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II II III'IITII IIIIIIIII III “III’IIIIIIIIII'IIIIIIIIIIII IIIII IBIIII-IITIIGIIIII :ITIII' IIIIIIILTIIIIIII II IIIIIII III IITIITI III II III I I . ~ ._ III II III III IIITI‘ I ITI II 'IIIIIIIIITT IIIIIJIIIIIITIIIII II I LIMIIIIIIII IIIIIIE I rH eels hm. "h‘ ’. LIBR a a Y i Michigan State University IllIllllllllflllllllllljllllllllllfllfllfllfll L This is to certify that the thesis entitled RELATIONSHIP OF DOLOMITE/LIMESTONE RATIOS TO THE STRUCTURE AND PRODUCING ZONES OF THE WEST BRANCH OIL FIELD, OGEMAW cgiérgytdgw I GAN LEWIS EARL TEN HAVE has been accepted towards fulfillment of the requirements for ' M.S. Geology degree in Chilton Prouty Major professor Date I 1-9-79 0-7639 OVERDUE FINES: 25¢ per day per item RETURNING LIBRARY MATERIALS: -——————_..._________ Place in book return to remove charge from circulation records “AP 1 4 "JQH RELATIONSHIP OF DOLOMITE/LIMESTONE RATIOS TO THE STRUCTURE AND PRODUCING ZONES OF THE WEST BRANCH OIL FIELD, OGEMAN COUNTY, MICHIGAN By Lewis Earl Teanave A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Geology I979 ABSTRACT RELATIONSHIP OF DOLOMITE/LIMESTONE RATIOS TO THE STRUCTURE AND PRODUCING ZONES OF THE WEST BRANCH OIL FIELD. OGEMAN COUNTY, MICHIGAN By Lewis Earl Ten~Have The West Branch Oil Field was studied to achieve a better understanding about the origin of dolomite in Devonian reservoir rocks and its relationship to structural configuration and hydro- carbon production. The top 170 feet of Dundee Limestone from 52 wells were analyzed using powdered x-ray diffraction, petrography and catho- doluminescence. It was found that the highest degree of epigenetic dolomitization occurred 80 to 110 feet below the top of the Dundee Limestone, which showed a close correlation to the highest zone of porosity as observed in mechanical logs. Early diagenetic dolomite may be present as seen petrographically. The degree of epigenetic dolomitization shows a close correlation with the Dundee structure and the Traverse Group isopach maps. The geometry of folds and distribution of dolomite percen- tages suggest a relationship to faulting. Dolomite percentages can be helpful in detecting these fault traces that may not be detected by other means. ACKNOWLEDGMENTS The writer wishes to express his sincere gratitude to Dr. C. E. Prouty, Chairman of the Guidance Committee, for his advice, encouragement, and extreme unselfish giving of his time during the course of this study. Thanks are also extended to Dr. Duncan F. Sibley and Dr. James w. Trow for their helpful suggestions and review of the thesis text and illustrations. Also, I would like to thank my mother, Mrs. Jeanella Ten Have, who made my college education possible. Foremost thanks must go to my wife Cindy for her love and continuing encouragement during the source of this study. Her patience and understanding made completion of this work possible. ii TABLE OF CONTENTS Page LIST OF TABLES . . . . . . . . . . . . . . . v LIST OF FIGURES . . . . . . . . . . . . . . vi INTRODUCTION . . . . . . . . . . . . . . . I General Statement 1 Previous Work 3 STRATIGRAPHIC FRAMEWORK . . . . . . . . . . . . 5 STRUCTURAL FRAMEWORK 9 THE WEST BRANCH OIL FIELD . . . . . . . . . . . I4 Location and Extent . . . . . . . . . . . 14 History and Development . . . . . . . . . . l4 Production . . . . . . . . . . . . . . l7 Lithology . . . . . . . . . . . . . . . l9 Structure . . . . . . . . . . . . . . . l9 Isopach . . . . . . . . . . . . . . . 23 LIMESTONE AND DOLOMITE ANALYSES . . . . . . . . . 28 Experimental Procedures . . . . . . . . . . 28 Source of Samples . . . . . . . . . . . 28 Sample Selection . . . . . . . . . . . 28 Sample Preparation . . . . . . . . . . 29 X— -Ray Diffraction Procedure . . . . . . . . 29 Calibration Curve . . . . . . . . . . . 32 Data Calculation . . . . . . . . . . . 33 Data Interpretation . . . . . . . . . . . 35 Petrogenetic Analyses . . . . . . . . . . . 35 Sample Preparation . . . . . . . . . . . 35 Petrology . . . . . . . . . . . . . . 35 Analyses . . . . . . . . . . . . . 38 Cathodoluminescence . . . . . . . . . . . 40 X- -Ray Data Interpretation . . . . . . . . . 4l Vertical Dolomite Variation . . . . . . . . 4T Lateral Dolomite Variation . . . . . 46 West Branch Field Dolomitization Models . . . . 59 iii Page Dolomite Occurrence in Relation to Hydrocarbon Production . . . . . . . . . . . . . . 67 CONCLUSIONS . . . . . . . . . . . . . . . . 7l APPENDICES . . . . . . . . . . . . . . . . 73 I. Sample Well Description . . . . . . . . . 74 II. List of Wells Used in Study . . . . . . . . 77 III. Dolomite Percent From Dundee Limestone . . . . 89 BIBLIOGRAPHY . . . . . . . . . . . . . . . . 93 iv LIST OF TABLES Table Page I. Different Components Used for Standardization . . . 3l Figure \Omemwa _a 0 II. I2. I3. I4. IS. I6. I7. LIST OF FIGURES Stratigraphic Succession Michigan Michigan Region Tectonic Map Location of West Branch Oil Field in Michigan . Nell and Cross Section Location Map Structure Map on the Top of the Dundee Limestone . Faults and Folds of a Wrench Deformation Model Traverse Group Isopach Map Calibration Curve of Dolomite Percent Typical Vertical Dolomitization Patterns in the Dundee Limestone Average Vertical Dolomitization Pattern and a Typi- cal Neutron Porosity Pattern in the Dundee Lime- stone Dolomite Ratio Map--0- -20 Feet Below the Top of the Dundee Limestone . . Dolomite Ratio Map--20- -50 Feet Below the Top of the Dundee Limestone . . . Dolomite Ratio Map--50- -80 Feet Below the Top of the Dundee Limestone Dolomite Ratio Map-—80- -llO Feet Below the .Top of the Dundee Limestone . . . . Dolomite Ratio Map--ll0- 140 Feet Below the Top. of the Dundee Limestone . Dolomite Ratio Map--l40- -l70 Feet Below the Top of the Dundee Limestone . Cross Section—-Ogemaw to Mills Township . vi Page IO I5 20 21 24 25 34 42 44 47 49 SI 53 55 57 69 INTRODUCTION General Statement Most of the oil in the Dundee Limestone (for discussion of nomenclature involving Rogers City and Dundee formations see Strati- graphic Framework, p. 6) is found in anticlines in the central area of the Southern Peninsula of Michigan. Most of the production from this formation is associated with a dolomitic limestone. The porosity associated with the dolomitic limestone is believed to be stratigraphically controlled by early diagenetic dolomitization and/or structurally controlled by epigenetic dolomite which formed along faults and fractures. Many workers on Michigan Basin stratigraphy and structure believe that dolomite has a tendency to form along bedding planes, seams, joints, faults and fractures within limestone formations (Landes, I946; Powell, I950; Jodry, I954; Tinklepaugh, I958; Egleston, I957; Jackson, I958; Paris, I977; Dastanpour, I977; Ham- rick, I978). Dolomitic facies have also been formed along shallow epi- continental shelves and carbonate platforms (Prouty, I948; Cohee and Landes, I958; Adams and Rhodes, I960; Deffeyes, et aI., I965; IIIing, et aI., I965; Bathurst, 1971). It has also been proposed that dolomite can form in emergent areas or structural highs where sea water and fresh water mix (Hanshaw, et al., l97l; Badiozamani I973; Land, I973). This research is to establish whether there is dolomite in the Dundee Limestone of the West Branch Oil Field. Next will be the examination and interpretation of the distribution of any dolo- mite relative to the field structures. The third step will be to determine what mechanisms could have produced the dolomite. The last step will be to determine the relationship between the dolomite zones and hydrocarbon production. Structural interpretation is based on maps produced by using picks (datum designations) established by the Michigan Geological Survey and verified where possible through sample and mechanical log examination. Lateral and vertical variations of the dolomite percentages derived from x-ray diffraction analysis will be inter- preted through the use of bar graphs and dolomite/limestone ratio maps. A petrographic and cathodo luminescence study will also be used to help evaluate the dolomite distribution. The West Branch Oil Field of Ogemaw County, Michigan, was chosen for three reasons: (I) it is a well-defined structure, (2) well samples are available, (3) no detailed study of this type has been attempted in this portion of the Michigan Basin. It is the hope and purpose of this writer that the results of this study will provide further helpful information regarding linear-producing fields. It is also hoped that these results may be of use in the exploration and development of these fields and in future exploration for oil and gas in Michigan. Previous Work A study of the West Branch Oil Field was included in the study of the Geology of Ogemaw County by Newman (I936). Bloomer (I969) described the lithology and porosity in a Middle Devonian core about 30 miles west of the West Branch Oil Field. His study was a regional study of the Middle Devonian Dundee Dolomite. Other regional dolomitization studies have been done by Newhart (I976) on the Middle Ordovician, Runyon (I976) on the Traverse Group, and Syrjamaki (I977) on the Lower Ordovician. Gardener (I974) made a 9 regional stratigraphic and depositional environment study of the Middle Devonian in the Michigan Basin. A number of studies have been made on determining the CaCO3/ CaMg (CO3)2 ratios of sediments in the Michigan Basin. Powell (I950), following suggestions by Landes (I946) in regard to local dolomitization, was the first to apply a chemical analysis to the Dundee Limestone in the Michigan Basin. Powell's (I950) work in the Pinconning Field was followed by Jodry (I954) who used the titration method for determining the Mg/Ca ratios of well samples in several producing oil fields in Mecosta County. He found these ratios an aid in predicting trends of secondary dolomitization. In the studies that followed, Tinklepaugh (I957), in the Rogers City- Dundee formations of the Central Michigan Basin, Jackson (I958), in the Rogers City-Dundee formations of the Deep River, North Adams and Pinconning Oil Fields, Dastanpour (I977), in the Rogers City— Dundee and Traverse formations of the Reynolds Oil Field and Hamrick (1978), in the Traverse limestone of the Walker Oil Field found a definite relationship between the degree of dolomitization and structural form. Young (I955), in the Traverse limestone of the Stony Lake Oil Field and Egleston (I958), in the Rogers City-Dundee and Traverse limestones of the Reynolds and Winfield Oil Fields, did not find a suitable correlation between degree of dolomitization and structural form. The regional studies by Newhart (I976), Runyon (I976), and Syrjamaki (I977), in addition to single structure studies of Dastan- pour (I977) and Hamrick (I978), conclude the presence of two types of dolomite: diagenetic (stratigraphic) and epigenetic (post con- solidation). STRATIGRAPHIC FRAMEWORK The Middle Devonian rocks in the Michigan Basin are repre- sented by the Traverse Group, the Dundee Limestone and the Detroit River Group (Figure l). The Traverse Group, with the Bell Shale formation at the base, lies conformably on top of the Rogers City formation, accord- ing to Cohee and Underwood (I945). The Traverse Group is divided into three major units by Cohee (I944): the upper Traverse Forma- tion, the middle Traverse Limestone, and the lower Bell Shale. Cohee (I947) describes the Traverse Group in the eastern part of Michigan as consisting largely of argillaceous limestones and shales with some purelimestone. This grades into calcareous shales with the limestone becoming more pure as you go westward. The Dundee Limestone was originally defined to include the rocks which lie between the base of the Traverse Group and the top of the Detroit River Group. Ehlers and Radabough (I939) divided the Dundee into two formations on the basis of brachiopod, gastropod and pelecypod fossils. They proposed the names Rogers City Lime- stone for the tap division and Dundee Limestone for the bottom. Cohee and Underwood (l945), along with many others, have since adopted these formation names. Figure l.