w i t h warm . 5"NTIaOH. e v a p o r a t e d on a h o t p l a t e d iz e d . p a p e r and p o l y e t h y l e n e in w ith th e l i d s c o v e r i n g t h r e e - f o u r t h s were p l a c e d or. the h o t p l a t e , fumes o f HCIO 4 . end th e s uspe ns ion was evap­ When dense fumes a ppeared, th e c r u c ib le s were c o v e r e d and th e suspension was c o i l e d g e n t l y l o r 15 minuses. "iiThen the c r u c i b l e s were c o o le d , 20 ml. o f d i s t i l l e d w a te r were added 40 2nd blie s uspension was c a r e f u l l y mixed and h e a t e d alm ost to b o i l i n g to d i s s o l v e th e s a lt s which have s o l i d i f i e d on c o o l i n g . s io n was th e n t r a n s f e r r e d was ta k e n t h a t no s i l i c a were added and the 1300 rpm. to 50 m l. was l e f t p o in te d c e n t r if u g e i n th e c r u c i b l e s , tu b e s . Care 2 m l. o f 61THC1 suspension was th o r o u g h ly mixed and c e n t r i f u g e d a t f o r 5 m in u te s to throw down th e d e h y d ra te d s i l i c a . su p ern a ta n t s o lu tio n c o n ta in in g d i f f e r e n t t h e c r u c i b l e s was c a r e f u l l y a t t a c h e d to The suspen­ s a l t s and n i c k e l The ta k en from sucked o f f by means o f a 50 m l. p i p e t t e a r u b b e r s u c t io n b u lb . The p r e c i p i t a t e d s ilic a was washed w i t h 1 . 2NH01 and c e n t r i f u g e d f o u r more tim e s and then th e r e s i d u e was t r a n s f e r r e d to 30 m l. p la tin u m c r u c ib le s . 10 drops o f (14=4) s u l f u r i c a c i d were added and th e suspension was s lo w ly e v a p o r a te d to dryness on an e l e c t r i c d rie d , hot p l a t e th e c r u c ib le s g e n tly , firs t a t about 1 00° C. A fte r the s i l i c a had been were p la c e d on a s i l i c a - t u b e w i t h a lo w fla m e Meeker b u r n e r , tria n g le and h e a t e d and th e n were h e a t e d w it h s t r o n g fla m e f o r about 10 m in u te s d u r in g which th e c r u c i b l e s were t h r e e - f o u r t h s covered. The c r u c i b l e s were th e n c o o le d i n f o r 5 m in u te s and w eighed. w e ig h t was o b t a i n e d . (1 4 *1 ) s u l f u r i c The i g n i t i o n was r e p e a te d u n t i l c o n s t a n t The s i l i c a was then m o is te n e d w i t h 2 drops o f a c i d and th e n 10 m i. o f HF were added. s lo w ly e v a p o r a te d to d r y n e s s on a h o t p l a t e Meeker b u r n e r , a d e s ic a to r c o o led i n The l i q u i d was and then i g n i t e d on the th e d e s i c a t o r and weighed. The l o s s i n w e ig h t due to v o l a t i l i z a t i o n o f s i l i c a by HF r e ­ p re s e n ts t h e amount o f S i0 2 e x t r a c t e d from th e s o i l . Any u s e o f g la s s w a r e b e f o r e was a v o id e d . th e a c i d p r e c i p i t a t i o n o f s i l i c a E x t r a c t i n g s o l u t i o n s were k e p t i n p o l y e t h y l e n e b o t t l e s . 5• a lu m in a i n Determi n a t i o n o f th e r e l a t i v e d i s t r i b u t i o n o f s o l u b le th e s o i l p r o f i l e s . S o lu b le a lu m in a was a ls o d e te r m in e d to see i f la tio n s h ip to it bore any r e ­ th e a p p a r e n t c e m e n ta tio n o f t h e f r a g i p a n h o r i z o n s . D iffe re n t e x tr a c tin g s o lu tio n s s u g g e s te d by d i f f e r e n t Holow ayckuk ( 4 7 ) a u th o r s . fo r " fre e McLean, alum ina" have been Henderson, B a r t l e t t and recommended 1. H CH3COOHH4 b u f f e r e d a t pH 4 . 8 . e x t r a c t e d more a lu m in a w i t h pH 4 . 0 b u ffe r, They but they p o s t u l a t e d t h a t A1 was p r o b a b ly removed from p r i m a r y and secondary m i n e r a l s a t the lo w e r pH. 0.1 N ammonium a c e t a t e (CH3 COOHH4 ) b u f f e r e d a t pH 4 . 2 was used in th e p resen t in v e s tig a t io n re la tiv e ly w ill weak and, be a v o id e d . b ility th e re fo re , in c re a s in g a c i d i t y . p r e c i p i t a t i o n b e g in s a t pH 3 . 0 th e re fo re , and i s am p h o te ric and i t s s o lu ­ I n th e p re s e n c e o f NH4OH, com pleted a t about pH 6 . 5 . a t t h a t pH. Ammonium a c e t a t e i s and f i n a l l y , D u p l i c a t e 15 gms. f r e e o f sub­ s o il it i s w e ll b u ffe re d . samples were weighed i n t o 150 m i. o f C . l h 250 m i. CK3 COONH4 b u f f e r e d a t pH 4 . 2 were added and the s uspe ns ion was shaken f o r 72 hours on an e l e c t r i c ta ry shak e r a t m oderate speed. in th e s o lu tio n , re s i due was then i g n i t e d gyro- The e x t r a c t was th e n f i l t e r e d 2 to 4 tim e s th ro u g h Ho. 42 Whatman f i l t e r were l e f t pH w i t h c o l o r i m e t r i c p ro c e d u re s and can De e a s i l y d e s t r o y e d by i g n i t i o n , E rlerm eyer f l a s k s , is c o n s id e r e d too h i g h a pH s in c e some f r e e a lu m in a would be p r e c i p i t a t e d s ta n c e s i n t e r f e r i n g It a p p r e c i a b l e d e co m p o s itio n o f m in e r a ls Hydrous aluminum o x id e i s in c re a s e s w ith 4 . 8 was, f o r t h e f o l l o w i n g re as o n s : pa per u n o i l n^ s o i l p<-u o i c l e s which was th e n e v a p o ra te d to dry n es s . f o r one hour i n an e l e c t r i c The fu r n a c e a t 5oCP C 42 to d e s t r o y c o l o r i n g o r g a n i c s ubstances and o r g a n ic a c i d s . in g , 5 - 7 drops o f 5 N KC1 were added (in C h o riz o n , e ffe rve s ce n c e ceased), more HC1 was added u n t i l by a d d i t i o n o f 100 m l. b o i l e d f o r one h o u r , d i s t i l l e d w ater. filte re d A ft e r c o o l­ th e samples o f th e c a lc a r e o u s fo llo w e d The s o l u t i o n was th e n g e n t l y and brought to 150 c c . volume. The e x t r a c t e d a lu m in a was d e te rm in e d by u s i n g t h e c o l o r i m e t r i c method d e v e lo p e d by R o b e rts o n ( 5 3 ) : R e a g e n ts . ( 1 ) Composite s o l u t i o n . (NH4 C I ) were d i s s o l v e d i n 1 1. o f 4 N ammonium a c e t a t e . was shaken and f i l t e r e d . 10 gms. o f powdered gum a r a b i c were d i s ­ a lu m inon ( s u r i n tric a rb o x ilie were d i s s o l v e d i n 25 m l. a c id ) o f w a t e r to which 1 drop o f NHs had been added, o f NH3 p e r s i s t e d , was o b t a i n e d , fin a lly , (2 ) H& was added u n t i l had a pH 4 . 5 T h io g ly c o lic S ta n d a rd s o l u t i o n : c o n t a i n i n g oO m l. s o lu tio n is a pH 4 . 4 to 2 1 , mixed w e l l and th e whole was th e n d i l u t e d a l l o w e d to stand 3 days b e f o r e u s e . to 100 m l. b o i l e d u n t i l no s m ell and th e n t h i s was added to the b u f f e r s o l u t i o n and th e whole d i l u t e d to 1750 m l. th is The s o l u t i o n 100 m l. o f w a t e r and added to th e f i l t e r e d b u f f e r s o l u t i o n . s o lv e d i n 0 . 4 gms. 107 gms. o f ammonium c h l o r i d e and 1C ml. o f t h i s s o l u t i o n d i l u t e d to 4 . 8 . a c id . 80-90t> 1 .8 6 0 gins, o f potash alum were d i s s o l v e d i n w a t e r of 5 N . Hl 1 ano t n i s e o u i v a l c n t to 0 .<- mg. was q 1luted. to 1 1. 1 m l. of AlgOb- Froc edur e. An a l i q u o t c o n t a i n i n g . 0 2 100 m l. c o n ic a l fla s k s . added to make t h e f i n a l .0 3 mg. A I 2O3 "as t r a n s f e r r e d to One drop o f U . i o g i y c o l i e volume 55 m l. ( f 2 m l.). a c i d and w a te r were 1C m l. o f com posrte 43 s o l u t i o n were added and tn e f l a s k s were immersed i n 30 m in u te s . b o i l i n g w a te r f o r They were th e n c o o le d i n r u n n in g w a te r to 1 5 - 1 8 ° s o l u t i o n was then t r a n s f e r r e d i n t o to volume and m ixed w e l l . a ICO m l. v o lu m e tric C. fla s k , The made up The c o l o r was d e te rm in e d w i t h o u t d e la y by means o f a Coleman U n i v e r s a l S p e c tro p h o to m e te r, Model 14, u s in g wave l e n g t h o f 530 m |JL. F ig h t prepared. v e lo p in g p le te ly A ll s ta n d a rd s c o n t a i n i n g s te p s d e s c r ib e d i n .01 - t h i s p r o c e d u re were f o l l o w e d i n de­ One drop o f t h i o g l y c o l i c a c i d was adequate to e l i m i n a t e com­ th e i n t e r f e r i n g by r e d u c in g i t 1. Fe'r° X - r a y d e t e r m in a t i o n s o f c l a y m i n e r a l s . was c a r e f u l l y f i v e m l. to th e f e r r o u s s t a t e . MirfRALOGICAL ANALYSTS The N a - s a t u r a t e d c l a y f r a c t i o n s e p a r a t e d from th e s i l t from th e m e ch a n ic al a n a l y s i s by r e p e a te d d e c a n t a t i o n s . About o f th e s u sp e n s io n c o n t a i n i n g 3 0 - 4 0 mg. o f c la y were t r a n s ­ to t e s t tu b e s . was shaken and l e t 5 drops o f g l y c e r o l were added, stand o v e r n i g h t . on a h o l d e r and a t t a c h e d to a vacuum. in to were th e c o l o r o f th e b la n k s and o f th e s ta n d a r d s . III. fe rre d .0 8 mg. A I 2O3/IO O m l. the w e l l o f th e h o l d e r . oorous p l a t e s , it A porous ceram ic p l a t e was p la c e d The c l a y suspension was p o u re d When the c l a y was a l l d e p o s it e d on the was le a c h e d w it n t h r e e in c re m e n ts o f .1 h Ca C I 3 c o n t a i n i n g 3$ g l y c e r o l by volume, s o lu tio n s . th e suspension The p l a t e s f o l l o w e d by 3$, were then removed and l e f t c a t o r c o n t a i n i n g Ca C l 2 . 10^ and 4 0 ^ g l y c e r o l o v e rn ig h t i n a dc s i - The samples were then mounted on th ^ N o re lc o X -ra y sp ectro m eter, u s in g a l / 4 n d iv e rg e n t s lit, and 1 / 4 ” s c a t t e r s lit in s lit, 0 .0 0 3 " the beam c o l l i m a t i n g re c e iv in g system. The 44 d i f f r a c t i o n u n i t was o p e r a t e d a t u s i n g a copper t a r g e t a t tim e c o n s t a n t fo u r, tu b e . &0 mi 11iam peres and 35 k i l o v o l t s The r e c o r d i n g u n i t c i r c u i t p a n e l was s e t m u l t i p l i e r one, and. s c a l e f a c t o r samples were scanned from two to t h i r t y t h e c e ra m ic p l a t e s were r e p la c e d i n d e g ree s . fo u r. C lay A fte r ir r a d ia tio n , th e h o l d e r s and th e c l a y was l e a c h e d t h r e e tim e s w i t h 1 0 - 1 5 drops o f .1 N K Cl and then washed w ith the d e s ic c a to r, and then d i s t i l l e d w ater, p la c e d i n to r. 110° C. d r i e d f o r 4 hours i n oven f o r f o u r ho u rs and l e f t The samples were then scanned a g a in . h e a t e d to 5500 C. 2. f o r one h o u r, D iffe re n tia l to c o o l i n t h e d e s ic a ­ fin a lly th e s e samples were c o o le d and scanned f o r th e t h i r d tim e . th e rm a l a n a l y s i s o f c l a y m i n e r a l s . The t e m p e r a tu r e changes i n 0 .2 b gnu o f a i r dry c l a y samples compared to th e te m p e r a tu r e changes i n aluminum o x id e were re c o rd e d . The c la y samples and aluminum o x id e were h e a te d to 1000° C. sam ples were p r e p a r e d by m ix in g d i f f e r e n t aluminum o x i d e . A u s tin , C lay T exas, amounts o f k a o l i n i t e w ith Model DTA-CS-2 and DTA 51/, and a Brown r e c o r d e i Standard b u ilt by I?. L. Stone o f were used f o r th e measurements. samples were run a t a tm os pheric p r e s s u r e w ith a r e s i s t a n c e o f 50 ohms i n th e re c o rd in g u n i t . The a m p litu d e o f the endoth e r m ic and exo­ t h e r m ic oeaks was u s ed as an a p p ro xim a te Q u a n t i t a t i v e measure o f th e s u bstances r e a c t i n g u ie s o f at th e s p e c i f i c th e ITester p r o f i l e t h e one used f o r th e © the' te m p e r a tu re s o f th e peaks. were run on a d i f f e r e n t two pro f i l e s . sample h o l d e r Santh a n A new s e t o f s ta n d a r d s was r u n as a b a s i s o f c om paris on f o r th e t e s t e r p r o f i l e . 3. T o ta l s p e c ific s u r fa c e o f c l a y s . The e t h y l e n e g l y c o l met nod proposed Dy Bower a.io ^eschwend. ( 6} 45 was u s ed . 0 . 5 gm. o f a i r d ry c l a y were p l a c e d i n w e ig h in g b o t t l e s and were e v a c u a t e d o v e r P2O5 u n t i l c o n s t a n t w e ig h t was o b t a i n e d . o f e t h y l e n e g l y c o l were added and th e b o t t l e s , p la c e d in a d e s i c c a t o r w i t h Ca C l 2 ana l e t 20 w i t h c o v e r s on, s ta nd o v e r n i g h t . drops were The c o v e rs o f th e w e ig h in g b o t t l e s were th e n removed and a vacuum was a p p lie d a t a te m p e ratu re o f 25° C u n t i l was removed. the excess o f e th y le n e g l y c o l The samples were th e n weighed a t h o u r l y i n t e r v a l s u n t i l t h e l o s s o f w e ig h t became s m a l l e r th a n 3^ o f th e w e ig h t o f th e r e ­ ta in e d e th y le n e g l y c o l . T o t a l s u r f a c e was c a l c u l a t e d by u s in g the f o r m u la . A r e a m^/gm. = (w t. o f e th y le n e g l y c o l r e t a i n e d (g m .) ) ( w t . o f vacuum d r i e d c l a y x 0 . 0 0 0 3 1 ) 4. T o t a l Potassium i n c l a y . A m o d i f i e d method proposed by Webber and Shivas (o 3 ) was used. 0.2 gm. o f oven d ry c l a y were weighed i n p l a t i n u m c r u c i b l e s and h e a te d c o o le d , to redness 1 ml. p la tin u m w ire . f o r one m in u te to d e s tr o y o r g a n ic m a t t e r . 1 : 5 H2 SO4 was added and th e m ix t u r e was s t i r r e d w i t h a 5 ml. o f c o n c e n t r a t e d h y d r o f l u o r i c arid e v a p o r a t e d s lo w ly to dryness on a h o t p l a t e . was r e p e a t e d once more. a c id were added The sane tr e a tm e n t The c r u c i b l e s were then p la c e d i n a 200 ml. b e a k e r and t h e r e s i d u e was removed w i t h a s o l u t i o n o f 200 m l. 10 m l. When HlTCh. O * and h e a t e d . r in s e d w ith w a te r. When h o t , th e c r u c i b l e s were removed and The s o l u t i o n was th e n e v a p o r a te d ^0 dryness and t h e r e s i d u e was ta k e n ud i n 0.1NPC1, h e a t e d , a volume o f 250 m l. HpO 4- filte re a and d i l u t e d to P o ta s s iu m was d e te rm in e d by means o f a F e r k i n 46 jilm e r fla m e p h o to m e te r , c o n ta in in g 5 tra tio n & Model 52 a . S ta n d ard pota s siu m s o l u t i o n s 40 ppm were p r e p a r e d i n 0.1IJHC1. vs. t r a n s m i s s i o n c u rv e was p l o t t e d . 5. M in e ra l A s ta n d a r d concen­ a n a l y s i s o f the f i n e s and. The m i n e r a l s o f th e f i n d sand f r a c t i o n which was about 5 0 $ o f th e t o t a l sand i n t h e ir per cent te rm in e d . a n ic a l th e p r o f i l e s fre q u e n c ie s i n sand a c c o r d in g to com rnunication) . mayer f l a s k s . were i d e n t i f i e d , and heavy f r a c t i o n s were de­ and s e p a r a te d as i n th e method suggested by K ilm e r Two gms. o f sodium h y d r o s u l f i t e by adding 1 0 $ HC1. s ta n d f o r one h our d u r in g which i t w a te r 3 t im e s . (p e r s o n a l E rle - (NasSsOd) p lu s 75 ml. The f l a s k s were s to p p e red and shaken f o r one to 3 . 5 - 4 . 0 s u p ern a ta n t l i q u i d the mech­ sand were p la c e d i n 200 ml. The suspension was then t r a n s f e r r e d to 250 ml. was a d j u s t e d cou n te d and I r o n and o t h e r c o a t in g s were removed from Two gms. o f f i n e o f w a t e r were added. h o u r. th e l i g h t F in e sand samples p r e t r e a t e d a n a ly s e s were u s e d . trie f i n e s tu d ie d , b e a k e rs , t h e pH The suspension was l e t was s t i r r e d several tim e s . The was th e n decanted and th e sands were washed w i t h They were th e n oven d r i e d . Heavy m i n e r a l s were s e p a r a t e d from the l i g h t ones by c e n t r i ­ f u g i n g 1 gm. o f c le a n e d f i n e sand i n a 15 m l. J e f f r i e s ' fu g e tu b e which c o n t a i n e d a t e t r a - b r o m o - e t h a n e , o f s p e c ific g ra v ity 2 .8 . oven d r i e d , w eighed, double c e n t r i ­ n i t r o b e n z e n e m ix t u r e The heavy m i n e r a l s were washed w i t h a c e to n e , and mounted on g la s s m ic ro s c o p ic s lid e s by u s i n g 1 drop o f 0 . 1$ g e l a t i n s o l u t i o n and 1 drop o f f o r m a l i n e s o l u t i o n as d e s c r i b e d by M a r s h a l l and J e f f r i e s (4 1 ). Trie g r a i n s were thus s tu c k on t h e s l i d e w i t h o u t b e in g immersed i n g e l a t i n e . F e l d s p a r s and q u a r t z were d e te rm in e d i n w ith th e a id o i th e p e t r o g r a p n i c m icro s c o p e . dex 1 . 5 4 3 was us ed. F i v e to th e l i g h t fra c tio n An im m ersion o i l o f i n ­ seven hundred g r a i n s from each h o r i z o n were c o u n te d . Heavy m i n e r a l s were d e te rm in e d i n im m ers ion o i l o f r e f r a c t i v e r a t e d from th e 1 gm. in d e x 1 . 6 6 5 . the same way by u s in g an A ll sample were c o u n te d . th e heavy g r a i n s sepa­ T h e i r numbers ra n g ed be­ tween 300 end 6 00 . IV . THIN SECTIONS OF SOILS H o riz o n ta l and v e r t i c a l th in s e c tio n s , 0 . 0 3 mm. th ic k , from each h o r i zon were s t u d i e d u n d e r the p e t r o g r a p h i c m icroscope. A ir sand p a p e r dry u n d i s t u r b e d lumps o f f i r m h o r i z o n s were trimmed w i t h to about 20 x 30 x 7 mm. were sampled w i t h th e a i d o f 1 . 5 " u n d i s t u r b e d b lo c k s . L a k e s id e No. The a i r s lic e s . x 1" x . 5 " Loose o r f r i a b l e h o r i z o n s aluminum fram es to secure dry samples were then im pregn ate d w i t h 70 C cement a c c o r d in g to th e method proposed by the manu­ fa c tu re r. A f t e r a i r d r y i n g th e s o i l on a h o t p l a t e w i t h s u r f a c e te m p e r a tu r e o f 180° - 2 0 0 ° C. th e n dropped q u i c k l y i n t o a ir. samples were h e a t e d f o r 15 m in u te s a v e s s e l c o n t a i n i n g x y le n e , and were to d r i v e out the Crushed L a k e s id e 70 C cement was p l a c e d i n a p y r e x c r y s t a l l i z i n g d is h which c o n t a i n e d 8 p a r t s o f a b s o l u t e e t h y l a l c o h o l . was p l a c e d on a h o t p l a t e w ith t h e e f f e r v e s c e n c e o f th e s o i l s u r fa c e te m p e r a tu r e o f 1 80° C. samples ceased, p la c e m e n t o f t h e a i r by x y l e n e , a lc o h o l - c e m e n t m i x t u r e . T h is m i x t u r e When i n d i c a t i n g c o m p lete r e ­ th e samples were t r a n s f e r r e d i n t o The m i x t u r e was a llo w e d to th e b o il g e n tly u n t i l th e s p i r i t s w ere c o m p l e t e l y e v a p o r a te d . t e n c o n d i t i o n and i t o u t o f and inm ersed a g a in i n th e m e l t , u n t i l th e l a r g e p o r e s were im p re g n a te d , c o o l to room t e m p e r a t u r e . h e a tin g o f th e cement i n mol­ r e p l a c e d th e x y le n e i n th e p o re s o f th e sam ples. The samples were l i f t e d a ll T h is l e f t and th e n removed and a llo w e d to The aluminum fram es were removed by o u ic k t h e i r edges on a bnnsen b u r n e r and p u s h in g o u t th e im preg­ n a te d b lo c k s . C a re was ta k e n t h a t th e s o i l would n o t be h e a t e d . The im p re g n a te d samples were s h ip p e d to CAL-ERSA L a b o r a t o r i e s , where t h e t h i n s e c t i o n s were p r e p a r e d . RESULTS 1. P h y s ic a l P r o p e r tie s The a v e ra g e o f measurements on s i x c o re samples from each h o r iz o n a r e g iv e n i n 1 . ta b le B u lk den s i t y o f th e p o d zo l sequa (A^, a ll th re e p r o f ile s is g r a y brown p o d z o l i c Ag and B h i r h o r i z o n s ) o f c o n s i d e r a b l y lo w e r th a n th e b u lk d e n s i t y o f th e sequa (B^, A2m, A3m, A & B, Bt and C h o r i z o n s ) . I s a b e l l a and McBride show a d e f i n i t e maximum i n t h e i r A2m and A3ra h o r i zons. N o n - c a p i l l a r y p o r o s i t y i s h i g h i n th e p o d zo l sequa and de­ c r e a s e s s h a r p l y on t h e to p o f th e f r a g i p a n T h e re i s (Bm o r A2m h o r i z o n s ) . a minimum o f n o n - c a p i l l a r y p o r o s i t y i n th e B^ h o r iz o n s a t N e s t e r and M cB ride, w h ile in I s a b e l l a t h e C h o r i z o n has a B l i g h t l y lo w e r v a l u e th e n t h e B^. C a £ i l l a ry p o r o s i t y does n o t show as g r e a t d i f f e r e n c e s t h e d i f f e r e n t h o r i z o n s as t h e n o n - c a p i l l a r y p o r o s i t y doeB, is a d e f i n i t e minimum i n The A i , th e f r a g i p a n h o r iz o n s o f a l l among but t h e r e th re e p r o f ile s . A2 and C h o r i z o n s have t h e h i g h e s t c a p i l l a r y p o r o s i t y i n a ll th re e p r o f i l e s . W a te r p e r m e a b i l i t y p o ro s ity . in th e pan, It fo llo w s p a r a l l e l i s v e r y h ig h i n th e p o d z o l sequa, end re a c h e s a minimum i n be m e n tio n e d , how ever, th a t tr e n d s w ith n o n - c a p i l l a r y shows a sharp de cre a se th e Bt and C h o r i z o n s . must th e r e p l i c a t e c o re s o f th e f r a g i p a n s showed t h e b i g g e s t v a r i a b i l i t y o f a l l th e o t h e r h o r i z o n s . v a l u e s w ere as extrem e as e . g . 0.2 - 2 . 