REGIONAL STUDY OF THE UPPER SILURIAN, SALINA EVAPORITES IN THE MICHIGAN BASIN Thesis Ior ”19 Degree oI M. S. MICHIGAN STATE UNIVERSITY James 'WiIIiam Burns 1962 :L‘ w w) I I I L I B R A R Y Michigan State University I i I I I A ~ ”~— 3 1293 10132 5243 ABSTRACT REGIONAL STUDY OF THE UPPER SILURIAN, SALINA EVAPORITES IN THE MICHIGAN BASIN By James William Burns The regional study was conducted to consolidate and analyze the dispersed information which has become available on the Salina formation primarily since 1945. Geographically this work encompasses the southern peninsula of Michigan. A series of fifteen maps and cross sections were constructed of the various units of the Salina formation. These maps were based primarily on the sample logs from 358 oil and salt brine wells drilled in the Michigan Basin. A practical application of this work is a disscusion of the possible use of several of the Salina evaporite units as underground, radioactive waste disposal containers. Geologically a large lateral area was found to exist in Michigan in which a radioactive waste disposal site could be established. The A—2 and B-Evaporite units possess significant radioactive waste disposal potential. The hundreds of feet of Salina evaporites were deposited in a shallow, restricted sea. The climate during Salina time was rather arid with a very high average daily temperature. James William Burns The importance of the Chatham Sag area as a major source of seawater to the Michigan Evaporite Sea is recognized. The Michigan Basin continually shifted toward the east and later toward the northeast during Salina time. There is excellent evidence for the elevation of the Salina formation to group level. REGIONAL STUDY OF THE UPPER SILURIAN, SALINA EVAPORITES IN THE MICHIGAN BASIN BY James William Burns A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Geology 1962 w 1—_.._ _ TABLE OF CONTENTS Page IMRODUCTION o o o o o oi . "-0 o 0 on; o o o o 0 1 “- HYPOTHETICAL BASIN DEVELOPMENT . . . . . . . . . 6 Formation of an Intracratonic, Evaporite Basin . . 6 Deposition of Evaporite Units. . . . . . . . \1 HISTORY OF DEPOSITION OF THE MICHIGAN SILURIAN. . . . 10 Deposition During the Silurian Period . . . . . 10 Geographical Framework During Salina Time. . . . 1. Origin of the Salina Evaporites . . . . . . . 16 Environment of Deposition of the Salina Formation . 19 DISCUSSION OF THE MAJOR ROCK UNITS . . . . . . . 23‘ Niagaran "Group" . . . . . . . . . . . . 23 Guelph or "Brown Niagaran". . . . . . . . 24 Discussion of Niagaran Structure Contour Map. . 25 Salina Formation or Group . . . . . . . . . 26 Discussion of the Salina Isopach Map . . . . 26 Discussion of the A-l Evaporite . . . . . . 29 Discussion of the Aml Carbonate . . . . . . 30 Discussion of the A-2 Evaporite . . . . . . 32 Discussion of the A-2 Isopach Map . . . . . 33 Discussion of the A-Z Carbonate . . . . . . :5 Discussion of the BnEvaporite. . . . . . 36 Discussion of the BwEvaporite Isopach Map. . . 37 Discussion of the B~Evaporite Structure Contour Map. . . . . . . . . . . . . . . 38 Discussion of the C~Unit . . . . Discussion of the D-Evaporite. . . . . . . 40 Discussion of the E-Unit . . . . o . . . 40 Discussion of the F-Unit . . . . . . . . 41 Discussion of the G-Shale . . . . . . . . 42 Discussion of the Salina Isopach Map . . . . 43 Bass Island Formation or H~Unit . . . . . . . 46 48 RADIOACTIVE WASTE DISPOSAL CONSIDERATIONS . . . . . Properties of Salt Bodies for Waste Disposal. . . 48 Discussion of Radioactive Waste Disposal Areas . . 49 Problems of Radioactive Waste Disposal. . . . Cultural problems . . . . . . . . Engineering problems . . . . . . . Geologic problems . . . . . . . . Discussion of the Composite Geologic Map . The A-Z Evaporite as a Waste Disposal Target The B-Evaporite as a Waste Disposal Target. POSSIBLE ECONOMIC IMPLICATIONS OF THE STUDY . . Oil and Gas Industry . . . . . . . . salt Industry 0 o 0 O 0 O o 0 O 0 SUMMARY AND CONCLUSIONS. . . . o o o . . ' BI BLIOGMPW O 0 0 0 0 O O 0 0 o) O 0 APPENDIX. 0 O 9 0 O O 0 G 0 0 0 0 G 60 60 61 63 Figures —-L— .__D. .. 1—. ‘-~_.__. . , LIST OF FIGURES Page Location Map . . . . . . . . . . . . 2 General Geologic Column of Michigan . . . . ll Tectonic Map of Michigan Area . . . . . . 15 Salina Geologic Column. . . . . . . . . 31 East-West Cross Section of the Southern Portion of the Michigan Evaporite Basin . . . . . Volume II East-West Cross Section of the Central Portion of the Michigan Evaporite Basin . . . . . Volume II Northeast-Southwest Cross Section of the Northern Portion of the Michigan Basin. . . Volume 11 Maps LIST OF MAPS (Found in Volume II) 7-... Structure Contour Map Based on the Top of the Niagaran "Group" Structure Contour Map Based on the Top of the Salina Formation Isopach Map of the Salina Formation Isopach Map of the A-2 Evaporite Structure Contour Map Based on the Top of the B-Evaporite Isopach Map of the B—Evaporite Composite Geologic Map of the Michigan Basin Index of Well Locations Map ACKNOWLEDGMENTS The writer is greatly indebted to Dr. C. E. Prouty, Head of the Department of Geology, Michigan State University, whose aid and many helpful suggestions have made the completion of this investigation possible. Special thanks are extended to Dr. J. H. Fisher, Dr. W. Hinze, and Samual Alguire for their critical examination of the manuscript. Greatful acknowledgment is also due G. D. Ells and other members of the Michigan Geological Survey who provided the necessary sample logs and an immeasurable amount of detailed knowledge of the Siluriam system in the Michigan Basin. INTRODUCTION The purpose of this study is two fold. The major purpose is to bring up to date and expand the work of Kenneth Landes's original decription of the various members of the Salina There is also incorporated several recent works The formation. on the origin and distribution of the upper Silurian. great number of deep tests which have been drilled since Landes's work was published makes this study feasible (Landes, 1945). Though this study has important economic relationships to the oil, gas, and salt industries; another consideration is the possible use of the Salina formation as a radioactive waste disposal container. Since salt units seem to have unique features which favor them as valuable radioactive waste disposal sites; this seems a worthy sector of geologic study. This regional study was conducted over the southern l peninsula of Michigan with major emphasis on that portion of the southern peninsula in which evaporite units were developed during Salina time. Figure 3 pictorially notes this area. When various sectors of the Michigan Basin an examination of are referred to, such as the southwest. Figure 1 should make these relative areas clear. MICHIGAN CENTRAL MICHIGAN I I WESTERN I MICHIGAN I BASIN I I I. I r' _____ ...I I I EASTERN __J INCHunm I ________ I I I I I” I u—-~# sou J'HfiFGSATNERN I‘ 1/ ‘C ' I SOUTHEASTERN g7 f _J MHHHGAN I CAN-- I L __.,_, I I LAKE IND IOHK) “\\\\ LOCATION OF DISTRICTS (FIGURE ONE) (MODIFIED FROM IVES AND ELLS, I957) -me -....'—— e-o—fin. NORTHERN \ The majority of the information used in preparing the and cross sections was obtained from 358 included maps sample logs. These sample logs were prepared and are on file at the Michigan Geological Survey, Lansing, Michigan. one of several cores in Kent, newaygo, Detrailed descripti and Wayne Counties were also studied. In a number of cases the tops of the various units, as picked by the Michigan Geological Survey, were in disagreement This was generally only the case in with those of my own. as deep tests which were described before 1950. Since 1 members of the Salina formation tho the terminology of severa h an evolutionary process, this would be has gone throug ity logs were expected. When electric or radioactiv available they were checked to see if a discrepancy did exist. The wells completed during 1960 posed a special pro- blem since the sample logs on many of them have not been completely prepared. In as many cases as possible this scout tickets problem was overcome by the examination of the and the related radioactivity logs. The deep tests used in this work are complete through January 1961. rmation composes approximately thirty The Salina fo the sedimentary rocks Per cent of the aggregate thickness of found in the Michigan Basin. The Salina formation is represented in the Michigan geologic column as most of the upper Silurian system or Cayugan series of Michigan. This formation is composed mainly of thick evaporite units inter- bedded with shale and carbonate units. As a result of earlier investigations it became apparent that the Salina formation could be divided into a number of distinct members which can be traced throughout most of the Michigan Basin (Landes, 1945). These members have been labeled alphabetically from A through G with the A members representing the basal units of the Salina formation. To complete the upper Silurian, the Bass Island group has been termed the H-unit (Landes, 1945). The original subdivision of the Salina formation has changed somewhat during the past fifteen years as more information became available on the Michigan Basin. For example the original A unit has been divided into four distinct members. Several terms are often referred to which demand explanation. The term Michigan Basin refers to the total area which was covered by the Michigan Sea as its limits were defined in the upper Silurian. The term Michigan Evaporite Basin is restricted to that portion of the Michigan Basin in which evaporites were deposited during Salina time. The hingeline of the Michigan Basin has been correlated with the zone of sudden thickening of the evaporite units. The term Southern Carbonate Shelf, first used by Briggs (1958), notes that portion of the Michigan Basin south of the evaporite pinchout (Figure 3). HYPOTHETICAL BASIN DEVELOPMENT Formatign of an Interacratonic, Evaporite Basin n much of the literature published on geosynclines -' I by Kay (1951), Sloss, and Krumbein (1955), the Michigan he prototype of the autogeosyncline Basin has been noted as t or intracratonic basin. The isolated intracratonic basin generally is represented as an ovate area in which the rate of subsidence decreases outward from the center of the The sediments deposited are mainly composed of fine ource or abundant carbonate basin. clastics derived from a distant s rocks often associated with major evaporite units (Krumbein, Sloss, and Dapples, 1949). An intracratonic basin is ely restricted from surrounding seaways generally not complet f normal sea through its existence. There are periods 0 circulation producing typical marine deposits. There are other intervals in which surrounding positive features or the estrict circulation thereby development of biohermal banks r sequences (Krumbein, Sloss, and developing thick evaporite thick salt sequences are associated Dapples, 1949). These With arid or semiarid climtes such as presently exist in the deserts of Arizona or California (King, 1947). Deposition of Evaporite Units problem of how thick beds of sal Ochsenius (1888) developed The t are formed has puzzled geoligists for many years. the Bar Theory to explain massive salt deposition. Branson (1915) and King (1948) suggested modifications to Ochsenius's theory which more fully explained geologic observations. King explains the problem presented by the presence of about a one to one volume ratio of calcium sulfate to sodium chloride as observed in the Permian, Castile beds of West Texas. The problem is that the ratio in normal seawater is about one volume of calcium sulfate to thirty volumes of sodium chloride. King noted that the Permian— f West Texas and New Mexico was an arid Delaware Basin 0 Eegion in which evaporation greatly exceeded the influx II of local meteric waters. The evaporation rate also exceeded the influx of normal seawater through a restricted The water in the basin which was below average rine formed by the excess channel. wavebase consisted of a uniform b of evaporation. At intermittent times normal marine waters flowed into the basin through the restricted channels and flowed over the uniform brine across the basin. Slowly by evaporation the newly arrived water was concentrated to a ensity of the underlying solution. As brine similar to the d 8 a compensation for the volume of sinking brine, King suggested rsaline water as a continuous seaward flow of dense hype reflux out of the basin (King, 1947). Since in the Michigan Basin the amount of sodium chloride (common salt) far exceeds the amount of calcium a; It! ' .