--Stratigraphic Succession in Michigan. 7 STRATIGRAPHIC SUCCESSION IN MICHIGAN rmmm mun-n cum fiAu.” mm mam—c.- ‘ A * -UD- CENOZOIC m .db-w _‘_ ‘ —— unusual-up..- . _' h—‘_-- OUTCROP NOMENCLATURE SUBSURFACI NOMENCLATURE - = “0‘“ ma smnoamq aocx steam lock-"uncut“ r “um I romnow 1mm caour o—nonm—n—u a... 6‘0”“ FORMATION mu m I--‘.‘- *Ifit-d—uo- Wm noun-h- new I“. E I: INFORMAL TERMS Widfl~l‘~“l~ ”d‘i-mdwumo. .4... WWW mud um —” tun—and \___ * ”-c—b III-.- ”I _—bl~ Wk I—OOI {nu-9 In... G- I‘— N‘h h‘ww—C.“ Ova-h ———--&oh Ion-Ink nun—a- Illa.- w-‘d ‘IC-I— imbul— '—-_—u|b m II I I—un—__~.h ”(an au- Du‘ou GH- tun-um.- I-‘dmh" no... one. *1 ~' .. III'. I-—-—~OH ‘ "“- l H...— I O-——~|&I 2| SI :23: --... 2i 0 n O Oi Bl uni-tit] G; CD".- ____'“_—a- ‘ I cbl— I I AIC-h-I M— hath LDC" coo—v l ”Oh—In... .—°l|& I‘w unu- MdWI-UI— ”In. I‘m "Ch (“5-— “WW— hut-I '—°‘|b Iupuu— ‘ o-uo. a .——”_—. snumau sauaum Cow-M'- man IMId-b WM IMlduh ”’Nmumoh—bflb-b. IA—In—l-O-w-b—nD-nh—u-‘h—I—auu Hm“t-|b-~|~.~fl_ -.b—_ I—I-I~-l.~—-I—-uO-.Iv-v ——-¢~¢—- The Rogers City Limestone is typically a dark-colored, brownish-buff dolomitic limestone or dolomite (Cohee, I948). Tinklepaugh (I957) describes the Rogers City Limestone as predomi- nately a fossiliferous, marine limestone altered locally to dolomite. The Dundee Limestone is underlaid by the Detroit River Group and is described as being buff to light brown becoming more dolomitic and anhydritic in western Michigan (Tinklepaugh, I957). Due to similar lithology, the Rogers City and Dundee formations are rather indistinguishable in the subsurface (Cohee and Underwood, I945). These two formations are treated as one unit in the subsurface by the Michigan Geological Survey and will therefore be treated as one unit in this thesis, being called the Dundee Limestone. STRUCTURAL FRAMEWORK The Michigan Basin is bounded on the west by the Wisconsin Arch in central Wisconsin; by the Canadian Shield on the north and northeast; by the Algonquin Arch on the east in Ontario; by the Findlay Arch on the southeast in northern Ohio; and by the Kankakee Arch on the southwest in northern Indiana and northeastern Illinois (Figure 2). Many theories have been postulated concerning the origin of the Michigan Basin by Pirtle (1932), Newcombe (1933), Kirkham (1937), Lockett (I947), Cohee and Landes (l958) and Hinze and Merritt (1969). Ells (1969) has written an excellent summarization of these theories. Pirtle (1932) and Newcombe (I933) believed that the early source of movement, folding and warping, were related to the Keweena- wan disturbance acting against the Wisconsin Arch in Precambrian time. Later stresses along the trends of weakness in the basement rock were responsible for folding and the present configuration of the Michigan Basin. Kirkham (I937) thought the downwarp of the Michigan Basin was the result of the movement of vast bodies of magma from one part of the earth's crust to another. The Precambrian surface was said to be composed of a pattern of joints, shear zones, faults and rifts which would be lines of weakness along which vertical movement was likely to occur. 10 Figure 2.--Michigan Region Tectonic Map. II Rf I I _l i! 'l AM IICAN TI, , I . j flu/vor/i ’ . Wl?~v. /a ’ I/Q‘V W .a (F .A/ . L { L . H. s _ A L.) IIIMI m M f/ ,.. . .. U . . . . (ii/if f 5‘.“ (w r, .O’Av "VI. .3 «(’1 \II 1 75¢ \ O s\1 12 Lockett (I947) claimed the positive structural features surrounding the Basin were undelaid by the cores of Precambrian mountains. Downwarping of the Basin was due to sedimentary loading deposited from the original mass of the mountains. Differential subsidence occurred along lines of weakness due to areas in the northeast and southwest remaining positive while the rest subsided. The parallel pattern of structural trends in the Basin were said to conform to these primary fractures along lines of weakness resulting from subsidence. Cohee and Landes (1958) believe the Michigan Basin first became a basin-type depression in Late Silurian time. Sagging and folding occurred intermittently throughout the Paleozoic. The main diastrophic activity occurred in Late Mississippian, Pre- Pennsylvanian time. This emergence caused or sharpened structural traps. Hinze and Merritt (1969), with studies based on gravity and magnetic highs believed a rift zone had a dominant role in the origin of the Michigan Basin. The isostatic sinking of the Basin may have been in response to the added mass of Keweenawan mafic rocks in the basement complex. Later deformation has been asso- ciated with movements along lines of basement weakness related to the rift zone. Structural patterns within the Basin are generally attributed to reactivation of the Precambrian lines of weakness. Prouty (I976) believes lineaments gleaned from LANDSAT imagery are faults. He I3 attributes these faults to a wrenching deformation model and the folds that are present in the Basin are related to these faults. These shearing stresses come from a generally eastward direction with the dominate stress occurring in Post-Osagean, Mississippian time. .1.I4 [-9 (.1i . I +...IIII~ THE WEST BRANCH OIL FIELD Location and Extent The West Branch Oil Field is located under the northeast portion of the city of West Branch, Ogemaw County, Michigan (Fig- ure 3). It spreads out from this point in a northwest-southeast direction. The West Branch Oil Field is approximately nine miles long and three fourths to one mile wide. This field includes sections l3, I4, 23 and 24 of Ogemaw Township (T22n-RIE), sections 1 and 2 of Horton Township (T21N- R2E), sections 18-21, 26-29, and 34-36 of West Branch Township (T22N-R2E), sections 5 and 6 of Mills Township (T21N-R3E) and section 31 of Churchill Township (T22N-R3E). History and Development Newman (1936) wrote the history of the West Branch Oil Field. He considered that there was a hint of some type of structure evi- denced by the exposure of sandstone ledges in the bed of the Rifle River in Mills Township. These sands were recognized as Marshall and were surrounded by the younger Michigan formation. Normal out- crop of the Marshall Sandstone occurs far away from Mills Township. With normal dip into the Basin, the Marshall Sandstone should have been far below the surface in Mills Township. For this reason, it must have been lifted by some structural condition, either a fault or a fold. l4 15 Figure 3.--Location of West Branch Oil Field in Michigan. 16 I N‘. van , . .rntso _1. cuanucvonfi W“. ' I A fieln I - .I- Jr- outback ALLEGAN aaanr I You . I ‘ '_ ‘ " ll“ ’ 'L..LL {Ii-i3 1314-: . :r. cum I : cauaoa ‘ ' U ' I I 3 I I a 1 cu.» stlaonnw I cunt-w . Iguana: Iii-NW“ I A. 11!.SWHME I ' ' I I7 The Pure Oil Company acted on this information and began a test well drilling campaign. A structure was confirmed and partially defined. In 1932 Pure drilled their first deep well in section 2 of Horton Township (T21N-R2E). It was a dry hole. The first producing well was completed July 20, 1933, in section 34 of West Branch Township (T22N-R2E). Production was from the Traverse formation. The first Dundee producer was drilled in section 27 of West Branch Township (T22N-R2E). From this locality, drilling expanded 4 several miles northwestward along the structural trend, and then later the field was extended to the southeast. The field developed rather slowly and by 1936 there were 138 oil wells and one Traverse gas well. The first Detroit River Sour zone well was produced in 1951. The next year production was also obtained from the Richfield zone. These two zones are in the Lucas Formation of the Detroit River Group. Production The West Branch Field produces oil from the Traverse Lime- stone, the Dundee Limestone, the Detroit River Sour zone and the Richfield zone. Traverse oil production is very erratic and water encroach- ment is rapid. For these reasons, most Traverse wells are deepened to the Dundee. Within the Traverse Limestone, a slight pay was 18 encountered from 8 to 10 feet and a good pay 120 feet below the top of the Traverse Limestone. In the early Dundee wells, three or more pays were produced. One around 10 to 15 feet, the second around 100 feet and the third around 150 feet below the top of the Dundee Limestone. Total thick- ness of the combined pay averages about 20 to 40 feet thick. Fig- ure 17 indicates the vertical and horizontal distribution of the pay zones along the long axis of the field, based on the driller's logs. In 1966, Marathon began a secondary recovery operation. New wells were drilled and logged. These wells were generally produced from 90 to 160 feet below the top of the Dundee. No infbrmation is available on the production in the Detroit River and Richfield zones. The West Branch Oil Field is still active with 232 wells producing at the end of 1977 (Mich. Geol. Survey, 1978). The West Branch Oil Field has produced 9,771,878 barrels of oil from 172 wells including 170 in the Dundee, one in the Traverse and one in the Traverse and Dundee. This is the main production in the West Branch Oil Field and it is this production with which this research is concerned. Other production in this field is 3,232,572 barrels of oil from 60 wells in the Detroit River Sour and Richfield zones. Samples are too incomplete for a study of this producing horizon. I9 Lithology The Dundee Limestone, as observed with a binocular micro- scope, is a fine to medium grained, generally tan to dark grey dolomitic limestone in this area. This formation typically con- tains fossils, stylolites, shale fragments and chert. Tinklepaugh (1957) describes the Dundee in the east and northeastern part of the Michigan Basin as being a marine limestone, predominately tan, con- taining stylolites and fossils and being altered locally to dolomite. A typical well is described lithologically in Appendix 1. Structure Structural interpretation was based on the picks given for formation tops in drillers logs from the 405 wells used in this study (Figure 4). Their locations showing formation tops are given in Appendix II. Wherever possible, these picks were verified or changed through the use of sample chips available, or the few electric logs available. A general structural contour map of the field on the tap of the Dundee Limestone is given in Figure 5. This map reveals the West Branch structure as an assymetrical, elongated, anticlinal dome with a northwest to southeast axis. The northeast side of the anticline has a slightly steeper slope than the southwest side. On the northeast flank, there are structural dips or slopes of 200 feet to the mile while the dip on the southwest does not greatly exceed 100 feet to the mile. 2, se 4: >32 94 as m « ; O) 2 293 290 3H 337 373 394 I I I I I «Mm—m— a I u .,.