3 c m ./h o u r . in It w a t e r p e r m e a b i l i t y was due to T h e ir T h is v a r i a b i l i t y th e p r e s e n c e o f c r a c k s and worm and./o 50 ro o t h o le s in It some o f th e c o re s w h i le th e y were absent from o t h e r s . has been o b s e r v e d t h a t th e pan i n h i b i t s age to a c e r t a i n w ater s a tu ra te d . d e g re e d u r in g Dr. P e n i n s u l a o f M ic h ig a n A. E. th e i n t e r n a l d ra in ­ the s p r in g months when th e s o i l i s E r ic k s o n (1 8 ) has ob s erv e d i n th e Upper t h a t i n s p r in g t h e p a r t o f th e p r o f i l e above th e f r a g i p a n was w a t e r s a t u r a t e d w h i l e th e p a r t below th e f r a g i p a n was a t o r b e lo w f i e l d file s c a p a c ity . o f r o a d c u t s s p r in g s He a ls o has obs erv e d t h a t on exposed p r o ­ form on to p o f th e f r a g i p a n and t h a t w a te r d ra in s l a t e r a l l y . The absences o f m o t t l i n g i n th e t h r e e p r o f i l e s c lu d e s t h e e x i s t e n c e o f s e a s o n al poor d r a in a g e , s t u d i e d ex­ p o s s i b l y because o f t h e a d e q u a te s u r f a c e d r a in a g e and th e p o s s i b l e i n t e r n a l to th e p r e s e n c e o f v e r t i c a l c r a c k s i n d r a in a g e due th e p r o f i l e . Hardness o r Cone P e n e t r a t i o n R e s is t a n c e d a ta g e n e r a l l y a g re e w i t h o b s e r v a t i o n s made i n th e f i e l d . The h a r d e s t o r f r a g i p a n h o r iz o n s c o in c id e w ith th e h o riz o n s o f h ig h e s t b u lk d e n s ity . how ever, does n o t e x c l u s i v e l y a s lig h t d i f f e r e n c e i n b u l k d e n s i t y between th e Agm and A3m h o r i z o n s o f I s a b e l l a and M cB ride, t h e i r hardness. depend on b u lk d e n s i t y , The h a rd n e s s , w h ile th e r e i s I n t h e N e s te r p r o f i l e t w i c e as h a r d as t h e Bt h o r i z o n i n d e n s ity i s a v e ry s harp d i f f e r e n c e i n t h e Agm h o r i z o n i s more th a n s p i t e o f th e f a c t t h a t i t s b u lk lo w e r th a n th e one o f th e B t. The t r a n s i t i o n a l Bm h o r i z o n s v a r i e d i n th a n one in c h to two in c h e s , v a lu e s o f p h y s ic a l p r o p e r tie s th ic k n e s s and th e y c o u ld not f i l l a c tu a lly th ic k la y e r c o n s is tin g o f E h ir, p ro file . as t h e r e i s o n l y Em, from l e s s a core. Given correspond to a t h r e e in c h es and A2m h o r iz o n s o f the McBride The u p p e r p a r t o f c e r t a i n c o r e s o f t h e I s a b e l l a p r o f i l e c o n s i s t e d e n t i r e l y o f t h e t r a n s i t i o n a l Bm h o r i z o n and hardness t e s t s w ere c o n d u c te d on them. fa c t th a t i t It however, th e o t h e r v a l u e s o b t a i n e d a r e somehow d i f ­ fro m t h e t r u e one s. 2. The I s a b e l l a sequa p r o f i l e s , M e c h an ic a l A n a ly s is and McBride s o i l s which have w e l l de ve lope d b i - show a d e f i n i t e maximum c o n te n t o f t o t a l sand i n t h e i r Bm and A2m h o r i z o n s . The N e s t e r s o i l , v e lo p e d bisequum p r o f i l e , which has a r a t h e r w eakly de­ shows a g r a d u a l d e c re a s e o f t h e t o t a l c o n t e n t w i t h i n c r e a s i n g depth w i t h a minimum i n v e r y s m a ll maximum i n er in the A2 / B h i r . th e p o d z o l sequa o f a l l p o d z o lic seoua. to ta l The d i f f e r e n t c o n c e n tra tio n o f s i l t sand f r a c t i o n s , in co n te n ts r e s p e c t iv e ly . T h e re i s a l o s s o f th e 5=2 p s iz e d th re e p r o f i l e s s ilt in of th e p a r t i ­ sand and T a b le 4 shows t h a t t h e r e i s d i s t r i b u t i o n o f th e 5=2 p f r a c t i o n o f s i l t Aq th e 5 0 - 2 0 p and 20=5 p f r a c t i o n s f o l l o w i n a g e n e r a l way th e tr e n d s o f t o t a l s ilt i s h ig h ­ than i n t h e i r g r a y brown The Al h o r i z o n s o f McBride and N e s te r and th e c u la r p r o f ile s . sand th e Bt h o r i z o n and a The c o n te n t o f t o t a l s i l t th re e p r o f i l e s I s a b e l l a have t h e maximum r e l a t i v e s ilt t h a t due to the was i m p o s s i b l e to h ave c o re samples made o f m a t e r i a l s fro m th e Bm h o r i z o n o n l y , fe re n t must be a d m it te d , a ll a re­ th re e p r o f ile s . i n the p o d z o l sequa o f the and a d e f i n i t e g a i n i n th e gra y brown p o d z o l i c o f M c B rid e and N e s t e r . w h e th e r t h e r e i s The r e s u l t s o f I s a b e l l a a r e i n c o n c l u s i v e as to a g a i n o f 5=2 p s i l t quum o f th e p r o f i l e . T h i s i s p r o b a b ly i n th e g ra v brown p o d z o l i c s edue to d i f f e r e n c e s i n th e p r e ­ sent m a t e r i a l o f th e p a r t i c u l a r h o riz o n s , as i t w ill be shown l a t e r . 52 T a h le I . P h y s ic a l P ro p e rtie s McBride i H o r i zon Depth in c h es B u lk D e n s it y i N o n -c a p il­ C a p illa r y l a r y p o ro ­ p o r o s i t y s ity Permeahi l i t y cm/ h r Cone pene­ tra tio n Besi stanc e Y g f cm A1“A2 1 -5 1 .1 9 20.6 2 8 .8 2 1 .0 9 B h ir 5= 17 1 .3 8 2 0 .5 2 5 .5 2 9 .0 0 Brn 1 7-19 1 .6 1 8 .5 20.1 6 .7 7 A2in 1 9-24 1.82 8. 1 1 7 .0 1 .4 5 3 1 .0 24-35 1.86 3. 6 2 1 .3 0 .1 3 122.6 3 5-53 1 .7 8 3 .2 2 3 .4 0.11 1 8 .2 -1= 53 1 .7 4 5 .8 2 5 .2 0 .2 4 Bt C 8 .5 — N e s ter Al 1-5 1 .0 3 2 0 .5 3 2 .7 52. 53 A2 / B h i r 5 -9 1 .3 8 1 6 .7 2 6 .8 1 5 .8 2 8 .3 A2m 9 -1 6 1 .6 1 9 .3 2 5 .5 1 .5 6 2 6 .3 A & B 16-27 1 .6 5 7 .4 2 9 .4 3 .1 1 20.2 Bt 2 8-48 1.66 4 .5 3 2 ,3 0 .9 2 1 1 .6 5 /•» KJ 4 9-65 1 .6 0 5 .4 3 3 .0 0 .1 5 — — 53 Table I. continued Is a b e lla 4 H o rizo n Depth in c h e s B a lk D e n s it y 4 N o n c a p il­ l a r y p o ro ­ s ity C a p illa ry p o ro s ity Permea­ b ility cm/hr Cone pene­ tra tio n R e s is ta n c e Y g /c m A1- A 2 1 -5 1 .1 0 8 1 6 .9 3 6 .2 22.26 B h ir 5 -1 1 1 .4 3 1 7 .0 2 6 .7 1 4 .6 3 1 0 .9 — 1 4 .9 — Bm 1 1-13 ^ 2m 13-21 1 .8 7 7 .7 I S . 15 0 .8 4 3 3 .3 A3m 21=34 1 .8 5 8 .9 1 9 .6 1 .0 4 7 7 .9 3 4-42 1 .7 8 3 .9 28.6 0.10 2 5 .8 42-55 1 .7 1 2 .4 3 4 .2 0 .1 6 1 6 .6 C += 55 1 .7 6 1.6 3 4 .2 0 .0 7 — T a b le la . P er c e n t A & B Bt — — H y g ro s c o p ic w a t e r H o r i zon Al A2 A2,/Bhi r B h i r Bm A2 m A3m A & B Bt C P ro file Me Br i de 1 .1 4 0.62 0.66 0 .3 8 0.21 0 .4 8 I s a b e lla 1 .6 3 0 .3 1 2 .6 7 0 .2 9 0 .3 0 0 .65 N e s te r 1 .7 2 0 .7 7 — ■ 0 .4 0 0 .6 9 0 .7 1 0 .9 7 1 .2 3 0 .6 5 1 .4 3 1 .6 0 1 .4 8 54 C la y c o n te n t shows two d e f i n i t e minima and maxima i n b e l l a and McBride p r o f i l e s . second i n The f i r s t minimum i s th e Bm and Agm h o r i z o n s . in th e A2 and th e The f i r s t maximum i s B h i r and t h e second and h i g h e s t one i n th e Bt h o r i z o n . p ro file in th e I s a ­ found i n th e The N e s t e r shows o n l y one minimum i n th e A2 / B h i r h o r i z o n and one maximum th e Bt h o r i zon. The r e s u l t s o f m e c h a n ic a l a n a l y s i s suggest t h a t a downward movement o f c l a y and v e r y f i n e The Bt h o r i z o n s c o n s t i t u t e s ilt takes p l a c e i n a ll th re e p r o f i l e s . the zone o f maximum c l a y a c c u m u la tio n . The f r a g i p a n h o r i z o n s have lo w e r c l a y c o n t e n t th a n the p a r e n t m a t e r i a l , and i f we assume t h a t m a te ria l, th e p r o f i l e s th e y c o n s t i t u t e an e l u v i a l b u l k o f th e sand f r a c t i o n a ll were formed from u n i f o r m p a r e n t and i t s zone. F in e sand makes up th e d is trib u tio n is f a i r l y u n ifo rm in t h e h o r i z o n s o f th e t h r e e p r o f i l e s , as shown i n t a b l e 3 . 3. C hem ical P r o p e r t i e s The pH v a lu e s o f t a b l e 5 show t h a t I s a b e l l a has th e most le a c h e d and c o n s e q u e n tly w e a th e re d p r o f i l e o f th e t h r e e s o ils . The d i f f e r e n c e s i n t h e c h e m ic a l p r o p e r t i e s among t h e d i f f e r e n t h o r i z o n s a r e a ls o more pronounced i n th e I s a b e l l a than i n th e o t h e r two s o i l s . O rg a n ic c arb o n and s o l u t i o n , l o s s v a lu e s suggest t h a t th e pod­ z o l sequum i s file s . b e tte r deve lo p e d i n I s a b e l l a th a n i n T h is c o n c lu s io n i s th e o t h e r two p r o ­ i n accordance w i t h th e f i e l d d e s c rip tio n o f th e s o i ls . A lk a li s o l u b l e s i l i c a i n c r e a s e s w i t h d e pth and show a maximum c o n c e n tra tio n in th e Bt h o r i z o n s o f McBride and N e s t e r and i n B h o riz o n o f Is a b e lla . The A2m h o r i z o n s o f a l l th e A & t h r e e p r o f i l e s have 55 T a b le 2 . McBride Depth F .G -C .S . 2 - 0 . 5 mm. M e c h a n ic a l A n a lys e s Ai A2 1-2 3 -5 7 .8 5 8 .7 6 B h ir Bm A2m A3m Bt 5 - 1 7 1 7 - 1 9 1 9 -2 4 2 4 - 3 5 3 5 - 5 3 8 .6 4 9 .9 0 9 .9 8 8 .7 7 C += 53 8 . 2.8 8 .4 8 M. S . 5 “ . 2 5 mm. 1 4 . 4 1 1 5 . 6 4 1 6 .0 9 1 8 . 4 7 1 8 .2 1 1 6 . 9 1 1 5 . 0 8 1 6 .4 6 F. S. . 2 5 - . 1 mm. 4 2 .0 9 4 2 .1 8 4 2 .4 0 4 4 .5 8 4 5 .3 3 4 2 .1 0 3 8 .4 5 4 0 .4 8 V. P. S. . 1 - . 0 5 mm. T o t a l sand 8 . 6 4 12. o3 1 2 .4 0 1 2 . 4 2 1 2 . 5 6 1 0 . 5 0 9 .4 0 9 .9 1 7 3 . 9 9 7 9 . 9 1 7 9 . 9 9 8 5 .3 7 8 6 . 0 8 7 8 . 2 8 7 1 .2 1 7 5 . 3 3 S ilt 50-20 p 9 .2 4 5 .3 3 5 .1 8 1 .5 5 2.66 0 .8 7 2 .0 9 2.02 2 0-5 8 .0 4 7 .3 5 5 .4 2 4.2.6 4 .0 2 4 .3 1 3 .3 4 6.21 2 .9 3 2 .8 0 1 .8 4 2 .5 0 2 .2 8 3 .4 8 2 .2 5 2 .4 1 20.21 1 5 . 4 8 1 2 . 4 4 8 .3 1 8 .9 6 8 . 66 7 .6 8 1 0 .6 4 7 .5 7 6 .3 2 4 . 9 6 1 3 .0 6 21.11 1 4 .0 3 p 5 -2 p T o ta l s i l t C la y 5 .8 0 4 .6 1 T a b le 2 . c o n tin u e d Is a b e lla Al A2 B h ir Depth 1=3 3=5 5 - 1 1 11=13 13=21 2 1 - 3 4 3 4 - 4 2 4 2 - 5 5 +■ 55 F. G-.-CS 2 - 0 . 5 mm. 1 0 .3 5 9 .3 6 M. S. . 5 - . 2-5 nan. 1 8 .8 8 F. S. .2 5 -.1 3 6 . 8 9 3 6 . 7 8 3 4 . 4 1 4 1 . 6 9 3 9 . 9 5 3 6 . C-3 3 5 . 7 7 3 1 . 9 6 3 0 . 5 7 A2m 9. 97 10. 63 1 0 . 4 3 1 7 .3 4 1 6 .4 0 2 0 . 1 5 1 7 .6 7 *3m 9 .0 7 A & B 8 , 26 Bt 6 .5 5 C 7 .5 0 1 6 .4 0 1 4 .7 5 1 2 .0 6 1 5 . 9 2 mm. V . F . S. . 1 - . 0 5 ran. T o ta l 3n sand 4 .? 5 6 .2 3 8.62 1 0 . 1 7 7 .3 6 5 .9 8 5 .8 9 4 .8 1 3 .4 3 7 0 . 8 8 6 9 . 7 2 6 9 .1 1 8 2 . 6 5 7 5 ,4 1 6 7 .4 8 6 4 . 6 8 5 5 .3 8 5 7 . 4 2 S ilt 5 0 - 2C p 2 0-5 p 5=2 p T o ta l s i l t C la y 9.1C 1 0 . 4 6 6 .0 3 4 .0 2 4 .9 5 4 .1 6 2 .7 4 4 .5 6 4 .5 8 1 0 . 3 7 1 2 .0 3 9 .9 2 5 .9 2 8 .3 6 7 .4 3 5 .3 3 6 .6 1 5 .5 8 3 .5 4 4 .5 2 3 .3 0 3 .7 1 3 . l<4 2 .7 8 4 .6 8 5 .5 0 3 .5 2 22. 9S 2 6 . 4 6 2 0 . 4 7 13.2-4 1 7 .0 2 1 4. 83 1 0 .8 5 6 .1 3 3 .8 2 1 0 .4 2 4 .1 1 1 5 .6 5 1 5 .6 6 7 . 5 7 1 7 .6 9 2 4 .4 7 2 8 .9 7 2 6 . 9 2 T a b le 2 . N e s ter c o n t in u e d Al Depth A2 / B h i r A3m A & B Bt C 1=5 5 -9 9 -1 6 1 6 -2 7 2 7 -4 8 4 8-65 7 .6 4 8 .4 3 7 .4 6 6 .7 2 5 .2 3 6 .0 6 F .G -C . S. 2- 0.5 mm. M. S .5 -.2 5 mm. 14 .1 5 1 3 .2 8 1 3 .6 3 1 0 .5 2 5 .7 2 9 .0 9 F. S. .2 5 -.1 mm. 3 2 .5 4 3 2 .5 5 3 0 .4 2 2 1.8 9 2 1 .1 4 2 4 .6 5 V. F. S. . 1-= .0 5 mm. 5 .7 8 8.22 6 .1 9 4 .0 7 5 .8 7 6 .2 5 6 0 .0 8 6 2.4 8 5 7 .7 0 4 3 .2 0 3 7 .9 6 4 6 .0 5 50-20 p 1 1 .1 8 9 .5 3 8 .9 5 5 .9 0 6 .7 6 5 . 63 20-5 p 12.66 1 2 .3 4 1 3.0 7 8.12 8 .5 6 9 .3 2 5 .3 8 6 .3 1 5 .3 6 5 .5 3 4 .5 8 4 .0 2 T o ta l s i l t 2 9 .2 2 28. 18 2 7 .3 8 1 9 .5 5 1 9 .9 0 1 8 .9 7 C la y 1 0 .7 0 9 .3 4 1 4 .2 2 3 7 .2 5 4 2 .1 4 3 4 .9 8 T o ta l sand S ilt 5 -2 p 58 T a b le 3 . o f P in e Sand i n th e T o t a l Sand F r a c t io n H o rizo n Ai A2 * B h ir Bm A2m ASm 5 3 .0 1 5 2 .2 2 5 2 .6 6 5 3 .7 7 — 5 3 .2 1 5 3 .7 4 5 2 .7 2 5 0 .9 2 — 5 6 .0 4 5 3 .5 8 5 2 .9 7 5 3.3 8 5 5 .2 7 5 4 .7 0 5 3 .2 4 Fro f i l e McBride 5 8 .2 3 5 2 .7 8 N e s te r 5 4 .1 5 5 2 . 1C Is a b e iia 5 2 .0 4 5 2 .7 6 T a b le 4 . P er c e n t o f 5* — — 4 9 .4 0 2 5 0 .4 7 ji s i l t in th e t o t a l s ilt C A & B fra c tio n H o r i zon Ai A 2* B h ir Bm Agm A & B Bt C P ro file M c B rid e 1 4 .5 1 8 .1 1 4 .3 3 0 .1 2 5 .4 4 0 .2 — 2 9 .3 '2 2 .7 Is a b e lla 1 5 .3 1 4 .4 22.1 2 4 .9 21.8 21.8 2 5 .6 2 9 .9 3 5 .5 N e s te r 1 8 .4 2 2 .4 -* = 1 9 .6 —— 2 8 .3 2 3 .0 21.2 * Ag c o r re s p o n d s — to A2/ B h i r in N e s te r. s o lu b le S i 0 2 c o n t e n t lo w e r than th e in r o e d ia t e l y o v e r l y i n g and u n d e r The A1 h o r i z o n o f I s a b e l l a has a re m a rk a b ly h ig h a l ­ ly in g h o riz o n s . k a li s o lu b le s i l i c a c o n te n t. S o l u b le a lu m in a d a t a show maxirrium c o n c e n t r a t i o n s i n and Bm h o r i z o n s o f th e I s a b e l l a and McBride p r o f i l e s . C h o riz o n s o f a l l m ina. In a l l th re e p r o f i l e s th re e p r o f i l e s a lu m in a a c c u m u la te . h o riz o n . T h is a r e r e l a t i v e l y poor i n th e B h i r The A j, A2 and s o l u b le a l u ­ th e r e e x i s t s a zone i n which s o l u b l e zone extends from the B h ir down to The f r a g i p a n h o r i z o n s a r e lo c a t e d i n th is zone, the Bt but th e y do no t c o i n c i d e w i t h th e p a r t o f th e p r o f i l e b l e a lu m in a c o n t e n t . The A2m h o r iz o n s o f I s a b e l l a lo w e r s o l u b l e a lu m in a c o n t e n t than the im m e d ia te ly o v e r l y i n g and u n d e r ly in g h o riz o n s . The d i s t r i b u t i o n o f th e s o l u b le a lu m in a i n th e p ro file s does n o t f o l l o w which has th e maximum s o l u ­ and McBride have th e d i s t r i b u t i o n o f c l a y and, g iv e n v a lu e s c o n ta in very l i t t l e if th e re fo re , the any aluminum e x t r a c t e d from th e l a t t i c e o f th e c l a y s . The d a ta o f t a b l e tio n s o f S i 02 a n d /o r A I 2O3 i n a ssum ption t h a t how ever, 5 w ill 4. did not r e v e a l o u t s t a n d i n g accumula­ th e f r a g i p a n h o r iz o n s to j u s t i f y th e y a r e m ajor f a c t o r s o f c e m e n ta tio n . be d is c u s s e d i n X -ra v th e T h e ir r o le , th e n e xt c h a p t e r . d e t e r m i n a t i o n o f c l a y m in e r a ls The g l y c e r a t e d and c a lc iu m s a t u r a t e d c l a y samples o f a l l h o r i zons o f th e t h r e e p r o f i l e s and 7 A. produced d i f f r a c t i o n maxima a t 10 A The 7 A peak d is a p p e a re d upon h e a t i n g th e sample to 5 5 0 ° C. These peaks suggest th e p re se n c e o f i l l i t e in a ll the th e h o r i z o n s o f th e t h r e e p r o f i l e s . and k a o l i n i t e , r e s p e c t i v e l y , Tne a r e a un d e r each peak 60 T a b le 5. C hem ical P r o p e r t i e s ____________ H o r i 20n McBride Depth in c h e s pH Loss i n a c i d s o lu tio n % O rganic carbon $ S o lu b le SiO* 4 S o lu b le AlbOo . rag. 100 gm. s o i l *1 1 -3 5 .4 0 .7 2 4 .4 4 .176 5 .0 A2 3 -5 5 .2 1 .6 3 2.00 .1 4 5 6.0 B h ir 5 -1 7 5 .3 1 .8 0 1 .1 5 .20 6 20.0 Bm 17-19 5 .6 .9 0 .2 7 .2 7 2 20.6 A2m 19-24 5 .8 .68 . 13 .137 1 3 .0 A3m 2 4-35 5 .6 .4 5 .11 .29 0 1 4 .2 Bt 3 5-53 5 .2 .66 .1 6 .41 7 1 4 .0 C 534= 7 .8 5 .6 0 .1 5 . 2-04 7 .0 1 -3 4 .7 0 .7 3 o. 12 1.000 3 .4 A8 3 -5 4 .7 0.12 .98 .3 0 5 5 .3 B h ir 5 -1 1 4 .6 2 .4 5 2 .6 3 .415 3 6 .7 Bm 11-13 4 .6 .20 .3 6 0 3 6 .0 ^2m 1 3-2 i 4 .9 .9 3 .1 5 .3 2 0 2 6 .4 •A3tn 2 1-34 5 ,0 1 .4 0 . 16 .5 4 0 3 3 .0 A & B 34-42 4 .6 1 .6 7 .1 8 .7 2 5 2 6 .6 Bt 42-55 5 .3 1.5 3 .13 .6 4 5 12.2 C 554= 7 .9 9 .2 0 . 12 .25 0 4 .2 00 *1 • r,o Is a b e lla 61 T a b le 6 . c o n t in u e d N e s ter H o r i zon Depth in c h e s pH Lo ss i n a c i d s o lu tio n i O rganic c arbon * S o lu b le A1203 mg. 1 00 gm. S o lu b le S i02 * Ai 1 -5 6 .0 1 .2 4 5 .1 2 . ^52 4 .3 A2./ B a i r 5 -9 5 .4 2 .2 6 .73 .3 4 5 8 .1 9 -1 6 5 .4 1 .1 6 .2 5 .315 9 .7 5 -16-27 5 .0 1 .8 1 .51 .6 3 0 1 6 .2 Bt 2 7-48 5 .0 2 .0 8 .26 .7 2 0 1 3 .4 C 48-65 7 .6 5 .7 7 .2 2 .4 9 0 6 .4 A is & B r e la te d to the amount o f the p a r t i c u l a r mine r a l p r e s e n t . h o w e v e r , such as amount o f i r o n o x id e s p r e s e n t , fa c to rs . t i o n o f th e c l a y p a r t i c l e s on th e porous p l a t e , th e m in e ra ls , peak's. e tc ., p a tte rn s based o n ly on X—ray d a t a i s v e i y which a r e shown i n c lu d e d t h a t the a p p e n d ix , th e amount o f i l l i t e b e l l a and McBride th a n i n due to th e o r i e n t a - t h e c r y s t a l l i n i ty o f th e re fo re , le s s c e r t a in , o f the c l a y d iffic u lt. From th e X -r a y i^ can g e n e r a l l y i s lo w e r i n th e po d zo l be con­ seoua o f I s a ­ t h e i r g ra y brown p o d z o l i c secrua. Any c o n c lu s io n on the amounts o f k a o i i n i t e h o riz o n is O th e r s t r o n g l y m o d ify th e a r e a and th e sharpness o f the A c c u r a te Q u a n t i t a t i v e d e t e r m i n a t i o n , m in e ra ls , s o il as t h e i n t e n s i t y o f th e 7 p r e s e n t i n each \ peak i s p a r t l y t h e second o r d e r d i f f r a c t i o n o f th e X - r a y s by th e b a s a l p la n e s o f m i n e r a l s h a v in g 14 A b a s a l s p a c in g ( c h l o r i t e , d iffe re n c e s in t h e 7 A peaks o f t h e No. 2 t r a c i n g v e rm ic c lite ). fo r The each sample (K 62 s a t u r a t e d and h e a t e d to te rn s 11C° C) and the No. show t h a t k a o l i n i t e o f Is a b e lla and i n th e is re la tiv e ly 3 ( h e a te d to 5 50 ° C) p a t ­ low i n th e Al and A3 h o r i z o n s o f McBride. Assumptions r e g a r d i n g t h e amounts o f i l i i t e based o n ly on X - r a y d a ta , and k a o l i n i t e , cannot be made f o r the N e s t e r p r o f i l e . W e ll e xp re s se d peaks c o r r e s p o n d in g to th e 1 7 .7 A s p ac in g were produced by t h e g l y c e r a t e d and Ca s a t u r a t e d samples o f th e A i , and Bm h o r i z o n s o f I s a b e l l a , A i h o riz o n o f N e s te r. by th e Al and A2 o f M cBride, These d a t a suggest th e i n th e s e u p p e r h o r i z o n s as a p u re m i n e r a l . o f g ly c e ro l, lo n ite o f how ever, were a b le to and by th e presence o f m o n tm o rillo n ite The r e p e a te d a p p l i c a t i o n s expand the l a t t i c e o f m o n tm o r il- th e Al h o r i z o n s o f I s a b e l l a and McBride o n ly to 1 7 .0 A. The s t r o n g l y absorbed o r g a n i c m a t t e r p r o b a b ly i n h i b i t e d o f some o f th e l a t t i c e s the expansion to 1 7 .7 A b a s a l s p a c in g which i s the g ly c e r a t e d m o n tm o r illo n ite . represent A2 , ty p ic a l o f The r e s u l t i n g 1 7 . 0 A peak may th e n th e r e s u l t s o f random i n t e r s t r a t i f i c a t i o n o f m o n t m o r i l l o n i t e c a p a b le o f a b s o r b in g two l a y e r s o f g l y c e r o l and o t h e r expanding l a y e r s which c o u l d p r o b a b ly ta k e o n ly one. M o n tm o rillo n ite is o f c h lo rite a ls o p r e s e n t as i n t e r s t r a t i f i e d w i t h l a y e r s a n d 'o r v e r r i c u l i t ? end possi Dly 0 .: i l l i t e o th e r h o rizo n s o f th e t h r e e p r o f i l e s , and lo w bands l o c a t e d in to st o f the as i n d i c a t e d by th e broad h ig h between 1 7 .7 A ana 14 A l e v e l s o f b a s a l s p a c in g . These bands a re h i g h e r and b e t t e r pronounced i n th e p o d zo l in th e g r a y brown p o d z o l i c zons o f I s a b e l l a seaus* and McBride do n o t The X - r a y p a t t e r n s o f the A2m h o r i ­ show the pre se n c e o f d i s c r e t e m o n t m o r i l l o n i t e i n th e s e two h o r i z o n s . as to secrua th a n th e p re s e n c e o f i n t e r s t r a t i f i e d The p a t t e r n s are in c o n c lu s iv e m o n tm o rillo n ite w ith c h l o r i t e 63 and m o n t m o r i l I o n i t e i n C h o riz o n o f N e s te r . d iffra c tio n th e Bt h o r iz o n s o f I s a b e l l a and McBride and the The 14 A peak, from an i n t e r s t r a t i f i e d X - r a y p a t t e r n s o f th e however, c ould be p a r t l y due to system o f i l l i t e - r n o n t m o r i l l o n i t e . m icron c l a y o f th e above h o r i z o n s showed t h a t i n t e r s t r a t i f i e d complexes o f expanding and n o n -e x p a n d in g c la y s p r e d o m in a t e i n th is fra c tio n . The p re s e n c e o f v e r r r . i c u l i t e was d e te rm in e d i n each h o r i z o n by c om paring the f o l l o w i n g r a t i o s : A m plitude o f tne 14 A peak. / tu d e o f th e 3 . 3 5 A peak o f q u a r t z , A m pli­ o f th e Ca s a t u r a t e d and g l v c e r a t e d sample a g a i n s t t h e same r a t i o o f th e sample when K s a t u r a t e d and h e a t ­ ed to 1 1 0 ° C. A d e c re a s e o f t h i s ra tio by h e a t i n g and K s a t u r a t i o n o f t h e c l a y would i n d i c a t e th e p re s e n c e o f v e r m i c u l i t e . The a m p litu d e s o f th e 14 A peaks as such c o u ld n o t be compared because a s i g n i f i c a n t change o f th e a m p lit u d e s o f a l l peaks r e s u l t e d by h e a t i n g and r e p l a c i n g t h e e x c h a n g e a b le Ca by K. The absence o f any peak a t th e 14 A basal s pac ing p o i n t i n the X - r a y p a t t e r n s o f th e Al and A2 h o r i z o n s o f I s a b e l l a suggest the ab­ sence o f b o th c h l o r i t e and v e r m i c u l i t e m i c u l i t e was found i n th e E h i r and Al h o r i z o n s o f N e s t e r and M cBride. and 14 A b a s a l from th e s e two h o r i z o n s . h o r iz o n s o f I s a b e l l a and i n ( p a t t e r n s No. 2 and 3 ) tn a t v e rm ic u lite is in te rs tra tifie d w ith c h l o r i t e . The bro a d bands between 14 A and 1 7 . 