‘ 3 :57) sulfate (ahhydrite) the reflux of hypersaline water is not entirely neccessary to explain the evaporite sequence. This point can later be used to show that the Michigan Evaporite Sea was more restricted than the Castile Sea. Scruton has stated that high brine concentrations are associated with a strong salinity gradient which produces various precipitated salts. The lateral segreation of the escaping deep current returns to the open sea those salts cipitated (Scruton, 1953). Fluctua- which have not been pre tions in the delicate equilibrium caused by changes in excess of evaporation or in the width, depth, or number of Channel openings cause migration of the horizontal salinity gradient along the longitudinal axis of the basin. This process produces vertical differentiation of the various evaporites (Scruton, 1953). He also noted that oh the evaporites are precipitated in the the order in whi n not only can be predicted from studies of vertical colum estuaries and lagoons which presently exist, but agree with the vertical sequences described in several Paleozoic formations. Scruton's horizontal gradient produced the following sequence of deposition. First a carbonate should be deposited, then anhydrite, then halite with anhydrite, and at last nearly pure halite. The following conclusions were ruton, reached by Scruton. on the deposition of evaporites (Sc 1953). in restricted arms of the sea in areas where evaporation exceeds precipitation. 2. Circulation in the basin is established similar to that a continuous inflowing surface current of partly concentrated solution is counterbalanced in part by a continuous return flow at depth of concentrated brine toward the sea. 3. High salinity is developed because of restriction to brine escape. The brine which does escape when equilibrium conditions are established returns to the open sea those salts which have not been precipitated. 4. Restrictions to escape l. Evaporites are deposited of the deep brine are in part static (as physical barriers) and in part dynamic (as relationship between pressures due to hydrostatic head and density distribution, friction between currents flowing in opposite directions, and friction between the deep current and the channel botton. The basin equilibrium is dynamic and is principally sensitive to fluctua- tions of excessive evaporation and degree of channel restriction. 5. The vertical sequence of beds which results from salinity changes can be predicted approximately from experiment on evaporation of seawater. 6. Extreme fluctuations in the precipitations-evapora- {tion budget, so that precipitation and runoff are predominant, can result in a change from conditions of a euxinic basin within the same physical framework. HISTORY OF DEPOSITION OF THE MICHIGAN SILURIAN Depgsition During the Silurian Period The Silurian period was ushered in by a widespread marine transgression from Canada to the north. This marine invasion is represented by the Manitoulin carbonate (Newcombe, 1933). These sediments show normal marine deposition indicating t feature in Manitoulin that the Michigan Basin was not a distinc time. The Kankakee and Findlay Arches, which are believed to be Ordovician structures, apparently existed as slightly' positive features which restricted circulation to the south. The Cabot Head shale which overlies the Manitoulin carbonates was probably derived from clays washed into the Michigan Sea through the Chatham Sag area. Since this shale unit becomes increasingly dolomitic to the north and west, the Chathan Sag provides an excellent avenue through which clastic sediments could have been transported. The red and green color of the shales possibly indicates deposition in a shallow water environment in which circulation conditions were fairly restricted (Melborn, 1958). The middle Silurian, Clinton shale formation was also nflux of clay muds from the east. This the result of an 1 formation indicates increased subsidence and deepening of the marine waters in the Michigan Sea (Melhorn, 1958). GENERALIZED GEOLOGIC COLUMN OF MICHIGAN (HGURE TWO) (MODIFIED FROM IVES AND ELLS, I957) SYSTEMSERIES FORMATION, GROUP LITHOLOGY TIE??? PLEISTOCENE GLACIAL DRIFT SAND, GRAVEL 040034;i PERMO: I SHALE, CLAY 80-95 CARBONIFEROUS RED BEDS j GRAND RIVER SANDSTONE ”39-35:? PENNSYLVAN'AN SAGINAw SHALE, SANDSTON 5.205311? BAY PORTw LIMESTONE 2-Io_o_j MICHIGAN SHALE 0—599; MICHIGAN STRAY SANDSTONE 0-80 I MARSHALL SANOSTONE Ice—400; MISSISS'PPIAN COLDWATER SHALE SOO-IIOq SUNBURY SHALE ONAO: BEREA—BEDFORD SANDSTONE,SHALE 0-325‘ ELLSWORTH—ANTRIM SHALE @0956} TRAVERSE LIMESTONE,SHALE Ice-80E}; BELL SHALE O-80_:I ROGER CITY-DUNDEE LIMESTONE 0-4755 DEVON'AN DETROIT RIVER DOLOMITE 50.4493 SYLVANIA SANDSTONE, DOL. 0-5;__o_I BOIS BLANC DOLOMITELCHERT 0499ng BASS ISLAND DOLOMITE 0.570 I SALT ANHYDRITE '7. ’ ’ loo-3200 SILURIAN SAL'NA SHALE,DOLOMITE ___j NIAGARAN DOLOMITE 15:6”qu CATARACT SHALELDOLOMITE 50-200; CINCINNATIAN SHALEJLIMESTONE 253.ng TRENTON LIMESTONE 20D- .‘ OR --——-—I DOV'C'AN BLACK RIVER DOLOMITE Ioogwi ST. PETER SANOSTONE owlI OZARK'AN PRAIRIE DU CHIEN DOLOMITE 0-4m OR 1... CANADIAN HERMANSVILLE DOLOMITE I5-SOOI MUNISING TI CAMBRIAN .J JACOBSVILLE SANDSTONE JZOO-ITCj 12 Niagaran time has been noted as the first extensive subsidence of the Michigan Basin. The Michigan Sea was cted to the Illinois Basin to the south by the Battle latively free circulation conne ek Trough‘thereby permitting re (Melhorn, 1958). The Cre between the two subsiding basins Chatham Sag was also an important link between the Appalachian seaway to the southeast and the Michigan Sea. The light colored, fine-textured carbonates contain various a normal marine environment. As fossils which indicate Niagaran time progressed an increasing number of bioherms were formed along the hingeline of the basin as small isolated, As the reefs became more prominent, discontinuous structures. the importance of the Battle Creek Trough as a link between the Illinois and Michigan Basin diminished. This was probably due to a slight rejuvenation of the Kankakee and Findlay Arches which remained as primarily positive features through- This increased restriction of the out the upper Silurian. on of the Salina evaporites basin resulted later in the depositi (Melhorn, 1958). The upper Silurian, which is represented by the Salina formation and the Bass Island dolomite, began with the Widespread depositiOn of carbonate muds and anhydrite. The deposition of the A—l evaporite which soon followed indicates 13 the development of a silled or barred basin in which intermittw ent influxes of normal marine water caused the deposition of carbonates in the predominently salt section of the Salina formation (Dellwig, 1954). As evaporitic conditions became more intense the reef structures of the upper Niagaran or Guelph member of the upper Silurian died out and were overw lapped by major evaporite units. These reefs in many places formed dome like or pinnacle structures in the overlying formations which are of economic interest (E115, 1958). Geographical Framework During Salina Time The positive features surrounding the Michigan Basin during the Silurian were the Canadian Shield to the north, the Wisconsin Dome to the west, the Kankakee Arch on the southwest, and the Findlay Arch on the southeast. None of these features was the source of large amounts of elastic material during Salina time. This indicates that these features were at best only slightly positive. Various authors such as Pirtle (1932), Newcombe (1934), and Lockett (1947), are in agreement that most of the regional tectonic features forming the freamework of the Michigan Basin were inherited from the late Precambrian time. Such features as the Kankakee Arch and Findlay Arch are believed to have first become 14 important during the early Ordovician (Melhorn, 1958). One of the major inlets through which seawater rem plenished that lost by evaporation was the Chatham Sag. Other than scattered evidence presented by the inclosed maps on the importance of the Chatham Sag as a link to a southw eastern seaway the following has been observed. 1. Shaly units in Oakland County, near the Chatham Sag, tend to be thicker and more common than in other parts of the evaporite basin. 2. In the International Salt Mine at Detroit, Michigan WW, the poor development of bedding, fragmentation of halite crystals, and the abundance of ripple marks note this area as one of turbulence of sea« water (Dellwig, 1954). This would be expected if a current was flowing through the Chatham Sag. 3. The Salina isopach map shows an extensive thick» ening of sediments in the Chatham Sag area. The Georgian Inlet located in the present Georgian Bay. Ontario area has been considered as an important possible source of seawater to the Michigan Evaporite Basin during Salina time (Briggs, 1958). Several of the enclosed maps indicate a possible source of sediments from the Georgian Inlet area. Briggs noted that the Clinton Sag J - ‘3‘". ..... a. K J /,./-‘\\_fl f “PW/J kJJ [/3 /Trf”‘/ \ ~7 / V‘s Q) < / / (.3 ll ~~~~~~~ I/ be IIII ...... . 4* \ ,x’ \x m \X‘ . ,x 6’000 q, p (v ’x’ 4/ \ ‘ v K \/ x “ : II 'I MICHIGAN EVAPORITE BASIN 3 ‘ I v x Q ’ y \\\ I” § \\\\ f ’I Q) r \\\ 531‘ // ‘\ 5) KCHA AG" ,j \\ Q’ ‘ .. 5- I NM} ‘~~. ,.-..