-._~,-1 5, N I600 —4 I625 —< l650 — l675 —« I700 —-¢ Depth (feet) below sea level I725 I 750 1775 WEST BRANCH OIL FIELD . M ‘ Ogemaw County, Michigan Axial Cross Section of the West Branch Field, I 1800 Ogemaw to Mills Townships o 5 I L 1 I a L I rmlee Figure 4. Well and cross section location map. WEST BRANCH OIL FIELD Ogemaw County, Michigan Structure Contour Map on the Top of the Dundee Limestone Contour Interval-Steet Sea level datum ———- Inferred toults —— Axes-cross tolds -— Axes-principle folds ,_ Z L i L Figure 5. Dundee structure contour map. 22 The axis of the field does not appear to be continuous but is broken into an en echelon pattern of short axes with an overall trend of NW to SE. As you go from right to left in this field, the axes tend to revolve from a NW to SE alignment to almost an east to west orientation (Figure 5). Cross-structure trends appear to be oriented in a northeast- southwest direction. These trends can be seen as possible drag folds (Figure 5). Possible fault traces line up at about 15° to the southeast of the folds on the northeast side of the anticline and 15° to the northwest of the folds on the southwest side of the anticline. A prominent en echelon pattern is observed between sections 35 and 36 of West Branch Township (T22N-R2E). The contour lines show a sudden southward movement as you go from section 36 to section 35 (Figure 5). Structural closures also show this northwest-southeast orientation. These closures also show some trend toward the northeast-southwest as evidenced in sections 19, 20, 34 and 35 of West Branch Township (T22N-R2E). Prouty (1970) states that there is a prominent NW-SE and NE-SW trend of folds associated with the lateral faults. Prouty (1976), through the use of LANDSAT imagery, has concluded that lineaments from these studies are shear faults and that the Basin folds are fault related. Shear faults are inferred specifically by structure contour offsets in the Pinconning (Jackson, 1958) and Howell (Paris, 1977) structures. These shearing stresses were 23 manifest in a wrenching deformation in the Basin proper as evidenced by en echelon faults of the Albion Scipio Oil Field structure. Iso- pach studies of these structures suggest principally an early Mississippian development and that the shearing stresses are related to structural activity in the east (Appalachian Orogeny). The geometry of the Dundee Limestone structure is suggestive of a wrenching deformation model with its associated faults and folds. The West Branch Oil Field appears to fit a left lateral wrench system with the principal forces from a general eastward direction (Figure 6). Isopach An isopach map of the Traverse Group was constructed using the same information as was used to construct the Dundee Limestone structure map. Isopachs could not be made of the Bell Shale or Dundee Limestone because of insufficient data. In the more recently drilled wells which are located in sections 21, 27, 28, 34 and 35 of West Branch Township (T22N—R2E), the Bell Shale could be differ- entiated. It was generally 70 feet thick, seldom varying more than 5 feet. The isopach map of the Traverse Group (Figure 7) shows the same northwest-southeast orientation as the structure map of the Dundee Limestone. There appears to be approximately 50 feet of thickening along the axis of the field. Prominant cross-structure thickening is observed with a northeast-southwest orientation as 24 W Figure 6.--Faults and Folds of a Wrench Deformation Model (constructed by J. D. Moody, 1973) WEST BRANCH OIL FIELD 26 evidenced in sections 19, 20, 21, 25, 29, 33 and 34 of West Branch Township (T22N-R2E). The location of this cross-structure thicken- ing is almost always associated with the faults and folds of the Dundee Limestone structure map (Figure 5). Based on the fact that the Bell Shale is a uniform thick- ness wherever it could be differentiated, the observed thickening of the Traverse Group must be caused by something in post-Bell Shale time. Because the Traverse Group isopach shows such a close simi- larity to the orientation of the Dundee structure map, the writer believes this thickening is structurally controlled versus a stratigraphic origin with a primary sedimentary build up. This thickening could be caused by some fracturing develop- ing along lines of weakness originating from the Precambrian base- ment rocks. Harding (1974), using a clay model of an oblique, divergent wrench system, observed in its early stage that there was a pattern of Opened en echelon, synthetic fractures and related sags. Their orientation almost exactly fits the thickening pattern in the Traverse Group isopach. A sag in the Dundee which could be responsible for the Traverse Group thickening could form in another way. Dolomitization could be occurring within the Dundee Limestone along fracture patterns. The sag would occur during contraction of the rocks dur- ing dolomitization. The pattern of dolomitization which will be discussed later should reflect the pattern of thickening. If this dolomitization pattern does not coincide with the isopach, but is 27 more closely related to the Dundee structure map, we can conclude that the dolomitization occurred during the time that the anti- clinal Dundee structure was formed which is believed to be post- Osagian of Mississippian time (Prouty, 1976). Another possibility exists to account for the iSOpach rela- tionship. Solution and karsting of the limestone along the faults (whether accompanied by dolomitization or not) could have produced the thickening of the overlying (Traverse) rocks into the areas of low relief. A glance at various isopach maps of £115 (1962) in the Albion Scipio Oil Field, shows thickening along what has been interpreted by Prouty (1979) as en echelon faults. Here again the sags along the faults into which thicker overlying sediments accumulated could be caused by either dolomite shrinkage porosity (production of oil follows the fault traces) and/or solution and karsting along the faults. LIMESTONE AND DOLOMITE ANALYSES Experimental Procedures Source of Samples In subsurface geological research, core samples or chips are regarded as the best materials for analysis due to lack of contam- ination and known vertical location. Samples from rotary drilled wells are usually contaminated, making it difficult to determine their exact depth within the well. Samples from cable tool drilled wells are comparatively pure and are satisfactory for depth location (Krumbein and Sloss, 1963). All samples in this study were cable tool samples. Sample Selection Samples were taken from 52 wells in the West Branch Oil Field area. These wells include both producing and nonproducing wells, on and off structure. The geographical spacing of these wells was the best possible based on availability of samples. All sample tops listed in drillers logs were verified by use of a binocular microscope. All but one of the tops given were accurate to within a few feet according to the writer's observations. Most of the wells in this research penetrated 170 feet into the Dundee Limestone and not much farther. For this reason, this is as deep within the Dundee as this study is concerned. This 28 29 170 feet of Dundee Limestone was divided into six intervals. A 20 foot interval was sampled at the top with 30 foot intervals the rest of the way down to 170 feet. Sample Preparation Most of the samples (taken from the M.S.U. Geology Depart- ment Sample Laboratory) employed in this study had been washed before. Those samples which appeared dirty were thoroughly washed with distilled water and dried. Sample representatives were taken from each vial within an interval. They were weighed proportionately to the footage the vial represented to make a 4.0 gram sample for each interval. Each sample from an interval was then crushed and ground by an electric grinder for about 10 minutes until the sample size was less than 256 mesh fractions. X-Ray_Diffraction Procedure The x-ray diffraction method of determining limestone and dolomite percentages of rock specimens offer speed without sacrific- ing accuracy and precision (Kutsykovich, I971; Gunatilaka and Till, 1971). Chemical procedures or point counting would be very time consuming and tedious. The x-ray diffraction method is based on the crystal phases of dolomite and calcite which are independent of other Mg, Ca, carbonate-bearing materials (Tennant and Berger, 1956). Various workers have been using the x-ray diffraction technique in the study of carbonate minerals (Tennant and Berger, 1956; Weber, 1967; 3O Gunatilaka and Till, I971; Badiozamani, 1973; Folk and Land, 1975; Supko, 1977). The Method.--The determination of the relative quantities of a multicomponent mixture by x-ray diffraction is based on the relationship between peak intensities and the absorptive properties of minerals (Jenkins and DeVries, I968. The method used in this study consists of recording the relative peak intensities for calcite and dolomite from mixtures of known proportions. A calibration curve is then constructed from these standards. Curves from unknown samples can then be compared with the calcite/dolomite standardization curve (Tennant and Berger, 1956). This procedure is mainly reliable for determining the quanti- tative ratio for the minerals present in the rock specimen. To determine the precise and accurate quantitative measurement of a single mineral, use of a spiking system (internal standard) becomes necessary (Gunatilaka and Till, 1971). Standardization sample preparation.--In this study, pre- viously prepared dolomite and calcium carbonate calibration stan- dards were used. These standards were prepared by M. Dastanpour (1977). Below is an accounting ofhis procedure in preparing the calibration standards, with Table 1 showing the different components used for standardization. The dolomite and calcium carbonate used in preparing the calibration standards were purchased specimens of analytical quality. 31 Table l.--Different Components Used for Standardization Grams Grams Weight Percent Dolomite Mass Dolomite Mass Calcite 15 0.3000 1.7000 25 0.5000 1.5000 30 0.6000 1.4000 50 1.0000 1.000 60 1.2000 0.8000 75 1.5000 0.5000 90 1.8000 0.2000 100 2.0000 0.0000 The dolomite grains were soaked in 5 percent hydrochloric acid for several hours to dissolve any fine calcite crystals that might have grown between the dolomite crystals. The dolomite grains were then thoroughly washed with distilled water and dried. Different proportions of dolomite and calcite were weighted to an accuracy'ofone tenth of one milligram. Each component was then completely mixed with another weighed component to produce the desired dolomite mixture. Table 1 illustrates the different mixtures which were prepared for use as calibration standards. Procedure.--Diffraction peak intensities are affected by grain size, sample packing and mineral orientation (Jenkins and DeVries, 1968). After the samples had been crushed to a uniform 32 size, they were packed with a consistent tightness into Bakelite sample holders, keeping the sample surface as smooth as possible. The sample was then placed in a General Electric X-Ray Diffraction Goniometer and irradiated using copper K radiation, with Ni filtration at 50 kilovolts and 10 milliamperes. Dolomite and calcite peak intensities were recorded by revolving the goniometer to their associated peak locations which was 29.40°2e far calcite and 30.96°2e for dolomite. Counts were taken for 100 seconds or until about 100,000 counts were recorded which put it in the 99.79% accuracy level. A background reading was also taken at 28°2e for 100 seconds. Each sample was scanned twice (the sample was rotated 180°) and the average intensity for both calcite and dolomite was found. Calibration Curve The meaning of dolomite percentage in this study is the amount of dolomite which is present in the total carbonate con- taining both dolomite and calcite. The dolomite described in this study is an ideal one which Goldsmith and Graf (1958) described as a rhombohedral carbonate containing equal molar proportions of calcium carbonate and magnesium carbonate. The characteristic spacing of atomic planes parallel to the 211 crystallographic plane is 2.88A° in an ideal dolomite. It is this character which is seen in the x-ray analysis as a symmetrical and sharp peak. Three samples from each of the standards were scanned (rotated 180°) twice at various times during the x-ray examination 33 of all samples. A calibration curve was established from the x-ray data of these standards (Figure 8). The points along this curve were derived from dolomite/(dolomite and calcite) X 100 intensity ratios as measured versus the weight percent dolomite in the mix- ture. Background readings were subtracted from each of the calcite and dolomite intensity readings. Each point on this curve repre- sents the average results from six points. Data Calculation The correlation coefficient between peak intensities and mass of dolomite percents from the standard samples is 0.996 (r = 0.996). This indicates a high correlation between the two variables. The calibration curve (Figure 8) shows that the calcu- lated peak intensity value, thg—FC'X 100, represents the dolomite percent concentrated in the sample. Expressed in another way: Dolomite = Dolomite mass X 100 Percent (Dolomite + Calcite) mass Dolomite peak intensity X 100 (Dolomite + Calcite peak intensity In this study, 289 samples from 52 wells were scanned twice and their average peak intensity for dolomite and calcite was determined. From these figures, the average dolomite percents were calculated for each sample using the following formula: Dolomite = Dolomite average peak intensity X 100 Percent (Dolomite + Calcite) average peak intensity 34 moo 90!