7 A i n d i c a t e s ( p a t t e r n No. th a t v e rm ic u lite is l) th e The broad bands between the 10 A s p a c in g o f th e c o l l a p s e d c la y s o f t h e above h o r i z o n s i n d i c a t e V e r- a ls o p ro b a b ly i n t e r s t r a t i f i e d w i t h m o n t . m o r i l lo n it e . The e x i s t e n c e o f b road bands between 10 and 14 A produced by th e h e a t e d to 110 and 5 50 ° C samples o f th e h o r i z o n s o f g ra y brown 64 p o d z o lic sequa s u g g e sts th e p o s s i b l e p r e s e n c e o f v e r m i c u l i t e as i n t e r ­ s tra tifie d rite w ith c h l o r it e and m o n t m o r i l i o n i t e i n th e s e h o r i z o n s - was d e t e c t e d by th e p re s e n c e o f the 14 A b a s a l s p a c in g , p e r s i s t e d upon F s a t u r a t i o n C hlo­ which and h e a t i n g to 110° C and 5 50 ° C ( p a t t e r n s 2 and 3 ) . X -rg y p a tte r n s in d ic a te and A2 h o r i z o n s o f I s a b e l l a , th e absence o f c h l o r i t e from the Al and p r o b a b ly from the Al o f McBride. A ll t h e o t h e r h o r i z o n s o f th e t h r e e p r o f i l e s produced X -r a y p a t t e r n s i n ­ d i c a t i n g t h e p re s e n c e o f c h l o r i t e , w ith v e r m i c u l it e m o n tm o rillo n ite which seems to be i n t e r s t r a t i f i e d and m o n t m o r i l l o n i t e i n th e podzol sequa and w it h and p o s s i b l y v e r m i c u l i t e i n th e g r a y brown p o d z o l i c sequa. I r o n o x id e s i n t e r f e r e d s t r o n g l y i n th e E h i r and Bt h o r i z o n s o f I s a b e l l a and they were removed from th e samples o f th ese two and o f th e A3m and A & B h o riz o n s o f t h i s p r o f i l e . By rem oving th e i r o n , h i g h e r and more d i s t i n c t peaks were o b t a i n e d . 5. D iffe re n tia l C la y s o f a l l Thermal A n a ly s is o f C la ys t h e h o r i z o n s o f th e t h r e e p r o f i l e s th e r m ic peaks a t t e m p e r a tu r e s o f 1 00=200° C, lo s s o f i n t e r l a y e r w a t e r . pro d u c e d r e l a t i v e l y in d ic a tin g o f a ll which corres p o n d to the The f r a g i p a n l a y e r s o f a l l s m a ll peaks at th re e p r o f ile s the above ra n g e o f te m p e r a tu re s , a lo w amount o f expanding c l a y m i n e r a l s . th re e p r o f ile s produced endo- The A3m h o r iz o n s and the A3m o f McBride showed d e f i n i t e m inima o f l o s s o f i n t e r l a y e r w a t e r w i t h i n t h e i r own p r o f i l e s . C la y s o f th e h o r i z o n s o f th e p o d z o l sequa produced s tr o n g exo­ th e r m ic peaks a t te m p e r a tu r e s between 3 0 0 ° C and 4 0 0 ° C, whi^h a r e due 65 to t h e com b u stio n o f t h e a s s o c i a t e d o r g a n ic m a t t e r . T h is o r g a n ic m a t t e r r e s i s t e d t n e H2 O2 t r e a t m e n t s d u rin g the p r e p a r a t i o n o f th e sam ples f o r m e c h a n ic a l a n a l y s i s . The Al h o r i z o n s o f I s a b e l l a and M cB ride h a ve a lso o r g a n i c m a t t e r s t r o n g l y absorbed by t h e i r c l a y s as i n d i c a t e d by th e e x o th e rm ic peaks a t te m p e r a tu re s between 6 0 0 ° C and 7 0 0 ° C ( 3 3 ) . E ndotherm ic peaks a t te m p e r a tu re s between 5 50 ° C and 6 0 0 ° C were a ls o produced by the c l a y s o f a l l h o r i z o n s . pond to S in c e , These peaks c o r r e s ­ t h e l o s s o f t h e OH w a te r from th e l a t t i c e o f k a o l i n i t e m a in ly . a ls o , o t h e r c l a y m i n e r a l s as i l l i t e , c h lo rite and v e r m i c u l i t e ( 2 2 ) undergo lo s s o f OH w a te r a t th e Same as above ra n g e o f tempera­ tu re s , t h e a reas u n d e r th e s e peaks have o n ly l i m i t e d v a l u e f o r th e q u a n tita tiv e d e te rm in a tio n o f k a o l i n i t e . o f k a o lin ite a re g iv e n i n Curves o f s ta n d a rd samples the a ppen dix a lo ng w i t h c u rv e s o f s o i l c la y s f o r com parison. Based on th e r e s u l t s o f D .T .A . , we can c o n clu d e t h a t expanding m in e ra ls in a r e p r e s e n t i n a l l h o r iz o n s but t h e i r amounts a re v e r y s m a ll th e fr a g ip a n h o riz o n s . o f k a o lin ite M cB ride, ffe can a lso conclude t h a t are s m a lle r in the Al and A2 h o r i z o n s o f I s a b e l l a and and i n t h e Al o f H e s t e r , 6. T o ta l T o ta l S p e c ific s p e c ific than i n the r e s t o f th e h o r i z o n s . S u rfa c e and K C ontent o f C l a y s . s u r f a c e d a t a show a d i s t i n c t minimum i n A2m h o r i z o n s o f th e t h r e e p r o f i l e s The v a lu e s th e q u a n t i t i e s and i n the A3m h o r i z o n o f M cBride. show th e p re s e n c e o f e xpanding m in e r a ls i n w ith a p o s s ib le e x c e p tio n i n the a l l h o riz o n s , the above m entioned f r a g i p a n h o r i z o n s . Both t h e p o d zo l seoua and th e i l l u v i a l zones o f t h e g ra y brown 66 p o d z o lic sequa seem to be e n r ic h e d w i t h expanding c l a y s . zonS of a l l The C h o r i = t h r e e p r o f i l e s have s m a lle r s u r fa c e a r e a s th a n th e and A & B h o riz o n s . The p o ta s s iu m c o n t e n t o f t h e c l a y s i s p o d z o l sequa and r a t h e r h ig h i n re la tiv e ly th e g ra y brown p o d z o l i c low i n sequa. th e The c l a y o f t h e pan o f McBride has th e maximum F 2O c o n te n t i n the p r o f i l e , i n I s a b e l l a and N e s t e r , te n t in how ever, t h e r e i s a second and h i g h e r con­ ¥20 th e c la y o f th e p a ren t m a te r ia l. The above d a t a suggest t h a t i l l i t i c d ra s tic w e a t h e r i n g and l o s s o f w e a th e r in g is ¥ not d e te c ta b le in in c l a y s undergo a r a t h e r th e pod zo l sequa, th e gra y brown p o d z o l i c sequa. must be n o t i c e d h e r e t h a t t h e A3m h o r iz o n o f th e McBride It p ro file w hich i s mum c o n te n t o f a l l h o r iz o n s o f th e t h r e e p r o f i l e s . ¥20 w h ile t h is th e h a r d e s t o f a l l th e h o r i z o n s t e s t e d has th e m axi­ The measured K can be assumed to come from th e c l a y o n ly , no f e l d s p a r s 7. were d e t e c t e d i n th e X -r a y as p a tte rn s . Summary on C la v Analyses Comparing th e r e s u l t s o f th e d i f f e r e n t methods f o l l o w e d i n c ls y a n a ly s is , illite in we n o t i c e t h a t th e jsn p litu d e s o f th e 10 A peak's o f t h e X -ra y p a t t e r n s do n o t c o r r e l a t e w i t h th e K20 c o n te n t o f th e p a r tic u la r th e f a c t t h a t sam ples. The l a c k o f c o r r e l a t i o n i s p r o b a b ly t h e d e g ree o f o r i e n t a t i o n o f th e c l a y p a r t i c l e s due t o and th e amount o f i r o n o x id e s p r e s e n t had s t r o n g l y i n f l u e n c e d th e a m p litu d e s o f th e X -ra y peaks. There i s a r a t h e r s p e c ific s a t i s f a c t o r y c o r r e l a t i o n between th e t o t a l s u r f a c e a r e a o f th e c la y s and th e a re a un d e r th e 100° C 67 T a b le 6 . T o t a l K c o n t e n t and t o t a l s p e c i f i c McBride H o riz o n % K2O Is a b e ll a T o t a l sp. s u rfa c e m2/ gm. H o r i zon N e s ter T o t a l sp. sur f ac e gm. 4 720 A1 3 .1 2 259 Al 2 .2 4 218 A3 3 .4 8 255 A2 3 .3 2 180 B h ir 3 .4 8 203 B h ir 2 .7 6 294 Bm 3 .9 6 252 Bm 3 .8 4 A2m 4 .8 0 120 A2m A3m 5 .0 4 114 A3m Bt 4 .2 0 266 A C 4 .2 0 221 T a b le 7 . s u r f a c e o f th e c la y H o ri zon % T o t a l sp. K20 s u r f a c e m2/ gm. 3 .4 8 217 3 .4 8 204 A2m 4 .2 0 126 214 A & B 4 .0 8 260 4 .2 0 139 Bt 4 .0 8 252 4 .2 0 201 C 4 .3 2 215 3 .9 6 273 B 4 .6 8 218 C 4 .6 8 217 & B P e r c e n t o f heavy m i n e r a l s i n Al A s /B h ir th e f i n e sand H o r i zon Al Asm A2 A s / B h i r B h i r Agm A & B Bt C Is a b e lla 1 .7 5 2 .2 0 — N es te r 1 .7 0 — 1.20 cn cn 1 0 .5 5 0 M cBride -Cf P ro file 2 .4 .6 5 .7 0 .6 5 1 ,3 0 1 .3 5 .7 8 1 .2 5 — .62 .68 .5 5 .7 2 .7 8 1 .0 0 1 .1 5 1.10 68 200 C e n d o th e rm ic peak o f th e D .T .A . p a tte rn s as i t is shown i n 1 . f i gar e The r e l a t i v e l y n rfg m . c la y ) ra th e r a b unda nt, lo w s u r f a c e a r e a o f I s a b e l l a ’ s J& h o r i z o n i n which th e X - r a y p a t t e r n s (ISO show t h a t m o n t m o r i l l o n i t e i s can be e x p l a i n e d by assuming t h a t th e a b s o r p t io n by t h e c l a y o f o r g a n i c m a t t e r i n h i b i t e d t h e p e n e t r a t i o n o f e th y le n e g l y ­ c o l in to th e i n t e r l a y e r space o f m o n t m o r i l l o n i t e . The l a r g e e x o t h e r ­ mic p e a k a t 3 0 0 ° - 4 0 0 ° C o f th e D .T .A . p a t t e r n o f th e above h o r i z o n c o n fir m s t h e p r e s e n c e o f l a r g e Q u a n t i t i e s o f o r g a n ic m a t t e r a s s o c i a t e d w ith th e c la y . I n s p i t e o f th e above shortc o m in g s, can be d e r iv e d (a) th e f o l l o w i n g c o n c lu s io n s from t h e c l a y s t u d i e s : Illite and c h l o r i t e and i n t e r s t r a t i f i e d systems are the main c l a y m i n e r a l s which w eather and t h e i r r e l a t i v e i n th e p o d z o l sequa o f t h e p r o f i l e . amounts a re s m a ll The s m all 10 A and 14 A peaks i n the X -ra y p a tte r n s , t h e r e l a t i v e l y h ig h s u r f a c e a r e a , c o n t e n t o f th e c l a y o f (b ) basal th e 1 7 .7 A and 14 A t h e d is a p p e a r a n c e o f th e s e peaks from th e p a t t e r n s o f th e h e a te d sam ples, c la y t h e p o d zo l seaua s u pport t h e above c o n c lu s io n . D i s t i n c t X - r a y maxima c o rr e s p o n d in g to s p a c in g , and th e lo w KpO and th e r e l a t i v e l y h ig h s p e c i f i c s u r f a c e o f th e i n d i c a t e s t h a t m o n t m o r i l l o n i t e and v e r m i c u l i t e a r e th e p r o d u c t o f t h e above m e ntione d w e a t h e r i n g . f o r m a t i o n o f new m i n e r a l s w i l l The process o f w e a th e r in g and th e be d is cu s s ed i n th e n e x t c h a p t e r . ( c ) M o n t m o r i l l o n i t e i s p r e s e n t i n most o f th e h o r i z o n s o f the g ra y brown p o d z o l i c seoua and i n th e p a r e n t m a t e r i a l as randomly i n ­ te rs tra tifie d la y e r s w ith c h l o r i t e , illite , T h is c o n c lu s io n i s to o . and p o s s i b l y w i t h v e r m i c u l i t e and based on th e p r e s e n c e o f broad bands R e la tiv e area under the 100-200° C, peaks of D*T«A 69 70 in t h e X - r a y p a t t e r n s o f th e s e f i e d l a t t i c e s o f 1 7 .7 to ta l s p e c ific h o riz o n s , c o r r e s p o n d in g to i n t e r s t r a t i ­ A and 14 A b a s a l s p a c in g , s u r f a c e o f th e c l a y , the r e l a t i v e l y h ig h end th e r e l a t i v e l y l a r g e e n d o th e r - mic peaks a t te m p e r a tu r e s o f 100 - 200° C i n th e D. T. A. p a t t e r n s . (d ) A h i g h KgO c o n t e n t and r e l a t i v e l y f a c e o f th e c l a y , 1 7 .7 A peaks i n (e ) re s u lt o f s p e c ific sur­ a lo n g w i t h w e l l expressed 10 A peaks and absence o f th e X - r a y p a t t e r n s tio n o f i l l i t i c low t o t a l c la y suggest t h a t a r e l a t i v e c o n c e n tr a ­ t a k e s p l a c e i n th e f r a g i p a n . The p e ak s a t 5 00 ° - 6 00° G o f th e D .T .A . p a t t e r n s a r e th e th e a d d i t i v e endotherm ic r e a c t i o n s o f k a o l i n i t e and i l l i t e . By rough com parisons o f th e above peaks w i t h th o s e o f s ta n d a r d samples o f pure k a o l i n i t e , i n th e c la y and o f th e zons i t it c o u l d be p o s t u l a t e d t h a t t h e amount o f k a o l i n i t e f r a c t i o n o f th e A l o f N e s t e r Ap and A2 h o r i z o n o f I s a b e l l a i s s m a l l e r than 1 0 - 1 5 $ , w h ile in and McBride the deeper h o r i ­ can be as h i g h as 2 0 - 3 0 $ . (f) The l e s s th a n . 2 m icrons c l a y o f t h e g r a y brown p o d z o l i c sequa c o n s i s t s m a in ly o f i n t e r s t r a t i f i e d expanding and n o n -e x p a n d in g m in e ra ls . 8. M i n e r a l A nalyses o f F in e Sand M i n e r a l a n a ly s e s were made on th e p o r t i o n o f th e f i n e which r e s i s t e d th e i t HCl t r e a t m e n t d u r in g the p r e p a r a t i o n o f samples f o r m e c h a n ic a l a n a l y s i s . e lim in a te d (a ) sand C a l c i t e and o t h e r a c i d s o l u b le m i n e r a l s were by th e above t r e a t m e n t . Heavy Min e r a l s . h eavy m i n e r a l s were found i n A r e l a t i v e l y h ig h p e r c e n t w e ig h t o f th e p o d z o l seouum o f I s a b e l l a , A3m and i t s u n d e r l y i n g h o r i z o n s h a d d is tin c tly w h ile s m a l l e r amounts o f the 71 h e a v y m in e r a ls . . T a b le 7 V c B r id e and N e s t e r showed a r a t h e r u n ifo rm d i s t r i b u t i o n o f heavy m i n e r a l s A ll w ith in th e ir p ro file s . th ree s o ils show s i g n i f i c a n t d iffe re n c e s in th e p e r c en t fr e o u e n c y o f l e s s r e s i s t a n t m i n e r a l s i n th e d i f f e r e n t h o r iz o n s 8 ). H o r n b le n d e , o l i v i n e and e p i d o t e w ea th e r r a p i d l y . r e s i s t a n t heavy m i n e r a l s a r e m a g n e t it e , lin e . zirc o n , Among th e most g arn et, and tourma­ The most pronounced d i f f e r e n c e s i n th e d i s t r i b u t i o n o f the e a s i l y w e a th e re d m i n e r a l s were found i n th e I s a b e l l a p r o f i l e . W e a th e r in g o f th e l e s s r e s i s t a n t m in e r a ls h o r i z o n s w hich o v e r l i e how e ve r, th e Bt h o r i z o n . ta k e s p l a c e in a ll The i n t e n s i t y o f w e a th e r in g , d e c re a s e s w i t h i n c r e a s i n g depth. O liv in e g r a i n s were v e r y h i g h l y w eathered and more o r l e s s opaque because o f t h e i r w ea th e re d s u r f a c e . ever, (T a b le th a t I t must be a d m it te d , how­ t h e a c c u r a t e d e t e r m i n a t i o n o f t h e i r o p t i c a l p r o p e r t i e s was n o t a lw a y s p o s s i b l e . Some o f th e g r a in s c a l l e d o l i v i n e , th e re fo re , c o u l d a c t u a l l y have been h i g h l y w ea th e re d h o rn b le n d e o r e p i d o t e . o b s e rv e d u n d e r th e p e t r o g r a p h i c and b i n o c u l a r m icro s c o p e s, o f th e l e s s r e s i s t a n t m i n e r a l s showed a decrease i n w ith in c re a s in g d e p th . The g r a in s o f h o rn b le n d e , and h e m a t i t e were c o n s i d e r a b ly w e a th e r e d i n th e A2m. When th e g r a in s th e w e a th e r in g a u g ite , e p id o te , w eathered i n th e p o d z o l sequa, l e s s A3m and A & B h o r i z o n s , and h a r d l y w e a th e re d i n th e Bt and C h o r i z o n s . The r a t i o o f m a g n e t it e to g a r n e t was used as a t e s t o f th e g e o l o g i c a l and l i t h o l o g i c a l u n i f o r m i t y o f th e r e s p e c t i v e p r o f i l e s . Cady ( 1 0 ) found t h a t m a g n e t it e , r e s i s t a n t m in e ra ls g a r n e t and z i r c o n were among th e most to p o d z o l i c w e a t n e i i n g . G arnet was chosen i n s t e a d 72 T a b le 8 . P e r c e n t F re q u e n c y i n th e Heavy F r a c t io n o f F in e Send. McBride H o r i zon M in e ra ls *1 B h ir A2 3m Agm 43m C Bt 5 3 .8 4 7 .3 5 0 .1 4 7 .7 4 8 .9 4 8 .0 3 8 .3 4 0 .5 7.2- 7 .2 9 .3 8 .5 8 .6 8 .8 6 .6 7 .4 2 2 .9 2 4 .2 1 9 .1 1 9 .6 2 1 .0 2 2 .3 2 9 .2 27. 9 O liv in e 4 .9 7 .2 7 .2 7 .8 6 .9 7 .0 9 .1 7 .7 E p id o te 3 .1 5 .8 6 .2 5 .8 5 .5 5 .7 7 .6 6 .9 H e m a tit e 4 .9 6 .1 6 .4 8 .0 7 .0 6 .0 6 .6 6 .9 Augi t e 1 .6 0 .8 1 .0 1.1 0 .9 O.S 1 .8 1 ,5 Z ir c o n 0 .3 0 .4 0 .2 0 .4 0 .5 0 .8 0 .5 0 .8 T o u r m a lin e 0 .3 — 0 .5 1 .1 0 .5 0 .6 0 .3 0 .6 M a g n e tite G arnet 7 .5 6 .5 5 .4 5 .6 5 .7 5 .4 5 .8 5 .5 M a g n e tite G arnet H o rn b le n d e Table 8. continued Is a b e lla H o ri zon Ai A2 B h ir Blm A2m A & B Bt C M in e r a ls 7 6 .8 7 7 .5 5 7 .0 5 9 .4 6 0 .9 4 5 .3 4 1 .6 3 8 .9 3 6 .9 G-arnet 6 .6 6 .5 5 .5 5 .2 6 .1 9 .1 4 .7 4 .1 4 .4 H o rn b le n d e 4 .2 6 .3 1 5.1 1 0 .7 9 .0 2 1 .2 2 2 .7 2 4 .6 2 3 .8 O liv in e 4 .0 3 .1 7 .5 7 .5 8 .0 7 .4 1 1 .5 1 2 .1 1 0 .8 E p id o te 1 .6 1 .2 7 .0 6 .8 6 .6 7 .6 9 .5 1 1 .1 1 1 .8 H e m a tite 5 .0 3 .9 3 .0 5 .8 5 .5 3 .7 7 .2 6 .7 9 .2 A u g ite 0 .6 0 .5 3 .0 2 .6 2 .1 2 .3 2 .3 1 .7 1 .7 Zi rc on 0 .6 0 .5 0 .6 0 .6 0 .4 1 .2 0 .3 0 .4 0 .7 T o u rm a lin e — — 0 .5 — 0 .6 0 .6 0 .2 0 .2 0 .7 Leucoxene 0 .6 — — 0 .2 0 .6 — B u tile — — 0 .6 — -- -- 0 .3 0 .2 -- — — 0 .2 — 1 .4 9 .9 4 .9 7 M a g n e tite S t a u r o li t e E n s t a t ite — 0 .5 B io tite — - - 1 1 .6 G-arnet' 1 1 .9 0 .8 1 0 .4 1 1 .4 — — — 0 .2 -- — — — 8 .8 9 .5 8 .2 — Table 8. continued N e s te r H o r i zon C B h ir ASm 3 9 .8 3 9 .5 3 6 .9 3 7 .4 3 2 .2 3 0 .5 7 .5 7 .2 6 .9 7 .5 6 .5 5 .4 H o rn b le n d e 2 3 .5 2 3 .3 2 6 .6 2 6 .9 3 5 .4 3 8 .8 O liv in e 1 2 .9 1 3 .2 1 2 .2 9 .6 1 0 .5 1 0 .0 E p id o te 8 .5 1 0 .5 9 .9 9 .3 8 .5 8 .3 Hemati t e 6 .1 4 .0 6 .3 4 .5 4 .8 4 ,4 A u g ite 1 .4 1 .9 0 .9 3 .3 1 .9 2 .0 Z ir c o n — 0 .4 0 .2 0 .6 0 .2 0 .4 T o u r m a lin e 0 .3 — 0 .2 0 .9 0 .2 0 .2 M a g n e tite G arnet 5 .3 6 .5 5 .4 5 .0 5 .1 5 .6 M in e ra ls M a g n e tite G a rn e t A1 A z! A & B Bt 75 T a b le 9 . P e r c e n t F re q u e n c y i n M c B rid e th e L ig h t F r a c t io n o f F in e Is a b e lla Sand N e s te r H o r iz o n Q u a r t z F e ld s p a r H o r iz o n Q u a rtz F e ld s . H o r iz o n Q u a r tz F e ld s . 8 5 .6 1 6 .4 Al 8 3 .7 1 6 .3 Al 8 3 .4 1 6 .6 A2 8 5 .0 1 5 .0 A2 8 6 .0 1 4 .0 Ag/ B h ir 8 5 .5 1 4 .5 B h ir 8 3 .7 1 6 .3 B h ir 8 4 .7 1 5 .3 A2m 8 3 .2 1 6 .8 Bm 8 4 .0 1 6 .0 Bm 00 1 5 .2 A & B 8 3 .9 1 6 .1 A2m 8 3 .9 1 6 .1 A2m 8 3 .0 1 7 .0 Bt 8 3 .5 1 6 .5 A3m 8 3 .1 1 6 .9 A3m 8 3 .5 1 6 .5 C 8 3 .5 1 6 .5 Bt to 00 1 6 .6 A 83 . 6 1 6 .4 C 8 3 .3 1 6 .7 Bt 8 3 .4 1 6 .6 C 8 3 .4 1 6 .6 B • & 00 Al 76 ol z i r c o n 136081186 th e l a t t e r was p r e s e n t o n ly i n v e r y s m all q u a n t i t i e s . D a ta show t h a t N e s te r b e lla 's and McBride have u n i f o r m p r o f i l e s , h o riz o n is u n d e r ly in g h o riz o n s g arnet r a t i o d is tin c tly which also and th e t o t a l d iffe re n t (b ) The m a g n e t it e - w eig h t o f heavy m in e r a ls suggest t h a t the and A2ra h o r iz o n s o f I s a b e l l a a re from t h e lo w e r p a r t o f th e p r o f i l e . L ig h t m in e r a ls . The p e r c e n t fre q u e n c y o f q u a r t z and fe ld s p a r i s r a t h e r u n i f o r m th ro u g h o u t th e t h r e e p r o f i l e s . d e c re a s e i n f e l d s p a r s i s n o t i c e a b l e i n th e A2 h o r iz o n s o f a l l p ro file s . i n d i c e s o f th e T h is in d ic a te s th e p r o f ile s c la s e , A s lig h t th ree T a b le 9 . The r e f r a c t i v e q u a rtz. Is a ­ from th e o v e r l y i n g and d i f f e r from each o t h e r . p o d z o l seauum and p r o b a b ly th e p e tro g ra p h ic a l l y d iffe re n t w h i le s tu d ie d . t h a t o n ly f e l d s p a r s were below th o s e o f and Na f e l d s p a r s a r e p r e s e n t i n Y. Q u a lita tiv e ly id e n tifie d f e l d s p a r s were o r t h o - m i c r o c l i n e and a l b i t e . (9 ) D e s c r i p t i o n o f th e T h in S e c tio n s T h in s e c t i o n s were s t u d i e d w it h th e a i d o f th e p e t r o g r a p h ic m ic ro s c o p e , u s i n g m a g n i f i c a t i o n s x 50 to x 1940. v a t i o n s were o f q u a l i t a t i v e g ra in s and p o r e s i z e s (a ) n a tu re . Average d is t a n c e s between sand were e s t im a t e d . Is a b e lla Micro s t r u e t u r e : o f a g g r e g a te s 1 . 0 o th e r M i n e r a l o g i c a l o b s e r­ Crumbly and v e r y lo o s e . 5 . 0 mm. i n d i a m e t e r , C o n s is ts which a re s e p a r a te d from each by empty pores and c rac k s o f v a r i o u s shapes and s i z e s . p o r e s have d ia m e te r s r a n g in g between 0 . 5 mm. and 1 . 