-- , a O V g a .. cu SOUTHERN A V 9‘" If CARBCNA E z 3 \15, I / IND. OHIO x; ,1... I "K ANKAKEE ARCH” TECTONIC MAP OF MICHIGAN DURING UPPER SILURIAN TIME (FIGURE THREE) ' .. _ 16 could have been a source of seawater into the Michigan Basin during Salina time (Briggs, 1958). The isopach map of the Salina formation indicates thickening of sediments in the Clinton area, but it is doubtful that the Clinton Sag contributed much seawater to the basin. During the deposition of such major units as the A-1 and A-2 carbonates the Clinton Sag might have been a significant source of is believed to have been seawater. The Battle Creek Trough blocked throughout most of Salina time by a slight rise of the Kankakee Arch (Melhorn, 1958). Origin oggthe Salina Evaporites Louis Dellwig made an interesting study on a core from the Glen Bradley No. 2 in Newaygo County and contributed some important information on the origin of the Salina evaporites (Dellwig, 1954). Dellwig”s thin section study, which was supplemented by an examination of polished slabs and water-insoluable residues, was conducted mainly on core from the A-l Evaporite unit. Dellwig determined that pyramidal shaped hopper crystals of halite were deposited during the time of the Aml Evaporite which are very similar to those formed by nature in salt flats or evaporite pans today. He also noted that these pyramidal forms were 17 outlined by liquid inclusions from which an estimate of the e salts could be determined. temperature of formation of th were trapped in the crystals Apparently small bubbles of air as they cooled. By determing when these air bubbles dis~ appeared when heated Dellwig was able to state that the salt crystals were deposited at a temperature ranging between 32.0 and 48.4 degrees centigrade (Dellwig, 1954). When converted to Fahrenheit this would mean that the temperature at the surface of the Michigan.Evaporite Sea varied between 90 and 119 degrees at the time of the salt deposition. To substantiate these figures, Dellwig noted the presence of Langeinite which is a rare mineral deposited at a minimum temperature of 37 degrees centigrade (Dellwig, 1954). He observed that a warm season produced smaller halite crystals than a cold season. This lead Dellwiq to the conclusion that higher temperatures were common during the formation of the Awl Evaporite than are found in solar salt flats today (Dellwig, 1959). The extremely high temperatures proposed by Dellwig Could be parcially explained by the heating effects of radiant heat (Douglas and Goodman, 1957). Radiant energy can pass through mediums which are transparent to the wave length of radiant energy such as semiwfresh water and heat 18 up the more saline solution below due to its lower specific heat. This would make it possible for a restricted evaporite sea to accumulate more heat during the day than it loses during the night (Douglas and Goodman, 1957). The radiant energy theory could greatly modify the effects of daily and seasonal variations in temperature. Dellwig noted that the salt was deposited in three distinct layers. 1. Cloudy layers of inclusionwrich pryamidal shaped hopper crystals of halite. Clear layers of inclusionwfree halite. and 3. Laminae of anhydrite and dolomite.’ These units are in part obscured in the recrystalm ized salt. The alteration of bands of clear and cloudy halite was the result of temperature changes. probably related to the seasons. The salt crystals initially formed on the surface, growing as pyramidal shaped hoppers. Until the brine became saturated, settling hopper crystals were dissolved. After the saturation point has been reached pyramidal shaped hopper crystals accumulated on the bottom of the basin to form a layer of cloudy salt. With subsequent cooling the brine passed into the supersaturated state and settling hopper crystals provided nuclei for clear overgrowths. ' These crystals which grew on the bottom of the basin are inclusionwfree and form layers of clear salt. The return of higher temperatures followed by lower temperatures would cause a repetition of this sequence. This cycle could have been inter- rupted at any time by the addition of brine to the basin or by periods of unusual climatic conditions. 19 Dellwig also mentions that there is very little evidence the salt crystals have undergone deformation and this probably indicates that little pore space existed between the salt grains at the time of deposition. Together with recrystallization and original growth the salt beds formed a rigid rock unit (Dellwig, 1954). Several minerals such as quartz, celestite, poly- halite, pyrite, and graphite are often found in very minor amounts when insoluble residue tests are made. The rare salts are quite unusual for apparently the sequence of precipitation was terminated before the development of the polyhalite phase as suggested in the theoretical sequence of salt deposition (Dellwig, 1954). Environment o§;deposition of the Salina formation There is little evidence of fossil life in the Salina formation. This often mades correlation of some of the members difficult, especially in the area of the Southern Carbonate Shelf. Some evidence of fossil life has been found in the form of long tubes of carbon which closely resemble those of the DevonianeSilurian Prototaxities plant. This form of life is of questionable marine or terresa trial origin (Arnold, 1952). 20 The following evidence indicates the depth of water in the Michigan Evaporite Sea did not exceed a depth of approximately fifty feet. In fact the average might well be between ten and thirty feet. It is also quite probable that large salt flats existed as slightly positive features in various parts of the sea. These salt flats could have actually separated the Michigan Evaporite Sea into a series of smaller bodies of brine for limited periods as was suggested by (Melhorn, 1958). Evidence for shallow water origin. 1. The presents of a great number of minute angular unconformities in the salt sections. Several of these have been noted in the core samples of gas storage wells in western Michigan. 2. Presence of ripple marks in the International Salt Mine in the evaporite sections (Kaufman and Slawson, 1950). 3. Presence of a twenty foot shaly conglomerate in southeastern Huron County (Figure 6). 4. The possible presence of wind blown salt in western Michigan; Whitehall Oil Corporation SP22839, Sheridian Twp. #1, 26-12Nel4W, (3680-3690 in D-Evaporite) (Ellis. personal communication). 21 5. The presence of patch reefs scattered over a wide area of the basin in late Nigaran and possible early Salina time. 6. Presence of hematite in small quanitities in association with the salt units. Notes oxidizing conditions indicating formation above wavebase. From the preceding discussions a summary of the environment of deposition of the Salina formation has been constructed. 1. The tectonic framework existing in the area of the Michigan Sea during Salina time was extremely stable. 2. The Michigan Basin subsided at a relatively uniform rate as sediments were deposited. 3. The lack of large volumes of clastics in the Salina geologic column indicates that the surrounding land masses were only slightly positive features at best. 4. The Michigan Sea during Salina time was predominently isolated from related water bodies. 5. Water lost by evaporation from the basin was mainly replenished through several narrow inlets or troughs. 22 6. Little organic life existed in the Michigan Evaporite Sea during the time of the evaporite deposition. 7. The average daily temperature was extremely high during the time of salt deposition. 8. The climate during Salina time was apparently quite arid. 9. The water in the Michigan Evaporite Sea was generally under fifty feet deep. DISCUSSION OF THE MAJOR ROCK UNITS Discussion of the Niagaran 'Group' The Niagaran group which underlies the Salina formation is composed predominantly of dolomite though in scattered areas in the Michigan Basin it is composed mainly of limestone. The upper unit of the Niagaran "Group is known as the Lockport Dolomite in the southern two-thirds of the Michigan Basin. In the northern penisula, where the Niagaran Group is exposed, the interval is known as the Engadine formation. The Lockport Dolomite is described in most sample logs as a white to blue-gray dolomite. In various portions of the basin it is light brown to gray-brown. The Lockport Dolomite possesses good porosity and in the Albion- Scipio oil field west of Jackson, Michigan excellent porosity is present along the proposed fault trend. The Guelph- Lockport dolomites contain a great number of biostromes and bioherms. In these reef buildups the porosity varies from extremely vugular to intercrystalline. The vugs in the Upper part of the reefs are often filled with salt or anhydrite which is believed to come from the overlying evaporite units (Melhorn, 1958). It is important to note that the reefs found closer to the center of the basin are more commonly salt filled. This is an important factor in 24 the economic exploration for petroleum in the reef zone. This would limit the importance of the reef zone normally to the outerfringe of salt deposition. The reefs formed an undulating topography over which the Salina evaporite units were deposited. They give the effect of buried mounds or pseudoanticlinal structures on structure contour maps of the upper horizons (3115. 1958). These features are apparent on the various structure contour maps in the St. Clair County vicinity of Eastern Michigan. figglph o;¥"Brown Niaqaran.“ This carbonate section varies from ten feet in thickness near the center of the basin to several hundred feet where the reef sections are developed. In the southern portion of the Michigan Basin the drilling term, "Brown Niagaran," has been applied to this distinct brown colored basal carbonate section. This unit presents a specially difficult strati~ graphic problem. Lithologically it seems that the Guelph or "Brown Niagaran" horizon should be included as part of the Niagaran Group. It is probable that the Guelph or "Brown Niagaran" horizon represents the first phase in the progressive evaporite sequence as presented by Scruton (1953). If the latter statement is the case, there is a sound reason for placing this unit as the basal horizon of the Salina 25 formation. Since the accepted top of the Niagaran group is often hard to distinguish except by an examination of the samples, the Guelph or "Brown Niagaran" is sometimes picked as the true Niagaran top on drillers logs. Actually this unit has little significance except in the reef areas. It is difficult to determine if the reef section should all be included in the Guelph or ”Brown Niagaran," or only partially included. This horizon does represent an important potential oil and gas pay zone. Discussion of Niaqgggn structurgfgontour map. 'The Howell and Freedom Anticlines appear as very distinct features on this map. These two major anticlinal trends appear to be converging towards their northwestern limits. Several smaller anticlines can be noted in Monroe County which appear to merge with the Freedom Anticline. Two anticlines are evident in the eastern portion of the basin. These two trends appear to be associated with the known bioherms in the Maccmb-w St. Clair County area. The regional dip of the basin is fairly uniform except in the northern and northwestern portions of the basin where the regional dip is steeper. The basin is quite ovate with a slight northwest-southeast enlongation. The structural center of the basin is located in central Gladwin County. 26 A structural low in southwest Hillsdale County and also one in southwest Cass County appear as distinct features. On the Salina structure contour map these features are largely absent since the upper Salina units have been truncated by the disconformity associated with the close of the Silurian. Salina Formation or Group There is an excellent case for the elevation of the Salina formation to group level. This would be in line with recent trends in stratigraphy and also in keeping with the present usage by a number of authors. The following evidence is presented for the elevation of the Salina forma- tion to group level. 1. The Salina formation can be readily segregated into ten distinct members which can be traced across most of the Michigan Basin. 2. The Salina formation reaches a maximum thickness of over 3200 feet near the center of the Michigan Basin. 