- :80» 70!- 1c 100 50 ‘40 tn) in) + In: 20H 30' 15 25 35 so 50 'is so too xoolomite Figure 8.--Calibration Curve of Dolomite Percent hD hC Dolomite Height peak at 2.88 Calcite Height peak at 3.03 35 Data Interpretation The dolomite percents from each of the samples representing the various intervals is listed in Appendix III. Bar graphs and isodolic (lines of equal dolomitization) maps were constructed from the dolomite percents for each of the intervals. Vertical and lateral dolomite variations are interpreted through these means. Petrogenetic Analyses Sample Preparation No core was available for this study. The petrography of this field was analyzed from well sample chips. Thin sections were made from these chips. Thin sections were made from the same intervals as those in the x-ray analyses. These thin sections from each interval included both high and low dolomite ratios. Calcite and dolomite stains and cathodoluminescence were used to help in this analysis. The use of chips instead of care has its drawbacks but appears to be very helpful in the better understanding of the geology in this field. These chips, where large enough, can show crystal size and sediment fabric from which the depositional environment and diagenetic history can be hypothesized. Petrology Within the study area, the Dundee Limestone is a wackestone. Abundant fossils, both whole and broken, are seen in a lime mud matrix. Fossils include brachiOpods, bryzoans, crinoids and 36 ostracods. Fossil fragments appear to have been more extensively recrystallized from 80 to 170 feet as evidenced by a greater abun- dance of larger crystals. The lime mud matrix appears dark due to a high organic con- tent. This matrix appears to be a micrite that is partially recrystallized to a microspar. The intervals 0 to 20 feet and 80 to 170 feet show more recrystallization of the matrix, with 20 to 80 feet being a micritic mud. Calcite cement is present in internal molds of ostracod shells. Some bivalves have lime mud as molds. Stylolites and microstylolites are found throughout the 170 feet of Dundee Limestone examined. These stylolites appear to be of the Non-Sutured Seam Solution or Solution Dolomitization type (Wanless, 1979). These stylolites appear as seams or microstylolite swarms. Euhedral cloudy dolomite rhombs are often found within and along the insoluble residue of these stylolites. Stylolites are more abundant in the top 20 feet and from 80 to 170 feet. Chert is found from 20 to 170 feet within the Dundee. It is found in trace amounts from 20 to 80 feet and is most abundant from 80 to 170 feet. Almost all the chert has euhedral to subhedral dolomite inclusions. In some of the chert, the sedimentary fabric of the limestone is preserved. Murray and Lucia (1967) point out that the fabric of an original limestone was more easily recognized in replacement chert nodules than in the host dolomite, meaning the chert may have been predolomitization. However, the dolomite rhomb inclusions show slight corrosion and have tiny embayments of chert 37 and occasional chert pseudomorphs of dolomite rhombs. These fea- tures suggest that the dolomitization process may have initiated before the formation of chert (Armstrong, 1970). Thus the evidence for the time of chertification appears contradictory unless there were at least two periods of chert introduction, one predolomitiza- tion and the other post-dolomitization. The situation may be com- plicated by the observations on dolomite occurrence (see beyond). Chert replaces part or all of the dolomite rhombs, but has not been observed to replace the saccharoidal dolomite (coarser crystalline than the microcrystalline lime matrix) which has been interpreted as replacement (epigenetic) dolomite. This then poses the possibility of two (or more) episodes of dolomitization. Dolomite is found throughout the 170 feet of Dundee Lime- stone examined. The dolomite is found in three associations: (1) in and along stylolites; (2) replacing the lime mud matrix; (3) within chert. Dolomite associated with the stylolites appears as cloudy euhedral rhombs. In the top 20 feet this is the only dolomite present. The dolomite which replaces the lime mud matrix is euhedral to anhedral. The amount of dolomite varies from a few floating euhedral rhombs to a mass of euhedral to anhedral rhombs surrounding minute patches of remnant lime mud where replacement has been more complete. This saccharoidal dolomite, composed of randomly oriented rhombs, has been interpreted to have been formed by the replacement of carbonate mudstone (Armstrong, 1970). Fossils are not replaced by this dolomite. The dolomite in the chert was described previously. 38 Analyses The high amount of lime mud present and fossil content of this 170 feet of Dundee Limestone indicate a quiet, shallow marine deposition. With burial and further deposition, the wackerstone was cemented and partially recrystallized. This is represented by the microspar in the matrix and recrystallized fossils. Because the amount of dolomite is neither laterally or verti- cally homogeneous, the selectivity of the dolomite must be con- trolled by the composition of the dolomitizing fluids or the nature of the sediment which is being dolomitized. If the dolomite is water controlled, one area may be dolomitized in preference to another simply because of the composition of the fluid. Dolomite may form in or under supratidal sediments and be absent from equiva- lent marine rocks which do not underlie the supratidal sediments (Murray and Lucia, 1967). Another possibility is that dolomitic fluids follow a fracture system and dolomitization occurs along the fractures but may not dolomitize nearby equivalent unfractured areas. The sediment controlled dolomite is dependent on the physical and chemical parameters of this rock. Permeability and particle size may be important physical controls while the solubility of the carbonate is chemically controlled. The dolomite associated with the stylolites could have three possible origins: (l) the dolomite was present prior to the stylo- lites, perhaps of early diagenetic origin. With dissolution of the 39 carbonate around the dolomite, the less soluble dolomite accumulated along with insoluble residue; (2) dolomite could form from a local source of in situ magnesium as dissolution of the carbonate occurs. This type of dolomite formation can be largely a closed-system process; (3) dolomitic fluids could come from an outside source. With vertical fracturing, which is abundant in this field, dolomitic fluids could follow these fractures and flow out laterally along bedding planes which become the stylolites. Stylolites could be penecontemporaneous with the dolomite formation. These pathways for dolomite would account for its distribution in and along these stylolites. The selectivity of the matrix replacing dolomite could be affected by all of the factors listed previously. Evidence shows that the selective dolomitization of'alime mud may be due to the presence of a more soluble carbonate in the lime mud (Murray and Lucia, I967). Fossil fragments were probably high-magnesium calcite and the mud commonly contains a high percentage of aragonite. Early diagenesis could change the high-magnesium calcite to a low-magnesium calcite which is more stable and aragonite could still be retained, leaving it available for selective dolomitization. Particle size is another factor. Lime mud is very fine and had a large surface area compared to the fossils. Many more dolo- mite crystals could nucleate in the mud. Evidence shows that this dolomite varies greatly in quantity, both vertically and laterally over short distances, even though the 40 lithology remains essentially the same. This may be due to changes in permeability (which could not be determined in this study). Cathodoluminescence Luminescence was observed in the different dolomite asso— ciations using the same thin sections as were used in the petro- graphic study. Manganese (Mn) is known to be the most important activator of luminescence in carbonates while iron (Fe) is the chief quencher of luminescence (Pierson, I978). Different episodes of dolomitization may have a different chemical combination of Mn and Fe which would show up as different lumination colors. In this area, cathodoluminescence showed the luminescence colors for the dolomite associations remained about the same, both laterally and vertically. Dolomite associated with chert, sucrosic dolomite and dolomite in the micritic matrix, showed a burnt orange to bright orange luminescence. The dolomite found in the stylolites and in the top 20 feet of the Dundee Limestone showed a dark brown luminescence. This evidence can be explained by one or more spisodes of dolomitization. If there was only one episode of dolomitization, the differences in lumination colors may be explained by a chemical change locally in the dolomitizing fluid. Higher iron content asso- ciated with the insoluble residue of the stylolites may inhibit the luminescence. The darker color of the top 20 feet may be explained by the fact that most of it was found near stylolites (therefore an iron rich area) or else because the dolomitizing fluid was dammed 41 here by the presence of the impermeable Bell Shale above. Iron would be the last mineral taken up by dolomite precipitation, therefore, in the lower dolomites, very little iron was taken into the lattice as dolomitizing fluids passed through. When these fluids reached the seal, they were iron rich and dark luminescence would be expected. This darkening of the luminescence colors otherwise could be explained by more than one period of dolomiti- zation. Zoning was almost nonexistent and where present appeared as bright centers and dark rims. This would show the fluid was becom- ing more iron rich with continuing dolomitization. X-RaygData Interpretation Vertical Dolomite Variation The dolomite percent values for each well were plotted against their depth below the top of the Dundee Limestone. These dolomite percentages for the various intervals were made into bar graphs. Some typical dolomitization patterns within the Dundee Lime- stone are shown in Figure 9. Two of the wells show the highest dolomite pattern in the 80 to 110 feet interval. One well shows the highest dolomite inter- val in the 20 to 50 feet interval and the other well shows the highest dolomite pattern in the 50 ya 80 feet interval. The bar graph showing the field average of dolomite percen- tage values versus depth interval is seen in Figure 10. The highest 42 Figure 9.--Typical Vertical Dolomitization Patterns in the Dundee Limestone oceru (seer) snow rue ouwoce roe 43 DOLOHITI PEIC‘NT _ N .- l l L l l l J J l L L l I J O ’20 0’20 4 .1 21°50 ZI'SO .4 51'80 51'80 BI‘IIO 81‘ HO d d III‘I4O III'I4O d > d 141‘170 l 141'170 J Well 74 W." 157 o 5 8 ‘5 3 o 5 8 8 l l l l l L L J l L l I L L J 0‘20 0'20 -i —1 21'50 2|‘50 .1 - 5I'80 5l'80 1-l. A eI-llo BI'IIO III'I4O III'I4O 4 i_’ q 1_' 141'170 141'170 Well 293 Well 378 44 Figure lO.-—Average Vertical Dolomitization Pattern and a Typical Neutron Porosity Pattern in the Dun- dee Limestone. 45 Well 210 IO 20 30 4o 50 m IIO- m w mm LOh Hun—2:9 u:.