5 mm. b i n d i n g a g e n t o f th e a g g r e g a te s i s o r g a n ic m a t t e r . The jhe p r im a r y The d is ta n c e s 7? between t h e n e i g h b o r in g sand g r a i n s o f th e a g g re g a te s ra n g e between 50 m icro n s and 600 m ic ro n s w ith a rough average o f 200 p . a g g r e g a te s t h e r e a r e numerous p o re s o f v a r y i n g s i z e s . e s tim a te o f t h e i r d ia m e te r s i s 150 |i. w ith A rough average N e i t h e r th e p o re s n o r the g r a i n s h a v e c o a t in g s o f o r i e n t e d c l a y . fille d I n s i d e the The i n t e r g r a n u l a r spaces a re a porous m a t r i x c o n s i s t i n g o f o r g a n ic m a t t e r , and i r o n o x i d e s . s ilt, The c l a y la c k s o f any o r i e n t a t i o n and i t te d w i t h th e o r g a n i c m a t t e r , so t h a t i t is c la y a s s o c ia ­ cannot be d i s t i n g u i s h e d . In ­ d i v i d u a l p a r t i c l e s o f c o ars e c l a y can o n ly be seen under crossed n ic o ls and h i g h m a g n i f i c a t i o n . I r o n o x id e s a lso s t i c k on th e decom­ posed o r g a n i c m a t t e r . O rg a n ic M a t t e r : it c o n s is ts o f f in e I t o c cu p ie s most o f th e m a t r i x and f r e e p a r t i c l e s o f decomposed o r g a n ic mixed w i t h e gg-shaped orange d roppings o f o r t h r o p o d s . todes and fungus hyphae, A few p l a n t m a t e r i a l s th e ir w ith s e p t a and f r u i t b o d ie s , substances “Efegs o f nema­ a re a lso p r e s e n t . a r e n ot c o m p le te ly decomposed and i n c l u d e , decomposed c a v i t i e s , in f r e e o r cemented droppings o f a r th r o p o d s . Some p l a n t r e s i d u e s have a w h i t i s h n u c le u s o f r e s i d u a l c e l l u l o s e n e t ­ work, which i s o p t i c a l l y brown l i g n i n . to The n u c le u s i s Hartmann ( 2 5 ) , have been decomposed by f u n g i . c o d s, surrounded by r e d These r e s i d u e s do not c o n t a i n d ro p p in g s and, h o riz o n c o n s is ts fie d a c tiv e . m a in ly o f l i g n i n and c o p io g e n ic and a c c o r d in g to Hartmann ( 2 5 ) as a r t h r o p o d s - The humus o f t h i s e lem ents o f a r t h r o — and K ubiena ( 3 9 ) , can be c l a s s i ­ f i n e moder. Y in e r a lo g y ‘ o f c fuartz and f e l d s p a r s h o r n b le n d e g r a i n s a c c o rd in g The b u lk o f th e sand f r a c t i o n c o n s i s t s (M ic ro c lin e , are d is in te g ra te d O r t n o c ia s e end A l b i t e ) . in to s ilt-s iz e p r is m s . Some A few c o n c r e t i o n s o f p r e c i p i t a t e d i r o n o x id e a r e p r e s e n t b u t th e y are h a rd to d is tin g u is h from l i g n i n . ¥1 c r o s t r u e t u r e : Aggregates a re absent and a r a t h e r m a s s iv e m i c r o s t r u c t u r e c h a r a c t e r i z e s t h i s h o r i z o n . t a n c e "between th e sand g r a in s i s are p re s e n t. about O . i mm. The average d i s ­ Many c r a c k s and p o re s T h e i r a ve ra g e d ia m e te r o r w id th i s about 0 . 2 mm. No c o a t i n g s o f w e l l o r i e n t e d c l a y are found around th e sand g r a i n s o r the pores. Some o f th e sand g r a i n s have around them d i f f u s e and d is c o n ­ tin u o u s c o a t i n g s o f w eakly o r i e n t e d c l a y . a c c o r d in g to F u b ie n a ( 3 7 ) , by a l t e r n a t e The m a t r i x c o n s i s t s m a in ly o f s i l t , p a rtic le s lo n g , o f c o a rs e c l a y , and v e r y f i n e l y These c o a t in g s a r e form ed, d r y in g and w e t t i n g o f the s o i l i n which a re random ly i n t e r m ix e d l a t h - s l i a p e d c l a y a g g re g a te s 1C-20 m icrons d i v i d e d o r g a n ic m a t t e r . The c l a y seem to have th e c l a y p a r t i c l e s o r i e n t e d along t h e i r a g g re g a te s long axes. Frac­ t u r e s o f some q u a r t z end f e l d s p a r g r a i n s c o n t a i n c l a y . O rg a n ic M a t t e r : lig n in a g g r e g a te s o f l e s s a r t h r o p o d s d ro p p in g s . c o n s i s t s o f re d brown than 50 m icrons d ia m e te r , No p re s e r v e d p l a n t few red brown r o o t b a r k s . a b ly s m a l l e r i n Most o f i t and o f broken ti s s u e s a re v i s i o l e , e xcept The amount o f o r g a n ic m a tte r i s c o n s id e r ­ t h i s h o riz o n than i n the A f. There a re few fu n g i hy­ phae w i t h s e p t a . Miner g ra in s a re c r a c k e d . h o r n b le n d e . ai ogy * Same as i n , but most o f the sand T here a re numerous p r i s m a t i c g r a i n s o f s i l t - s i z e d Very l i t t l e i r o n o x id e i s a s s o c i a t e d w ith th e o r g a n ic mat t e r . ■g^^r 1 fa b ric . Mi cro s t r u c t u r e r Loose, Average d i s t a n c e between ric h i n c a v i t i e s and spongy the sand g r a in s i s about m,... , 79 but i t ra n g e s pores 0 .2 from 0 . 0 5 mm. - 0 . 0 mm. i n th e f l o c u l a t e d m a t r i x . to 0 . 4 0 mm. d ia m e te r , There a re numerous l a r g e r and many t i n y ones c o n f i n e d w i t h i n The pores do n o t have o r i e n t e d c o a t in g s but mos . o f th e sand g r a i n s a re surrounded o r c o a te d by a m ix t u r e o f c l a y , o r g a n i c m a t t e r and p r e c i p i t a t e d i r o n . The c l a y o f th ese c o a t in g s shows a weak: o r i e n t a t i o n on th e s u r fa c e o f th e g r a i n s . ness ra nges between. 10 and 50 m ic ro n s . tween th e c o a t e d sand g r a i n s i s r a t h e r and a g g r e g a te d m a t r i x . m icro n s i n T h e ir th ic k ­ The i n t e r g r a n u l a r spaces befille d w ith a h i g h l y porous The micro a g g r e g a te s o f the m a t r i x are 2 0 -1 0 0 d i a m e t e r and c o n s i s t o f th e same m a t e r i a l s as the sand c o a t in g s p l u s embedded s i l t g r a i n s . O rg a n ic M a t t e r : brown c o l l o i d a l th a t i t is s u b s ta n c e , d iffic u lt It c o n s i s t s o f h i g h l y d is p e r s e d r e d w e l l mixed w it h c l a y and i r o n o x id e s , to be d i s t i n g u i s h e d from them. so Pew o r g a n ic p a r t i ­ c l e s o f 10 m ic ro n s d ia m e te r and o f d a rk brown r e d c o l o r a re no t mixed w ith m in e ra ls and can be d i s t i n g u i s h e d as such. Fungi hyphae and a n im a l d ro p p in g s a re a b s e n t. M in e ra lo g y ; and f e l d s p a r g r a i n s te d w ith c la y M ic ro s t r ue t u r e ; th a n th e B h i r . v a rie s a r e f r a c t u r e d and much more i r o n o x id e i s a s s o c ia ­ and o r g a n ic m a t t e r i n t h i s h o r i z o n . Bm 0 . 1 5 mm. Same as i n A2 but o n ly v e r y few q u a r t z The Bm h o r iz o n i s a little denser The a v e ra g e d i s t a n c e between th e sand g r a in s i s Many cores a r e a ls o p r e s e n t i n t h i s h o r i z o n . from 0 . 1 to 1 .0 mm. about T h e i r d ia m e te r A few o f th e pores and c hann els have on t h e i r p e r i p h e r y d is c o n tin u o u s 5 - 1 0 m icrons t h i c k l a y e r s o f w e l l o r i e n ­ ta te d c la y . s ilt g ra in s . Some o f th e pores a r e p a r t i a l l y o r e n t i r e l y fille d The sand p a r t i c l e s have ai ound them 2=5 m icions w ith tn i^ k c o a t i n g s o f w eakly o r ie n t e d , c l a y . and c o n s i s t s m a in l y o f s ilt wnich i s i n t e r m i x e d w i t h u n - o r i e n t e d c l a y . I n a few n a r r o w i n t e r g r a n u l a r r a d ii The i n t e r g r a n u l a r m a t r i x i s porous spaces ana i n p a r t s o f p ores w ith s m a ll a r e m e n is c i o f w e l l o r i e n t e d c l a y . b rid g e s b in d in g Some o f th ese m e n is c i a c t as the n e i g h b o r in g sand g r a i n s . s p re a d s m a ll c l a y a g g re g a te s o f d i f f e r e n t I n the m a t r i x a re a lso shapes and s iz e s which seem to have t h e i r c l a y o r i e n t e d a lo ng an a x i s or around a n u c le u s . n a t u r e as t h a t O rg a n ic M a t t e r : The o r g a n ic m a tte r i s o f th e same o f th e B h ir but i t i s c o n f i n e d to o n ly a few spots o f th e m a t r i x and i t s amount i s s ig n ific a lly M in e ra lo g y s g ra in s a re fra c tu re d in to s m a l l e r than i n Same as i n th e B h i r . s i l t - s i z e d p ris m a tic th e B h i r . Mamr h o rn b le n d e g r a in s and some o f them show r e l e a s e o f i r o n o x i d e around them and fo r m a tio n o f c l a y which i s h e a v i l y co ated w ith ir o n o x id e s . is s ig n ific a n tly than i n th e B h i r . M ic ro s t r u c t u r e ; A 2 jn h o riz o n i s s m a lle r its G e n e r a l ly th e amount o f i r o n o x id e s dense f a b r i c , A s tr ik in g c h a ra c te ris tic o f th is which i n c e r t a i n a re a s approaches th e f a b r i c o f s an d s to n e . The d i s t a n c e between th e sand g r a i n s ranges be­ tween 1C w i t h a rough a verage o f 3 0 -4 0 p . y and 8C y ., T h i s m ass ive m i c r o s t r u c t u r e i s l a r g e p o re s (1 .0 mm. - l a r m a cro s tru e tu re . 1 . 5 mm. i n d i a m e t e r ) , T h is h o riz o n , th a n th e o v e r l y i n g ones. ( 1 0 - 2 0 m icro n s t h i c k ) nowever, some p a r t s w ith which produce th e v e s ic u ­ has much lo w e r p o r o s i t y More po re s and e s p e c i a l l y la y e r s o f w e ll o r ie n te d c la y The l a r g e p o re s have c o a t in g s o f f i n e and i n broken by d i f f e r e n t c ra c k s and than i n th e Bq . s i l t mixed w itn u n - o r i e n t e d c l a y sharp c u r v a t u r e s in g s o f w e l l o r i e n t e d c l a y . s m a ll ones c o n t a i n th e y have d is c o n tin u o u s c o a t ­ A number o f pores a re fille d w ith s ilt- 81 s iz e d g r a in s . s im ila r Sand g r a i n s have t h i n c o a t in g s o f w eakly o r i e n t e d c l a y to th o s e d e s c r i b e d i n th e Bm. In v e r t ic a l s e c t i o n s a re seen l o n g , o r i e n t e d p la n e s o f weakness, and d i f f e r e n t cracks i n TheBe p la n e s o u t l i n e t h e Bm, which have l a r g e r i n t e r g r a n u l a r which f i n e s ilt and c o a rs e c l a y i s spaces d e p o s it e d . th e c o a rs e p l a t y u n i t s o f th e m a c r o s tr u e tu r e . The m a t r i x has fe w er p o r e s , in narrow and h o r i z o n t a l l y little more c l a y and h i g h e r d e n s i t y th a n and forms s e v e r a l s o l i d b r id g e s between th e sand g r a i n s . Th e re a r e a ls o h e r e more meniscus -s h a p e d b r id g e s o f w e l l o r i e n t e d c la y th a n i n t h e Bm. O rg a n ic M a t t e r : Very few and s p o r a d ic re d brown a g g r e g a te s . M in e ra lo g y : which i s Same as i n Bm w i t h l e s s i r o n o x id e , a s s o c i a t e d m a in ly w ith some w e l l o r i e n t e d c l a y c o a t in g s . T h e re a r e a few d i s i n t e g r a t e d h o rn b le n d e g r a i n s , but t h e r e i s no e v i ­ dence o f c h e m ic a l w e a t h e r in g and f o r m a t io n o f i r o n o x id e s o r c l a y , Ar^m e le m e n ts M ic ro s tru e tu re i (s a nd and c o a r s e s i l t The arrangem ent o f th e s k e l e t a l g ra in s ) zon i s much th e same as i n th e A2m* and the p o r o s i t y o f t h i s h o r i ­ Tbe m a t r i x o f the i n t e r g r a n u l a r spaces and th e f i l m s o f o r i e n t e d c l a y , however, ences i n c e r t a i n p a r t s o f the w h i le i n o t h e r s im ila r to th e ones i n Most o f o f w e ll o rie n te d they a re v e ry th e A2m. the po re s have on t h e i r p e r ip h e r y f i l m s 2 0 - 4 0 |r t h i c k ( b i r e f r in g e n t ) c la y . w hich a r e e x f o l i a t e d w e ll o rie n te d c la y w hich a r e s e c tio n , show d i s t i n c t d i f f e r ­ in to two o r t h r e e p a r a l l e l s h e e ts . are a ls o lo c a te d in A few p ores have t h i c k e r film s C o a tin g s o f tound arounu th e ed^es o f sand g r a i n s , th e v i c i n i t y o f tn e p o re s . Some o f th e s e c o a t in g s 62 fo rm b r i d g e s between t h e g r a i n s . d e p o s its o f f i n e s ilt Most o f th e l a r g e r p o re s have thick: m ixed w i t h u n - o r i e n t e d c l a y . Most o f th e sand g r a i n s h a v e c o a t i n g s o f w eakly o r i e n t e d c l a y . The m a t r i x i n c e r t a i n a reas i s forms more s o l i d b r id g e s than i n denser and r i c h e r i n c l a y and th e A2m. The m enisci o f w e ll o r i e n ­ t e d c l a y and o t h e r a g g r e g a te s o f o r i e n t e d c l a y in t h i s h o riz o n . Some o f th e m enisci have p a r a l l e l T h e re a r e a ls o i n o rie n te d c la y . lin e d by t h i n are a ls o r o r e abundant e x fo lia te d t h i s h o r i z o n some l a r g e a g g re g a te s v e ry r i c h i n un­ W i t h i n th e s e a g g re g a te s a re found t i n y r o o t h o le s o u t ­ film s o f w e ll o r ie n te d c la y . The p a c k in g o f th e sand g r a i n s , th e dense s i l t - c l a y m a t r i x and t h e l a r g e number o f b r id g e s which b in d the sand p a r t i c l e s w ith s h e e ts . c o rre la te th e h i g h i n d u r a t i o n o f t h i s h o r i z o n . O rg a n ic M a t t e r : M in e ra lo g y ? Not v i s i b l e . Same as i n ASm w ith few er d i s i n t e g r a t e d h o rn b le n d e s and more i r o n o x id e a s s o c i a t e d w ith c l a y . A & B M ic ro s tru c tu re : T h is h o r i z o n i s d is tin c tly les s compacted than th e i s l a n d th e ASn h o r i z o n s . There a re numerous p o r e s , c r a c k s and c h a n n e ls o f a l l k in d s r a n g in g i n w id th o r d i a ­ and shapes, m e te r from 50 m icro n s up to 1 o r 2 mm. c r a c k s ha ve c o m p a r a t i v e l y c la y a ll the po re s and t h i c k c o a t in g s o f w e l l o r i e n t e d c l a y . c o a t in g s a r e p a r t i c u l a r l y g e n e ra lly P ra c tic a lly The t h i c k i n th e c o r n e r s o f t h e p o re s o r i n p l a c e s where th e p e r i p h e r y o f the p o re s shows s tr o n g c u rv a tu re . 150 m ic ro n s . The t h i c k n e s s o f th e s e c o a t in g s ranges from 30 m icrons to A g r e a t number o f sand and c o a rs e s i l t w i t h th e same ty p e o f o r i e n t e d c l a y . g reg ates w ith in th e i n t e r g r a n u la r g r a in s a r e c o a te d The number o f o r i e n t e d c l a y ag- spaces i s c o n s i d e r a b ly h i g h e r than 83 in t h e p r e v i o u s l y d e s c r ib e d h o r i z o n s . Most o f th e o r i e n t e d c l a y c o a t ­ in g s o r a g g re g a te s a r e e x f o l i a t e d i n t o 2 - 5 p a r a l l e l in to s m a lle r p ie c e s . and have a v e r y t h i n sand g r a i n s . s h e e ts o r c r a c k e d Many o f the c o a t in g s o f th e g r a i n s a re d e ta c h e d empty c r a c k between them and th e s u r f a c e o f th e The most common d i s t a n c e between the n e ig h b o r in g sand g r a i n s ra n g es r o u g h ly between 0 . 1 5 - 0 . 2 5 mm. In the i n t e r g r a n u l a r spaces a r e numerous ro u n d p ores 3 0 - 5 0 m icrons i n d ia m e t e r . A ll o f th e s e t i n y p o re s a r e c o a te d w i t h o r i e n t e d c l a y and presum ably have been form ed by r o o t h a i r s . c o n s is ts o f c la y s titu e n t. ted c la y and s i l t The m a t r i x o f th e i n t e r g r a n u l a r but th e c l a y fra c tio n is spaces th e dominant con­ T h is c l a y i s more o r l e s s a m i x t u r e o f a g g re g a te s o f o r i e n ­ and u n - o r i e n t e d c l a y , ance as i n t h e A3m h o r i z o n . o f v a rio u s s iz e s th ro u g h o u t th e m a t r i x . which has more o r l e s s th e same appear­ The a g g reg a te s o f the o r i - n t e d c l a y are (fro m 5 to 100 m ic ro n s ) and a r e w e l l d i s t r i b u t e d Some o f them a re fragm ents o f d i f f e r e n t c l a y c o a t in g s and some have t h e i r c l a y o r i e n t e d around a p o i n t . g ra in s , which a r e n o t c o a te d w it h w e l l o r i e n t e d c l a y , w e a k ly o r i e n t e d c l a y d e s c r ib e d by K ubiena (3 ? ) th e v e r t i c a l s e c tio n s . i n g c h a n n e ls form ed b e s id e decayed r o o t s . an i n i t i a l l a y e r o f mixed f i n e s i l t la y e r o f w e ll o r ie n te d c la y * found by H a e s id e In (5 2 ) have around them f i l m s as d e s c r ib e d p r e v i o u s l y . Flow s t r u c t u r e s h o riz o n e s p e c ia lly i n Sand a re p r e s e n t i n th is They a re m o s tly c o n d u c t­ T n e i r d e p o s it s c o n s i s t o f and c l a y on top o f which i s a These f e a t u r e s a re s i m i l a r to th e ones in A u s tra lia n s o ils . s p ite o f th e f a c t th a t th e m a t r i x i s cruite r i c h in c la y , t h e r e a r e n o t many s o l i d b r id g e s c o n n e c tin g th e sand g r a i n s , because o f t h e g r e a t number o f m ic ro p o re s and m i c r o f i s s u r e s which b re ak th e s e 84 b rid g e s . The d e s c r i b e d m icro s t r u c t u r e i s h o riz o n ; some s i t e s , however, the pre d o m in an t one f o r t h i s have m i c r o s t r u c t u r e s i m i l a r to th e one o f Agjn ©n d 0 r g a m p Mat t e r ; Not v i s i b l e except i n a few r o o t c h a n n e ls which ha ve d a rk brown c o a t in g s which are re g a r d e d to be H g n i n s and o t h e r p r o d u c ts o f d e com po sition o f the r o o t b a rk . M in e ra lo g y ; Same as i n A3m w ith s t i l l few er d i s i n ­ t e g r a t e d h o rn b le n d e s and more i r o n o x id e a s s o c i a t e d w i t h c l a y . Bt ag g reg ates, M ic ro s t r u e t u r e ; N u c ifo rm w ith c l a y c r u s t s on th e as d e s c r i b e d by F r e i and C l i n e s o i l s o f New Y o rk . p o re s o f v a r i o u s The a g g reg a te s have a spongy f a b r i c s iz e s , e tc ., w it h many and th e y a r e s e p a r a te d by l a r g e c r a c k s . g e r p o r e s and c o n d u c tin g c h an n els a r e a lso cracks, ( 2 0 ) i n g ra y-b ro w n p o d z o l i c ha ve e x f o l i a t e d abundant. A ll L a r­ th ese p o re s , film s o f w e ll o r ie n te d c la y . The con­ d u c t i n g c h a n n e ls have la m in a t e d flo w s t r u c t u r e s o f w e l l o r i e n t e d c l a y bu t s i l t d e p o s it s a re m is s in g . t h i s h o riz o n is The amount o f w e l l o r i e n t e d c l a y i n th e h i g h e s t i n th e p r o f i l e , ©nh the t h ic k n e s s o f i t s f i l m s r a n g e s between 30 and 150 m icrons . The d i s t a n c e between th e sand g r a i n s i s u s u a l l y 0 . 2 The m a t r i x c o n s i s t s a g a in o f a c l a y - s i i t a l s r g e number o f w e l l q •p ry ^g d ia m e te r. th a t i t m ix t u r e and c o n t a i n s d e f i n e d and c l a y c o a te d f i n e po re s o f 3 0 —100 Its s t r u c t u r e i s more u n ifo r m and i t c o n t a i n as many m i c r o f i s s u r e s te d c la y to 0 . 5 mm. a re n o t common. as th e A The g e n e r a l & B h o riz o n . appearance Oi does n ot M e n is c i o f o r i e n ­ th e m a t r i x suggests has n o t s u f f e r e d s e r io u s movement and re a rra n g e m e n ts o f th e o r ig in a l c la y s . The o r i e n t e d c l a y o f th e p o r e s , e tc ., o rig in a te s , 85 th e re fo re , from o u t s i d e th e Bt h o r i z o n o r i g i n . O r g a n ic _ M a tte r : M in e ra lo g y : Same as i n A & B h o riz o n . Same as i n A & B but no d i s i n t e g r a t e d g r a i n s o f h o r n b le n d e ha ve been observed. Mi 9. 1 c r . o s t r u e t u r e : N u c ifo rm w ith o u t c l a y c r u s t s on the s u r f a c e o f th e a g g r e g a te s . th e s k e l e t a l e le m e n ts , c la y in th e m a trix , T h is h o r i z o n shows the same arrangem ent o f po re s and c r a c k s and o f the s i l t as th e Bt h o r i z o n . and o r i g i n a l A s tr ik in g d iffe re n c e is th e absence o f th e o r i e n t e d c l a y fro m the m a j o r i t y o f th e p o re s and c r a c k s . A few p o r e s i n t h e up p e r p a r t o f t h i s h o r i z o n have t h i n c o a t in g s o f o r i e n t e d c l a y s i m i l a r to those d e s c r ib e d i n th e Am and ABm h o r i z o n . A th in s e c t i o n ta k e n a few in c h e s deeper was f r e e from o r i e n t e d c l a y c o a tin g s . The m a t r i x c l a y c o n s i s t s a g a in o f o r i g i n a l e n te d v e r y c le s . It f i n e a g g r e g a te s o f o r i g i n a l c la y seems t h a t i n th is h o rizo n , fin e c la y , o f o ri­ and o f c o a rs e c l a y p a r t i ­ t h e o r i g i n a l c l a y shows more a re a s o f weak o r i e n t a t i o n which produce under c r o s s e d n i c o l s a c lo u d y p ic t u r e o f th e m a trix . P r o b a b ly th ese w eakly o r i e n t e d r e s u l t o f a g g r e g a tio n o f c l a y s . a n i s o t r o p is m o f th e m a t r i x . T in y c a l c i t e c r y s t a l s areas a re a a lso add to the Sand g r a i n s u s u a l l y have c o a t in g s o f o r i ­ e n te d c l a y . O rg a n ic M atter? M in e ra lo g y : th at lim e s to n e g ra in s fin e The d i f f e r e n c e between t h e C and Bt i s t h e amount o f i r o n o x id e i s fo rm o f i s o l a t e d c o n c r e t i o n s . Not v i s i b l e . s m a lle r i n th e C and i t The C i s r i c h i n Ca c a r b o n a te s . aT-e p r e s e n t but most o f th e c a l c i t e s i l t - s i zed c r y s t a l s , oc cu rs i n is in Pew form o f which a r e spread through th e m a t r i x . th e 86 (b ) N e s te r AL M ic ro s tru e tu re : o f I s a b e l l a ’ s A l, m a trix o f s i l t , c la y , M a tte r; It It here, to the m i c r o s t r u c t u r e a re embedded i n a denser i s more decomposed and d is p e r s e d c o n s i s t s o f w i d e l y spread d ro p p in g s o f a r t h r o p o d s and d i s p e r s e d f i n e l i g n i n fra g m e n ts o f p l a n t r e s i d u e s . few p l a n t r e s i d u e s r e v e a l th e s t r u c t u r e o f t h e i r p a r t l y composed t i s s u e s . Is a b e lla . M u ll, s im ila r o r g a n i c m a t t e r and i r o n o x id e s . t h e Al o f I s a b e l l a . O n ly v e r y is b u t t h e sand g r a i n s , O r g a n ic than i n It de­ The fu n g i hyphae a r e more common th a n i n th e Al o f The humus o f t h i s h o r i z o n can be c l a s s i f i e d a c c o r d in g to Hartmann* s (2 5 ) as © rth ro p o d s - scheme, o r as M o d e r - M u ll , a c c o r d in g to K u b ie n a ( 3 8 ) . M in e ra lo g y ; Q u a r t z and K, Na f e l d s p a r s dominant m i n e r a l s o f t h e sand f r a c t i o n . are d is in t e g r a te d in to a re the p r e ­ Some o f th e h o rn b le n d e g r a i n s s i l t - s i z e d p ris m s . I r o n o x id e i s a s s o c ia te d w ith c o l l o i d a l o rg a n ic m a tte r . A 2 /B h ir cracks. M ic ro s tru e tu re : Massive but w i t h many p o re s and A verage d i s t a n c e between th e sand g r a in s about 0 . 