3. The Salina formation represents the majority of the upper Silurian column in the Michigan Basin. Discussion of the Salina Isopach Map. The isopach map of the Salina formation indicates a basin which is elongated 27 in a northwest-southeast direction. The area of maximum thickness is located in the northwest corner of Arenac County. The approximately 3200 feet of Salina rock proposed for this area is located northeast of the structural center of the basin. This map tends to confirm the shift of the center of , deposition toward the east and northeast which is noted in the later discussions of the various maps and cross sections. Though the basin has been portrayed as closed on the north- east it is possible the basin extends farther to the east and northeast than it has been mapped. For example Salina salt units have been commercially exploited for many years along the eastern shore of Lake Huron in Ontario, Canada (Caley, 1945). The hingeline of the Michigan Basin has been defined as the average line of pinchout of the Salina salt units (Map No. 7). The hingeline of the basin is very apparent on the Salina formation isopach map. The hingeline of the basin is extremely steep parallel to the Howell and Freedom Anticlines. There does appear to be a definite thinning of the sediments over the Freedom Anticline as can be observed by the sharp break of the contour lines over this structure. The Chatham Sag, Clinton Sag, and Battle Creek Trough are apparent features. A rather distinct narrow reentrant can 28 be observed plunging south into Monroe County. The reef structures in the Macomb-St. Clair County area are extremely evident, but all the basinward extentions do not conform with reefs which have been detected at present. Another distinct area of thickening in northern St. Clair County approximates the position of the Port Huron Monocline or fault. There are two anticlinal trends on the Southern Carbonate Shelf. one of which is in the area of the AlbionQScipio oil field and the other to the west of the Battle Creek Trough in Van Buren, Cass, and Kalamazoo Counties. The Van Buren projection hints there might actually be two projections of thin sediments separated by a narrow thick lens of Salina sediments. The area in Macomb County, which Landes (1945) be- lieved was due to the leaching of the upper Salina evaporites and later collapse of the sediments, is represented by a hachured symbol since the contour interval of 100 feet would be impractical to adhere to in this area. Recent evidence from an unpublished cross section indicates collapse after leaching is not the case (Ells, personal communication). It appears the FoEvaporite units were either not deposited or have been removed so slowly that the interbedded carbonates and overlying Siluriam sediments 29 subsided without losing their identity. This is an interests ing area in which more research will have to be done before the actual cause can be safely stated. In the northern portion of the basin it is difficult to distinguish local structure from the regional dip since few wells have been drilled through the Salina formation. There does appear to be an area of thinner sediments in southwestern Charlevoix County which could represent a local structure. In the western portion of the Michigan Basin a fairly pronounced wedge of sediments is noted. This is located in Oceana and Mason Counties. Description of the A-l Evaporite. The Ael Evaporite unit is the basal evaporite in the Salina column. It rests upon the Guelph or “Brown Niagaran" carbonate. The Ael Evaporite is composed mainly of a relatively clear salt section which includes some anhydrite and carbonate. It reaches a maximum thickness of about four hundred feet of relatively clear salt near the center of the basin. Near the flanks of the basin it is represented by an anhydrite section which has a maximum thickness of about thirty feet. The anhydrite grades into a carbonate section as the edge of the Michigan Evaporite Basin is reached. 30 In those areas where GuelphuLockport reefs have been developed the A-l Evaporite generally is not present as a salt unit, but is represented by an anhydrite unit which pinches out over the reefs. This can be noted in the Berlin reef field, the Boyd reef field, and the Peter°s reef field in St. Clair County. The A-l Evaporite has a much greater westward extent than the other salt units. This is evidence of the continuous shifting of the basin toward the east with the later deposition of younger units. Description of the Ael Carbonate unit. The Aul Carbonate rests directly upon the Awl Evaporite. It is a dark brown carbonate which is shaly and anhydritic in places. Its thickness vaires between 50 and 130 feet within the area of evaporite deposition. t may not be present over the higher portions of reef sections. This unit may be entirely dolomite or limestone or a combination of the two. No definite relationship between the dolomite and limestone was established relative to geographic position in the basin. It can be advanced that the Aml Carbonate in the northern and northwestern portion of the basin is composed mainly of limestone though this is not always the case. The texture of the carbonate varies from sublithographic to (:7 5‘ f I h at; THE 'MsCHICAM .vf 1;..1 ::;;;R E.\x'£xF-"=’3Fv‘ITE BASH-.1 (FIGURE FOUR) ',_ , .r” . a.“ l ' w. ' I ._-‘ ’ I \ ,p . . xx _ . . . FORMATION MEMBER LITHCLOGY 7:be BASS ISLAND IOO- f OR DOLOMITE-ANHYDRITE,SHALE 2 H-UNIT GOOFU G-SHALE SHALE-DOLOMlTE,ANHYDRITE 40’ ; IZO FT.. “'1 IOO- I: F- UNIT SALT, DOLOMITE-SHALE,ANHY. IOOO 9 FT. : E- UNlT DOLOMITE-SHAME ANHYDRITE IOO- ! S ’ I70 FT; A ti 0— : L - .. . D EVAPORITE SALT SHALE,DOLOMITE,ANHY. 80 FT! ' 4 N C-SHALE SHALE-DOLOMITE ANHYDRITE 30" ' A ’ I40FI; B-EVAPORITE SALT-DOLOMiTE,SHALE,ANHY. 0‘ 440 FT. OLOMITE-SHALE,ANHYDRITE A-Z E ____________ loo" 1 CARBONATE 2—0—0}: LIMESTONE-SHALE,ANHYDRITE ’ A-2 _ . O— EVAPORITE SALT DOLOM‘TE, ANHYDRITE 480FT‘ A" DOLOMITE, 'SHALE ANHYDR 50‘ CARBONATE LIMESTONE ' ”E 13cm A-l _ O- EVAPORITE SALT OOLOMITE.ANHYDRITE 4OCF f — _ GUELPH DOLOMITE,LIMESTONE bog—.5}: 32 finely crystalline. Various horizons of the A-l Carbonate have been referred to as the ”poker chip" shale (Elle, 1958). Cores of particular lenses of this unit'split rather easily into thin wafers of chips of about an eighth of an inch thick. The "poker chips" are composed of minute laminae of dark brown, finely crystalline dolomite separated by eveh thinner carbonaceous partings (Ells, 1958). The "poker chip“ horizons also contain thin partings of dark anhydrite. The ”poker chips" as described probably represent annual cycles. Changes in salinity due to variations in tempera- ture, evaporation, sea level, or wind could separately or cumulatively have caused the formation of the "poker chips" (Adams, 1944). These ”pdker chip" horizons are found scattered over much of the southern half of the basin. The porosity of some of thses dolomite laminae is extremely geod. The A—l Carbonate is much lighter in color and of a more consistent dolomite lithology to the south of the hingeline of the basin. The A-l Carbonate contains oil and gas pays (Ells, 1960). I Discussign of the A-2 Evaporite. ‘The A-2 Evaporite extends from the top of the A-l Carbonate to the base of the A-2 Carbonate. It is composed primarily of salt with some 33 interbedded anhydrite, shale, and dolomite. These impurities are mainly concentrated within the upper 100 feet of the unit. The A-2 Evaporite reaches a maximum known thickness of 463 feet of relatively pure salt to the northwest of Bay County near the theoretical center of the Michigan Basin. The average thickness of this unit is about 250 feet within the area of salt deposition. The A-2 Evaporite grades into a twenty foot anhydrite near the salt pinchout. The A-2 Evaporite has definately shifted eastward from the A-l Evaporite. Discussion of the A-2 Evaporite isopach map LMap N 4,4). This map notes a maximum known thickness of more than 470 feet of salt in a northwest-southeast elongated basin. A bicentered basin is presented forming an odd horsehoe shape. One center is located in central Gladwin County and the other in southwestern Tuscola County. This horseshoe shape is probably due to the greater amounts of carbonate and shale that is present in the Saginaw Bay area. This /unusual thickness of non-evaporite sediments could be from the proposed Georgian Inlet to the northeast of the southern peninsula of Michigan in Ontario, Canada (Briggs, 1958). 34 The A-Z Evaporite is generally present westward of the B-Bvaporite and somewhat southward of it. The A-2 Evaporite wedges out very rapidly in the southwestern portion of the basin. Within ten miles the salt section thins from 250 to 0 feet. Several large embayments can.be observed. Of particu- lar importance is the thickness of the evaporite section in the Chatham Sag area. In Oceana County there also is a noteworthy thickening of the evaporite section. There is an unusual thickening of the section in Barry County in the southwestern portion of the basin. This unusual thickening could be related to a yet unnamed sag somewhat west of Melhoun's (1958) proposed Battle Creek Trough. The Salina isopach (Map No. 3) and B-Evaporite isopach (Map No. 6), also notes a thickening of sediments in this area. Detailed, unpublished structure contour maps indicates a sag plunging southwest from Barry County through Kalamazoo and Cass Counties (Elle, personal communication). Gravity and magnetic geophysical data from the geophysical section of the Department of Geology, Michigan State University also support the existence of a narrow sag plunging southwest from Barry to Kalamazoo County (Dr. W. Hinze, personal communication). Several recent wells drilled in this area since the completion 35 of the enclosed maps support the preceding statement. The A-2 Evaporite thins very rapidly in the reef areas. This is noted on the map by the hachured areas. This very rapid thinning of the A-2 Evaporite over reef sections may be an aid to drillers in determining the presence of nearby reefs. Discussion of the A-2 Carbonate. The A-2 Carbonate unit extends from the top of the A-2 Evaporite to the base of the B-Evaporite. This unit varies between 100 and 200 feet in thickness. From a study of the included cross sections it appears the A-2 Carbonate averages 120 feet thick in the northern two-thirds of the basin and closer to 200 feet in thickness in the southern one—third of the basin. In general the carbonate units tend to thicken as the A—2 and B-Evaporites thin out near the edges of the Michigan Evaporite Basin. This situation is not what would be expected in a large sedimentary basin. Within the area of salt deposition the A-2 Carbonate is mainly a limestone, but in many sections it is represented by a buff to brown dolomite or alternating beds of limestone and dolomite. The typical section in the basin is a 100 foot limestone section topped by a 20 foot dolomite. This can be distinctly noted on two Of the included cross sections. The A-2 Carbonate can be 36 split into an A—2 Limestone and an A-2 Dolomite. This differentiation of the A-2 Carbonate is noted on the Salina geologic column (Figure 4). The A-Z Limestone and A-2 dolomite are terms which have been used for a number of years on drillers logs. In places the A-Z Carbonate tends to be shaly or anhydritic. Some horizons of the A-Z Carbonate also split into the thin "poker chip" laminae similar to those noted in the A-l Carbonate. In the area south of the pinchout of the major evapor- ite units the A-Z Carbonate is generally a buff to brown, dense to crystalline dolomite. Cores from the Overisel field in Allegan County show that the A-Z Carbonate is locally fractured. These fractures in a number of cases were completely resealed with anhydrite (Ells, 1960). The A-2 Carbonate is an oil and gas producer, especially in southwestern Michigan in the dolomite section of the Southern Carbonate Shelf. “Discussion of the B-Evaporite. The B-Evaporite extends from the top of the A-2 