— 39;. can“: aha-u: IZO I40 150 15 20 25 DOLOMITE I IO 10 5 POIONTY 20 46 dolomite percentage is seen in the 80 to 110 feet interval. The dolomite percentage decreases downward in the two succeeding inter- vals down to 170 feet. The dolomite percentage in the bottom three intervals are higher than any average dolomite percentage found in the top three intervals. A large decrease in dolomite percentage is depicted as you go from the 80 to 110 feet interval upward into the 50 to 80 and 20 and 50 feet intervals. From 0 to 20 feet there is a slight increase in the amount of dolomite present. Figure 10 also shows the corresponding typical porosity pattern for this 170 feet of Dundee Limestone. There is a positive correlation between high dolomite values and high porosity values. Lateral Dolomite Variation The dolomite analyses provided data for dolomite ratio maps, which indicate the degree of dolomitization relative to the Dundee Limestone structure. Dolomite percentage values were plotted on a base map of the area for each of the six depth intervals (0 to 20 feet, 20 to 50 feet, 50 to 80 feet, 80 to 110 feet, 110 to 140 feet and 140 to 170 feet). Using this data, lines of equal dolo- mite percentages (isodols) were drawn (Figures 11, 12, l3, I4, 15 and 16). The dolomitization patterns of each of the intervals show a close correlation to the structural (Figure 5) and isopachal (Figure 7) alignments of the area. The degree of dolomitization increases along the axes of the field and decreases as you move 47 Figure lI.--West Branch Oil Field, Ogemaw County, Michigan, 0-20 Feet below the Top of the Dundee Limestone. I I J O h «p 3 0w 0 Q h. a 3 F N 48 .5 a i j + / / I'll. lllIJ/ u z . as up «a an «a 3 / va\«\flw an «a . . . o Vacs. . 2.828 e\e~ . .933... £232 2.2.2:...— ooucao (w 9 3 hp 2: .o no. 2: to...- uoo... ON .0 . ca! 2.3. 33200 525:: .3280 .5530 v 8 .0? a o 01.2.... 4.0 3024"; had? no: wax u:- 49 Figure 12.--West Branch Oil Field, Ogemaw County, Michigan, 20-50 Feet Below the top of the Dundee Limestone. 50 mac 2;. «p p- or «w p N 0N ON a— cm as 23:63 03.30 2: .o no. 2.: 322. 3.... on . ON no! 2.3. 3.6200 . 23.23 {owl-.32... 5:33. .3922! .2530 .6630 aJuE ..:0 1023.0 .595 Cw or «— mac was up.» 51 Figure l3.--West Branch Oil Field, Ogemaw County, Michigan, 50—80 Feet Below the Top of the Dundee Limestone. 52 UH: r NC U=¢ a s a = o. o o s a, = a a pa h a n o . a «a no 5 on an +i o a... /m M/ on 8 8 I . a V 2 Wei; . 2 8 o 8 p a 2 . . x if; 7/ o/oll. w. 2.523 £31.53... £23: 1]. ii\ p 3 233254 02:50 1p $4 0 up or 9 2: .o as 2: :22. .8“. 3-3 go! 2.8. 3.9330 .3022: £2.25 IeELoo . 8 ow a o 5 up 2. ad: .:o .8233 #33 . . no: mac . up: 51 Figure 13.--West Branch Oil Field, Ogemaw County, Michigan, 50-80 Feet Below the Top of the Dundee Limestone. 52 o 2 3 b a «a ON 2 ON «a h e I u 2.62.... e\e~ . .922... £252. I o i\ n p 3 2.2.2:... 02:50 3 w o 9 9 o... 3 no. 2.. to...- 2:“. 00.0n an! 2.2. 2.8030 .3253 .2560 32.3.00 ,3 Op 0 h 3 04!..— 45 zuzcmo hum? an: mac . m:- 53 Figure l4.--West Branch Oil Field, Ogemaw County, Michigan, 80-110 Feet below the top of the Dundee Limestone. 54 T 21 a W .. ‘ efiw” “ 7W4 2 N 11 12 . l___i___ RIIE 53 Figure l4.--West Branch Oil Field, Ogemaw County, Michigan, 80-110 Feet below the top of the Dundee Limestone. 54 I ,” xvii: ll V’ s“. I... .K‘ E 2 a? 7.. e“ \9 33V 2 + a M ale— 2 N 11 ‘3 . i.____l__ BIIE 55 Figure 15.--West Branch Oil Field, Ogemaw County, Michigan, 110-140 Feed Below the Top of the Dundee Limestone. 56 Mac 9;. . iiJj o s a. = 0. 0 0 s a. 3 z “N {\I/A. Ru]: 9“ . \ i... . . a... o o ,. a n v a o p a . o o OM/ a 11/1 ax . Fe 8 3 .V a 8 «a a 8 3 A 0 CI iii V/ A (JR 6 c. + (12.0. . 3 on an 3 0 an on an on e o F \N/l z A J4 2 up... 8 a. on as «a .« l\.w.«// a] 3 as «ha a .IIIII/{IIII + /. IIIII. 0 2.3330 $0.322... £23.. 6. 323...... 3250 3 0p 2 up 0w 9 3 2: 3 no. 22 no.2. 23¢ 02-0.. .3! 23¢ 2.5200 32:22 5:30 .3530 3 2 a o s Np 8 04m... ...o zoz<¢0 .503 uwc 57 Figure 16.--west Branch 0i] Field, Ogemaw County, Michigan, 140-170 Feet Below the Top of the Dundee Limestone. 58 I . u...- ” A. ‘ “J“ J o h «w up or a o b «w 3 z z r a a h b «V . II. a 3“ . a a v a a p a _ MM )4. my; I u «a 5 W f@ 8 8 5 on 8 m . fl/Mgce 3+ on on 8 . 2.. /.. V g. 8 on 8 8 u N\ O 2 8 a. w“ 3 «u . 8 W 8 a p I ~ I p . a 4 9 2.523 oxoulozz... 5:3: / «'3!ka 2.3.05... 0.230 3 hr 8 hp 0.. up .5 .0 00. 2.. 30.00 .00... ONT 0! ca! 2.3. 2.50.00 52.3.! 5250 .5530 3 Op 0 c u up 3 ad: .8 .8233 5a; . no: mm: up: 59 off the structure. This pattern represents the same NN-SE trend- as seen in the structure and iSOpach maps of this field. The isodolic maps also show many NE-Sw trends of high dolo- mite percentages. In almost every case, these cross-trending dolomite percentage patterns align along the cross-structures of the structure map and the cross-trending thicks of the isopach map. This evidence shows a direct correlation between the struc- tural trend of this field and the degree of dolomitization. The inference can be made that the channels along which the dolomitiza- tion occurs are related to the axes and origin of these folds. This implies faulting and fracturing, in which case the isodolic maps may give a better location for faults and fractures than can be found through the use of structure and isopach maps. West Branch Field Dolomitization ME; The dolomite percentage in the West Branch Field varies greatly over a short distance, both vertically and laterally. The distribution of the dolomite, both laterally and vertically, suggests structural control (epigenetic) of dolomitization. The petrography of this field shows possible evidence of two types of dolomite. In one type, dolomite rhombs are being replaced by chert, which might be early diagenetic. The other type, epigenetic dolomite, is associated with stylolites and principally occurs as sucrosic dolomite and composes the majority of the dolomite present. High percentages of this dolomite show a structurally related 60 distribution. The association of floating dolomitic rhombs in a lime mud appear to have the same size, texture and distribution in the matrix as those being replaced by chert and therefore could be due to an early diagenetic dolomitization. Consideration must then be given to the possible types of early diagenetic or structurally controlled epigenetic dolomitization which have occurred in this field. These models must apply to local dolomitization such as is seen in this field. Wilson (l975) lists certain conditions necessary for dolomiti- zation: (l) a sufficiently porous and permeable calcareous sediment to act as host for the Mg replacement; (2) a fluid of the correct chemical composition to react, capable of dissolving CaCo3 and releasing Mg; (3) a long-enduring supply of Mg and (4) a hydro- dynamic head to force great volumes of water through the sediment. One model that fits these conditions is the theory based on the development of Mg-rich brines through evaporation (Adams and Rhodes, 1960; Deffeyes et al., l965; Illing et al., 1965). Dense saline brines with a high Mg/Ca ratio due to the loss of Ca through evaporative precipitation of gypsum and anhydrite in tidal flats, ponds and supratidal areas (sabkas), move down through the lime sediment and dolomitize it. This seepage of a brine through a sedi- ment underlying a supratidal environment would induce dolomitization. Bloomer (l969) has proposed seepage refluxion of hypersaline brines as a mechanism for early diagenetic dolomitization in the Dundee Limestone in the Michigan Basin. Dastanpour (l977) also supported 61 this model. Both of these studies were based on information in the western part of the Michigan Basin where a supratidal environment may have existed due to the positive presence of the West Michigan High (Jodry, l957). The environment for the area of this study has been pr0posed to be marine (Cohee and Underwood, l945; Gardner, l974). Petrographic evidence indicates the presence of an Open- marine fauna. A lack of mud-cracks, algal mats and evaporites suggests other than supratidal deposition and dolomitization. These observations eliminate the likelihood of a restricted lagoon or supratidal area necessary for this dolomitization model. Another possible early diagenetic model of dolomitization was proposed by Badiozamani (l973). His "Dorag" model represents dolomitization by a mixture of sea and ground water. The process would start with a regression of the sea, exposing some part of the sediment to fresh water from rain. Runnels (l969) pointed out that fresh phreatic water with only small amounts of Mg, when combined with marine water, forms a fluid which may be undersaturated with respect to calcite. Saturation of this fluid, with reSpect to dolo- mite, increases continuously with increasing sea water added to the phreatic zone. Badiozamani (l973) calculated that in brackish water in the range of 5% to 30% sea water, the solution is under- saturated with respect to calcite and many times supersaturated with respect to dolomite. The dolomitization process requires a continuous supply of Mg derived from the sea water and mixing with meteoric water. The dolomitizing zone occurs at the interface 62 where phreatic lens of fresh water impinges on the underlying marine or saline connate water. With regression and transgression of the sea, this dolomitizing zone could pass through a large thickness of sediment. Support for this type of theory by Land (l973), Folk and Land, et al., (l975) is evidenced by their studies which indicate that the freshwater phreatic zone, in places of slight mixing of sea water, may be an important zone of dolomitization. This type of dolomitization would generally be regional but could be fairly local. If early diagenetic dolomite were to form in this way in the West Branch Field, the West Branch structure would have had to been present early or else this area needed to be close to an emergent high. This high is necessary for the origin of the fresh water. There is no evidence that this area was structurally high prior to post Bell Shale time or that this area was close to any source of fresh water. This suggests that this model is also inapprOpriate. The dolomite may have been formed penecontemporaneous with sedimentation at the interface of the lime mud and sea water. With periodic enrichments of Mg and the right chemical parameters, this small amount of dolomite may have formed. As mentioned earlier, the pattern of dolomitization shows a definite relationship with the structural alignments (Figure 5 and 7) of the West Branch Field. The highest magnitude of dolomitiza- tion occurs along the axes of the field and along possible cross 63 faults. Dolomite isodols (lines of equal dolomite percentage) drop to very low percentages rapidly as you move away from the structure of the field. This is evidence that the dolomitization was local rather than regional. Whether these low percentages drop off to zero or are representative of a regional dolomite, is beyond the scope of this study. The secondary epigenetic replacement dolomite is probably brought about by percolating ground water through existing joints and fractures in the brittle carbonate rocks (Dastanpour, 1977, and Hamrick, l978). Landes (l946) believed that local diastrophism had produced master fissures in the limestone section, artesian circulation has been developed which carried the water through deeper dolomites and up into the limestone; and that these waters had replaced some of the limestone with dolomite that is locally porous where there was an excess of solution over precipitation during the replacement process or shrinkage dolomitization. Syrjamaki (1977), found evidence of solution along faults in the Albion Scipio Field. The Prairie du Chien is composed entirely of dolomite and should be approximately 350 to 500 feet thick there, but 350 feet has been removed. It is believed that subsurface solu- tions operating along fault systems dissolved this dolomite and may have acted as a source of magnesium for the dolomitization of the overlying formations. The sucrosic dolomite appears to be evidence for this type of dolomitization model. The dolomite in the stylolites and lime 64 mud matrix could also be related to this dolomitization episode. It would be necessary here to assume that dolomitization occurred considerably later than the stylolitization process. This type of dolomitization has been documented by various other studies within the Michigan Basin (Landes, 1946; Powell, 1950; Jodry, 1954; Egles- ton, 1958; Tinklepaugh, 1957; Jackson, 1958; Paris, 1977; Dastan- pour, 1977; Hamrick, 1978. Connate water in a lime sediment would provide only a small fraction of the magnesium needed for its dolomitization, therefore the formation of large amounts of