1 mm. The p o r e s and c r a c k s have d ia m e te r s o r w id th s r a n g in g from 50 m icrons to 0 .6 mm,; most o f them, how ever, a re about 0 . 2 0 - 0 . ^ 5 mm. i n s iz e . Some o f t h e sand g r a i n s have c o a t i n g s o f w eakly o r i e n t e d c l a v , w h i le a v e r y few s m a ll p o r e s and sand g r a i n s have around them d is c o n t in u o u s film s o f w e ll o r ie n te d c la y . The m a t r i x i s C oarse c l a y p a r t i c l e s w ith s ilt. o rie n ta tio n ra th e r dense and s i l t is its and m i c r o - a g g r e g a t e s o f c la y main c o n s t i t u e n t . a r e a ls o i n t e r m i x e d Some o f th e s e c l a y a g g r e g a te s show un d e r c ro s s e d N i c o l s a lo n g t h e i r lo n g axes, as d e s c r ib e d i n the A2 h o r iz o n o f 87 Is a b e lla . O r g a n ic th e A l , and i t c o llo id a l sep tated is M a tte r: found i n Its amount i s much s m a l l e r th e m a t r i x as i s o l a t e d substan c e which i s o n l y l o c a l l y than i n spots o f r e d brown in te rm ix e d w ith c la y . A few f u n g i hyphae a r e p r e s e n t . M in e ra lo g y : b le n d e s a r e Some as i n A i- O nly v e r y few h o rn ­ d i s i n t e g r a t e d but t h e r e i s an abundance o f s i l t - s i zed p r i s m a t i c h o r n b le n d e s i n t h e m a t r i x . A3m M ic ro s tru e tu re ; u n i f o r m m icro s t r u c t u r e . T h is h o r i z o n does n o t e x h i b i t a C e rta in p a rts o f i t and o t h e r s th e B t o f I s a b e l l a . The d is t a n c e between th e sand g r a i n s ra n g e s from about 30 to 400 m ic ro n s . cracks, 0 .2 s tru c tu re . m ic r o n s to of s ilt - 0 . 6 mm. w id e, which o u t l i n e th e p l a t y u n i t s o f m ic ro ­ and u n - o r i e n t e d c o a r s e c l a y . c l a y 1 0 - 1 0 0 m ic ro n s t h i c k . a re a ls o p r e s e n t i n The s i l t - c l a y dense and i n o t h e r s w hich a r e soaces a r e fille d d ia m e te r s ra n g e from 50 Most o f t h e l a r g e c r a c k s and p o r e s have d e p o s it s t h e p o re s and sand g r a i n s a re c la y Th e re a r e numerous h o r i z o n t a l P o r e s a r e a ls o abundant and t h e i r 1 . 5 mm. resem ble th e A2m o r A3m I n c e r t a in p a r ts o f the s e c tio n surrounded by f i l m s o f w e l l o r i e n t e d Plow s t r u c t u r e s o f s i l t and w e l l o r i e n t e d some c r a c k s and c o n d u c tin g c h a n n e ls . m a t r i x i s n o t u n i f o r m but i n c e r t a i n fis s u re d . There a r e spaces, 2 - 4 mm. w i t h u n - o r i e n t e d c l a y and f i n e s i l t . found n o re s 2 0 - 1 0 0 m ic ro n s i n d ia m e t e r , o f w e ll o r ie n t e d c la y a re a s i s i n d ia m e te r, W i t h i n th e s e which have f i l m s 1 0 -2 0 m icro n s t h i c k . Some sand g r a i n s have c o a t in g s o f w eakly o r i e n t e d c l a y . O r g a n ic M a t t e r : its amount i s c o n s i d e r a b l y s m a l l e r . Same as i n th e o v e r y i n g h o r i z o n but 88 M in e ra lo g y : a re a s s o c ia te d w ith Same as i n th e A 2 / B h i r . th e w e ll o r ie n te d c la y f ilm s , shows a l t e r a t i o n o f h o r n b le n d e on i t s o x id e and some c l a y A & B Iro n a r e th e p r o d u c ts o f t h i s a l t e r a t i o n . M ic ro s tru c tu re : s i m i l a r to A r o c k fragm ent edge and c le a v a g e l i n e s . N u c ifo rm w ith and w ith o u t c l a y c r u s t s on t h e s u r f a c e o f t h e a g g r e g a te s . tu re I r o n o x id e s Few spots h a v e m i c r o s t r u c - th e one o f I s a b e l l a * s A3m h o r i z o n . Sand g r a i n s a re a t d i s t a n c e s r a n g i n g from 5 0 - 4 0 0 m icrons w i t h a rough a verage o f 200= 250 m ic r o n s . There a r e a g r e a t number o f p o re s which have d ia m e te rs r a n g i n g fro m 50 m icro n s to 2 . 0 ram. Cracks and c o n d u c tin g c h a n n e ls 2 0 0 - 5 0 0 m ic ro n s wide a r e a ls o a bundant. h o riz o n g e n e r a lly the A & is v e r y porous, and resem bles th e m icro s t r u c t u r e o f B h o riz o n o f I s a b e l l a but i t has h ig h e r c l a y c o n t e n t . Most o f t h e p o r e s have e x f o l i a t e d o rie n te d c la y . The m i c r o s t r u c t u r e o f t h i s and f r a c t u r e d film s o f w e ll Many sand g r a in s a r e c o a t e d by w e l l o r i e n t e d c l a y , to o . C o n d u c tin g c h a n n e ls have f l o w s t r u c t u r e s o f la m i n a t e d and i r r e g u l a r l y fra c tu re d , w e ll o r ie n te d c la y and o f s i l t s c i a r e a ls o p r e s e n t e s p e c i a l l y The t h i c k n e s s o f th e d i f f e r e n t in d e p o s it s . E x f o l i a t e d m eni­ the n a rro w i n t e r g r a n u l a r spaces. f i l m s o f w e l l o r i e n t e d c l a y ranges be­ tween 20 and 200 m ic r o n s . The m a t r i x o f film s s ilt and o r i g i n a l c l a y c o n t a i n s many d i f f e r e n t and a g g r e g a te s o f w e l l o r i e n t e d c l a y . O r g a n ic M a t t e r : brown c o l l o i d a l zon, Mor e i r o n ox r d e i s th a n i n spots o f re d s u b stance a s s o c ia t e d w i t h i r o n o x id e s and c l a y . M in e ra lo g y ; zons . Very few i s o l a t e d t h e A2rn. C om p o s itio n same as i n o v e r l y i n g h o r i ­ as so c i at ed w i t h o r l e n t e d c l a y on t h i s ho r i — Th e re a r e a ls o some a g g re g a te s o f p r e c i p i t a t e d 89 i r o n o x id e s * th e ir Some m a g n e t it e g r a i n s s u rfa c e . M iC -ro s tru e tu re : s u r f a c e o f tn e a g g r e g a te s . a b o u t 0 . 3 mm. vary There a r e numerous p o re s and c rac k s o f which th e s iz e s th e d i f f e r e n t i s u n iq u e i n ITuciform w i t h c l a y c r u s t on th e Average d is ta n c e "between sand g r a i n s from 20 m ic ro n s to 1 . 5 mm. The abundance and t h e th ic k n e s s o f film s o f w e ll o r ie n te d c la y t h is h o riz o n . o f t h e sand and c o a r s e s i l t c la y . seem to d i f f u s e i r o n o x id e s from and o f th e f l o w s t r u c t u r e s .All th e p o r e s , c h a n n e ls , c r a c k s and most g r a i n s have c o a t in g s o f w e l l o r i e n t e d The th i c k n e s s o f these c o a t in g s ra n g es between 2 0 - 3 0 0 m ic ro n s . T here a r e a ls o q u i t e a few pores f i l l e d c o m p le te ly w i t h w e ll o r i e n t e d c la y . The i n t e r g r a n u l a r m a t r i x c o n s i s t s o f s i l t , o r i g i n a l c la y and o f w e l l o r i e n t e d c l a y which forms c o a t in g s o r d e p o s its around th e m ic r o p o r e s and sand g r a i n s , and i n th e m i c r o f i s s u r e s . It seems t h a t t h e o r i g i n a l c l a y i s more mixed w ith w e l l o r i e n t e d c l a y i n zon than i n th is h o r i­ th e Bt o f I s a b e l l a . The m a t r i x i s h i g h l y porous and o c c u p ie s a much l a r g e r a r e a th a n th e sand g r a i n s . O rg a n ic M a t t e r : M in e ra lo g y : Q Not v i s i b l e . Same as i n M icro s t r u c t u r e : th e o v e r l y i n g h o r i z o n . N u c ifo r m w it h o n ly few and d i s ­ c o n tin u o u s c l a y c r u s t s on th e s u r f a c e o f some a g g r e g a te s , s e l v e s ha ve a spongy i n t e r i o r th e fa b ric . sand g r a i n s i s about 300 m ic ro n s . po res, The average d i s t a n c e between T h e re th e d ia m e te r s o f which r a n g e from 0 . 1 few c ores which them­ a re a g r e a t number o f mm.to 1 .5 and c r a c k s have f i l m s o f w e l l o r i e n t e d c l a y mm. Only a and flo w s tru c tu re s . c o n s is t o f to about Around c e r t a i n p o r e s a re found c a r b o n a te d e p o s it s which irre g u la rly -s h a p e d c a l c i t e 5 m icro n s i n s iz e , and which c r y s t a l s o f l e s s th a n i m icron show h ig h b i r e f r e n g e n c e . The m a t r i x i s h i g h l y porous and f i s s u r e d and c o n s is t s o f s i l t and c l a y w h ich i s s im ila r to t h a t d e s c r ib e d i n the C h o r i z o n o f I s a - b e l l aSome sand g r a i n s a re c o a te d w ith w eakly o r i e n t e d c l a y . O rg a n ic M a t t e r ; M in e ra lo g y : and w i t h Not v i s i b l e . Same as i n Bt but w i t h l e s s i r o n o x id e a number o f l i m e s t o n e g r a i n s o f v a rio u s s iz e s . ( c ) McBride A1 M icro s t r u c t u r e : t h e Al h o r i z o n s o f I s a b e l l a fro m each o t h e r by 0 . 5 mm. i n th e ir a b le to and N e s t e r . to th e m i c r o s t r u c t u r e s o f The a g g re g a te s a r e s e p a r a te d 1 . 0 mm. wide c r a c k s . d i a m e t e r a r e a bundant. d ia m e te r. S im ila r 200 m icro n s i s Large p o re s 0 . 5 an ave ra g e e s t im a t e o f The d i s t a n c e between th e sanu g r a i n s i s (5 0 -4 0 0 m ic ro n s ). P ores and sand g r a in s to 1 .5 q u ite v a r i ­ do not have c o a t in g s o f o rie n te d c la y . The m a t r i x c o n s i s t s o f a m i x t u r e o f s i l t , t e r and i r o n o x i d e s . c la y , o r g a n i c mat­ The c l a y and o x id e s a r e w e l l m ixed w i t h o r g a n ic m a t t e r and c an n o t be d i s t i n g u i s h e d . O niy p a r t i c l e s o f c o a is e c l o y c an be seen u n d e r c r o s s e d n i c o l s . O rgani c M a t t e r : a rth ro p o d s -M u ll s m a lle r h ere (2 5 ), than i n The humus can be c l a s s i f i e d as b ut the number o f the d roppings i s c o n s i d e r a b l y th e Aj_ o f I s a b e l l a and N e s t e r , g a n ic m a tte r c o n s is ts o f f i n e l y d iv id e d l i g n i n - l i k e Most o f th e o r ­ amorphous a ggre­ g a t e s which a r e a s s o c i a t e d w ith c l a y and some i r o n o x i d e s . It seems 91 th a t th e d e c o m p o s itio n o f th e o r g a n i c m a t t e r i s i n more advanced s ta g e here tn a n i n th e o t h e r two p r o f i l e s . A few fu n g i, w it h s e p t a , and eggs o f nematodes a r e p r e s e n t . M in e ra lo g y : mary m i n e r a l s . Some o f th e h o rn b le n d e g r a in s a r e d i s i n t e g r a t e d . A2 h 'ic ro s tru e tu re ; 0 .5 - 2 mm. i n d ia m e t e r and 0 . 5 a d d itio n to l a r g e p o r e s , th e re i s which t h e a v e ra g e d i a m e t e r i s tw e en t h e a r e t h e main p r i ­ f e l d s p a r s a r e m a in ly m i c r o c i i n e s and a l b i t e s w ith some o r t h o c f a s e pores, Q u a rtz and f e l d s p a r s sand g r a i n s i s R a th e r m assive w i t h numerous l a r g e to 1 . 0 mm. w ide c r a c k s . In a g r e a t number o f s m a lle r po re s o f about 0 . 2 mm. about 0 .1 The a ve ra g e d i s t a n c e be­ mrn. T o re s and sand g r a i n s a r e f r e e o f w e l l o r i e n t e d c l a y c o a t i n g s . Some sand g r a i n s have c o a t in g s o f w eakly o r i e n t e d clay. The m a t r i x o f th e i n t e r g r a n u l a r spaces i s trix o f Is a b e lla 's A2 h o r i z o n but i t O rg a n ic M a t t e r : and d is p e r s e d re d brown l i g n i n o u s a r th r o p o d s r i c h e r i n o rg a n ic m a t t e r . c o n s i s t s o f h i g h l y decomposed s u b stan c e , mixed w i t h c l a y . w i t h s e p ta , m a t t e r i s c o n s i d e r a b l y h ig h e r p h ir a r e a ls o p r e s e n t . in th is h o riz o n Same as i n Al w it h l e s s V ic ro s t rue t u r e : and more empty spaces i n i t s sand g r a i n s is iro n o x id e . Loose and spongy f a b r i c . from the B h i r o f I s a b e L i a i n h a v in g l e s s c l o y m a trix . It d if­ and o r g a n ic m a t t e r Thr average d i s t a n c e between th e about 0 . <• mm. The m a t r i x c o n s i s t s o f s i l t are w e ll A few th e c o r r e s p o n d in g A2 o f I s a b e l l a . M in e ra lo g y i fe rs It d ro p p in g s and fungus hyphae, The amount o f o r g a n ic than i n is s i m a la r to th e ma­ and c l a y . The c l a y and f i n e m ixed w it h r e d brown amorphous o r g a n ic m a t t e r , s ilt and p r e c i p i t a t e d 92 ir o n o x id e . Most o f th e m a t r i x substance surrounds th e sand and coarse s i l t g ra in s , and forms <^0-00 m icrons t h i c k c o a t in g s l e a v i n g empty spaces o f d i f f e r e n t shapes and s i z e s . th e s e spaces i s about 0 , 5 mm. The a ve ra g e s i z e o f The c o a t in g s show a weak o r i e n t a t i o n o f t h e i r c l a y on th e s u n ace o f the g r a in s and th e y do no t a c t as c e m e n tin g a g e n ts . O rg a n ic M a t t e r ; d e s c rib e d here. in It It i s o f th e same n a t u r e as t h a t th e E h i r h o r i z o n o f I s a b e l l a , i s a ls o but i t s amount i s s m a l l e r th a n i n th e o v e r l y i n g A2 h o r i z o n , s m a lle r ko fu n g i are p re s e n t. M in e ra lo g y : Same as i n few h o r n b le n d e g r a i n s a r e d i s i n t e g r a t e d . th e p r e v io u s h o r i z o n s . Only- Some i r o n o x id e s form s i l t ­ s i z e d a g g r e g a te s which a r e not mixed w i t h c l a y and o r g a n ic m a t t e r . 3m M ic ro s tru c t u r e : th a n t h e B h i r but i t s till spaces o f 0 . 1 nrr.. i n to 0 . 3 It i s c o n s p ic u o u s ly more packed has a g r e a t number o f p o re s and empty d ia m e te r . d i s t a n c e between t h e sand g r a in s i s An a p p ro xim a te e s t im a t e o f th e about 50 m ic ro n s . h a ve t h i n c o a t in g s o f weakly o r i e n t e d c l a y . The sand g r a in s The p o re s do n o t have film s o f w e ll o rie n te d c la y . The m a t r i x c o n s i s t s o f a m i x t u r e o f s i l t o f o r i e n t e d c l a y 1 0 - 5 0 m icrons i n t h e send g r a i n s c la y p a rtic 3 .e s do n o t I n n a rro w spaces between a r e found m e n is c i—shaped c l a y a g g re g a te s i n which the are o r ie n te d p a r a l l e l Ir o n o x id e s a re a s s o c ia te d ci d ia m e te r . and b i g a g g r e g a te s w ith t h i s to th e s u r f a c e o f th e m e n is c i. type o f c l a y . Most o f th e m enis­ form b r i d g e s between t n e sand g r a i n s . O r g a n ic M a tte r: r e d brown s ubstanc e m ixed with c l a y Few a g g re g a te s o f h i g h l y and i r o n o x i d e . Its decomposed amount i s S3 c o n s i d e r a b l j ' s m a l l e r h e r e than i n th e o v e r l y i n g h o r i z o n s o f the p r o ­ file . M in e ra lo g y : in th e B h i r . th e m a t r i x , Same as above but l e s s i r o n o x id e s than Ho d i s i n t e g r a t e d h o rn b le n d e s were o b s e rv e d . how ever, is ric h in p ris m a tic The s i l t o f t i n y h o rn b le n d e which u nder c ro s s e d n i c o l s Can be c o n fu s e d w ith a g g re g a te s o f o r i e n t e d c l a y . Some m a g n e t it e s h a ve d i f f u s e d i r o n o x id e around them. A2m M icro s t r u c t u r e : It is as packed as th e Bm above and t h e A2m o f I s a b e l l a . The number o f th e po re s i s in T h e i r d ia m e te r s r a n g e from 0 . 1 th e o v e r l y i n g Bm. b u t t h e m a j o r i t y o f th^m have d ia m e te r s o f 0 . 1 d i s t a n c e between t h e sand g r a in s i s a little about 10 m ic ro n s . about 50 m ic ro n s . Some o f th e p o re s are f i l l e d o f them h a v e d e p o s it s o f f i n e s ilt to 1 . 5 mm. to 0 . 3 mm. pores have d i s c o n t in u o u s f i l m s o f w e l l o r i e n t e d c l a y . is mm. s m a lle r th a n The a verage A few o f the T h e i r t h ic k n e s s w ith s i l t mixed w ith c l a y . and most On th e v e r t i c a l s e c t i o n a r e seen h o r i z o n t a l p la n e s o f weakness in which th e d i s t a n c e betw een t h e sand g r a i n s i s about 0 . 3 mm. Many sand g r a i n s have c o a t ­ in g s o f w ea k ly o r i e n t e d c l a y . The m a t r i x i s r a t h e r lo o s e and forms o n ly a few s o l i d b r id g e s betw een the sand g r a i n s . e i t h e r m ixed w ith th e I t c o n s is ts o f s i l t s ilt w ith o u t a g g r e g a te s which show o p t i c a l m e n is c i o f o r i e n t e d l y i n g one b u t v e r y c la y m a in ly . The c l a y i s any o r i e n t a t i o n o r i n form o f s m all a n is o t r o p is m ( o r i e n t e d c l a y s ) . a re p r e s - n t i n t h i s h o r i z o n than i n More th e o v e r - few o f them form o rid g e s between p l a i n s . O rg a n ic M a tte r; Very few i s o l a t e d r e d brown f i n e a g g re g a te s . M in e ra lo g y « Same as i n Bm but th e amount o f i r o n 94 0 x i u e a s s o c i a t e d w i t h c l a y i s c onsi d e ra b ly s m a l l e r h e r e . h o r n b le n d e g r a i n s ^5™ la r are d is in te g r a te d . M ic ro s tru e tu re : and c o a r s e s i l t Very few g ra in s The degree o f p a c k in g o f th e sand and th e p o r o s i t y o f t h i s h o r i z o n a r e v e ry s i m i ­ to t h e o v e r l y i n g A2m and th e c o r r e s p o n d in g h o r iz o n s o f I s a b e l l a . The number o f th e p o r e s which have f i l m s o f w e l l o r i e n t e d c l a y , ever, to is g re a te r in t h i s h o r i z o n th a n i n be more c o n tin u o u s h e r e . tw een 5 and 20 tn ic r o n s . The d i s t a n c e between the sand g r a i n s ranges In h o r i z o n t a l c ra c k s 0 . 1 - 0 . ? mm. w id e, clay. and th e f i l m s te n d The th ic k n e s s o f th e s e f i l m s ranges be­ m a in l y between 20 and 100 m icro n s . o f u n -o rie n te d th e A2m, how­ th e v e r t i c a l s e c t i o n a re seen h a v in g d e p o s it s o f f i n e s ilt and These c rac k s c o n t r i b u t e to the p l a t y macro s t r u c ­ t u r e o f th e h o riz o n . The m e n is c i o f w e l l o r i e n t e d c l a y in A2m and form s e v e r a l The m a t r i x i s s o l i d b r id g e s between th e sand g r a i n s . dense and forms s o l i d b r id g e s n e i g h b o r i n g sand g r a i n s . c la y tends to a re more abundant h e r e th a n f i r m l y c o n n e c tin g I n n a rro w i n t e r g r a n u l a r spaces the o r i g i n a l form m e n is c i which show a weak a n is o t r o p is m ( o r i e n t a ­ tio n o f th e ir c la y ), These m e n is c i a ls o p r o d u c in g c lo u d y i l l u m i n a t i o n u n d e r c ro s s e d n i c o l s . form s o l i d b r i d g e s between th e sand g r a i n s . Sand g r a i n s have c o a t i n g s o f w eakly o r i e n t e d c l a y . The m i c r o s t r u c t u r e o f t h i s h o r i z o n suggests t h a t i t s h a rd n e s s i s m a in ly due to th e c lo s e p a c k in g o f tn e sand g r a i n s , rfte r r a n g e m e n t o f th e m a t r i x and tn e b rid g e s c o n n e c tin g f i r m l y extrem e th e fo r m a t io n o f numerous s o l i d the sand and c o a rs e s i l t g r a i n s . O r g a n ic M a t t e r : M in e ra lo g y : Not v i s i b l e . Sane as i n o v e r l y i n g h o r i z o n s , b u t no 95 d i s i n t e g r a t e d h o r n b le n d e g r a i n s have been n o t i c e d i n t h i s h o r i z o n . Ir o n o x id e i s film s m a in ly a s s o c i a t e d w ith and m enisci.. A few i s o l a t e d i r o n o x id e a g g r e g a te s a r e random ly s c a t t e r e d th r o u g h o u t th e g a te s a r e n o t as w e l l s e c tio n . Somewhat n u c ifo r m , d e f i n e d as i n th e y a r e o n l y p a r t i a l l y tin c tly th in M icro s t r u c t u r e ; I& th e w e l l o r i e n t e d c l a y o f the but th e aggre­ th e Bt o f I s a b e l l a c o ated w i t h c l a y c r u s t s . and N e s t e r , T h is h o r i z o n i s d is ­ l e s s packed th a n th e o v e r l y i n g f r a g i p a n h o r i z o n s . The a v e ra g e d i s t a n c e between th e sand g r a i n s i s In and some s i t e s , h ow ever, th e s e d is ta n c e s a r e as sm all The p o re s a r e more abundant h e r e than i n zon and t h e i r irre g u la r about 0 . 1 5 mm. as 3 0 - 5 0 m ic ro n s . th e o v e r l y i n g h o r i ­ s iz e s ra n g e from 00 m icrons to 1 . 