Carbonate to the base of the C-unit. The top of the B-Evaporite section has been Picked asthe top of the first salt bed found below the C- unit. This pick is in line with the view that the B- Evaporite is a stratigraphic unit which was originally 37 deposited during a time of fairly uniform environmental conditions. V The B-Evaporite averages between 200 and 300 feet in thickness within the salt section, but reaches a thickness of at least 440 feet near the center of the Michigan Basin. This unit is composed predominantly of salt, but there are often shale, dolomite, and anhydrite lenes interbedded in the section. This is especially true in the upper half of the section where shale and dolomite lenses reach a thickness of as much as 50 feet. Dolomite and shale impurities in some areas of the basin compose up to 25 per cent of the total B-Evaporite unit. In the norther portion of the basin a 10 to 20 foot anhydrite bed is often present close to the base of the B-Evaporite. This unit has slightly shifted toward the east of the A-l and Ar2 Evaporites. Discussion of the B-Evaporite Isopach Map (M§p_No. 6). The B~Evaporite isopach map notes a definite embayment in the area of the Chatham Sag. Another significant embayment is noted in St. Clair County just south of the proposed Port Huron Monocline as observed on the B-Evaporite structure contour map. The B-Evaporite varies in thickness from 150 to 300 feet in the reef zone in St. Clair County. An embay- ment is also noted in the northern portion of the basin in 38 Cheboygan County. The salt pinchout though indicated by a fairly smooth line is quite probably a very irregular feature. The pinchout was probably greatly influenced by minor structural features and the presence of reefs in the wedgeout area. The B-Evaporite rapidly pinches out parallel to the Howell Anticline. In Wayne County a drop from 250 feet to O is recorded within one township. It is also interesting to note the great irregularity of the isopach contours over the Howell Anticline where enough sample logs were available to give a somewhat detailed picture. The trace of the evaporite pinchout indicates that the Michigan Evaporite Basin is far from the present geo- graphic center of the southern peninsula of Michigan. The basin quite likely underlies a good portion of Lake Huron (Figure 3). Again the fact that major sections of salt have been recorded in the Salina formation of Ontario, Canada tends to confirm this statement (Caley, 1945). Discussion of the structure contour map based on top of the B-Evapgrite (Map no. 5). This map is very similar to that of the Niagaran and Salina structure contour maps. The center of the basin is located in central Gladwin County. The 39 regional dip is fairly uniform over the Michigan Evaporite Basin though it is somewhat steeper in the north. The basin is ovate with almost an east-west lineation on this particular map. The Howell Anticline is a very prominent feature, but the Freedom Anticline is obscured since the B-Evaporite wedges out in that area. The presence of a fault or series of faults along the southwestern flank of the Howell Anticline is extremely apparent. An anticline or more possible a fault trend exists in the Sanilac County area. This feature is in the vicinity of the Port Huron Monocline and has a northwest-southeast trend which is sub-parallel to the Albion-Scipiooil field trend. Discussion o§_the C-Unip. The C-Unit extends from the top of the B-Evaporite to the base of the D-Evaporite. This unit is composed primarily of dolomitic shale with minor amounts of anhydrite. In some sections it is represented by an argillaceous dolomite. It is often termed the C— Shale and a study of the three included cross sections prove this term valid. The C-Unit is present over all of the basin except where it has been eroded. The C-Unit varies in thickness from about 140 feet near the center of the basin to 30 feet in the southern 4O portions of the basin. The northern and eastern portions of the basin are a fairly consistent 100 feet of dolomitic shale. Nb oil or gas shows have been reported and the porosity of this unit is extremely poor. Discussion of the D-Evaporite unit. The D-Evaporite is almost entirely composed of salt with some shale, dolomite, and anhydrite present in a few scattered sections. The average thickness of the D-Evaporite is 50 feet with the thickest section of 80 feet being observed in the central portion of the basin. In the southern portion of the basin this salt is usually about 30 feet thick and in some of the reef areas it is not present. A migrational trend of the lateral distribution of the sediments toward the northeast can again be noted. The D-Evaporite unit is.not considered in later discussions as a serious target for radioactive waste disposal due to its limited stratigraphic thickness and the presence of the often porous E-Unit above it. Discussion of the E-gnig. The E-Unit extends from the top of the D-Evaporite to the base of the F—Unit. It is an argillaceous dolomite which does possess distinct 10 to 20 foot shale beds. In the western and southwestern areas of the Michigan Basin the E—Unit has been described 41 as a crystalline dolomite which is very often porous and water-bearing. This porous zone in the E-Unit has been termed the "Kintigh" zone by drilling operators. This zone appears to be present over much of the southern one-third of the Michigan Basin (Ells, 1960). Oil and gas shows have been reported from this zone, and in Allegan County oil is produced in the Diamond Springs field (Ells, 1960). The "Kintigh" zone may become of increasing importance as an oil and gas pay zone in the coming years. The thickness of the E-Unit in the area of salt deposition averages 120 feet with the thickest section of 170 feet being recorded in southern Shiawassee County. Informa- tion from deep tests near the center of the basin indicate that the E-Unit is slightly thicker than the 120 feet average. Discussion of the F-Unit. The F-Unit is predominently a salt section with major shale and dolomite beds scattered through the section. Considerable anhydrite is disseminated throughout the section, especially in some of the shale units. It extends from the top of the E-Unit to the base of the G-Shale. The thickness of the F-Unit varies irregularly from one county to another. The following general figures were computed for the F-Unit within the boundaries of the major 42 evaporite section. The FwUnit varies from an average of 370 feet in the southern part of the basin to approximately 650 feet thick in the northern portion of the Michigan Evaporite Basin. In the center of the basin the F—Unit reaches a thickness of over 1000 feet. The per cent of salt in the F-Unit varies considerably throughout the basin. It is generally from 30 to 50 per cent in the south and 60 to 70 per cent in the northeast. The number of distinct salt beds in the F-Unit varies from one to five and the thickness of the individual beds from 20 to 250 feet. Again a definite shift of the basin toward the northeast can be noted in the F-Unit. Discussion of the G-Shafi. The GmShale unit extends from the top of F-Unit to the base of the Bass Island forma- tion. It is composed mainly of a green to gray dolomitic shale. In random places in the basin the shale has a reddish color. Anhydrite is also commonly present, but not in major amounts. The thickness of the G-Shale varies from 120 feet in the southeast to 40 feet nearer the center of the basin. In the north the average thickness is about 70 feet. A recent opinion of some geologists is that the G-Shale in the northern portion of the basin is actually composed of two 43 shale units with a salt section separating them. In the western portion of the state the G-Shale is somewhat harder to distinguish for it is often quite dolomitic. It can normally be easily picked on radioactivity logs. The maximum thickness as noted on the inclosed cross section .was 160 feet of shale and dolomitic shale in northern Oakland County. Since the G-Shale seems to be quite thick near the Chatham Sag and appears to thin somewhat toward the west and the center of the basin it is suggested that the calcarous mud was brought in through the Chatham Sag. Since the shale unit thickens slightly in the northern portion of the basin, it is probable that the fine mud came from the area of the Canadian Shield. Discussion o§_the_§tructure contour map based on the top of the Salinafifgrmation jMap No. 2). An attempt was made to pick the top of the GmShale as the true top of the Salina formation when preparing the structure contour map on top of the Salina formation. In many of the older sample ~logs the Salina top had been picked as the top of the upper salt in the Silurian geologic column. The Salina shale is the first major shale unit above the upper salt in the Salina formation. In most areas this pick can be easily distinguish- ed on a radioactivity log. The top of the Salina formation 44 is much easier to distinguish than the top of the Niagaran formation. This is one reason the included cross sections use the Salina top as datum level. The structure contour map on the top of the Salina formation indicates that the Michigan Basin is fairly symmetrical, but with a somewhat elongated northwest—south- east axis. The center of the basin is located in south- western Gladwin County. The Howell, Freedom, and Deerfield Anticlines are prominent features. It is extremely evident from the steep southwestern slope of the Howell Anticline that major faults exist in this area. Several anticlinal noses can be observed in the Macomb-St. Clair County area. It is difficult to say if these are true anticlines or only a reflection of the reef masses beneath the Salina evaporites. It is possible that they are anticlinal trends which have been accentuated by the reef buildups. Several prominent highs can be observed in southern Kent and northwest Allegan Counties. These are due mainly to structures in the Salina formation since they are not prominent on the structure contour map at the base of the Salina formation. Though structurally the Chatham Sag is not very apparent, there does seem to be a definite low in the Clinton Sag area. This effect might 45 have been increased by faulting on the southwestern side of the Preedom.Anticline or by the erosion of upper Silurian sediments in this area. Two major lows can be noted in Mason and Oceana Counties. Structural features appear to control the thinning of the salt units in the Salina formation to a limited extent. Examination of the isopach maps of the A-2 and B-Evaporites indicate this especially in the area of the Howell Anticline. This could be considered evidence that this structural feature was present in at least early Salina time though not as a very prominent feature. The Howell Anticline is not believed to have been formed as it is noted today before middle Mississippian time. (Kilbourne, 1947). Kilbourne also noted that the Howell Anticline was probably associated with a weakness or fracture in the basement rock. The orientation of the evaporite basin's hingeline nearly parallel to the Howell structure indicates that there might have been a slightly positive region present here at various timeséduring the Silurian. It is interesting to observe the steepness of the regional dip in the northwestern portion of the basin. Though the hingeline of the Michigan Evaporite Basin can , 46 not easily be distinguished, a general leveling of the regional dip is noticeable in the area of the Southern Carbonate Shelf. Discussion of the Bass Island Dolomite or H-Unit. The Bass Island Group is directly above the Salina formation within the Michigan Evaporite Basin. The Bass Island group is composed predominetly of dolomite with several thin anhydrite horizons appearing in random places in the basin. Near the center of the basin, shaly lenses have been noted. The color of the Bass Island Dolomite varies from a light cream to buff on the margins of the evaporite basin, to a darker brown near the center of the basin. The thickness of this unit varies from 100 feet near the margins of the evaporite deposition to about 600 feet near the center of the basin. The close of Bass Island time is marked by a wide- Spread disconformity which corresponds to the general unwarp of the Silurian throughout the midwest. This disconformity is not readily recognized near the center 0f the basin and its existence there is doubted by a number of geologists. As one proceeds outward from the center of the Michigan Basin one Silurian unit after another is truncated (Ells, 1958). This is especially noteworthy in the area of the Southern Carbonate Shelf. Since the disconformity does not truncate any of the Salina evaporite members it was not studied in detail. 