dolomite requires an import of magnesium by the movement of subsurface waters. This subsurface dolomitization depends on a hydrodynamic flow for a continuous supply of magnesium. The extent of dolomitization could be limited by hydrologic conditions, even if the chemical conditions are ubiquitously favorable (H50, 1966). Using average flow rates of 3 to 30 cm/year and an esti- mated magnesium content of 2000 ppm for an oil field brine in the Michigan Basin (Lovering, 1969), the maximum extent of dolomitiza- tion can be calculated as follows: Since 1 c.c. of dolomite weighs 2.85 g. and contains 0.377 9. magnesium, to convert l c.c. of lime sediment to 1 c.c. dolomite with 10% porosity would require an addition of 0.34 9 magnesium. The amount of calcium subtracted from the system would depend on the original porosity of the sedi- ment. 65 Total magnesium available for dolomitization at an annual flow rate of 30 cm/year (3 c.c./year) with a content of 2000 ppm (3.2 millimoles/liter) Mg2+ is (8.2 x 24.3 x 10'3/1000) x 3 or 6.0 x 10'4 g. per unit cross sectional area per year. Maximum rate of dolomitization by this aquifer flow would be (6.0 x 10'4/0.34) = 1.8 x 10"3 cm per year. Maximum rate of dolomitization by an annual flow rate of 3 cm/year (0.3 c.c./year) would be (6.0 x 10'5/0.34) = 1.8 x 10‘4 cm per year. Maximum lateral migration of dolomite away from faults is 0.8 Km. To dolomitize this much area would require 44 million years at a fluid flow rate of 30 cm/year and 444 million years at a fluid flow rate of 3 cm/ year. These calculations are based on fluid flow through a uni- form sediment and do not take into account vertical and lateral fracturing which are believed to be present in this field. These fractures would be avenues of increased fluid flow and, therefore, areas of greater dolomitization in shorter periods of time. Certain problems exist in applying an epigenetic model to the West Branch Field: (1) dolomite does not replace fossils to a great extent; (2) dolomite is seen as floating euhedral rhombs in the lime mud; (3) dolomite is being replaced by chert. The first two of these problems can be explained by an absence of one or more of the necessary conditions for dolomitiza- tion (Wilson, 1975) as listed previously. This writer believes fossils are not generally dolomitized and floating dolomite rhombs 66 are present without the entire matrix being dolomitized because of the lack of a long-enduring supply of Mg or lack of a fluid with the correct chemical composition 'U) dissolve CaCO3. These dolomitizing fluids probably followed the existing areas of permeability and porosity within the rock. Areas with access to greater volumes of dolomitizing fluid were more thoroughly dolomitized than those with limited access. This is verified through the study of 60 neutron porosity logs within the West Branch Field. The greatest areas of porosity correspond closely to the vertical variation of the dolo- mite (Figure 10). Porous intervals are laterally equivalent both on and off structure suggesting stratigraphically controlled poros- ity (and probably permeability) in this field. The amount of dolomite corresponds positively to these logs (i.e., high porosity- high dolomite) but only along the structure of the field. This means that even though high porosity may exist off structure in these permeable zones, dolomite may not be present. The highest dolomite percentage in the field was 43%. This shows dolomitization was not very complete. The micritic matrix may have been more easily replaced due to the more numerous nuclea- tion sites and larger surface area of the lime mud as compared to fossils. If dolomitization had occurred for a longer time, the fossils may also have been replaced. Dolomite within the stylolites could form from these same dolomitizing fluids, using the stylo- lites for lateral migration paths. The dolomite rhombs being replaced by chert could also be of this same episode of dolomitiza- tion. This is based on the observation that the isodolic patterns 67 of dolomitization are structurally controlled which points to the epigenetic dolomitization of this field. If the chert replaces this dolomite of the same episode of dolomitization, chertification would have to be post-dolomitization in this field. 0n the evidence that the chert is only seam replacing dolomitic rhombs in the lime mud and not observed in association with the sucrosic epigenetic dolomite, this writer believes that at least some early diagenetic dolomitization has occurred, followed by chertification. The isodols drop off to a very small percent of dolomite off structure, suggesting the amount of early diagenetic dolomite must have been very low or coincidentally occurred in the area the structure later formed. Evidence compiled in this study suggests the possibility of two types of dolomite. An early diagenetic dolomite could have formed followed by chertification and then later epigenetic dolomite. The time of the epigenetic dolomite is problematic. It is possible that the dolomitization process could have occurred along structures (faults, fractures) syncronous with Middle Devonian rocks. 0n the other hand, it is conceivable that the dolomitization occurred during the post-Devonian time of shear faulting and folding consid- ered the time that most basin linear folds were formed in the Michigan Basin. Dolomite Occurrence in Relation to Hydrocarbon Production Hydrocarbon production in the Dundee Limestone throughout most of the field is outlined by the 1925 feet contour line t-.. .rl.‘ V.’(' 11 - ‘1"b' "ll-Filly. bN‘f r. (lfflll.. l . 68 (Figure 5). All wells within this line are within 45 feet of the top of the structure. In the southeast three quarters of this field, the only Dundee oil wells outside this line are well 251 in section 34 of West Branch Township, well 332 in section 2 and well 348 in section 1 of Horton Township and well 364 in section 31 of Churchill Township. These are all located near areas of high dolomitization or proposed faults. From section 19 of West Branch Township through the northwest quarter of this trend many Dundee oil wells are found outside this -1625 feet contour line. One well, number 32 in sec- tion 23 of Ogemaw Township, is found at 1701 feet below sea level. This is 121 feet below the highest point in this field which lies 1580 feet below sea level. The primary producing zones of this field are fairly uni- form laterally, both on and off structure as seen in the cross section (Figure 17). These zones appear to fade at random laterally but actually correspond very closely to the porosity zones observed in mechanical logs which are laterally continuous. Oil is produced from these zones of permeability and poros- ity whether a high percentage of dolomite is present or not. Studies of mechanical and driller's logs from recently drilled wells in this field indicate that dolomite correlates with the higher porosity of the producing zone. Dolomite formation may be the cause of this porosity or the dolomite accumulates there because the area contained higher porosity (and permeability) due to early diagenetic incomplete recrystallization and cementing. In L nah _.‘A>£l w I..._-W‘ aha-a...- . _ ‘ .. ._‘~¢..‘... .‘pA-er‘ ' .1 lg.- WEST BRANCH OIL FIELD IOgemow County, Michigan Well and Cross Section Locotion Mop +Dry hole oProduclnq well «Injectionswoll p— r— J. L 1 J 1’ miles 5\ 3?, 233 ‘1 ‘r\ “)0 3O 5 40 #' Figure 17. Cross section, Ogemaw to Mills township 70 either case, the dolomite has not destroyed porosity as far as this study can tell. This writer believes that the stratigraphic dis- tribution of the porosity indicates the porosity to be earlier than the dolomitization process which was dependent upon that porosity (permeability) for access of dolomitizing fluids. The source of hydrocarbons could come from within the Dun- dee limestone. The Dundee Limestone contains abundant organic material and driller's logs indicate some intercrystalline oil stain throughout the section. Bloomer (1969) believes the overlying Bell Shale to be the source of oil in the Dundee Limestone. The Bell Shale disappears in western and southwestern Michigan (Gardner, 1974). Where there is no Bell Shale, there is very little Dundee production so this could be a very plausible source for Dundee hydrocarbons. Other possibilities are that the source of the hydrocarbons came from organic rich beds below the Dundee such as those in the Detroit River Group or the thick organic shales of the Cincinnatian Series (Upper Ordovician). CONCLUSIONS From the analytical data obtained from the rocks of the Middle DevonianDundee Limestone, certain conclusions can be drawn: 1. The highest values of dolomite percentages were found in the 80 to 110 feet range below the top of the Dundee Limestone which correlates with the zone of highest porosity. There is a significant relationship between the dolomi- tization patterns and the structural configuration of the Dundee Limestone in the West Branch Field. Wide variation of dolomite percentages, both laterally and vertically, over short distances indicates epigene- tic dolomitization along faults and fractures. Primary porosity in this field is due to early diagene- tic processes and may have been enhanced by epigenetic faulting, fracturing, folding and solution activity. Early diagenetic dolomite may also be present as seen petrographically but not by dolomite distribution patterns. There appears to be a good correlation between faults and folds possibly due to a left lateral wrenching deformation model. 71 72 Dolomite percentages can be helpful in detecting fault traces in the folded structures of the West Branch Field that may not be detected by other means. The intersection of folds (faults) and cross-folds (cross-faults) appears to be the loci of high dolomite percentage where epigenetic dolomite is believed to OCCUY‘. APPENDICES 73 APPENDIX I SAMPLE WELL DESCRIPTION 74 APPENDIX I SAMPLE WELL DESCRIPTION Well Name: F. Estey #E-B Location: SW—NW—SE Sec. 28, T22N-R2E Permit No. 32190 Elevation: 956 feet above sea level Dundee Limestone T0p: 2553 Dundee Limestone 2638.0 2643.0 Limestone, light gray, dense, paper thin shale laminations every 1“, no oil. 2643.0 2644.5 Limestone, as above, banded wet streaks 1", vertical fracture 43.4 - 44.0. 2644.5 2647.2 Limestone, tan, inch layers of porosity mixed with layers of low porosity rock, oil stained stylolite at 46.5. 2647.2 2648.4 Limestone, tan, fine, crystalline, fair porosity, oil stained, bleeding oil from a small fracture through the interval. 2648.4 2668.1 Limestone, slightly dolomitic, tan, dense, bleed- ing along stylolites and small hairline frac- tures. 2668.1 2676.7 Limestone as above, more oil staining than above, vertical fracture 76.4 - 77.0. 2676.7 2677.8 Limestone, tan, fine, crystalline, pinpoint bleeding, good porosity. 75 2677.8 2681.3 2684.5 2698.0 2729.7 2735.7 2681.3 2684.5 2698.0 2729.7 2735.7 2750.0 76 Limestone, tan, fairly dense, small stylolites every 4", some staining. Limestone, tan, some good porosity, pinpoint bleeding, stained, also bleeding along vertical hairline fracture 82.1 - 82.7. Limestone, tan, dense, pinpoint bleeding along the entire interval, small stlolites scattered throughout. Limestone, tan, dense, several stylolites approximately every foot; streaks with porosity are 98.5-02.0, 02.5-04.0, 05.0-09.1; the rest of the interval has pinpoint bleeding throughout. some small vertical fractures throughout. Limestone, light gray, dense, no porosity, no saturations, several thin stylolites scattered throughout. Limestone, light gray, dense, appears wet, vertical fracture 35.0-36.1, 36.4-3619; biostrome at 43.2; large vertical fracture 44.0-46.0. APPENDIX II LIST OF WELLS USED IN STUDY, OGEMAN COUNTY 77 APPENDIX II LIST OF WELLS USED IN STUDY. OCEliAI-I COUNTY 78 $511 Permit Section ‘Eround Traverse Dundee Dundee 30. No. Location Elev. Group Ton Ls Top Ls Top S.L. Datum fiqemaw Townshtp, IZZN, RlE Easy-9.0.12. 1 18210 SE-NE—SW 1090 ~2016 ~2806 —1716 2 4347 SE—NW~SE 1103 «2020 ~2801 91698 3 4406 SE-NE-SE 1107 —1950 «2767 -1690 4 3320 NE-SE-SW 1066 ~1985 -2787 -l721 5 4320 NB-SH-SE 1076 -1937 ~2754 ~16/8 0 17590 C—E1/2-SE—Sw 1071. 