0 mm. The c ra c h s a r e ana ha ve random o r i e n t a t i o n . P ra c tic a lly a ll ( 2 0 - 1 0 0 m icro n s t h i c k ) th e p ores and most o f th e c r a c k s have f i l m s o f w e ll o r i e n t e d c l a y - have la m in a te ;! f l o w s t r u c t u r e s , sand and c o a r s e s i l t o f w e ll o r i e n t e d c l a y g r a in s but s i l t Conducting c hann els d e p o s its a r e m is s in g . a r e c o a t e d by w e l l o r i e n t e d c la y . a r e more abundant and b ig g e r th a n i n h o r i z o n o f th e p r o f i l e . Most o f th e above f i l m s , c o a tin g s , Many M e n is c i any o t h e r e tc ., a re e x fo lia te d or fra c tu re d . The m a t r i x i s h i g h l y porous and f i s s u r e d , n a t e d by a n e tw o rk o f f i s s u r e d f i l m s c la v . I n o n l y a few s i t e s o f its c o n s titu e n ts . v g ry egw s o l i d and i t i s im p reg ­ and la m in a e o f w e l l o r i e n t e d the m a t r i x has not s u f f e r e d re a rra n g e m e n t Because o f th e e x f o l i a t i o n s b r id g e s connect sand g r a in s O rgan ic M a t t e r ; M in e r a lo g y - and f i s s u r e s , o n ly in th is h o rizo n . Not v i s i b l e . Same as i n o v e r l y i n g h o r i z o n s . More 96 i r o n o x i des arp assoc i a t no w itc tite g ra in s d iffu s e 2. the wel o rie n te d c la y - i r o n o x id e around them. M ic ro s tru e tu re : s u r f a c e o f t h e a g g r e g a te s . N u c ifo rm - i t h o u t c l a y c r u s t s on the The f a b r i c o f the a g g re g a te s i s The a v e ra g e d i s t a n c e between th e sand g r a i n s i s a r e abundant and t h e i r spongy. about 0.2 mm. Fores d ia m e te rs r a n g e m ostly between 0.1 and 0.6 mm. T h e re a re no c l a y f i l m s , c la y in Some magne- flo w s t r u c t u r e s and c o a t in g s o f w e l l o r i e n t e d t h i s h o r i z o n e x c e p t i n i t s upper p a r t . Sand g r a in s have c o a t ­ in g s o f w ea k ly o r i e n t e d c l a y . The m a t r i x c o n s i s t s o f a m ix t u r e o f s i l t and c l a y and i t is h ig h ly f r a c t u r e d o r f i s s u r e d and forms empty spaces 1 0 - 5 0 microns i n s iz e . The c l a y o f th e m a t r i x shows c lo u d y , n ic o ls as d e s c r ib e d i n p o s itio n s i l l u m i n a t i o n under c ro ss e d th e C h o r i z o n s o f I s a b e l l a o f c a r b o n a te s have been observed i n O rg a n ic M a t t e r : M in e ra lo g y : s to n e and c a l c i t e g ra in s , It and l e s s and N e s t e r . No de­ th is h o riz o n . Not v i s i b l e . d iffe rs from the Bt i n h a v in g l i m e ­ i r o n oxicie. {j ENERAL discussion and evaluation OF THE RESULTS 1. Changes due to s o i l fo rm a tio n ( &) U n i f o r m i t y o f th e p r o f i l e s . file Changes o c c u r r i n g i n d u r i n g th e developm ent o f a s o i l can "be f u l l y t h e p a r e n t m a t e r i a l i s known. "by t h e C h o r i z o n , we w i l l If the p a r e n t m a t e r i a l i s r e p r e s e n t e d w hich have o c c u r r e d i n th e p a r t i c u l a r h o r i z o n s , t h e whole p r o f i l e had, at ze ro , p r e s e n t c o m p o s itio n o f th e C h o r i z o n . file e v a lu a te d o n ly when he a b le to e v a l u a t e o b j e c t i v e l y time th e p r o ­ o n ly i f th « changes, we p ro v e t h a t c o m p o s itio n i d e n t i c a l Th a t i s to the to show t h a t t h e p r o ­ has been formed i n u n i f o r m p a r e n t m a t e r i a l . Sand s i z e d i s t r i b u t i o n s and th e c r u a r t z / f e l d s p a r r a t i o s r a t h e r u n i f o r m th ro u g h o u t th e t h r e e p r o f i l e s . t o t a l heavy m i n e r a l ever, fra c tio n s are The d i s t r i b u t i o n o f the and t h e m a g n e t i t e / g a r n ^ t r a t i o s , how­ show t h a t o n ly N e s t e r and McBride have been formed from u n i f o r m narent m a te ria ls , w h ile I s a b e l l a c o n s i s t s o f th e f o l l o w i n g t h r e e d i f ­ fe re n t s t r a t a . 8 1s t - The 0 to 21" l a y ^ r , i n c l u d i n g th e Ao, A i , Ag, E h ir, Bm and A2m h o r i z o n s i s c h a r a c t e r i z e d by a r e l a t i v e l y h ig h amount o f heavy m i n e r a l s i n ra tio th e f i n e and a m a g n e t i t e / g a r n e t o f 11 to 9 . 9 . 2nd - is sand f r a c t i o n The 2 i - 3 4 " l a y e r c o n s is t s o f th e A3m h o r i z o n c h a r a c t e r -! zed by a s m all amount o f heavy m in e r a ls tite /g a r n e t ra tio o f about 5 . 3rd - Bt and C h o r i z o n s , and a magne­ is The m a t e r i a l below 34*', in c lu d in g th e A & B, c h a r a c t e r i z e d by a s m all amount o f heavy m i n e r a l and a m a g n e t i t e / g a r n e t r a t i o o f 8 .2 - 9 .5 . The q u a l i t a t i v e m i n e r a l - 98 o g i c s l c o m p o s itio n o f t h i s th e f i r s t s tr a tu m i s s i m i l a r to th e c o m p o s itio n o f s tr a tu m . S o i l g e n e s is , how ever, o f th e p a r e n t m a t e r i a l , proceeds r e g a r d l e s s o f th e u n i f o r m i t y and c o n s e q u e n tly , it w ill be s t u d i e d i n a l l th re e p r o f i l e s . ( b ) Changes i n physi c a l p r o p e r t i e s . fa c to rs as d e s c r ib e d by Jenny ( 3 1 ) c o n t r o l The f i v e s o il fo rm in g th e changes i n p h y s i c a l as w e ll as i n a l l t h e o t h e r p r o p e r t i e s o f th e s o i l . tie s which have undergone s i g n i f i c a n t changes d u r in g th e development b u lk d e n s i t y , The p h y s i c a l p r o p e r ­ o f t h e s t u d ie d p r o f i l e s are: pore s i z e d is trib u tio n , m e c h a n ic a l c o m p o s it io n , and arrangem ent o f the s o i l c o n s t i t u e n t s . The m agn itu d e o f o t h e r p h y s i c a l p r o p e r t i e s such as w a te r p e r m e a b i l i t y and h a r d n e s s depend on t h e m agnitudes o f the above p r o p e r tie s . B u lk d e n s i t y d a ta show a s i g n i f i c a n t in c re a s e in p o d z o l seoua and a de cre a se i n volume i n th e w e l l Agm h o r i z o n s . z o l re g io n , If we can c a l c u l a t e m e n tio n e d changes i n the developed A2m and we r e g a r d q u a r t z as a r e s i s t a n t m in e r a l i n q u a r t z sand i s c o n f i n e d i n T a b le 1 0 . volume i n the pod­ the volume i n which one gram o f f i n e each h o r i z o n . T a b le 10 shows the above volume o f th e McBride p r o f i l e . Volume o c c u p ie d by one gram o f f i n e sand s i z e d q u a r t z MeEri de H o r iz o n B h ir A l-A g Vo lu me c . c . f g r. q u a rtz 2 .4 8 2 .1 1 Bm 1.66 A2m 1 .4 4 A3m 1 .5 4 Bt 1.20 0 1 .7 ? 99 The i n c r e a s e i n crease in th e po d zo l senna i s n o n - c a p i l 1a r y p o r o s i t y and i n o r spongy s t r u c t u r e . lo s s o f c la y , (4 ) volume i n (2 ) a d d i t i o n o f o r g a n ic m a t t e r , (5) rangem ent o f th e s o i l c o n s t i t u e n t s . s tru c tu re fre e z in g (3 ) b io lo g ic a l a c tiv ity , and th a w in g and r e a r ­ How th e s e p ro c e s s e s de ve lop th e i n th e b u lk d e n s i t y o f th e A2m arid A3m h o r i z o n s th e r e s u l t o f th e c lo s e p a c k in g o f th e sand and c o ars e s i l t and s e c o n d a r i l y o f th e d e s c rib e d in fillin g o f th e po re s w i t h s ilt as i t has been th e m i c r o s c o p i c a l s t u d i e s . The p a c k in g o f th e sand g r a i n s has n o t been i n h e r i t e d p a r e n t m a t e r i a l but i t s o il. tio n s , (l) i s w e l l d e s c r ib e d by B&ver ( 4 ) . The i n c r e a s e i s m a in l y th e fo r m a tio n o f lo o s e crum bly P ro c e s s e s which produced th e s e changes a r e : a l t e r n a t e w e t t i n g and d r y in g , s o il due to th e i n ­ from th e has been developed d u r in g th e fo r m a t io n o f The d i s t a n c e s between t h e sand g r a i n s , are c o n s id e ra b ly g r e a t e r i n the as seen i n t h e t h i n sec­ th e C h o r iz o n s th a n i n th e pan ho r i zo n s . W ater p e r m e a b i l i t y depends on the volume o f the n o n - c a p i l l a r y pores, sequa. and t h e r e f o r e , has been greatly in c re a s e d i n I n th e pan h o r i z o n s , th e c r a c k s , th e podzol th e w a t e r p e r m e a b i l i t y i s c o n t r o l l e d by r o o t h o l e s a n d /o r worm h o le s . M e c h a n ic a l a n a ly s e s and t h i n h o r i z o n s w h ic h o v e r l i e clay. it s e c t i o n s t u d i e s show t h a t th e th e Bt h o r i z o n have l o s t v a r i o u s amounts o f I s a b e l l a and McBride show a s m all a d d i t i o n o f c l a y i n t h e i r B h ir h o rizo n s but th e amount o f c lo y added has not compensated th e amount o f c l a y l o s t . The o n ly t r u l y c l a y e n r ic h e d h o r iz o n s a re th e Bt h o r i z o n s . The b is e o u a p r o f i l e s , th e re fo re , have two zones o f i l l u v i a t i o n : 100 th e B h ir h o riz o n how ever, is and th e Bt h o r i z o n . d e p o s it e d i n The b u lk o f th e i l l u v i a l c l a y , th e l a t t e r . The f i l m s o f w e l l o r i e n t e d c l a y , s e c tio n s , F rei have been r e g a r d e d by many a u th o rs as Brewer ( 7 ) , and C l i n e (2 0 ) and H a e s id e ( 5 2 ) , d e p o s it e d by p e r c o l a t i n g w a t e r s . c la y i s which a re seen i n b e in g d e p o s it e d i n If th is is a l l h o r iz o n s tru e , or at d iffe re n t s ta g e s d u rin g th e s o i l f o r m a t i o n , A we must adm it t h a t but th e A l, ana i l l u v i a t i o n have ta k en p l a c e which i n c l u d e s th e B h i r - Cady ( 1 1 ) , as c o n s i s t i n g o f i l l u v i a l c l a y th a t e lu v ia tio n p ro file the t h i n A£> and C, and e i t h e r s im u lta n e o u s ly i n t h e p a r t o f th e B s e rie s o f h o riz o n s . & The abundance and t h i c k n e s s o f th e c l a y f i l m s i n c r e a s e s w ith d e p th . The f i l m s o f th e pan h o r i z o n s a re d is c o n tin u o u s and t h i n - t h e y do n o t c lu s io n th a t but show any e v id e n c e o f e r o s io n which would l e a d to the con­ th e s e h o r i z o n s were i l l u v i a l a t p r e v io u s tim e s and t h a t th e y a r e b e in g e l u v i a t e d a t th e p r e s e n t s ta g e o f s o i l g e n e s is . The m e n is c i o f w e l l o r i e n t e d c la Y o f the pan h o r i z o n s c o u ld be form e d by l o c a l in r e a rra n g e m e n t o f th e o r i g i n a l c l a y through d i s p e r s i o n w a t e r and subseouent c o n c e n t r a t i o n and e f f l o r e s c e n c e i n c e r t a i n narrow in t e r g r a n u la r spaces as d e s c r ib e d ty r u b ie n a Y a r i l o v a and P a r f e n o v a ( 6 9 ) (3 7 ). s t u d i e d th e c l a y ra n g e o f s o i l s o f th e p o d z o l and g ra y brown p o d z o lic T h e i r s t u d i e s showed t h a t th e c l a y o rig in . r e g io n o f B u s s ia . f i l m s always c o n s i s t e d o f a r i c h i n i r o n c 1ay m i n e r a l o f th e m o n tm o rilT o n i o f s y n th e tic f i l m s o f a wide group w hich, They ha ve named t h i s m in e r a l they s u g g e s t, as T o l y n i t e i n honor o f F o ly n o v . The most l o g i c a l processes assum ption i s ta k e p l a c ^ d u r i n g the s o i l th a t a l l fo r m a t i o n . is the above d e s c r ib e d 101 F ie ld illu v ia l b ut i t c la y is s t u d i e s and t h i n s e c t i o n o b s e r v a t io n s showed t h a t i s n o t u n i f o r m l y d i s t r i b u t e d i n th e i l l u v i a l d e p o s it e d a lo n g c o n d u c tin g c h a n n e ls , th e zone ( 20 ) , po re s and i n th e v e r ­ t i c a l cracks. #e can c o n c lu d e e lu v ia l h o riz o n is from th e above d is c u s s io n t h a t th e o n ly p u r e l y th e A2 and th e o n l y p u r e l y i l l u v i a l h o r i z o n i s th e B t. The p o d zo l sequa o f I s a b e l l a and McBride show a. c e r t a i n r ic h m e n t i n g ra v e lly file s , s ilt, which p ro b a b ly i s r o c k and c h e r t y B e s id e s c l a y , th e s o il p a r t i c l e s en­ due to the d i s i n t e g r a t i o n o f fragm ents which a re abundant i n th e s e p r o ­ very fin e s ilt i s th e o n ly o t h e r f r a c t i o n o f which undergoes r e d i s t r i b u t i o n i n th e p r o f i l e . T a b l e 4 shows an e n ric h m e n t o f th e A3m and A & B h o r i z o n s i n v e ry fin e s ilt. The downward movement and d e p o s i t i o n o f th e v e r y f i n e p ro b a b ly f a c i l i t a t e d c. p ro file s , s ilt is by th e p re se n c e o f th e v e r t i c a l c r a c k s . Changes i n m i n e r a l o g y . I n th e case o f McBride and N e s t e r th e m i n e r a l o g i c a l changes can be e v a l u a t e d on th e b a s is o f t h e m i n e r a l o g i c a l c o m p o s itio n o f tn e C h o r i z o n s ( p a r e n t m a t e r i a l ) . I n th e c a s e o f I s a b e l l a , w i t h o n ly r e la tiv e 1, was shown i n m in e ra ls however, th e m in e r a l changes can bo e v a l u a t e d a c c u ra c y , Primary rn in o ra l changes i n tn e f i n e sano. t r a c t i o n . th e p r e v i o u s c h a p t e r , As i t w e a th e r in g o f p r im a r y s i l i c a t e ta k e s p l a c e o n ly i n the p a r t o f th e p r o f i l e which o v e r l i e s t h e Bt h o r i z o n . i n c lu d e d i n Vfhen c o n s i d e r i n g c a l c i t e , th e zone o l howevei , th e 3t, h o r i z o n i s w e a th e r in g . The r a t e o f w e a t h e r in g d e c re a s e s w i t h i n c r e a s i n g depth from 102 th e s u rfa ce o f th e s o i l , pec te d as t h e i n t e n s i t y in T h is de cre a se i n w e a th e r in g sho u ld he e x o f l e a c h i n g i s h i g h e r n e a r th e s u r f a c e th a n th e s u b s o il. The m i n e r a l s which show most w e a th e r in g i n th e s t u d i e d p r o - file s a ls are c a l c i t e , are q u a rtz , spars. o liv in e , m a g n e t it e , T h is c l a s s i f i c a t i o n w e a th e rin g There i s to u rm a lin e R e s i s t a n t m in e r and F-T'Ta f e l d - agreement w i t h th e a u th o rs and summarized by a d is a g re e m e n t, however, re g a rd in g as moderately resistant. 1'atelBki found t h a t g a r n e t decreases in size due to weathering, th e s t u d i e d s o i l s , however, w e a th e rin g o f g a rn e t. The d e cre a se i n in d ic a te s there was very little evidence of P r o b a b ly because this garnet is different in c o m p o s it io n th a n the g a r n e t h o rizo n s z irc o n , o f th e m in e r a ls i s i n which some p e o p le c l a s s i f y and T u rk ( 4 3 ) In garn et, sequences worked o ut "by d i f f e r e n t Jackson and Sherman. g arn et, h o rn b le n d e and e p i d o t e . s tu d ie d by the above authors, t h e number of ST-Na feldsxjar grains in the Ag a s l i g h t weathering of the above minerals in this p a r t o f th e p r o f i l e s . In th in s e c t io n s i t g r a t i o n o f h o r n b le n d e ) c la y ) was observed that both physical (disinte- and chemical (release of iron and formation of w e a t h e r i n g o f t h e m i n e r a l s takes place in the profile. Evidence o f c h e m ic a l w e a th e r in g was seen only in a few thin sections of the g r a v brown p o d z o l i c th e p o d z o l ic sequa, w h i le this evidence has been obscared in sequa by l e a c h i n g a n d /o r mining of the products with organ- m a tte r, Th<= i n c r e a s e d roughness of the surface of the weathered m i n e r a l s o f t h e p o d zo l th e c h e m ic a l sequa i s an indication of the importance of w e a th e r in g i n t h i s pai t of the profile, "Regarding th e fa c t th a t th e easily weather -mi primary minerals, 103 w i t h tn e e x c e p t i o n o f c a l c i t e , s o il c o n s titu e n ts , r e p r e s e n t a v e r y s m a ll we can conclu d e t h a t t h e i r ro le in f r a c t i o n o f th e s o i l g e n e s is i s s e c o n d a ry . ods o f c l a y in C la y m i n e r a l changes. The r e s u l t s o f th e d i f f e r e n t meth­ a n a ly s is a w e a th e r in g o f c l a y s th e p r o f i l e . in d ic a te th a t ta k e s p la c e The r a t e o f t h i s w e a th e r in g decreases a g a in w it h i n ­ c r e a s i n g d e p th from t h e s u r fa c e o f th e s o i l . The p r i n c i p a l c l a y m in e r a ls which w eather a r e i l l i t e and th e i n t e r s t r s t i f i e d complexes o f i l l i t e - c n l o r i t e - v e r m i c u l i t e - m o n t m o r i l I o ­ n ite , which a r e a ls o p r e s e n t in illite and o f the i n t e r s t r a t i f i e d s u r f a c e o f th e s o i l complexes s h a r p ly de cre a se n e ar th e and presumably a re th e p ro d u c ts o f w e a th e r in g . seauence o f w e a th e r in g has a ls o been found i n by M urray (50) and i n v e rm ic u lite s o i ls o f In d ia n a s o i l o f W isconsin by W hitting and Jackson ( 6 5 ) . I n cas e s o f advanced w e a th e r in g , b e lla , The amounts o f and d i s c r e t e p a r t i c l e s o f m o n t m o r i l l o n i t e become t h e dom inant m i n e r a l s , T h is th e p a r e n t m a t e r i a l . as i n trie Ai and h o r iz o n s o f I s a ­ a ls o w e a th e rs and m o n t r r .o r illo n it e rem ains as the ■only end p r o d u c t. Wurman ( 68) near found an i n c r e a s e i n the amount o f r m n t m o r i l l o n i te th e s u r f a c e o f th e W a lla c e and Montcalm s e r ie s o f M ic h ig a n . i s o b v io u s , th e re fo re , th a t n o n tn o r illo n ite is It fo rm in g i n th e podzols o f M ic h ig a n , which have been developed on p a r e n t m a t e r i a l s r a n g in g from sand to sandy c l a y o r c l a y loam. A n o th e r s tr o n g i n d i c a t i o n Io n ite is c a n tly le s s o f t h e g e n e t i c o r i g i n o f montmori] - t h a t on th e s u r f a c e o f th e N e s te r p r o f i l e , le a c h e d and w eathered m o s tly i n t e r s t r a t i f i e d than th e I s a b e l l a w ith o th e r m in e ra ls , which i s p ro file , s ig n ifi­ it p o s s ib ly because i t is has 104 n o t been s u b j e c t e d to p ro file s . If th e degree o f w e a th e r in g im p re s s e d on th e o t h e r th e m o n t m o r i l l o n i t e o f the I s a b e l l a s u r fa c e had been b r o u g n t i n by w ind, a ls o i n N e s t e r , we should e xpect to s in c e t h e two p r o f i l e s fin d d is c r e te m o n tm o rillo n ite a r e o n ly one mile a p a r t . The w e a th e r in g sequence o f c la y s o f the s t u d i e d p r o f i l e s i s i n agreem ent w ith th e s t a b i l i t y sequence o f c l a y s suggested by Jackson and Sherman ( 2 8 ) . ta lk e r to (6 2 ) v e rm ic u lite . found i n P o r t la n d lite by l e a c h i n g b i o t i t e th a t th e i n i t i a t i n g from i l l i t e is s o i l s o f S c o tla n d (4 9 ) th a t b i o t i t e formed d i s c r e t e p a r t i c l e s o f v e r m ic u - f l a k e s w i t h 0 . IN N a c l. mechanism f o r Murray ( 5 0 ) th e o x i d a t i o n o f th e fe r r o u s i r o n i n th<= o c t a h e d r a l ( 48 ) s ls o a t t r i b u t e s th e decrease i n P o rtla n d which i s a. r e s u l t o f th e t r a n s f o r m a t i o n o f b i o t i t e t o t a l c h a rg e , to v e r m i c u l i t e by to th e o x i d a t i o n o f t h e o c t a h e d r a l i r o n . Some o f th e A1 suggests the fo r m a tio n o f m o n trn o r illo n i te la y e rs . p l a n t g r o w th , w eathers and. T’e o x id e s o f c l a y m in e r a ls th e s o i l are p r o b a b ly s y n t h e s iz e d from S i, s o l u t i o n which a re th e p ro d u c ts o f the c o m p le te d e c o m p o s itio n o f th e p r im a ry and c l a y m i n e r a l s . Y a v ilo v a and P a r f e n o v a ( 6 9 ) have proposed th e s y n t h e t i c n a t u r e o f th e c l a y film s , n ite o f t h e R u s s ia n s o i l s . from d i l u t e H enin ( 2 6 ) has s y n t h e s iz e d m o n t m o r i l l o - s o l u t i o n s o f £ 102, A I 2O3 and Fe203 u n d e r atmo s p h e r ic condi t io n s . C la y a n a l y s i s d a t a snowed a p r e f e r e n t i a l rem oval o f e xpanding c l a y s fro m t h e f r a g i p a n h o r i z o n and a r e l a t i v e and o t h e r n o n -e x p a n d in g c l a y s . in th e t h in The e x f o l i a t i o n o f s e c t i o n s o f the i l l u v i a l c la y s c o n s t it u t e a c c u m u la tio n o f i l l i t e the c l a y f i l m s seen zones i n d i c a t e s t n a t e xpanding a s i g n i f i c a n t p o r t i o n o f tnese f i l m s . Tne expanuing 105 c la y s expana and c o n t r a c t upon a l t e r n a t e w e t t i n g and j i y i n g the "breaking o f th e f i l m s i n t o p a r a l l e l c la y and cause Assuming t h a t the s h e e ts . f i l m s ha ve "been formed by p h y s i c a l i l l u v i a t i o n o f c l a y th ro u g h tn e p e r c o la t in g w a te rs , n o n -e x p a n d in g c l a y s i n g e n e ra lly s m a lle r we can e x p l a i n t h e r e l a t i v e th e f r a g i p e n . th e then a c c u m u la tio n o f V o n t r r o r i l l o n i te m i n e r a l s a re n o n -e x p a n d in g m in e r a ls ( 22 ) . 