47 RADIOACTIVE WASTE DISPOSAL CONSIDERATIONS Prgperties of Salt Bodies for Waste Disposal The United State Atomic Energy Commission has consider- ed the possibilities of underground radioactive waste disposal in subsurface rock formation. Those formations containing stagnant brines and solution caverns in salt beds or salt domes have been of special interest. The possibilities of storing the waste in underground excava- tions such as in impermeable shales has also been consider- ed (Deutsch, 1960). There are several apparent advantages which make salt units more desirable then other types of rock storage containers. 1. The cavity which is to contain the radioactive waste can be produced by standard saltbrine well techniques. The salt would be dissolved in the cavity by pumping fresh water into the salt unit and then removing the saturated solution. This technique eliminates the need for an expensive mine shaft which could also be difficult be seal. 2. Salt units have a tendency to seal off possible avenues of radioactive waste escape along faults. Salt under 49 pressure is believed to flow somewhat thereby sealing any porous zones in the rock. 3. Upon completion of the cavity the salt will form a fairly hard, impermable crust on the interior of the sealed cavity. Discussign 9f Radioactive Waste Disposal Areas Several formations in the Michigan Evaporite Basin have been suggested as possible areas which would be suitable for the disposal of high-level, semi-liquid, radioactive wastes (Joseph, 1955). These formations possess various amounts of connate waters or brines which are believed to migrate at rates not in excess of several feet per year (Deutsch, 1960). The Salina formation has been selected as one of the most desirable formations in which waste could be economically stored. The Salina formation is at least 1000 feet below the surface where- ever the salt sections are developed. Since there are several major evaporite units in the Salina formation, it offers an unusual opportunity for the development of radioactive waste disposal sites. Eggblemg 9f Radioacgive Wast Disposal Upon the detailed examination of any particular rock 50 unit there are many problems which make the exact site selection extremely complicated. These problems have been divided into three major classes; cultural problems, engineer- ing problems, and geologic problems. Cultural problems. One of the major cultural problems is the education of the public on the dangers or lack of dangers which a radioactive waste disposal site might possess. Though safety devices would eliminate any danger to nearby residents it would still seem advisable to place the site in a relatively unpopulated area. Other cultural problems would be the relationship of the site to the various methods of transportation and also its relationship to potential sources of radioactive waste. Engineering problems. One of the possible engineering or chemical problems which would have to be studied would be the effect of the radioactive waste on the rock surrounding the underground disposal area. This would include the chemical and heat effects on the surrounding rock. The fact that radioactive wastes often give off a significant amount of heat could indeed be a major complication. Heat combined with the highly corrosive nature of the waste could POSSibly produced unusual chemical effects (Gorman, 1955). Another problem presently being considered by members of the 51 civil engineering department at Michigan State University is the possible flow of evaporites under differential stress. Geologic problems. The third and major class is that of geological problems which would effect the selection of an. underground radioactive waste disposal site. This class can be broken into several subclasses. The first subclass which has been considered is that of structural problems which could effect the selection of a waste disposal site. Any area which has been subjected to fairly extreme folding would be considered a question- able area to place such a site. Such areas of folding as the Freedom Anticline, Port Huron Monocline, and the Howell Anticline would be important examples. Not only are structural anomalies potential oil and gas provinces, but they are also areas in which larger faults could be expected to be concentrated. The major faults in Michigan, which generally have a northwest—southeast trend. would definitely be areas Which would represent poor risks for radioactive waste disposal sites. These faults could act as potential avenues of escape for the semi-liquid radioactive waste to important aquifers above the Salina formation. Examples would be the Albion-Scipio trend and the apparent series of 52 faults concentrated in the Freedom-Howell Anticline areas. Polution of possible aquifers should be recognized as one of the most definite dangers of underground waste disposal. Since in the case of the Albion-Scipio trend, important oil and gas reserves could be contaminated, this would be another reason to avoid areas of known faulting. One feature which can be considered a secondary structural feature is Landes's proposed collapse area in southeastern Macomb County. This feature is noted on several of the maps accompanying this paper. During the discussion of the Salina isopach map, it was noted that new evidence indicates non-deposition or possibly slow removal causing the sediments to subside without losing their identity (Ells, personal communication). It is noteworthy that the salt units are very inconsistent to the east of this unusual area in Canada as the proposed evaporite pinchout is approached (Caley, 1945). An area where leaching could well be significant is in southern Wayne County where an abrupt thinning of the B and F salts can be noted. Landes presented the following evidence for collapse after leaching in this area (Landes, 1945)- 53 l. The abrupt termination of the salt north of Trenton, Michigan. 2. Differences in the structure below and above the salt series where the B and F salts wedgeout. 3. The presence of small faults, abnormal and variable dips, and breccia of probable collapse origin in the outcroping bedrock in this area. The abrupt pinchout of these salts coincides roughtly with the Howell Anticline. Possible areas of leaching appear to exist all along the zone of pinchout of the salt units. Most of the leach~ ing was probably on a small scale and was caused by the influx of very small amounts of meteric waters from the associated low land masses at or near the original time of deposition of the evaporites. The second subclass of geologic limitations on the selection of a radioactive waste disposal site may be considered of a generally stratigraphic nature. These are problems which are closely related with the environment 0f deposition of the original sediments. To gain a complete stratigraphic picture, a detailed knowledge of the lateral and vertical extent of the major evaporites in the Salina formation is required. To complete the picture, the study has to be expanded to include those 54 members of the Salina formation which lie above and below the major evaporite units. Based on this work the following questions are selected as essential in establishing the criteria for the selection of an exact radioactive waste disposal site. 1. Are there porosity zones present in the particular salt which is to contain the radioactive waste? Are there any unusual minerals present which could be affected by the corrosive nature of the radio- active waste? Is the salt unit being considered of a consistent thickness over a large lateral area? Are there major dolomite or shale stringers scattered through the salt section? Are there porosity zones in the rock units above and below the selected salt unit? Is the general area of the site near the salt pinchout where leaching and collapse are more probable? Are there minor angular unconformities or thin conglomerate beds in the salt section? Are there more than one section which.could be used in case the primary salt section is found to be 55 unsatisfactory? 9. Is the salt section of sufficient vertical thickness to contain the desired volume of waste? 10. Are reef sections suspected to exist in the column in the selected area? 11. Is there a thick section of glacial drift in the proposed region of the site? Most of the above questions can be answered for a select area by a study of the inclosed cross sections and maps. The third subclass of geologic problems which might interfere with the selection of a particular disposal site is that of possible interference with reserves of economic minerals. For example it would be reasonable to isolate the disposal sites from possible future petroleum provinces. This would not only influence the Salina formation pay zones, but any deep tests that had to pass through the Salina formation. It is very difficult to accurately predict future oil fields from a regional study of this tYPe- A good general rule would be to avoid the pre- viously discussed structural features which indicate rapid reversals in dip. To avoid possible stratigraphic oil fields, such as the reef zone, it would be wise to 56 stay at least thirty miles basinward from the hingeline of the Michigan Evaporite Basin. These principles would also largely avoid any chance of interfering with future gas storage facilities or future uses of the salt sections by the chemical industry. Discussion of the Composite Geologig Map (Map_No. 7) The previously mentioned principles have been adhered to in the creation of a composite map of the Michigan Basin. This map does not point out specific areas which should be selected as possible radioactive waste disposal sites, but does point out those areas where geologic problems would discourage their selection. This composite map of geologic features notes the major structural trends which are believed to have been important during the deposition of the Salina formation. This map notes the areas around the evaporite basin in which reefs are known to exist or could possibly exist. The exact line as noted on the map is based on the relationship of the known structural features as determined from the total series of maps. There- fore the Composite Map of Geologic Features (Map No. 7), is the general summation of information gathered in this paper which is pertinent to the selection of a radioactive waste disposal site. 57 The A-2 Evaporite A§_A Radioactive Waste Disposal Target The A-2 Evaporite has many of the characteristics which would make it an excellent radioactive waste disposal target. The following is a list of advantages of the A~2 Evaporite as a waste disposal target. 