4995 -1783 «1717. 7 4497 SE~SE~SW 1034 -2015 ~2791 ~17F7 8 17831 C—SW-SE 1096 -2008 «2793 ~Ewfi7 9 4087 SE-SW—SE 1080 -1990 «”766 ~1686 10 4231 SW~SE-SE 1069 -1970 ~2749 -1030 11 3639 58—58-88 1048 ~1915 —2729 91031 5: 353531-110 -13. 12 2475 su-nw-sw 1088 ~1988 —2771 -1683 13 4277 SE-NW~SH 1074 «1960 -2749 1675 14 1775 NE-HE—Sw 1055 —1965 -2750 -1695 15 18738 SE—NE-SE 1027 -1909 ~2697 ~1670 10 3760 00-50—50 1058 -1951 ~2728 ~1670 17 5041 NE-°W~Sw 1067 ~1960 -2735 "1668 18 2342 E?J~SV-SW hJ41 «1910 —2708 -1667 19 3571 SE«SU-SW 1034 ~1915 ~2704 «1670 20 2856 SW—SE-QW 1027 ~1903 «2695 —1668 21 18587 SE~9E~SW 1043 -1897 «2699 «1656 22 4691 SW-SW-SE 1009 -1879 -2656 -1647 23 3348 88-30-88 1001 -1870 ~2600 -1599 24 3897 sw—SE-SE 1003. —1860 -2054 —1651 Section 23 25 18065 NE RZ-NW 1058 «1970 —2773 «1715 26 18048 NE~NW~H€ 1064 —1940 —2758 «1694 79 Well Permit Section Ground Traverse Dundee Dundee No. No. Location Elev. Group Top 1.9 Top 1.3 Top S.L. Datum Ogemaw TownshipL TZZN, R113 Section 23 27 3613 NW-NE-NE 1044 -1950 -2727 -1683 28 3347 NE-NE-NE 1038 -1915 -2710 -1672 29 4170 SW-NE-NE 1042 ~1932 -2726 -1684 30 4033 SE-NE-NE 1052 -l952 -2730 -1678 31' 19520 NE-SE-NN 1028 -1965 ~2755 ~1727 32 4169 NE-SE-NE 1051 -1965 -2752 -1701 33 2857 SW-SW-NE 1035 -1986 -2770 ~1735 34 19754 SE—SW-NE 1028 -1958 -2740 -1712 35 17946 NE-NE-SE 1016 -l943 ~2738 -l722 36 1770 SE-SE-SE 1004 -1970 —2755 -1751 Section 24 37 1856 Nw-NW—Nw 1018 -1900 -2670 —l652 38 4259 NE—NW-NW 1020 -1865 -2677 ~1657 39 3327 NW-NE-Nw 1015 -1870 -2676 —1661 40 4692 NW-Nw-NE 1001 ~1860 -2644 ~1643 41 3460 NE-NW-NE 998 -1860 -2644 —1646 42 2433 NW-NE-NE 991 —1815 —2625 «1634 43 18669- SE-NW—NW 1022 ~1875 -2701 ~1679 44 4474 SE-NE-Nw 1001 -1870 -2663 —1662 45 3492 SW-NW—NE 1000 —1860 —2662 -1662 46 3349 SE-NW-NE 994 -1850 ~2660 -1666 47 2323 SW-NE—NE 985 -1850 -2626 —1641 48 18217 SE-NE-NE 980 -1825 -2620 -l642 49 3869 NW-Sw-NE 992 -1850 -2677 -1685 50 2135 NE-SW-NE 987 -1836 -2640 ~1653 51 2157 NW—SE—NE 984 —1830 -2628 -1639 52 2309 NE-SE-NE 981 ~1824 —2615 ~1634 53 20090 SE-SW-NW 1017 ~1913 ~2693 -1676 54 20366 SW-SE-NW 1012 -1879 ~2680 ~1668 55 4451 SWésw-NE 994 -187O -2665 —1671 56 6244 SE-SW-NE 984 -1842 -2628 -1644 57 18908 NE-NW-Sw 1007 -1912 -2707 —1700 58 19181 SE-NE-SW 1002 -1900 -2692 -1690 59 3427 SE—NW-SE 983 -1875 —2663 -1680 60 3770 SW-NE-SE 977 -1854 -2645 -1668 61 19532 SE-SE-SW 1015 -1940 -2745 «1730 West Branch Township, T22N,_R2E Section 18 62 19752 SE-SW-NW 1034 -2008 —2722 ~1688 80 Ground Traverse Well Permit Seetion Dundee Eundee No. No. Location Elev. Group Top Ls Top Ls Top __5 S.L. Datum fleet Branchgownghig1 T2ZEL7R2E Section 18 *63 19638 SE-SE—NW 1026 -2010 -2784 -1758 '64 19762 SE-SW-NE 1021 -2045 -2820 -1799 65 19566 SE-NW-SW 1023 -1935 -2708 -1685 66 19282 SE-NE-SW 1014 —1920 -2696 -1682 67 19516 SE-NW-SE 1025 -1960 -2731 -1706 68 3638 sw-swgsw 984 -1830 —2612 -1628 69 18608 SE-SW-SW 991 -1832 -2624 -1633 70 19233 SE-SE-Sw 1010 -1868 -2650 -1640 71 18975 SE-SW-SE 1010 -1881 -2662 —1652 72 19167 SE-SE-SE 1015 -1900 -2694 -1679 Section 17 73 1963 SE-SW-SE 978 -1952 -2744 -1766 Sectiongg 74 3491 Nw-Nw-Nw 980 -1830 -2618 -1638 75 3520 SW—NW-NW 977 -1818 -2598 -1621 76 3858 SE-NW-NW 981 -1822 -2611 —1630 77 2306 SW-NE-NW 976 -1790 -2587 ~1611 78 2286 SE-NE-NW .970 -1775 —2575 -1605 79 18776 SE-NW-NE 988 -1811 -2604 -1616 80 4751 SE-NE-NE 990 -1853 -2628 -1638 81 3332 NW-SW-NW 975 -1810 -2626 -1651 82 3131 NE-SW—NW 966 -1782 -2562 -1596 83 2198 NE-SE-NW 966 -1780 -2575 -1609 84 1900 NE-SW—NE 968 -1782 -2582 -1614 85 4529 NE-SE-NE 981 -1792 -2572 -1591 86 2296 SE-SW-NW 976 -1804 -2596 -1620 87 2309 Sw-SE-NW 970 -1785 -2578 -1608 88 2303 SE-SE-NW 968 -1783 -2564 -1596 89 2225 SW—SW-NE 966 -1786 -2582 -1616 90 18500 SE-SW-NE 965 -1783 -2570 -1605 91 2943 SE-SW-NE 964 -1750 —2572 -1608 92 3350 SW-SE-NE 969 ~1783 -2563 -1594 93 2978 SE-SE-NE 976 -1760 -2558 -1582 94 2513 SW-SE-NE 966 -1758 -2558 -1592 95 3542 NW-Nw-SW 974 -1832 -2609 -1635 96 2287 NE-NW-SW 969 -1758 -2588 -1619 97 2381 NE-NW—SW 970 -1775 -2590 -1620 98 3658 NW-NE-SW 970 -1747 -2592 -1622 99 2321 NW-NE-SW 968 -1798 -2574 -1606 100 2720 NE-NE—SW 965 -1767 -2572 -1607 101 2012 NW-NW-SE 966 -1782 -2582 -1616 102 3351 NE-NW-SE 965 -1785 -2571 -1606 81 Ground Traverse Dundee Dundee Well Permit Section No. No: Lécation Elev. Group Top Ls Top Ls Top S.L. Datum West Branch Township1 T22Ni R2E Section 19 103 2329 NW-NE-SE 964 —1760 -2558 -1594 104 3268 NE-NE—SE 975 -1750 -2575 -1600 105 2224 SW-NW-SE 960 —1760 -2581 —1621 106 4035 SE-NW-SE 958 -1761 -2551 -1593 107 2194 SE—NW-SE 960 -1766 -1560 -1600 108 1758 SW—NE-SE 959 -1778 -2561 -1602 109 3555 SW-NE-SE 962 —1786 -2558 -1596 110 2254 SE-NE-SE 978 -1804 -2581 -1603 111 3975 E112 NE-SE 988 -1792 -2588 -1600 112 3822 NE~Sw-SE 954 -1760 -2560 -1606 113 3960 NW-SE-SE 966 -1770 -2560 -1594 114 3205 NE-SE-SE 967 -1781 -2560 —1593 115 3206 SW-SE-SE 948 -1750 -2557 -1609 116 3764 SE-SE-SE 965 -1775 -2572 -1607 Section 20 117 18230 SE-NW-NW 979 -1835 -2604 -1625 118 18942 SW-NE-NW 970 -1830 —2612 —1642 119 4795 NW-SW-NW 999 -1828 -2605 -1606 120 4293 NE-SW-Nw 970 -1783 ~2580 -1610 121 3200 SW-SW-NW 974 -1768 ~2560 -1586 122 3921 SE-SW—NW 969 -1755 -2575 -1606 123 4341 SE-SE-NW 963 -1814 -2578 -1615 124 3523 NW-NW-SW 997 -1786 -2593 -1596 125 3702 Nw-NE-sw 966 -1760 -2563 -1597 126 4740 NW-NW-SE 968 -1795 -2572 -1604 127 3534 SE-NW-SW 974 -1783 -2569 -1595 128 3042 SW-NE-SW 957 -1752 -2549 -1592 129 2158 SE-NE-SW 950 -1700 —2552 -1602 130 1850 SW-NW-SE 947 -1753 -2551 -1604 131 3547 SE-NW-SE 952 -1760 -2547 -1595 132 2206 SW-NE-SE 959 -1789 -2573 -1614 133 3060 NW-SW-SW 985 -1790 -2573 -1588 134 2314 NE-SW—SW 972 -1780 —2559 —1587 135 3590 NW-SE-SW 957 -1765 -2547 -1597 136 2727 NE-SE-Sw 955 -1756 -2557 -1602 137 1897 NW—SW-SE 949 -1715 -2548 -1599 138 3468 NE-SW-SE 950 -1765 -2537 -1580 139 2351 NW-SE-SE 947 -1766 -2554 -1607 140 2681 SW-SW-SW 969 -1818 -2570 -1601 141 1670 SE-SW-SW 972 -1725 -2556 -1584 142 2410 SW-SE-SW 961 -1780 -2555 -1594 143 1896 SE-SE-SW 947 -1748 -2542 -1595 144 2726 SW-SW-SE 957 -1757 -2538 -1581 145 1631 SE-SW-SE 947 ~1745 -2545 -1598 82 Well Permit Section Ground Traverse Dundee Dundee No. No. Location Elev. Group Top Ls Top Ls Top S.L.Datum West Branch Township, T22N17R2E Section 20 146 1632 SW-SE-SE 934 -1735 -2550 -1616 147 2182 SE-SE-SE 930 -1747 —2559 -1629 148 2332 SW-SW-SW 975 -1790 -2578 -1603 Section 21 149 31338 NW-NE-NW 970 -2000 -2820 -1850 150 18600 SE-NW-SW 942 -1799 -2592 ~1650 151 1858 SW-SW-SW 944 -1760 -2552 —1608 Section 29 152 2257 NE-NW-NW 967 -1780 —2574 -1607 153 1739 NE-NW-NW 956 -1755 -2563 -1607 154 2265 NW-NE-NW 964 -1755 -2564 -1600 155 1861 NE-NE-NW 946 -1752 -2554 -1608 156 2279 NW-NWANE 939 -1751 -2534 -1595 157 2580 NE-NW-NE 938 -1735 -2538 -1600 158 2543 NW-NE-NE 941 -1750 -2540 -1599 159 2375 NE-NE-NE 912 -1715 -2510 —1598 160 18986 SE-NW-NW 954 -1774 -1565 -1611 161 2743 NE-SE-NE 914 -1728 -2505 -1591 162 2312 SE—SE-NE 910 -1728 -2516 -1606 163 2311 NE-NE-SE 911 -1685 —2518 —1607 164 4844 NW-SE-SE 905 -1754 -2545 -1640 Sectionfi28 165 2307 NW-NW-NW 937 -1740 -2528 -1591 166 2308 SW-NW-NW 934 -1720 -2530 -1596 167 5390 SW-NE-NW 967 -1779 -2556 —1589 168 4314 SE-NE-NW 960 -1762 -2555 -1595 169 3559 SW-NW—NE 971 -1776 -2569 -1598 170 4239 SW-NE-NE 947 -1764 -2559 -1612 171 4483 SE-NE-NE 946 -1780 -2560 -1614 172 2310 NW-SW-NW 932 -1719 -2529 -1597 173 3130 NE-SW-NW 953 -1755 -2541 -1588 174 3434 NW-SE-NW 962 -1768 -2562 -1600 175 4802 NE-SE-NW 964 -1772 -2558 -1594 176 5084 NW-SW-NE 961 -1760 -2545 -1584 177 31118 NE-SW-NE 965 -1750 -2562 -1597 178 66 8 NW-SE-NE 937 -1754 —2545 —1608 179 50 5 NE-SE-NE 937 -1758 -2553 -1616 180 224 SW—SW-NW 927 -1730 —2526 -159 181 320 SE—SW—NW 952 -1755 -2550 ~159 83 Well Permit——Section Ground Traverse Dundee Dundee No. No. Location Elev. Group T0p Ls Top Ls Top, 5.1“ Datum West Branch Township. T22N, R2E Section 28 182 5048 SW—SE-NW 954 —1768 -2554 -1600 183 5874 SE-SE-NW 953 -1773 -2556 -1603 184 15952 SE-SW-NE 939 -1747 -2525 -1586 185 31119 SW-SE-NE 951 -1725 -2540 -1589 186 31115 SE-SE-NE 942 -1725 -2538 -1596 187 2159 NW-NW-SW 915 -1724 -2517 -1602 188 4157 NE-NW—SW 931 -1740 -2540 -1609 189 7114 NW-NE-SW 943 -1754 —2545 -1602 190 8064 NE-NE-SW 939 -1748 -2530 -1591 191 32431 NW-NW-SE 956 -1762 -2541 -1585 192 31116 NE-NW-SE 952 -1750 -2543 -1591 193 31117 NW-NE-SE 951 ~1750 -2542 -1591 194 3412 NE-NE-SE 943 —1747 —2523 —1580 195 32190 SW-NW-SE 956 -1771 -2553 -1597 196 2765 SE—NW-SE 943 -1746 -2548 -1605 197 3120 SW-NE-SE 950 -1747 -2547 -1597 198 5086 SE-NE-SE 941 -1741 -2539 —1598 199 2278 NE-SW-SE 936 -1747 -2534 -1598 200 2277 NW-SE-SE 930 -1736 -2538 -1608 201 3843 NE-SE-SE 936 —1743 -2538 -1602 202 6172 SE-SE-SE 921 -1750 -2531 —1610 Section 27 203 3450 NW-SW-NW 922 -1741 -2541 -1619 204 14485 SW—SW-NW 923 -1746 -2531 —1608 205 31620 SE-SW—NW 931 -1730 -2538 -1607 206 32452 SW-SE-NW 941 -1756 -2537 -1596 207 3207 NW-NW—SW 934 -1720 -2536 -1602 208 3535 NE-NW—SW 928 -1760 -2543 —1615 209 31619 NW-NE-SW 930 -1730 -2532 -1602 210 32453 NE-NE-SW 921 -1750 -2523 -1602 211 3409 SW-NW-SW 942 -1749 -2540 ~1598 212 3738 SE-NW-SW 929 -1753 -2525 —1596 213 ' 31120 SW-NE-SW 930 -1730 -2530 -1600 214 32432 SE-NE-SW 919 -1738 -2518 -1599 215 32472 SW—NW-SE 907 -1726 -2520 -1613 216 32143 SE-NW—SE 921 -1730 -2542 -1621 217 3509 NW—SW—SW 926 -1747 -2531 -1605 218 3612 NE-SW-SW 931 -1755 -2536 -1605 219 30925 NW-SE-SW 927 -174O -2530 -1603 220 30921 NE-SE-SW 920 -1725 -2518 -1598 221 13990 NW-SW-SE 896 -1705 -2505 -1609 222 30923 NE-SW-SE 907 -1725 —2520 -1613 223 32435 NW-SE-SE 921 -1746 -2526 -1605 224 3686 SW-SW-SW 916 -1729 -2527 -1611 84 Well Permit Section No. West Branch TownshiprTZZNL R2E No. Section 21 225 1815 226 1848 227 31114 228 30922 229 2172 230 2084 231 3121 Section 26 232 2276 233 4754 Section 25 234 3475 Section 33 235 4753 236 1742 Section 34 237 5243 238 2280 239 2581 240 30918 241 30916 242 1838 243 1751 244 1565 245 5087 246 31669 247 32434 248 30924 249 31150 250 14029 251 4512 252 32145 253 30979 254 31149 255 30917 256 5083 257 3243 258 452 259 31167 Location SE-SW-SW SW—SE-SW SE-SE-SW NE-SW-SE SE-SW-SE SW—SE-SE SE-SE-SE SW-SW-SW SW-SW-SE SW-NE-SW NE-SE-NE NE-NE-SE 22222222222222 222222222222222 222222 II II mmmmmng tflbdiflfltdiflfl' FJEHH=EEFE SE-NE-SE 921 910 930 915 892 905 908 907 915 911 933 925 896 _895 895 900 914 914 912 900 886 893 900 898 895 889 879 879 868 872 Ground Traverse Elev. Group Top -1739 -1723 '1735 -1725 ~1701 -1726 -1717 -1600 -1733 -1851 -1736 -1728 -1725 -1739 -1725 -1750 -1635 -1713 -1710 -1715 -1728 —1730 -1740 -1730 -1705 -1690 -1737 -1725 -1705 -1720 -1705 -1705 -1713 -1675 -1708 Dundee Dundee Ls Top Ls TOP -2534 -2525 -2531 -2517 -2504 -2518 -2513 ~2515 —2512 -2624 -2522 -2528 -2514 -2522 -2526 -2540 -2531 -2508 -2499 -2504 -2516 -2522 -2523 -2532 -2504 -2499 —2521 -2515 -2510 -2505 -2508 —2483 -2495 -2486 -2500 S.L. Datum -1613 -1615 -1601 -1602 -1612 -1613 -1605 -1611 -1630 -1745 —1628 -1661 -1607 -1607 -1615 -1607 -1605 -1612 -1604 -1609 -1616 -1608 -1609 -1620 -1604 -1613 -1628 -1615 -1612 -1610 -1619 -1604 -1616 -1618 —1628 85 Ground Traverse Dundee Dundee Elev. Group Top Ls Top Ls TOp S.L. Datum Well_ Permit Section No. No. Location West Branch Township, T22N1_R2E Section 35 260 1784 NW—NW-NW 893 -1711 -2505 -1612 261 32144 NW—NE-NW 895 -1700 -2518 -1623 262 29779 NE-NE-NW 879 -1680 -2496 -1617 263 12898 SE-NW-NW 903 -1743 -2520 -1617 264 3411 SW-NE-NW 892 -1716 -2505 -1613 265 31159 SE-NE—NW 887 -1715 -2508 -1621 266 14028 SW—NW—NE 875 -1695 -2492 -1617 267 31666 '.SE—NW-NE 883 -1715 ~2502 -1619 268 29767 NW—SW-NW 879 -1672 -2485 -1606 269 3408 NE-SW—NW 872 -1709 -2482 -1610 270 3119 NW—SE-NW 885 -1716 -2500 -1615 271 29778 NE-SE-NW 879 -1694 —2495 -1616 272 29765 NW-SW-NE 878 -1676 —2489 -1611 273 29776 NE-SW—NE 882 -1673 -2480 -1598 274 30920 NW-SE-NE 887 -1715 —2500 -1613 275 14011 NE—SE-NE 884 -1710 -2501 -1617 276 4522 SW-SW-NW 876 -1711 —2490 -1614 277 28938 SE-SW—NW 879 -1690 -2491 -1612 278 28936 