7- r a y p a t t e r n s o f the (.2 m icrons c l a y show t h a t i t m a in l y o f i n t e r s t r a t i f i e d complexes o f i l l i t e - c h l o r i t e c la y s , w h ile i l l i t e than i n and k a o l i n i t e th e t o t a l c l a y o f s m a lle r fra c tio n . a re p r e s e n t f r a g i p e n h o r i z o n s by p e r c o l a t i n g w a te r s more and expanding in much s m a lle r The expanding c l a y , s i z e than th e n o n -e x p a n d in g c l a y , c o n s is ts th e re fo re , i s removed from e a s ily amounts b e in g the th a n th e n o n -e x ­ p a n d in g one. The a c c u m u la tio n o f i l l i t e th e fr a g ip a n a ls o i n d i c a t e s o f th e c l a y s in and o t h e r n o n -e x p a n d in g c l a y s i n t h a t t h e r e i s no s i g n i f i c a n t th is p a r t o f th e p r o f i l e . The d e cre a se o f th e amounts o f k a o f i n i t e th e s o i l s re g a rd e d cannot be a t t r i b u t e d near th e s u r fa c e o f to c hem ical w e a th e r in g ?s k a o l i n i t e as a vey v s t a b l e m in e r a l i n Sherman ( 2 9 ) have found. exert a lte ra tio n th e podzol r e g io n , B lo o m fie ld (5 ) found as Jackson and t h a t l e a f le a c h a t e s 3 marked d e f l o c u l a t i n g e f f e c t on K a o l i n i lc suspensions. lo g ic a l th ^ re fo ^ e , s u r f a c e o f th e s o i l to assume t n e t k a o l i n i t e is It is i s C’-ung j. amoved fr^.n th e by pe 1col a tin*:. wptei ■ According to t h e h y p o th e s is t h a t th e r e has been p r e f e r e n t i a l re m o v a l o f th e e xpanding c l a y i n such re m o va l illu v ia tio n should a ls o o c c u rrin g in the f r a g i p e n , we m ight e x p e c t t h a t be t a k i n g p la c e i n th e p o d z o l secua and th e u n d e r l y i n g f r a g i p a n . Some such a rem oval 106 un do u cte dl y toom p l a c e i n p r e v io u s h a s lo w a r c l a y c o n te n t tim e s , as t h i s te e n t r i e C h o r i z o n , 'cn.it i t moval o f c 1 ay was e i t h e r by s o l u t i o n o r t h a t i t til it reached t h e Bt h o r i z o n or i t c r a c k s and no t i n the mass o f th e The r e l a t i v e p o d z o l sequa i s th e r a te o f th e ir th a t c la v r e m o v a l. the r e ­ was d e p o s ite d o n ly i n the v e r t i c a l fra g ip a n h o riz o n s , found t o d a y i n th e th a t th e r a te o f t h e i r I n th e t h i n s e c t i o n s i t fo r m a tio n exceeds has been observed end o r g a n i c m a ttp r form s t a b l e complexes and a g g r e g a te s . The a g g r e g a t i o n o f th e c l a y s e rio u s ly i n h ib it s p o d z o l sequa a t th e p r e s e n t s ta g e . h o riz o n s in d ic a te s c re te p a rtic le s by p r e c i p i t a t i o n (d ) th a t c la y I s rem oval from the the two o v e r l y i n g end u n d e r l y i n g b e in g d e p o s ite d t h e r e e i t h e r as a r e s u l t o f p h y s i c a l i l l u v i a t i o n or is as d i s ­ b e in g formed from th e s o l u t i o n o r both. Chem ical c h an g es . th e c h e m ic a l w e a t h e r i n g , re a c tio n its The i n c r e a s e i n c l a y c o n te n t a t t h e p o d zo l B h i r h o r iz o n s compared to cal seems t h a t ".to f i l s was n o t d e p o s ite d un­ i n c r e a s e i n expanding c la y s an i n d i c a t i o n o a r t o f th e The c h e m ic a l change? a r e th e r e s u l t o f a d d i t i o n o f o r g a n ic m a t t e r , between th e s o i l c o n s t i t u e n t ? , s o lu tio n , chem i­ l e a c h i n g and p r e c i p i t a ­ tio n . The main c h a n g e s d e t e c t e d 1. th e Loss o f c a r b o n a te s C h o r i z o n and i n c r e a s e o f t h e i r 2. Iv in t in t h i s p e c ia lly in t r i p po d zo l - . from the h o r i z o n o v e r l y i n g a c id ity . A d d i t i o n o f o r g a n ic m a t t e r to th e h o r i z o n s t h e Ch o r i z o n and m ain ly i n 3. study a r e : bver- one podzol sequa. T b rm a tio n o f c l a y - o r g a n i c m a t t e r complexes es­ sc-qua. f o r m a t i o n o f s e s a u i o r i d e - o r g a n i c m a tte r complexes 10? and. precipitation o f them in th e B h i r horizon. A ccum u la tio n o f ' ' f r e e *1 alumi . ua i n th e zone o f o. th e p ro file s o c c u p ie d by th e B h ir , 5:r, A2m. and A Azm & B h o riz o n s . 6. Acrumu.ia.tion o f a l k a l i 7. Loss o f s c s q u io x id e s from the A2 h o r iz o n s and s o l u b le s i l i c a i n th e B^ h o r i zons. a c c u m u la tio n o f i r o n o x id e s i n th e B h ir h o r i zons' where th e y a r e asso­ c ia te d w ith w i t h o r g a n i c m a t t e r and c l a y and i n th e clp.y f i l m s . 8. pan Thin s e c tio n s tu d ie s and t h e l i g h t c o l o r o f th e i n d i c a t e t h a t t h e A2m and A3m h o r iz o n s o x id e s , F o rm a tio n o f th e f r a ^ i u a n In v e s tig a tio n s c a rrie d th a t the tio n to th e p e c u l i a r fra g ip a n is out i n o t h e r p a r t s arrangem ent o f the s o i l p a r t i c l e s . Vany a u th o rs as C a r l i s l e R e s u lt s o f second e l u v i a l th is zone o f h a ve found i n s o i l s d i s t i n c t maxima i n d a t a suggest illite S ilic a is not ( 1 4 ) c o n s id e r th e com paction o f the t h e b in d in g study showed t h a t O th e rs ( 3 8 ) suggest t h a t agent. th e f r a g i p a n c o n s t i t u t e s th e bisequum p r o f i l e of Illin o is . as Grossman e.t a l the (7 4 ) B u lk d e n s i t y measurements showed th e A2m and A3m h o r iz o n s o f the pan, t h a t h ig h maximum i n d u r a t i o n . is in d u ra ­ th e f r a g i p a n . as a m ajor f a c t o r o f c e m e n ta tio n . and e s p e c i a l l y o f th e c o u n tr y adm it a r e v e r s i ’oly i n d u r a t e d pan which owes i t s assumed to have a c em e n tin g r o l e i n fra g ip a n s u f f e r a lo s s o f i r o n to o . 2. c la y the Bt where th e y a s s o c i a t e ’cut ha rd n es s b u lk d e n s i t y a lo n e i s not enough to produce E e s u l t s o f c h e m ic a l ■a n a ly s e s s i g n i f i c a n t c o n c e n tra tio n o f a lk a li s o l u b le s i l i c a fa ile d in to r e v e a l th e pan. any 108 'E y i ' T q .c .ta b le a lu m in a , however, showed a remark,able i n c r e a s e i n th e a r e a o f th e pan* f i g u r e 2 shows t h a t w ith a more o r l e s s c o n s t a n t h u lk d e n s i t y , t h e h a rd n e s s o f th e f r a g i p a n i n c r e a s e s w ith c la y c o n te n t u n t i l optimum" i s re ac h e d and then i t decreases w it h i n c r e a s i n g c l a y con­ The ^optimum 11 amount o f c l a y s te n t. an f o r fragi.pans h a v in g m e chanical c o m p o s it io n s analogous to the s tu d ie d ones seems to be about 1 5 * . The g r e a t e s t d i f f e r e n c e s i n hardness w it h changing c l a y c o n te n t f a l l between 7 and 22 p e r c en t o f c l a y . is necessary fo r la te d not of th e ma.rimu.rr. hardness o f the pan has a lso been p o s tu ­ d u r i n g th e f i e l d s tu d ie s . B e s u lt s o b ta in e d by Grossman (2 3 ) show any "optimum" cl,ay c o n t e n t , fra g ip a n fir m n e s s o f in c re a s e s c o n te n t, because he t e s t e d d rie d and because he did no t measure hardness o f the d r i e d s o i l c lo d s , ? i t h i n c r e a s i n g c la y F i g u r e 2 a ls o in The "optimum" c l a y c o n te n t which d id samples the par. but th e which under dry c o n d i t i o n s n o r m a lly c o n te n t. shows t h a t w i t h i n th e narrow ranges o f c l a y ha rd n es s in c r e a s e s w i t h i n c r e a s i n g b u lk d e n s i t y , e s p e c ia lly the range o f 4 - IT - c l a y . High b u lk d e n s ity and optimum c l a y c o n te n t a r e , th e main end n e c e s s a ry c o n d i t i o n s io n t h e i n d u r a t i o n o f t h e pan. Alumina m ikh t a c t as a c em enting agent 'out i t s s ec o nd p ry ro le appears to be o f i moor t anc e . T h in s e c t i o n studies r e v e a le d o f th e o a r h o r i z o n s i s g ra in s , th e re fo re , which i s Peeper h o r i sons, t h a t th e most im p o r t a n t f e a t u r e th e c lo s e p a c k in g o re s p o n s ib le how ever, fo r one saim and c o a r s e s i l t th e h ig h b u lk d e n s i t y o f th e pan. i n s p i t e o f t h e i r h ig h cul.v d e n s ity , have low h a r d n e s s and much l e s s packed sand g r a i n s than th e pan. It % Clay Effect of the clay m - /-* a content and of the bulk density Bulk on the D e n s it y hardness of the s o il 109 s u io / 3 m r>oue^STsaji cioT'+saiaued 3110 110 appeei s, g ra in s th e re fo re , is d e n s ity th a t tn e i m p o r t a n t th e c lo s e p a c k in g o f the sand and c o srs e s i l t f a c t o r o f th e i n d u r a t i o n and n ot th e h ig h h u l k its e lf. In o rd er th a t must not th e c lo s e p a c k in g he o b t a i n e d , exceed a c e r t a i n amount. We have, th e c l a y c o n te n t th e re fo re , another- support o f t h e i d e a o f '‘ optimum c l a y c o n t e n t " . r he c l a y co n n e c tin g acts as a cem enting agent by fo rm in g s o l i d b rid g e s t h e neig h b o rin g ; sand g r a i n s . The i n c r e a s e o f hardness w it h i n c r e a s i n g c l a y c o n te n t can be a t t r i b u t e d c la y b rid g e s . If th e c l a y c o n te n t g r a n u l a r spaces w i l l c la y b rid g e s te rn a te o f th e i l l u v i a l exceed th e "optimum", la rg e r in te r - be r e o u i r ^ d and f r a c t u r e and d i s c o n t i n u i t y o f the ' - i l l occur, w e ttin g to th e f o r m a tio n o f more because o f t h e i r l a r g e r s i z e and o f the a l ­ and d r y in g , ©s i t has been seen i n th e t h i n s e c tio n s Bt h o r i z o n s . C la y a n a ly s e s have shown t h a t th e c l a y o f th e A2m and A3m h o r i z o n s c o n s i s t s l a r g e l y o f n o n -e x p a n d in g s p e c ie s . found i n h o ld s f r a g i p o n s o f New York t h a t i l l i t e to g e th e r th e pan, th e g r a i n s o f sand and s i l t . th e re fo re , th e y c o n s is t sume t h a t ©re n o t f r a c t u r e d Knox ( 3 6 ) was the m a t e r i a l Clay b r id g e s which formed i n oy w e t t i n g end d r y in g , o f n o n -e m e n d in g m in e ra ls . This i s a lso tr u e o n ly i f because we as­ d i s p e r s i o n does n o t ta k e p l a c e . upon w a t e r s a t u r a t i o n the cores o f the ABm and A3m h o r i z o n s d id n o t show any change o f volume as d id the cor^s o f o t h e r h o r i z o n s c o n ta in in g th e in g . e xpanding c l a y s . fra g ip a n i s formed it T h is means t h a t once th e s t r u c t u r e o f cannot be changed by mere w e t t i n g and d r y ­ Ill H y p o th e s is o f In the g e n e s is o f the pan the p r e c e d i n g d is c u s s io n we have shown t h a t c lo s e p a c k in g o f th e sand and s i l t g ra in s , a c e r t a i n oijtimum c l a y c o n t e n t and a p r o p e r a rran g e m e n t o f t h e s o i l p a r t i c l e s s ib le a r e the main f a c t o r s f o r th e i n d u r a t i o n o f the pan. The p a r e n t m a t e r i a l s o f t h e s t u d i e d p r o f i l e s above t h r e e p r o p e r t i e s combined. which cause i t s tio n . respon­ in d u ra tio n , The f r a g i p a n s fo rm a tio n s That i s , and n ot g e o l o g ic the p r o p e r t i e s o f the pan, have been developed t h a t were s t u d i e d , co not h a ve the d u r in g the s o i l th e re fo re , are g e n e t i c forma­ s o il f o r m a tio n s . The g e n e s is o f th e f r a g i p a n h o r i z o n s ta k e s p l a c e p a r a l l e l th e g e n e s is o f th e o t h e r h o r i z o n s . A f t e r th e l e a c h i n g o f th e c a rb o ­ n a te s and a c i d i f i c a t i o n o f the p r o f i l e , la te d fo r th e to th e fo llo w in g steps a re p o s tu ­ f o r m a t i o n o f th e pan: ( a ) ‘Removal o f a. p a r t o f th e c la y f r a c t i o n , and p r e f e r e n t i a l l y o f th e exp e n d in g c l a y . (b ) C o n t r a c t i o n f o l l o w i n g the rem oval o f c l a y T h i s c o n t r a c t i o n which r e s u l t e d in s te p by s te p . th e c lo s e p a c k in g o f the g r a in s was g r a d u a l and no t u n i f o r m . '?orces which caused t h i s c o n t r a c t i o n were th e g r a v i t a t i o n a l w ith in fo r c e s o v e r ly in g h o riz o n s , pressures e ve rte d pressures d u r in g w e t t i n g developed in g o f t h e soil d u r in g th e e a r l y tio n t h e r e fo r e , re s u lte d in the h o r i z o n , by ta p r o o t o f th e and d r y in g plus 30 b ii and The c o n t r a c ­ 1.t d i . e e . i o;.s, s h r in k a g e o f th e pan and i n m a tio n o f v e r t i c a l crac>s and th e coarse c ol'ronar known t h a t ct tre e s, f r e e z i n g and thaw­ sta g es o f developm ent. ceu sod by” I ore e s ac t i n ^ a three d im en sio n a l the lo a d o f th e s tru c tu re . tn e f o r ­ It is t h e f o r m a t io n o f a h e xa g o n a l P a t t e r n o f c ra c > s causes the 112 le a s t c r a c k i n g due to s h r in k a g e . I n case o f a u n i forrr. body "being g r a d u a l l y c o n t r a c t e d from th e t h e hot tom a h^-y agonal p r i s m a t i c to p to tn is way th e s t r u c t u r e i s produced. f o r m a t i o n o f p o ly g o n a l p a t t e r n o f c ra c k s In found, i n many fra g ip a n s th r o u g h o u t th e c o u n tr y and th e v e r t i c a l c r a c k s o f Michigan fra g ip a n s can he e x p l a i n e d . (c ) s k e le ta l F o l l o w in g the c o n t r a c t i o n and the c lo s e p a c k in g o f the e le m e n ts , t h e m a t r i x substances ( f i n e s ilt and r e m a in in g c l a y ) undergo a r e a r r a n g e m e n t. The c lo s e p a c k in g o f the sand has p r o v id e d th e c a p i l l a r y te rg ra n u la r spaces, tu re le v e ls "below f i e l d c la y is i n which th e s o i l c a p a c ity . d e p o s it e d fo r , r i n g o p t i c a l l y suspension i s c o n fin e d a t mois­ Upon e v a p o r a tio n o f th e w a t e r , o r i g i n a l m a t r i x and p a r t l y h o riz o n s illu v ia l •'■eni s c i i s p a r t l y c la y brought i n by the p e r c o l a t i n g - w a te rs during from o v e r l y i n g th e stage o f c o n t r a c t i o n . re le a s e d to amount o f i l l u ­ d r y . (d ) ta te d g ra in s . ^he c la y o f th e The Agm h o r i z o n o f I s a b e l l e has a c o n s i d e r a b le v ia l th e a n i s o t r o p i c m e n is c i v h ic h serve as b r i d g e s c o n n e c tin g t h e n e ig h b o r in g sand and c o a rs e s i l t The c l a y o f th e a n i s o t r o p i c in - D u rin g th e course o f t h e s o i l from th e decomposing m i n e r a l s , from t h e s o i l developm ent, aluminum i s pno a p a r t o f i t s o l u t i o n i n th e a rea o f the pan, is p re c ip i­ p o s s ib ly adding t h e c e m e n ta tio n o f th e pan. ^he above hypothesis d i f f e r s b a s i c a l l y from th e h y p o th e s is proposed by C a r l i s l e tio n o f the s tu d ie d (14) i n t h e f o llo - .- ir .fc- two p o i n t s : f r e r i p m s o f M tchlrfH . s o i l s V s from t h e P a r e n t m a t e r i a l hut i t is The compac­ not h e m i n h e r i t e d the r e s u l t o f s o i l e e n m i s . The 113 o tr .e i p o i n t tio n is t h a t t h e v e r t i c a l c ra c k s gre th e r e s u l t o f th e c o n t r a c ­ due to l o s s end re a rra n g e m e n t o f th e c o n s t i t u e n t s o f the pan and n o t o f t n e a l t e r n a t e w e t t i n g and d r y in g . tn e ty p e and amount o f d r y ‘E x p e r im e n ta l e vidence and o f th e pan exclude volume changes o f the pan d u r i n g w e t t i n g and d r y in g which c o u ld account f o r the c ra c k in g . The s o f t e n i n g o f the pan upon v e t t i n g can be e x p l a i n e d by assuming t h a t w a t e r a c t s as a l u b r i c a n t d e c re a s in g the betw een th e s o i l p a r t i c l e s AljgOg, and p o s s i b l y by d i s s o l v i n g o r h y d r a t i n g th e as t h e pH o f t h e pan fa v o r s i t s The p l a t y p la in e d adhesion f o r c e s s o lu tio n . and v e s i c u l a r s t r u c t u r e o f th e pan has been ex­ by F i t z p a t r i c (1 9 ) as due to f r o s t a c t i o n . He p ro v ed th a t th e v e s i c u l a r p o re s have been formed by th e d is s o lv e d gases d u r in g th e fr e e z in g o f s o il w ater. C zeraski fro s t (16) a c t i o n and i t s a c tio n o f s o il (1 ) fro s t i n Germany has done a c om plete study o f th e e f f e c t on the s o i l s tru c tu re . He d e s c r ib e s the as accompanied by th e f o l l o w i n g phenomena: Expansion, o f w a t e r by f r e e z i n g (9 $ o f i t s v o lu m e ). ( 2 ) f i i s e o f w a t e r from the u n d e r l y i n g h o r i z o n s zen zone and d e p o s i t i o n o f t h i s w a te r i n (3 ) L i f t i n g o f th e s o i l end o f the w a t e r t h a t a. th e o f th e from below. however, is th e second one, s tru c tu re s : M assive o r homogenous s t r u c t u r e which i s c h a r a c t e r i s t i c sandy s o i l s h. phenomenon, th e f o l l o w i n g s h e e ts . through the f r e e z i n g o f the o r i g i n a l r i s e s by c a p i l l a r i t y The most e f f e c t i v e v h ic h produces form o f i c e tow ard th e f r o ­ and Lam inated o r heterogenous s t r u c t u r e which i s fin e r of s o ils . c h a ra c te ris tic 114 The h e te ro g e n o u s s o ils s t r u c t u r e s a rc b e t t e r developed on compact th a n on lo o s e s o i l s . oo ly n e d r e l , e tc .) The p a r t i c u l a r type ( p l a t y , depends on the t e x t u r e o f th e s o i l p o ly g o n a l, and on the r a t e o f fre e z in g . The maximum r i s e o f w at~ r and the best developed p l a t y s t r u c ­ t u r e s o c cu r on compacted loess and loams. C zeraski o f fro s t (17) a ls o produced ana photographed th e development s tru c tu re s in th e l a b o r a t o r y S o i l from A3 h o r i z o n o f a F’a r a - b r a u n e r d e formed on lo e s s and h a v in g s i m i l a r p r o p e r t i e s to th e s t u d i e d fra g ip a .n s produced upon f r e e z i n g a n e tw ork o f h o r i z o n t a l and z ig z a g ic e s h ee ts . The p l a t y seen i n by f r o s t s tru c tu re , th e f r a g i p a n th e re fo re , and m a in ly i n i t s s c ie n tis ts w ith T. Ten M itte rt and Steve S hetron, M itte rt, s o il Mich­ mere n o t f r o zen because o f a t h i c k snow c o v e r . D a ta o f p r e v i o u s y e a r s i n th a t h o r i z o n a re p r o b a b ly caused the S o i l C o n s e r v a tio n S e r v ic e i n O s c e o la County, found th ese s o i l s made by A2m a c tio n . D u r in g th e w i n t e r o f 1959, ig a n , and th e t h i n h o r i z o n t a l c r a c k s tne v i c i n i t y o i "East L a n sin g and o o s e r v a t i o n s c h i e f o f th e C s c e o la s o i l survey p a r t y , v e rify f r e e z i n g does oc cur at dept/is where th e pan i s l o c a t e d . It g ra tio n seems, th e re fo re , th a t s o il o f th e pan by b r e a k in g i t s g ra tio n is 3, f r o s t may cause the d i s i n t e ­ m assive s t r u c t u r e . T h is d i s i n t e ­ more pronounced i n th e Brn and. A£m h o r iz o n s o i C l a s s i f i c a fJ_ldI The s t u d i e d p r o f i l e s ori fa ll zon -ith in G ardn er and W h ite s id e as double ( b i s e q u a ) brown p o d z o l i c in te rg ra d e s , th e pan. monc 1 a t u r e th e group o f s o i l s named by p r o l i l e s o* p o a z o l - ^ r a y - which r e p r e s e n t th e zonal s o i l s o f t h e 115 studied area. Such soils have also been found in ITex York and Ontario. 'he fragipan is a genetic formation in the stucded profiles, fo^ ...ed in the eluvi&l zone of toe Gray Bro mi Po a so lie sequum, and falls within the concept of fragipan hori zous defined; in the Soil Survey Manual. The typical sequence of ^anetic horizons of the soils of Northern Michigan "hichi have Vn^ textural range of the studied pro­ files are: Pirst, a Podzol sequum characterized by maximum physical, chemical and biological activity or changes, ana by an increase in vo lu'ne. f-oo A very thin layer of undecomposed lit tern The proper genetic resignation of this horizon is Od*. Al A crumbly ana loose mineral horizon of acid reaction. It has been enriched by arthropods fine moder or ar­ thropods mull humus. Intense chemical weathering and formation of discrete particles of expanding clay minerals, decomposition of organic materials ana formation of clay-organic matt -r are the pre­ dominant processes which take place in this horizon. The genetical designation of this horizon is Vh. A2 A b l e ach ed ac ia ho ri zo n c. h ?rac t- i zed bp c1ay a::d sesauioxiae eluviatior., massive friable structure, * These genetic designations have be-~n recently proposed by Dr. T. ?. Whiteside in his article pi; dished in Soils ana rtili zer, V: EX aI, 1959, 1 -8 . 