1. The A-z Evaporite is a very chemically uniform salt across much of the Michigan Basin both laterally and vertically. The.200-450 feet of vertical thickness should be ample for protection from possible migration of the semi-liquid waste by normal means of migration. The A-2 Evaporités great lateral extent makes the selection of an exact site less difficult. Its stratigraphic position between the Aml and B- Evaporite adds a degree of safety ifwaste were to migrate up or down a fracture zone. The depth to the A-2 Evaporite varies between 2,000 and 7,000 feet depending upon the position of the site in relation to the center of the Michigan Basin. Disadvantages of the A:;7Evapopite as a radioactive waste disposal target. 10 The A-2 Evaporite is situated between two potential oil and gas pays. The upper portions of the A-l 58 Carbonate often possess shows of oil and gas. The Ar2 Evaporite thins to less than 10 feet over the reef zones. Reefs have been found at least 30 miles from the salt pinchout toward the center of the basin. This would significantly limit the lateral extent over which the A-2 Evaporite could be selected as a waste disposal target. Less information is available on the A-2 Evaporite than on the upper salt units. This is especially true in Kent and Wayne Counties. The B-Evaporite as a Radioactive Waste Disposal Eapgg_. The following is a list of advantages of the B- Evaporite as a radioactive waste disposal target. 1. The B-Evaporite has a vertical thickness of several hundred feet with intervals of as much as 100 feet of clear salt. The B-Evaporite has a wide lateral extent similar to that of the A-2 Evaporite. The B-Evaporite though it thins slightly over reef zones is usually at least 250 feet thick over the crest of the reefs. The C-Shale which is directly above the B—Evaporite generally acts as a good seal against possible migration 59 of radioactive wastes into good aquifers occuring higher in the column. Though not as chemically uniform as the A-2 Evaporite. it is composed of a fairly consistent lithology over much of its lateral extent. The B-Evaporite is located at a depth of between 1500 and 6500 feet below ground level. ' Disadvantages of the B-Evaporite as a radioactive wagte disposal target. I. The B-Evaporite contains a greater number of dolomite, shale, and anhydrite lenses than does the A-2 Evaporite. The A-2 Dolomite horizon of the A-2 Carbonate is at the base of the B-Evaporite. This horizon is often porous and is an oil and gas pay. The B-Evaporite is commercially used for gas storage and is also a source of commercial salt in southeastern Michigan. POSSIBLE ECONOMIC APPLICATIONS OF THIS STUDY The Oil and Gas Industry The Salina formation in the past several years has become an increasingly important rock unit to the Michigan petroleum industry. The large number of bioherms which apparently surround the Michigan Evaporite Basin have, in a number of locations, proved important sources of oil and gas. The reef production is presently concentrated in southeastern Michigan in Macomb and St. Clair Counties. A recent field in Jackson County and abnormal thinning of the A-2 Evaporite unit in other areas indicate that a considerable number of reefs will be found in the future. A general principle which has been noted from a study of the isopach map of the A-2 Evaporite indicates that these reefs will be primarily located within 30 miles of the salt pinchout. The ”Kintigh" porosity zone which is present in the E-Unit of the Salina formation may also become an important Pay zone. This horizon has been recognized as possessing good porosity and oil shows over much of the Southern Carbonate Shelf area (Ells, Unpublished Maps). The “Kintigh“ zone is generally from 5 to 10 feet thick and can be easily noted on radioactivity logs. In the last several years the 61 A-1 and A-2 Carbonate pay zones have become of increased interest. to the petroleum industry. The Port Huron Monocline or fault could well represent a situation similar to that of the Albion-Scipio trend. More drilling in this area should prove extremely interesting. Another recent important economic use of the salt beds in the Salina formation is that of gas storage in southern Kent County, western Ottawa County, and along the crest of the Howell Anticline; LPG storage areas have been developed in the Salina evaporite units. With the growth of population in southern Michigan, it can be expected that gas storage facilities in the Salina formation will be expanded in the future. The Salt Industry The Salina evaporite units have for many years been a source of salt brines in southeastern Michigan. Rock salt is mined by conventional underground methods in southern Wayne County. The salt in these two areas is extremely important to the rapidly expanding chemical industry. There is a possibility that some of the valuable rare salts which are found in extremely restricted conditions might be found in small basins that have been partially 62 isolated from the much larger Michigan Evaporite Basin. This would suggest that the rare salts would be expected within the reef zone near the hingeline of the evaporite basin. This hypothesis has been deductively derived from Scruton's theory of evaporite deposition (Scruton, 1953). SUMMARY AND CONCLUSIONS The importance of the Salina formation as a source of economic minerals in the years to come should now be quite apparent. As a source of oil, gas, common salt, and possibly the rare salts; the presence of the Salina formation should represent a major stimuli to the growth of industry in Michigan. The use of the Salina formation for gas and radioactive waste storage should also become more 1 « '.. 35‘. _- a significant. A means of disposal of radioactive waste '2. :8- A [y can be of great assistance to the State of Michigan in competing with other geographic areas for nuclear power developments. From a geological standpoint several conclusions have been highlighted by the analysis of the various regional maps and other sources of information gathered for this study. These have been separated into several categories for continuity of thought. Theopetical relationships. 1. The.Michigan.Evaporite Sea of Salina time closely resembles those conditions which have been proposed for a theoretical evaporite basin. 2. Scruton's theoretical sequence of deposition as 64 predicted from experiment on the evaporation of sea- water is closely related to the sequence noted in the Salina formation. First a carbonate is deposited, followed by an anhydrite, then halite with anhydrite and at last nearly pure halite (Scruton, 1953). sgpuctural relationships. The majority of the structural features in the Michigan Basin have a northwest-southeast orientation. The Howell and Freedom Anticlines were present during the upper Silurian, but as much subdued structures when compared with their prominence during the Mississippian. Much of the local structure in the Salina formation is due to the reef sections in the Guelph or "Brown Niagaran" horizon. The regional dip in the northwestern portion of the basin is steeper than in other portions of the Michigan Basin. Stratigraphic relationships. There is excellent evidence for the elevation of the Salina formation to group level. The Salina formation can be readily segregated into ten distinct members which can be traced across most 65 of the Michigan Basin. The thickening of the Salina formation toward the center of the basin is due mainly to the sudden thickening of the evaporite sections. The carbonate units are fairly constant in thickness across the Michigan Basin. The salt units generally grade into a thin anhydrite near the hingeline of the basin and then into a carbonate in the shelf region. The hingeline of the Michigan Basin can be considered as the zone of pinchout of the Salina salt units. The Michigan Evaporite Basin continuely shifted toward the east and northeast throughout Salina time. Environmental relationships. The Michigan Basin during Salina time appears to have a northwest—southeast orientation, but when the unexplored region under Lake Huron is considered the basin is quite probably ovate. The depth of the Michigan Sea was generally under 50 feet. The average depth was probably between 10 and 30 feet. Large brine marshes and salt flats could have existed at random locations across the Michigan Evaporite Basin. 66 The Chatham Sag was a major source of seawater to the Michigan Evaporite Sea during Salina time. Salt was deposited in the Michigan Evaporite Basin due to the high rate of evaporation and isolation of the basin from surrounding seaways. The average temperature during the intervals of Salina salt deposition was equal to or greater than that found in the deserts of southwestern United States at present. Economic relationships. The ”Kintigh" zone, the "Brown Niagaran" horizon, and portions of the A-1 and A-2 Carbonates are potential oil and gas pays. The erratic thinning of the A-1 and A-2 Evaporites often indicates the close proximity of Guelph- Lockport reefs which can be excellent oil and gas reservoirs. An important possibility exists that some of the rare salts will be found in restricted arms of the Michigan Evaporite Basin. Radioactive waste disposal relationships. A large lateral area exists in Michigan in which a radioactive waste disposal site could be established. 67 2. The A-2 and B-Evaporites appear to be the best suited targets for the disposal of radioactive wastes. The A-l Evaporite might also prove to be an excellent target. Several techniques were not explored in this study which could well add many missing details. The production of a structure contour map on one of the formations higher in the geologic column such as the Dundee Limestone could well point out some of the obscure geologic features of the Salina formation.) This would be especially true near the center of the basin where information on the Salina formation is very limited. Since more information is available on the Dundee formation, its structure might reflect the deeper Salina structure to some extent. The construction of an isopach map of the A-l Evaporite could add important detail to the reef complex and information on the significance of the shifting of the center of the basin during early Salina time. A more detailed study of the F-Unit would also add valuable information on lateral shift of the basin. As more information becomes available, the production of these maps should become of more importance. 68 .An attempt has been made to combine all of the scattered sources of information on the Salina formation. This has been done to present a consolidated picture of the geography and environmentiexisting during Salina time. From this study it is desired that the interests of a greater number of people might be aroused on the importance of the Salina formation to the economic future of the State of Michigan. BI BLIOGRAPHY BIBLIOGRAPHY Adams, J. M. (1944) Upper Permian Ochoa Series of the Deleware Basin, West Texas and Southeastern New Mexico: Bull. Amer. Assoc. Petrol. Geol., V. 28, No. 11, p. 1596-1625. Alling, H. L., and Briggs, L. I (1961) Stratigraphy of Upper Silurian Cayugan Evaporites: Bull. Amer. ASSOC. PetrOJ-o (3601., V0 45, N00 4, p. 515-5470 Briggs, L. I., and Lucas, P. T. (1954) Mechanism of Salina Salt Deposition in the Michigan Basin: Bull. Geol. Soc. America, V. 65, No. 12, P. 1233. Briggs, L. I. (1957) Quantitative Aspects of Evaporite Deposition: Vol. XLII, Papers of the Michigan Academy of Science, Arts, and Letters. . (1958) Evaporite Facies: Jour. Sed. Petrology: v0 28’ P. 46.56. Branson, E. B. (1915) Origin of Thick Gypsum and Salt Deposits: Bull. Geol. Soc. America, V. 26, p. 231- 242. Caley, J. F. (1945) Paleozoic Geology of the Windsor- Sarnia Area, Ontario: Geol. Sur. of Canada Mem. 240. Cloud, P. E. (1952) Facies Relationships of Organic Reefs: Bull. Amer. Assoc. Petrol. Geol., V. 36, p. 2125-2149. Cohee, G. V., and Landes K. K. (1958) Habitat of Oil: Amer. Assoc, Petrol. Geol. Dellwig, L. F. (1954) Origin of the Salina Salt of Michigan: Ph. D., Univ. of Michigan. . (1958) Flowage in Rock Salt at Lyons, Kansas: Kansas Geol. Sur. Bull. 130. 