SW—SE-NW 872 -1668 -2479 -1607 279 29764 SE-SE-NW 874 -1675 —2488 -1614 280 29777 SW-SW-NE 877 -1675 -2480 -1603 281 3751 SE-SW-NE 874 -1705 -2485 —1611 282 3118 SW-SE-NE 877 -1700 -2483 -1606 283 31668 SE-SE-NE 880 -1712 -2494 -1614 284 4266 NW-NW-SW 875 -1713 -2488 —1613 285 28937 NE—NW-SW 876 -1670 -2485 -1609 286 28399 NW-NE-SW 878 -1668 -2482 -1604 287 9760 NE—NE-SW 869 -1704 -2481 -1612 288 30980 NW-NW-SE 870 -1670 -2482 -1612 289 3575 NE-NW-SE 866 -1692 -2477 -1611 290 3410 NW-NE-SE 868 -1670 -2480 -1612 291 29775 SW-NW-SW 869 -1670 -2498 -1629 292 5082 SE-NW-SW 872 -1690 -2488 -1616 293 5081 SW-NE-SW 864 -1691 -2470 -1606 294 29766 SE-NE-SW 869 -1705 -2478 -1609 295 30919 SW-NW-SE 861 -1661 -2470 -1609 296 31760 SE-NW-SE 856 -1690 -2472 -1616 297 31665 NW-SW—SW 868 -1680 -2487 -1619 298 4831 NE-SW-SW 856 —1694 -2473 -1617 299 4659 NW-SE-SW 853 -1677 -2471 -1618 300 30981 NE-SE-SW 862 -1663 -2474 -1612 301 32165 NW-SW-SE 859 -1678 -2472 -1613 Section_36 302 4713 SE—NW-NW 859 -1696 -2474 -1615 86 Graund_Traverse Dundee —Dundee Elev. Group Top Ls Top Ls T0p S.L. Datum Well Permit Section No. No. Location West Branch Townshipi T22N, Egg Section 36 303 5079 SW-NE-NW 856 -1694 -2466 -1610 304 4103 SE-NE-NW 849 ~1697 -2467 -1618 305 4523 SW-NW-NE 859 -1700 -2482 -1623 306 5080 NE-SW-NW 870 —1695 -2476 —1606 307 3649 NE-SE-NW 859 —1682 -2461 -1602 308 4627 NW—SW—NE 858 -1690 -2457 -1599 309 15966 SW-SW-NW 863 -1686 -2475 -1612 310 2320 SW—SE-NW 852 -1671 ~2455 -1603 311 3229 SE-SE-NW 850 -1672 -2451 -1601 312 3236 SW-SW—NE 838 -1677 -2440 -1602 313 14348 NW-NW-SW 865 -1685 -2488 —1623 314 14269 NE—NW-SW 864 —1679 -2476 -1612 315 2930 NW-NE-SW 858 -1665 -2471 -1613 316 3266 NE-NE-SW 848 -1690 -2455 -1607 317 2204 NW-NW-SE 823 -1659 -2432 -1609 318 4077 NE-NW-SE 820 -1660 —2424 -1604 319 18012 NE-NE-SE 822 -1656 -2425 -1603 320 3000 SE-NE-SW 828 -1671 -2438 -1610 321 3114 SW-NW—SE 828 -1671 -2430 —1602 322 3622 SE-NW-SE 829 -1664 -2441 -1612 323 4322 SW-NE-SE 824 -1685 -2425 -1601 324 4626 SE-NE-SE 822 —1652 -2430 -1608 325 3844 NE-SE-SW 865 -1690 ~2480 -1615 326 2764 NE-SW-SE 840 -1667 -2466 —1626 327 4104 NE-SE-SE 849 -1685 —2498 -1649 328 3117 SE-SE-SW 857 -1695 -2481 -1624 329 3055 SW-SW-SE 855 -1683 -2460 —1605 330 2804 SE-SW-SE 850 -1677 -2458 -1608 331 2805 SW-SE—SE 841 -1666 -2443 -1602 flgrton Township; T21N, R2E Sectionpg 332 4830 NE-NE-NW 839 -1683 -2475 -1636 333 5154 NW-NW-NE 845 -1698 —2479 -1634 334 1246 E%-NE 832 -1687 —2480 -1648 335 16508 SE-NE-NE 840 —1698 -2490 -1650 336 19324 SE-SE-NE 848 —1744 -2524 -1676 Section 1 337 2864 NW-NE-NE 848 -1684 -2457 -1609 338 18095 SE-NE-NW 856 -1703 -2497 -1641 339 2735 SE-NE-NE 846 -1675 -2453 —1607 340 3366 NE-SW—NE 846 -1680 -2475 -1629 87 Well Permit Section Ground Traverse Dundee Dundee No. No. Location Elev. Group Top Ls Top Ls Top S 3.111. Datum figrton Township, T21N, RZE Section 1 341 3068 NW-SE-NE 848 -1696 -2470 -1622 342 2809 NE-SE-NE 846 -1682 -2468 —1622 343 19684 SE-SW-NW 850 -1718 -2513 -1663 344 19351 SE-SW-NE 850 -1710 -2480 -1630 345 3225 SE-SE—NE 847 -1698 -2470 —1623 346 19683 SE-NW-SW 857 -1760 -2545 -1688 347 19472 SE-NE-SW 845 -1706 -2510 -1665 348 2822 NE-NW-SE 842 -1700 -2479 -1637 349 19096 SE—NW-SE 844 -1713 —2490 —1646 350 16827 SE-NE-SE 844 -1727 -L465 -1621 351 19253 SE-SW—SE 840 -1711 -2519 -1679 Churchhill Township, T22N, R3E Section 31 352 4625 SW-SW-NW 852 -1710 -2479 -1627 353 1281 NW—SW-NE 808 -1670 -2522 -1714 354 4321 NW-NW-SW 817 -1650 -2427 -1610 355 4044 SW—NW—SW 823 -1650 —2428 -1605 356 19794 SE-NW—SW 824 —1649 —2437 -1613 357 3837 NW-SW-SW 848 -1680 -2458 -1610 358 4794 NE-SW-SW 848 -1680 —2458 -1610 359 3650 sw-sw-Sw 849 -1688 -2460 -1611 360 2823 SE-SW-SW 847 -1692 -2464 -1617 361 2669 SW-SE-SW 844 -1685 -2455 -1611 362 2518 SE-SE-SW 843 -1683 -2458 -1615 363 2275 SWeSW-SE 842 -1685 -2464 -1622 364 2418 SE-SW-SE 839 -1715 -2470 -1631 Mills Township, T21N, R3E Section 6 365 3030 NW—NW-NW 847 —1671 —2454 -1607 366 2674 NE-NW-NW 848 -1680 -2457 -1609 367 2612 NW-NE-NW 942 -1680 —2457 -1615 368 2436 NE-NE-NW 842 ~1681 -2446 -1604 369 2622 NW-NW-NE 841 -1680 -2460 -1619 370 2807 SW-NW-NW 845 -1685 -2463 -1618 371 4475 SE-NW-NW 842 -1679 -2467 -1625 372 5421 SW—NE-NW 843 -1675 -2458 -1615 373 3106 SE-NE-NW 842 -1675 -2439 -1597 374 2915 SW-NW-NE 839 -1682 -2445 ~1606 375 19345 SE-NW-NE 839 -1678 -2459 -1620 88 Well Permit Sectian Ground Traverse Dundee Dundee No. ‘ No. Location Elev. Group Top Ls Top Ls T0p S.L. Datum Mills Township,_T21N, R3E Section 6 376 2806 NW—SW—NW 842 -1673 -2453 -1611 377 8040 NW-SE-NW 841 -1667 -2465 —1624 378 2288 NE-SE-NW 838 -1675 -2437 -1599 379 2324 Né-SW-NE 837 -1676 -2453 -1616 380 16826 SW-SW—NW 844 -1678 -2448 -1604 381 3301 SE-SW-NW 841 -1676 -2453 -1612 382 2798 SW-SE—NW 840 -1683 —2447 -1607 383 2389 SE-SE-NW 839 -1677 -2442 -1603 384 2168 SW—SW-NE 837 -1595 -2442 -1605 385 1704 SW-SW-NE 837 -1680 -2456 -1619 386 18843 SE-SW-NE 837 -1677 -2448 -1611 387 19614 SE-SE-NE 834 -1697 -2473 ~1639 388 2535 NE-NW-SW 840 -1684 —2459 -1619 389 2721 NW-NE-SW 838 -1664 -2459 -1621 390 2814 NW-NE-SW 838 —1680 -2455 -1617 391 2692 NE-NE-SW 837 -1694 ~2458 -1621 392 2993 NW-NW-SE 836 -1685 -2457 -1621 393 2750 NE-NW-SE 834 -1680 -2456 -1622 394 2600 NW-NE-SE 834 -1672 -2450 -1616 395 19663 SE-NW-SW 841 -1702 -2459 -1618 396 19735 SE-NE-SW 834 -1689 -2465 -1631 397 19187 SE-NW-SE 833 ~1694 ~2479 -1646 398 19180 SE-NE-SE 824 -1690 -2461 -1637 399 19798 SE-SE-SW 837 -1714 —2502 -1665 Section¥5 400 2503 SW-NW-NW 836 -1734 -2495 -1659 401 20016 SE-SW-NW 832 -1721 -2497 -1665 402 19365 SE-NW-SW 829 —1725 -2487 —1658 Section 7 403 16606 NE-NW-NE 829 -1711 -2499 -1670 404 2808 NW-NE-NE 832 -1730 —2503 -1671 Section 8 405 19813 SE-NW-NW 824 -1729 -2507 -1683 APPENDIX III DOLOMITE PERCENT FROM DUNDEE LIMESTONE 89 APPENDIX III DOLOMITE PERCENT FROM DUNDEE LIMESTONE Depth Below the Top of Dundee Ls Well 0-20 20-50 50-80 80-110 110-140 140-170 No. feet feet feet feet feet feet 6 3 2 1.5 4.5 8 7 11 4.5 1 5 3 4 5 X 37 3.5 1 1.5 7 6.5 5 36 3-5 5 X X X X 20 17 1 5 2.5 6.5 3 X 23 5 1 1 11.5 4.5 8 74 4 10 O 18 6 1 107 3 1.5 1 10 6 5.5 155 2.5 1 1 5 4 4 157 4 1 7 6 3.5 2.5 151 6 1 .5 14.5 2.5 X 164 3.5 1.5 1 17 3 3 1.88 3.5 .5 1 5 2 2 168 4 2 2 2 2 3 182 9 2 2 5 2 2 196 2.5 .5 1 14 4 X 200 3 1 1 17 7.5 7 201 2.5 1 1 36 3 212 6 3 1 8.5 12 15.5 239 X .5 2.5 40 10.5 5.5 91 Depth Below the Top of Dundee Ls 4:2 22: 22° 220 222.10 22:9 122-1170 245 1.5 1 3 43 15 1.5 235 4 1 1 15.5 5 6.5 244 3 .5 1 11 11 6 260 1.5 1 3.5 10.5 17 10 276 6.5 .5 2 17 10 5 258 5 1 1 12.5 19 5.5 233 18 2 1 34.5 16 6 293 3.5 .5 1 36.5 14.5 4 298 2-5 -5 -5 35-5 11. 2 281 2.5 2 .5 30.5 12 2.5 289 2 2 2.5 31.5 6.5 2 333 3 -5 1. 31.5 15 9 234 .5.5 2 0 23.5 X X 302 2.5 3 1 25 10 8.5 306 1.5 -5 6 29-5 5-5 3-5 335 3 -5 -5 2.5 X X 317 3 1 1.5 31 14.5 3 328 2 1 1.5 29 14.5 4 326 2.5 .5 5 22 8.5 7 327 1.5 2 12.5 25.5 5 X 337 2 2 2-5 25 13-5 7 339 3 -5 4-5 22.5 9-5 . 3.5 348 .5 1 4.5 34 14 X 380 4.5 X X 21 24.5 9 366 .5 1 2 X X X 92 Depth Below the Top of DundeE Ls Well 0—20 20-50 50-80 80-110 110-140 140-170 No. feet feet feet feet feet feet 372 3.5 .5 18.5 21.5 6.5 2.5 369 3-5 1 2 23.5 22-5 5-5 378 3 1.5 2 5 34 9 2-5 388 4 9 1 23 19.5 5 393 1.5 1 1 37.5 10 1.5 404 1 2 1.5 34 X X 21’ X X 1.5 2.5 2.5 3.5 BIBLIOGRAPHY 93 BIBLIOGRAPHY Adams, J. E., and Rhodes, M. L. 1960. Dolomitization by Seepage Refluxion: Am. Assoc. Petroleum Geologist Bull., v. 44, pp. 1912-1940. Armstrong, A. K. 1970. Mississippian Dolomites from Lisburne Group, Killik River. Mount Bup to Region, Brooks Range. A1aska: Am. Assoc. Petroleum Geologists Bull., v. 54, No. 2, pp. 251-264. Badiozamani, K. 1973. The Dorag Dolomitization Model--Application to the Middle Ordovician of Wisconsin: Jour. of Sed. Petrology. v. 43. pp. 965-984. Bathurst, R. G. C. (ed.). 1976. Carbonate Sediments and Their Diagenesis: Developments in SedimentoloQY. v. 12, Elsevier, Amsterdam, 658 p. Bernardon, M. A. 1957. A Mechanical and Statistical Analysis of the Middle Devonian Rogers City-Dundee Formations in Michigan: Unpublished Master's Thesis, Michigan State University. Berry, L. G. (ed.). 1974. Selected Powder Diffraction Data for Minerals: Joint Committee on Powder Diffraction Standards, lst Edition, 833 p. Bloomer, A. T. 1969. A Regional Study of the Middle Devonian Dundee Dolomites in the Michigan Basin: Unpublished Master's Thesis, Michigan State University. Chillinger, G. V. 1956. Use of Ca/Mg Ratio in Porosity Studies: Am. Assoc. Petroleum Geologist Bull., v. 40, pp. 2489- 2493. Cohee, G. V. 1944. Thickness and Character of the Traverse Group and Dundee Formation in Southwestern Michigan: U. S. Geol. Survey Oil and Gas Inv. Prelim. Chart 4. 1947. Lithology and Thickness of the Traverse Group in the Michigan Basin: 0. S. Geol. Survey Oil and Gas Inv. Prelim. Chart 28. 94 95 Cohee, G. V., and Landes, K. K. 1958. Oil in the Michigan Basin: in Habitat of Oil: Am. Assoc. Petroleum Geologists Symposium, pp. 473-493. , and Underwood, L. B. 1945. Lithology and Thickness of the Dundee Formation and the Rogers City Limestone in the Michigan Basin: U. S. Geol. Survey Oil and Gas Inv. Prelim. Map 38. Dastanpour, M. 1977. An Investigation of the Carbonate Rocks in the Reynolds Oil Field, Montcalm County, Michigan: Unpub- lished Master's Thesis, Michigan State University. Deffeyes, K. 5., Lucia, F. J., and Weyl, P. K. 1965. Dolomitiza- tion of Recent and Plio-Pleistocene Sediments by Marine Evaporite Waters on Bonaire, Netherlands Antilles: Soc. of Econ. Paleontologists and Mineralogists, Spec. Publ. No. 13, pp. 71-88. Dunham, R..J. 1962. Classification of Carbonate Rocks According to Depositional Texures: Am. Assoc. of Petroleum Geolo- gists, Memoir 1, pp. 108-122. Egleston, D. C. 1958. Relationship of the Magnesium/Calcium Ratio to the Structure of the Reynolds and Winfield Oil Fields, Montcalm County, Michigan: Unpublished Master's Thesis, Michigan State University. Elhers, G. M., and Radabaugh, R. E. 1938. The Rogers City Lime- stone, a New Middle Devonian Formation in Michigan: Acad. Sci., Arts, and Letters, Paper 23, pp. 441-446. Ells, G. D. 1962. Structures Associated with the Albion-Scipio Oil Field Trend: Mich. Geol. Survey. . 1969. Architecture of the Michigan Basin: Mich. Basin Geol. Soc. Ann. Field Excursion, pp. 60-88. Fang, J. H., and Bloss, F. D. 1966. X-Ray Diffraction Tables: Southern Illinois University Press, unnumbered pages. Fisher, J. C. 1969. The Distribution and Character of the Traverse Formation of Michigan: Unpublished Master's Thesis, Michigan State University. Fisher, J. H. 1969. Early Paleozoic History of the Michigan Basin: Mich. Basin Geol. Soc. Ann. Field Excursion, pp. 89-95. Folk, R. L., and Land, L. S. 1975. Mg/Ca Ratio and Salinity: Two Controls over Crystallization of Dolomite: Am. Assoc. Petroleum Geologists Bu11., v. 59, pp. 60-68. 96 Fowler, J. H., and Kuenzi, W. D. 1978. Keweenawan Turbidites in Michigan (Deep Borehole Redbeds: A Foundered Basin Sequence Developed During Evolution of a Protoceanic Rift System: Jour. of Geophy. Research, Michigan Well Volume, March. Gardener, W. C. 1974. Middle Devonian Stratigraphy and Depositional Environment in the Michigan Basin: Mich. Basin Geol. Soc. Spec. Papers, No. 1, pp. 43-48. Goldsmith, R. E., and Graf, D. L. 1958. Structural and Composi- tional Variations in some Natural Dolomites: Jour. Geology, v. 66. pp. 678-693. Goodrich, R. E. 1957. Geology of the Reynolds Oil Field in Mont- calm and Mecosta Counties, Michigan: Unpublished Master's Thesis, Michigan State University. Gunatilaka, H. A., and Till, R. 1971. A Precise and Accurate Method for the Quantitative Determination of Carbonate Minerals by X-Ray Diffraction Using a Spiking Technique: Mineralogical Magazine, v. 38, pp. 481-487. Hamrick, R. J. 1978. Dolomitization Patterns in the Walker Oil Field, Kent and Ottawa Counties, Michigan: Unpublished Master's Thesis, Michigan State University. Hanshaw, B. 8., Back, W., and Dieke, R. G. 1971. A Geochemical Hypothesis for Dolomitization by Groundwater: Econ. Geol., v. 66. Pp. 710-724. Harding, T. P. 1974. 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