115 and i n t e n s e c h e m ic a l w e a th e rin g g e n e tic H iir d e s ig n a tio n i s p s in th e Aj_. Tan, An a c id h o r iz o n o f loos-j spongy s t r u c t u r e , iro n , Its r ic h e r in a lu m in a and c o l l o i d a l o rg a n ic m a t t e r . It is c h a r a c t e r i z e d by a secondary in c r e a s e i n c l a y con­ te n t and oy the fo r m a tio n o f c l a y - i r o n - o r g a n i c t e r com plexes. mat­ The fo rm a tio n o f d i s c r e t e p a r t i c l e s o f expanding c l a y i s l e s s pronounced h e r e th a n i n th e o v e r ly in g h o riz o n s . Its g e n e tic d e s ig n a tio n i s ^Iibh, Bm An a c i d h o r i z o n , r i c h i n a lu m in a and t r a n s i t i o n a l •between th e podzol is , Its has l o s t most o f i t s sand i s p la ty t i e s . T h e re i s th is p art c l a y through e l u v i a t i o n . s lig h tly in d u ra te d . d e s ig n a tio n fo r t h is h o rizo n i s a Gray-Erow n F o d z o l i c and r e l a t i v e l y no strong illu v ia l somewhat c lo s e packed, has a c o a rs e s t r u c t u r e and i s g e n e tic n h y s ic a l a c t i v i t y T h is h o r iz o n i n s o f a r as s e s o u io n id e s a r e concerned, but i t Second, sequum and th e pan. sequum, The |Ib i Eq c h a r a c t e r i z e d by h ig h lo w chem ic al and o i o l o g i c a l a c tiv i­ e v id e n c e of fom a t i n r, o f expanding c la y in o f th e p r o f i l e . A£m An a c i d , b le a c h e d , e l u v i a l h o r i z o n which has s u f­ f e r e d p r e f e r e n t i a l lo s s e s i n and i r o n o x id e s , in g c l a y , expanding ty pes o f c l a y a r e l a t i v e i n c r e a s e i n non-expand­ c lo s e p a c k in g o f sand and coarse s i l t g r a i n s w it h a l o s s i n volume and re a rra n g e m e n t o f th e m a t r i x s u b stan c e s. The above changes have 117 r e s u l t e d i n th e r e v e r s i b l e i n d u r a t i o n o f the h o r i z o n u n d e r d ry c o n d i t i o n s . p la ty and v e s i c u l a r a c tio n . A3m s t r u c t u r e produced by f r o s t I t s g e n e tic Same as above, s tru c tu re , Th is h o r i z o n has a c o ars e d e s ig n a t io n i s E ql but w ith more p o o r ly exp re s se d p l a t y h i g h e r c l a y and f r e e a lu m in a c o n te n t and w i t h a s m all amount o f i l l u v i a l c l a y i n film s . form o f T h is h o r i z o n i s c o n s i d e r a b ly more i n d u r a t e d than any o t h e r h o r i z o n i n the p r o f i l e . I t s g e n e tic d e s i g n a t i o n i s Eq / H o t . A & B An a c i d h o r iz o n which i s p a r t l y illu v ia l. It e lu v ia l c o n s t i t u t e s a t r a n s i t i o n between the o v e r l y i n g A3m and the u n d e r l y i n g B td e s ig n a tio n i s Bt llti & Its c la y i l l u v i a t i o n . zone o f maximum I r o n o x id e s a ls o accum ulate i n t h i s h o r i z o n and they film s . g p n e tic Eq . An a.cid h o r i z o n t h a t c o n s t i t u t e s th e c la y and p a r t l y Except are m a in ly a s s o c ia te d w ith th e f o r the decom po sition and l e a c h ­ i n g o f th e c a r b o n a te s , th e r e i s no s i g n i f i c a n t wea­ t h e r i n g o f p r im a r y and c la y m i n e r a l s i n t h i s h o r i ­ zon. The sand g r a i n s a r e n o t p a ck e d . i s c h a ra c te riz e d flo w Its T h is h o r i z o n by t h e abundance and t h ic k n e s s o f s t r u c t u r e s and f i l m s o f v e i l o r i e n t e : c l a y . s tru c tu re is u s u a lly trib u tio n blocky and th e r o o t d i s ­ i s h i g h e r h e r e than i n o f t h * Grey-Brown r o d z o l i c d e s ig n a tio n any o t h e r h o r i z o n sequum. Tne g e n e t i c f o r t h i s h o r iz o n i s i l t i . 118 Third, "unaltered par put material. ^ Calcareous glacial till. It constitutes the parent material (P). - h e po&zol oi sequa o f the t h r e e p r o f i l e s t n e M ic h ig a n s o i l s which f a l l s tu d ie d and g e n e r a l l y w i t h i n t h i s l i t h o s e q u e n c e , have not th e c h a ra c t e r i s t i e s o f th e c l a s s i c a l po d zo ls o f Russia and "Europe. Namely, th e y do n o t have a c c u m u la tio n o f raw humus on t h e i r and t h e i r does n o t B h i r h o r i z o n s a re not cemented. accept th a t a s o i l p o d z o l. R ussian p o d z o ls , s o ils are m o rp h o lo g ic a lly processes a re re s p o n s ib le fo re , the u p p e r sequa o f th e s t u d ie d s o i l s ’Ve can c l a s s i f y , is g e o lo g ic a lly h o rizo n s and i t s s h o u ld be I I d iffe re n t o n ly I s a b e l l a has th e t y p i ­ from th e o v e r l y i n g and u n d e r l y i n g the n e x t best d e ve lo p e d p r o f i l e c o n t a i n s much more o r g a n i c m a t t e r d e fin e d in than a t y p i c a l d e s i g n a t i o n should be EmVh. Me Agm h o r i z o n , system, Ib t. McBride i s g e n e tic Its d e s ig n a t io n a c c o ra in g to W h i t e s i d e ’ s ( 6 4 ) Eq The A & Ag but i t s As h o r iz o n should have, B h o r i z o n i s n ot w e l l developed p r o f i l e is th e N e s t e r p r o f i l e . It in g t y p i c a l and s e p a r a b le A3 and B h i r h o r iz o n s i n i t s In s tea d , has a g r a d a t i o n o r m i x t u r e o f th e s e two h o r i z o n s , t h * g e n e tic quum, and B rid e . The l e a s t it th e re ­ as p o d z o ls . sequence o f g e n e t i c h o r iz o n s as d e s c rib e d above. how ever, its gra y wooded and s i m i l a r and the same fo r t h e i r fo rm a tio n . Among th e s t u d ie d th r e e p r o f i l e s , cal however, th e presence o f raw humus i s i m p o r t a n t i n c a l l i n g A c c o rd in g to him, A u s t r a l ia n p o a z o lic B lo o m fie ld ( 5 ) , s u r fa c e d e s ig n a tio n is E m /J lh i. p o iz o l is la c k ­ sequum. o f which In th e g ra y -b ro w n p o a z o l i c th e A3m h o r i z o n has not y e t been d e ve lo p e d . se- US SUMVARY - The t h r e e p r o f i l e s i-ill and th e y r e p r e s e n t v e lo p m e n t. CONCLUSIONS s t u d i e d have b e m developed on c a lc a r e o u s d iffe re n t sta g es o f w e a th e r in g and s o i l de­ The I s a b e l l a p r o f i l e i s v e lo p e d and the N e s t e r p r o f i l e is H i r i n g t h e developm ent o f th e most weathered, and b e s t de­ the l e a s t de ve lo p e d . the p r o f i l e s , th e c a rb o n a te s were d i s s o l v e d and removed from th e zone which o v e r l i e s As a r e s u l t , a ls o an a c i d i f i c a t i o n o f th e p r o f i l e s removed from the illu v ia tio n d e p o s it e d zone o v e r l y i n g the o r c o m p le te d e m m p o sit i 'm . th e C h o r i z o n . took p l a c e . C la y was h o r iz o n by e i t h e r p h y s i c a l A p a r t o f the removed c l a y was i n th e Bt h o r iz o n s which have th e h i g h e s t c l a y c o n te n t i n each h o r i z o n . The expanding i n t e r s t r a t i f i e d v e rm ic u lite -m o n tm o rillo n ite removed from th e e l u ’u a l complexes o f i l l i t e - c h l o r i t e - being s m a ll i n s iz e were p r e f e r e n t i a l l y A2m and A3m h o r i z o n s , which thus re la tiv e i n c r e a s e i n n o n -e x p a n d in g c l a y s . th e c la y and o f th e le s s r e s i s t a n t p r im a r y m i n e r a l s i n o f th e p r o f i l e s s ilic a The in t e n s e w e a th e r in g o f the r e l e a s e o f 11fr e e " sna i n t h e fo r m a t i o n o f d i s c r e t e p a r t i c l e s rno a t mo r i 11 o n i t e . m in e r a ls re s u lte d in Conseou e n t l y , an i n c r e a s e i n tooh p l a c e n e a r the s u r fa c e o f show a the upper p a r t Fe o x id e , alu m in a and o f v e rm ic u lite and the amount o f th e s e me s o il. The a d d i t i o n o f o r g a n ic m a t t e r formed the humus o f the Ap, A2 me B h i r h o r i z o n s and i n i t i a t e d 'h e form ation, ox ^ l a y —o r g a n ic m a tte r and i r o n —o r g a n ic m a t t e r complexes o f tn In th e e l u v i a l podzol zone o f the g r a y - b r o m p a c V in g o f sand and c o a rs e s ilt sep^a- p o fz o lic spqua, g r a i n s to o ’* p i e c e and r e s u l t e d a c lo s e in the 120 r e d u c t i o n 01 th e volume o f t h a t •.ra c tio n , re s u lte d a r e a r r a n g e m e n t o f th e c l a y in F o l l o v i n g o r during; t h i s conand f i n e s ilt to o k p l a c e , which th e f o r m a t i o n o f s o l i d c 1ay "bri dgeg c o n n e c tin g th e n e i g h ­ b o r in g sane g r a in s in la y e r. and tnus a never s i b ly i n d u r a te d pan was developed th e A2:n and A^y, h o r i z o n s . The h a r d e s t pan has "been developed i n the McBride p r o f i l e cause i t s p a r e n t m a t e r i a l had n e a r l y th e optimum m e ch a n ic al composi­ t i o n n e c e s s a r y f o r th e fo r m a t io n o f th e pan. pan o f th e t e s t e r p r o f i l e On th e c o n t r a r y , i s o n l y p o o r ly developed, m a t e r i a l had c o n s i d e r a b ly h i g h e r c l a y c o n t e n t , th e a d eq u ate t r a n s l o c a t i o n m a tio n o f th e r o o t s . th e f o r e s t g ro w th , out, reeded. c u l t u r a l la n d s, At f i r s t parent which has inn i hi te d g la n c e , however, substan c e s. no s e r io u s d e c l i n e o f due to th e pre se nc e o f f r a g i p a n , has been n o t i c e d more i n f o r m a t i o n and r e ­ The f r a g i p a n can be more h a r m fu l i n where i t s the t h e b ra n c h in g and causes a s e r io u s d e f o r ­ b e f o r e we reach any g e n e r a l c o n c lu s io n , s e a rc h i s as i t s and r e a rra n g e m e n t o f th e s o i l The f r a g i p a n l i m i t s be­ presence l i m i t s eroded a g r i ­ th e p h y s i o l o g i c a l depth o f lhe soil. The n a t u r e o f th e pan i s by m e c h a n ic a l b re a k in g , such t h a t i t when the s o i l i s w i t h tn e o v e r l y i n g h o r i z o n s . c o u ld p roduce and s t a b i l i z e can e a s i l y wet, and by thorough mi wing A d o i t i o x i o i c la y a fa v o ra b le s o il be d e s tro y e d and o r g a n ic m a t t e r s tru c tu iv and p r e v e n t vhe reformation of the pan. Below the fragipan is the zone of maximum clay illuviation characterized by the abundance of flow structures and other clay films which are rich in precipitated iron oxides. From the above discussion, we can c /uoiude that the Fodzol sequa are charecteri zed by high states o: cnysicni, chemical and tiological activities which result in drastic changes in the physical, chec.ical and mineral ogical properties of the soil. Th underlying Gray-Frown Fodzolic sequa are characterized mainly oy high physical activity such as clay illaviation, eluviation, contraction, and rearrangement of soil particles. 122 BIBLIOGRAPHY 1. Anderson, J. V. , and W h ite , J. L. A study o f f r a g i p a n i n some s o u th e r n I n d i a n a s o i l s . S o i l S c i. Soc. Amer. P r o c . 2 2 : 4 5 0 - 4 5 - . 1958. 2. B a i l e y , H. H. , W h ite s id e , E. F. , and E ric k s o n , A. P. Y in o r a l o g i c a l c o m p o s itio n o f g l a c i a l m a t e r i a l s as a f a c t o r in th e mor­ phology o f some p o d z o l, g ra y wooded, g ra y -b ro w n , p o a z o l ic and n u m i c - g l e y s o i l s i n M ic h ig a n . S o i l S c i. Soc. Amer. P roc. 21: 4 3 3 - 4 4 1 , 1957. 3. Bar shed, I . C h e m is try o f th e s o i l . R e in h o ld F u b l. C o ., Hew Y ork, 1955. 4. B aver, L. D. S o i l P h y s ic s , Yew Y o r k , 1S56. 5. B l o o m f i e l d , C. L e a f l e a c h a t e s as a f a c t o r i n p e dogenesis. S c i. Ftood Agr. Ho. 1 1 : 5 4 1 - 6 5 1 , 1955. 6. Bower, C. A . , and Geschwend, F. B. E th y le n e g l y c o l r e t e n t i o n by s o i l as a measure o f s u r fa c e a re a and i n t e r l a y e r s w e l l i n g . S o il S c i . Soc. Amer. F r o c . 1 5 : 5 4 2 - 3 4 5 , 1952. 7. B rew er, P. O p t i c a l l y o r i e n t e d c la y s i n t h i n s e c t io n s o f s o i l s . T ra n s . 6 th I n t . Congr. S o il S c i. B : 2 l - 2 5 , 1956. 8. __________ _ R e n o rt o f O verseas V i s i t . Commonwealth S c i. Org. , D i v i s i o n o f S o i l s , A d e la id e , A u s t r a l i a , 195 7 . 9. B r i n d l e y , G. W. , and Rustem, it. A d s o rp tio n and r e t e n t i o n o f o r ­ g a n ic m a t e r i a l by m o n t m o r i l l o n i t e i n th e presence o f v /a te r. Amer. M in e r . 4 3 :5 2 7 -6 4 0 , 1958. 10. ed. 3, Chapt. 1: S o il Development. John W ile y and Sons, In c ., In d . J. Res. Cady, J. G. Some m i n e r a l o g i c p l c h a r a c t e r i s t i c s o f podzol and brown p o a z o lic , f o r e s t s o i l p r o f i l e s . S o il S c i. Soc. Am^r. P ro c . 6 : 3 3 2 - 3 5 4 , 194 1 . Rock w e a th e r in g and s o i l C a r o l i n a Fiedm ont r e g io n . S o i l S c i. 3 4 2 , 1950. fo r m a tio n i n th e ITorth Soc. Aomr. P ro c . 15:527- 1 2. Cann, D. B. , and T h i t e s i d e , Y. F. A study o f th e g e n e s is o f a Pod z o l-g T e y brown p o d z o lic i n t e r g r a d e t o i l p r o i i l e i n M ic h ig a n . S o i l S c i. Soc. Amer. P ro c . 1 9 : 4 9 7 - 5 0 1 , 1955. 13. Capper, P. L . , and C a s s ie , S. F. The mechanics o f e n g i n e e r i n g s o i l s , MeCraw H i l l Book C o., H .Y . p. 249, 1923. 125 14. ^arlisle, 9. J, Characteristics of soils with fragipan ir. a podzol region. Fh.D. Thesis, Cornell rnivcreitv Ithaca, :".Y. 1254. _________„ct al. Fragipan horizons in New York soils. T. General characteristics and distribution. Soil- Sci. Soc. Amer. Froc. 21 520-3?'L, 1957. : 16. Czeraski, '5. Zur Ti rt-&ng .}es Frostes auf die Stmktur des Bo dens. Zeitschrift fur Pflanzcner Nehr, Burn, Boderdninde. 72. (117.): 15-52, 195*. I7 - ____________ Boden-Struc turbi ldur.g durch Frost (T/ouellversuche). ^issensch. Film C 724/1956. Inst, fur dec FissenscheftI ichen Film, Gottingen, Germany, 1957. IF. Frick son, A. F. F-~rson&l communication. 19. Fitzpatrick, p. AAn indurated soil horizon forced by oermafrost. J. Soil Sci. 7 7:249-454, 1956. 20. Frei, P., and Cline, V, G. Fro file studies of normal soils of N.Y. II i.'icr.omorcho logic el sti-di.es of the gray-brown podzolicbrown poozolic soil sequence. Soil Sci. 38:533-344, 1942. 21. Gardner, D. P., and Whiteside, H. ?. Zonal soils of the transi­ tion region between *he podzol end gray-brown poazolic region in Michigan. Soil Sci. Soc. Amer. Proc. 16:137-141, 1952. 72. Grim, R. F. N.Y., 1953. Clay Mineralogy, McGraw-Hill Hook Company, Inc., 23. Grossman, R. B. , and Cline, V. G. Fragipan horizons in Ner York soils: IT Relationships between rigidity and particle size dis­ tribution. Soil Sci. Soe. Aner. Proc. 21 iO -2— 225, IS..’7. 24. Grossman, Soil Sci. P. B. et at. Fragipan soils of Illinois: Soc. Amer. Froc. 73:-5-75, 1959. I, II, III. 75. Ha.rtir.em* F. Ikr Wald tod =n . nst-^rreichi sches Prodvkti vi tats Zen tru m , Pi en, 17 51. 26. Henin, S. Synthesis of cloy minerals at low temperatures. Swi neford, *A. , Fdit-or. Clays an: Slav Minerals, publication 456, Nat. Ac a. Sci . — Nat-. as • v^oon. , Yasni -igt;n, D. v»., 1 . 77. Hi 17 ebrand, W. T. , an- Lunde'l, G. F. Applied inorganic analysis, ed. 2, John ^i ) '-y an 1 Sons, Inc., N.Tr., 1955. 29. Jack so a, V. I., ani Sherman, B. G. Chemical weathering of mi nereds in soils. Norman, A. G. Hditor. Advances in Agror.ony, Academic Fress, N.Y., 5:719-31*, 1953. 124 29, J a c k s o n , ?/. L. , Soil chem ical Snglev/ood C l i f f s , Y. J., 1959. a n a l y s is , F r o n t i e r - H a l f , In c . oO. Jefaries. o. B. A double centrifuge tube for the separation of the soil minerals by means of heavy liquids. Soil Sci. 52:157171, 1941. 21. Jenny, H. Factors of soil formation, ?'cCraw-Hill Book Compare, Inc., U.7., 1941. 22, Jongerius, A. Etude micromorphoiogiqua des sols sableaux secs de hois et bruyeres an Fays-Bss. Trans. 6th Int. Cong. Soil Sci. E:263-257, 1956. 53. Jordan, J. 'V. Alterations of tlv^ properties of bentonite by re­ action with amines. Miner. Mag. 29:59 9—60o, 1949. 54. Felly, F. L. , and Jndcl, D. B. The ISCC-NBS method of designating colors and a dictionary of color names. 1TBS Circular 552, U.S. Gov. r rint. office, Washington 25, B.C., 1955. 3-5. Fil.nor, V. J. , and Alexander, L. T. 1/ethofs of making mechanical analysis of soils. Soil Sci. 55:15-24, 19^9. 36. F o o t , E. G. Fragipan horizons in Few Yor’< soils: III The basis of rigidi ty. Soil Sci. Soc. Amer. Froc. 21:32n-2-3- f 1957. u f/ Fubiena, W. L. Iowa, 1938. 30. I'icrops dology • Th~ sails of 'Europe. Coll egiate Press, Inc., Ames, Thom;as Mur by and Co., London, 1953. 59. Leveret t, Surface geology of 'liehi pan. Surv. Pub Lie. 251 1915. 40. Mgr but, C. F. Soil?: Their genesis and class i ficatio.. Sci. Soc. of America, 1951. 41. Marshall, C. F. and Jeffries, C. D. Mineral ogi cel methods in soil research. Soil Sci. Soc. Ai.rr. t no c . 10 :39 <-^.0 ,5 ? 19-o. 42. Martin, H. M. Map of the surface for-gtions of the Southern Peninsula of Michigan. I>?t. of Cons ervstio n, Geological Surrey Civ., 1955. L Z M 7 . Vich. Geol. Biol. Soil Matelski, F. P. and Turk, L. V. Heavy minerals in some podzol soil profiles in Michigan. Soil Sci. 64:459-487, 1947. Mr Caleb, S. B. F r o f i l e studies of normal soils of New Tor1-: IV Miner ©logical properties of the fray-bro^ po dzolie-brown podcolic soil sequence. Soil Sci. 19rr*. 125 45, VcCooL, V. v, , Veatch, J. 0. r-rxd Spurway, 9. H. Soil profile studios in Michigan. Soil Soi. 16:95-106, 1023. 46. focKenzie, L. J. Oidation-r-luction studies -n the mechanism of B horizon formation in podzols. Ph.D. Thesis S.U, v LansinUich., 1957. ’ ' 47. Lean, . B., Heddleson, 1*. P., Bartlett, P. J. andFolovaychuk, Aluminum in soils: I Extraction methods and magni tuc.es in clay and Ohio soils. Soil Sci. Soc. Amer. "froc. 22:392-337, 1.956. \ : c \ V . 43. Portland, 1. V. , Lawton, K". ,ana TJehara, G. Alteration of biotite to verrniculite by plant growth. Soil Sci. 82:477-481, 195o. 49. Idortland, M. 7. Finetics of potassium release froa'i biotite. Soil Sci. Soc. Amer. Froc. 22:503-585, 1959. 50. Murray, H. F, and Leininger, P. F, The effect of wreathe^ing on clay minerals. Swine ford, A., Editor. C1ay s an -5 C1ay Mi n er al s . Publication 455, Hat. Acad. Sci. - Hat. "Res. Coun. , Washington, D. C., 1956. 51. Piper, 0. S. Soil and plant Inc., K.Y., 1950. 58, Raeside, J. D. Yellow-gray earths of South Island, Hew Zealand. Ai exarm)1 e of polyger.csis in soil development. Trans. 6th Internat. Congr. Soil Sci. F: Sob-672, 1956. 53. "Robertson, G. Colorimetric determination of aluminum in silicate materials. J. Sci. Food. 1,59, 1950. 54. Potzger, J. F. Thy to socio logy of the primeval forest in centralnorthern Wi scons in and Upper Mi chi gan, and a brief post-glacial history of the lek^ forest formation. Ecological Monographs. 16:211-250, 1946. 55. Sawhney, B. L. , and Jackson, J/. L. Soil rrontno rillonit e formulas. Soil Sci. Soc. Acer. Froc. 8 1 : 1 1 5 - 1 1 9 , 1958. 56. Sn^ll TT. f). , end Snell, 0. T. Colorimetric methods of analysis. Volume 8, ed. 3. D. Vanho s ^rano ^o ., Inc., ...Y., 194 9. oV m„ c M 'f t o o - analysis. In teasel --nee publishers, r a r p n n i s ' l l v frozen ground in Alaska, i t s o r i g i n * £ ■ ' % o c . h , r . Bui 5 4 :1 4 5 3 -1 5 4 8 . 1 9 4 3 . and 58 Uni end, R. F. , and C'Ueal, A* M. Soil permeability extermination for use in soil and water conservation. U.S.U. A. S.C.S. - T.P. - 101, Washington, I). C., l?ol. 59. V e a tc h , J. cover. 7. S -H mops as a basis for -apping^original Mich. Acad. Sci. -Faper. 15 :^67-cm«_>, I9 u , forest 25 ^ soils i n M ic h ig a n . 1954. Hilar, C. E. Some characteristics of mature J. Art 'h 172 (n.s.) Vi ch. Agr. Fxo. Sta., ___________ •Soils and land of Fress, 1255. Michigan. Th-= Mich. St. Coll. Walker, F, G. The decornposi ti 'n Mag. 2?: 593-705, 1949. of biotite in the soil. Mineral S«o. Webber, L. B. an; Shivas, J. A. Th~ identification of clay min­ erals in some Ontario soils: I. parmat materials. Soil Sci. Soc. Amer. Froc. 17:95-99, 1955. 54. ’Ani t e s i d e , E. F. A proposed system of genetic soi 1-horizon de­ s ig n a tio n s . Soils and Fertilizers, Vol. XXII:1-8, 1959. 55. Whi t t i n g , L. D. and Jackson, M. L. Mineral content and distribu­ tion as index oweat h e r i n g in the Omega and Ahmeek soils of northern Wisconsin. Sminefor", A., Editor. Cl a"'s and Clay Mir­ er als. Publication 455, Mat. Acad. Sci. - Met. Fes. Coun., Wash­ ington, D.C. ,1956. 66. Wills, M. H. Climate of Michigan, Yearbook of Agriculture, T’.S.T).A., U.S. Gov. Print. Office, Washington, P. C. , pp. 914924, 1941. 57. Winters, M. H. , and Simonson, B. 7*. The subsoil. Norman, A. G. , Editor, Advances in Agronomy, Acad. Press, Inc., V.Y, 5:1-92, 1951 . 63. Wurman, E. , Whites! E. P., and Vortland, V. Properties and genesis of fine textured subsoil bands in some sandy Michigan soils. Soil Sci. Soc. Amer. Proc. 25:135-145, 1959. •-9 . Yarilova, E. A ., and Parfenova, 2. I. Poorly formed clay minerals in soils. Pochvo ve ^enie . 9: *^7-it", 19 o7. U . APPENDIX 1 X-RAY DIEFATIOM PATTERNS OF CLaY Patterns 'Mo. 1 correspond to Patterns No. 2 correspond to samples which were A- saturated and ^ and glycerol saturated, samples heated to 110° C. Patterns Ho. 3 correspond to samples which were heated to 550° C. saturated and I 3 A B E .L L A NESTER MCBRIDE 2 ° 20 CD . 2 mIcron s ez 15 PATTCTS 0 Tr DIFTnF^TIAX TH’SPVAL ANALYSIS OF CLAY The numbers correspond to degrees °C. OJ o o KAOLI NI TE 35% KAO LI NITE 50% KAOLI NI TE ~o - I7 o m <0 I o CO 35 % C \J KAOLINITE < or UJ F” C/> U 2: Ll J - 'T CBCFHO?hG?APRS O F THITT S E C T IO N S O F TJ1TDISTT8BFD S O U 1. Seal e Fach small division corresponds to 10 microns. ^. Bhir horizon of the McBride profile n A2ir. 4 . Bt 5. Q 5 . ti it ti M n 11 (1 (t ii it II II M ii n A3m hori zo n o f the Me 3r x ie pro fi1e Detailed microstructure of t h l° M e n is c i b rid g e s of c la y fo rm s o lid c o n n e c tin g th e sand g ra in s . in CM