71 Deutsch, M. (1960) Effects of Dissemination of Radio- active Materials on Water Resource Conservation with Special Reference to Michigan: Dept. of Resource Development, Agricultural Experiment Station, Michigan State Univ. Douglas, G. V., and Goodman, N. R. (1957) The Deposition of Gypsum and Anhydrite; Bull. Soc. Econ. Geol., V. 52, p. 831-838. DeWitt, W., Jr. (1960) Geology of the Michigan Basin with Reference to Radioactive Wastes: United States Dept. of Int. Geol. Sur., Rept. 771. Ells, G. D. (1958) Netes on the Devonian-Silurian in the Subsurface of Southwest Michigan: Mich. Geol. Sur. Progress Report No. 18. . (1960) Silurian Oil and Gas Developments in Michigan: Geol. Sur. Div., Mich. Dept. of Conservation. Ehlers, G. M., and Kesting, R. V. (1957) Silurian Rocks of Northern Peninsula of Michigan: Mich. Geol. Soc., Annual Geological Excursion. Evans, C. S. (1950) Underground Hunting in the Silurian of Southwestern Ontario: Proc. Geol. Assoc. Canada, V. 3, p. 55-85. Gale, H. S. (1951) Geology of Saline Deposits; Bristol. Dry Lake, San Bernadino County, California: Calif. Div. Mines Spec. Rept. l3. Ginell, W. S., and Martin, J. J., and Hatch, C. P. (1954) Ultimate Disposal of Radioactive Wastes: Nuclecnics, V. 12, p. 14. Goodman, E. 1., and Brightsen, R. A. (1958) Disposal of Atomic Wastes: Nuclear Eng. and SCi. Cong., Proc. Preprint 188. Waste Disposal as Related to Site Gorman, A. E. (1955) Proc., Selection: Nuclear Eng. and Sci. Cong., Preprint 3. 72 Hatch, L. P., and Regan, W. H. (1955) Processing of Highlevel Atomic Wastes with the View to Ultimate Disposal: Nuclear Eng. and Sci. Cong. Proc., Preprint 175. Hills, J. M. (1942) Rhythm in Permian Seas--A paleographic Study: Bull. Amer. Assoc. Petrol. Geol., V. 26, p. 217-255. Ives, R. E., and E115, G. D. (1957) Developments in Michigan in 1956: Bull. Amer. Assoc. Petrol. Geol., V. 41, NO. 6’ p. 1062-1073. . (1959) Developments in Michigan in 1958: Amer. Bull. Assoc. Petrol. Geol., V. 43, No. 6, p. 1197- 1207.” . (1960) Developments in Michigan in 1959: Bull. Amer. Assoc. Petrol. Geol., V. 44, No. 6, p. 730- 741. Joseph, A. B. (1955) The Status of Land Disposal of Atomic Reactor Wastes: Nuclear Eng. and Sci. Cong. Proc., Preprint 195. Kaufmann, D. W., and Slawson, C. B. (1950) Ripple Mark in Rock Salt of the Salina Formation: Jour. of Geol., V. 58, No. 1, p. 24-29. Kay, M. (1951) North American Geosynclines: Geol. Soc. of America, Mem. 48. King, R. H. (1947) Sedimentation in Permian Castile Sea: Bull. Amer. Assoc. Petrol. Geol., V. 31, P. 470- 477. (1949) Krumbein, W. C., and Sloss, L. L., and Dapples, E° C° Amer Sedimentary Tectonics and Sedimentary Environments: Assoc. Petrol. Geol., V. 33, p. 1859-1891. Krumbein W. D., and Sloss, L. L. (1955) Stratigraphy and Sedimentation: W. H. Freeman and Co., San Fransisco, Calif. 73 Lockett, J. R. (1947) Development of Structures in Basin Areas of Northeastern United States: Bull. Amer. Assoc. Petrol. Geol., V. 31, p. 429-446. Lowenstam, J. A (1950) Niagaran Reefs of the Great Lakes Area: Geol. Soc. Amer., Mem. 2, p. 215-248. Lucas, P. T. (1954) Environment of Salina Salt Deposition: Masters Thesis, Univ. of Michigan. Maebius, J. B. (1942) The Results of the Drilling of a Deep Test Near Bay City, Michigan: Amer. Assoc. Petrol. Geol., Bull., V. 26, No. 5, p. 915. Micks, R. (1948) Brine Deposits of Michigan: The Compass, V. 25, No. 3, p. 121-132. Morris, R. C., and Dickey, P. A. (1957) Modern Evaporite Deposition in Peru: Bull. Amer. Assoc. Petrol. Geol., V. 41, p. 2474-2474. NeWcombe, R. B. (1933) Oil and Gas Fields of Michigan: Michigan Geol. Sur. Div., Pub. 38. Newell, N. D. (1957) Paleoecology of Permian Reefs in the Guadalupe Mountains Area: Geol. Soc. Amer., Mem. 67, V. 2, Po 407-436. Martin, H. M., and Straight, M. T. (1956) An Index of Michigan Geology: Pub. 50, Geol. Sur. Div., Michigan Dept. of Conservation. Melhorn, W. N. (1951) A Quantitative Analysis of Silurian Sediments in the Michigan Basin: Masters TheSis, Michigan State University. . (1958) Stratigraphic Analysis of Silurian Rocks in Michigan Basin: Bull. Amer. Assoc. Petrol. Geol., V. 4'2, P. 816-838. On the Formation of Rock-Salt Beds and . 1888 - Ochsenius, C ( ) Proc. Acad. Nat. Sci. Philadelphia. Mother Liquor Salts: V. 40, p. 181-187. 74 Pirtle, G. W. (1932) Michigan Structural Basin and Its Relationship to Surrounding Areas: Bull. Amer. Assoc. Petrol. Geol., V. 16, p. 145-152. Roliff, W. A. (1949) Saline-Guelph Fields of Southwestern Ontario: Bull. Amer. Assoc. of Petrol. Geol., V. 33. Scruton, P. C. (1953) Deposition of Evaporites: Bull. Amer. Assoc. Petrol. Geol., V. 37, p. 2498-2512. Sloss, L. L. (1953) Deposition of Evaporites: Jour. Sed. Petrology. V. 23, p. 143—161. U. 8. Atomic Energy Commission, (1956) Major Activities in the Atomic Energy Programs, July-December, 1955: U. S. Atomic Energy Comm., 19th Semi-annual Report. APPENDIX APPENDIX The information contained in this appendix was largely obtained from 358 sample logs which are on file at the Michigan Geological Survey, Lansing, Michigan. In a number of cases the tops of the various units, as picked by the Michigan Geological Survey, were in disagreement with those of my own. This was generally only the case in those deep tests which were described before 1950. The various unit tops were used to produce the included maps. The location of the wells are given in accordance with the Michigan township-range grid system as portrayed on The Index of Well Locations Map (Map No. 8). The location of the wells are accurate to the nearest section. are in relationship to sea level. Several symbols have been used in this appendix which demand explanation. e-uu Information not available. NP Unit not present. PO Pinchout. The elevations 77 chem macm acme oaom mmssa hem BmHIZmHImm .em mnmm IIII mmme Hmmm mmnmm Hmm .zeHIZmHIom .mm memm mmmm meet mmam mooma 0mm SeHIZmHIom .mm IIII Hamm cede ommm mmeam mam SRHIszIem .em ommm momm mono monm ca Ham zeaIszImH .mm mnam come omen mane momma mam 3¢HI2mmIva .mm some mmam nemm momm momma mom mmImeImm .Hm IIII mmmm ammo hmam mowed mes zmaIzemImm .om IIII IIII IIII Hmmm movam mmaa 3HI2¢mImm .ma Homo oasm deem moss mamma moaa SOHImeIm .ma mmmm omom moem mono momma mam BmHImeImm .ha IIII IIII mace msmm moaoa coca smaImeIm .ma IIII IIII eemm Hood momma mmma SmImeImH .ma comm comm osmm mace momma mama SmImeIma .ea mmmm momm mmmm omeo mmema amma zmImeIom .ma momm Hamm ommm mmmm nmmmm mam 3HHIZOmIm .ma omsm omem Hmmm comm mmmmm mom ZmImeImH .AH IIII momm made deem «mama com zmImeIem .OH amen vmom omoo mmom ommm mom mmImeIma .m oamm mmom ommm mood mmama Hmm mHImeIm .m IIII IIII IIII coma IIIII com mmImeIm .s IIII IIII mammm moam mmema mom SmIZVmIm .m IIII whmm cmmm mnea memom mmm EmlzomIH .m IIII mmmm mmmm mmca mmmam mom SHIzomImH .v IIII memm ommm omma IIIII omm umIvaIm .m IIII IIII mmmm omma mmmmm mmm mmIzemIom .m IIII Hmom mmmm oaaa emaom mom mmImeIHm .H mos mum mos one mos nos .02 cows coHumuoq .oz Iuommpm mIm Iuomm>ulm cmummmHz meadow pseudo Im>oam . é 78 mean mmmm mmmm IIII momma mmm SmaIZmHImH .mm hmam mvmm nmmm IIII comma 0mm BmHIZmHImH .mm nmom mz omen ooom mmORH mam zmHIZmHIom .mm moon mz Homm mmmm IIIII mom 3SHI2mHIom .Hm omoe omen cone namm mommm mom zvaIZmHImm .om vome .mheo mmam momm mamma mmm 3MHI2mHIHH .mv mmmm mommm IIII Hmam hemma hon SmHIZmaloa .mv mama cave ommm ommm Haw omm SmHIZmAImA .nc IIII comm IIII comm mmmaa vow SmHIszIHm .mm IIII Adam IIII emsm momma mmm SmAIzoaIm .mm comm momm mvoo meam amm mmm 3SHIZVHImm .mm mmmm moon omee IIII Hmoma mmm SSHIzoalma .mv IIII mmvm IIII mmom mmmma mmm ZSHIzoanm .mv ommm ommm onmm ome doom mmm mvlzoaIm .Hv IIII memo IIII oamm Hmmoa mam maIZmHIvm .oo mmov mace mmom Hoam mmhaa Hmm mmaIZmHIam .mm comm mmmm Home mamm momma mom SSHIZmAIm .mm IIII comm IIII mmmm vmama mmm BmHIZmHImH .mm IIII IIII IIII mmmmm meom mmm umHIZmHIoa .mm comm mmmm mmme mmmmm mmmma 0mm zmaIZmHIm .mm mmnm moom IIII IIII mmm mom BSHIZmHIma .Vm name comm mmmv mmom mmm mmm BmHIZ>AImm .mm IIII comm momm mmom «mmaa mmm mmHIZnHImm .mm mmmm oon moms Hmmm momma mmaa zoaIZmHImm .Hm mmhm mmmm memo HOOM mHHom mom SmHIZmaImm .om comm hvmm memo Noom mmmea mmm SmHIZmHIem .mm mmnm mmom mama omom vmhna com SmHIZmHImm .mm mos one mos one mos mos .02 now» coaumooq .oz Iuomm>m mId Iuommemlm cmummmaz momamm assume Im>on 5| 79 moon mmom hmma IIIII mom weal ZmImm .om IIII comm omom mmma Hooaa mom MSHI ZmIm .mm dz oz omam mmmm mmmm mmm zeal ZeImm .mm m2 m2 mmam mamm oae mam BmHI ZSIsm .mm as as mean «mom mooam mmm .3mnu zsumm .om mamm wmnmm omma mmnm omom who so: zsumm .ms IIII oaov mmom mmmm mmhma Hom mHHI ZeIoa .om whom emsm amom oama mmmma mmm mmHI thHm .mm IIII comm ommm omma momma ocs mmHI ZhImH .mm IIII momm omen mesa mmmmm mmm weal ZeImH .mm emmm ommm momma Hmam mmm mmm BoI ZmIoa .om Hmam «mono momm mmao mhmma hob Sol zm.>m .mm mmm¢ hemm memo mmmm momma «on umHI ZmIom .mm mmmm mmmm omem IIII mama. mmm mmaI Zthm .mm IIII omsm IIII mmaom mmoma mmm mmHI zmImH .mm mmmm mmmm mama mmmm mmm «on SmHI ZmIm .mm ommm comm came IIII hmoma mom BmHI ZmImm .em IIII IIII IIII omom mamoa Hmb final ZmImm .mm IIII mmmm IIII mmmm mmmm mmm amaI ZmIem .mm omom IIII comm mmmm mom mmm ZmHIZOHIm .mm IIII omae IIII omoe mm mmm BOHIZOHIHm .om emom mmmm mmmm smvo momom mmm mmlzoaIm .mm emoe momm come mmem mooaa Hmh mmHIZOHImH .mm omen mmmm meme mmem momma mob mmHIZOHImm .mm mmee mmoe «mam mmmm mmm mmm smaIzHHImH .mm mmam mmmm mooem omen emmmm ems mQAIzHHIn .mm mos one mos one mos mos .oz soap coaumooq .oz Iuommem m14 Iuomm>m1m cmummMHz meadow umeumm Im>oau memo emmm mmmc cmom mmmma mam mmI ZmImm .mca mavo comm hmmm mmam mnmmm mmm mmI ZmIm .mca cemm omnm mmmm mmom Hamma ems mmHI ZmImm .ooa «Hem IIII IIII momm ancmm mmm mmaI ZmIm .moa mamm mmvm mmmv mmmm Hammm mmoa mHaI ZmIca .mca boom ommm camm mmmm mmcmm mmm umal ZmIe .HcH mcom mmmm mcmm mmma memam mos meaI ZmImm .coH mcmm ommm msmm mmma mosmm mmm mcaI.2mIem .mm mmmm omam mocmm IIII smmsa mmm mmHI ZmImm .mm mamm momm omam mosa omomm mom MmHI ZmIHm .mm mamm ovam namm coma mmomm com mmaI ZmImm .mm mmmm smom comm mmma semam mmm MmaI ZmIom .mm smsm mamm maam boom mmmam mmm umHI ZmIvH .om mnmm meem emmm mama ocmam con mmaa ZmIm .mm momm mmom mmnm mmma mmmma mmm umHI ZmImm .mm mmmm meom mmmm mama memos omo moan ZmImH .mm dz m2 omcm mmmm omcam mmm SmaI ZmIHm .om IIII IIII IIII mmmm mmmmm one SmHI ZmIm .mm mbmm omen IIII macm cmmma mmm SmI ZmImH .mm IIII IIII IIII comm mmmma Hem HHHI ZmImm .mm mccv ommm same mmmm cmmmm mom mmHI zmIma .mm mamm oocm mmcmm mmmm mmamm mom mmaIZmImm .mm mmmm IIII comm cmma cmmam mmm mmHI ZmIma .om Hmmm mnvm mcmm emba mmmma mmm umHI ZmImH .mm neon mamm omen omma mmmma mmm HmHI ZmIHH .mm mamm mocm comm msma mmmmm cmm mmHI ZmImH .Hm mos mum .moe one mos mos .oz c0mu cofiumoon .oz Iuomm>u mI4 Iuomm>uIm cmummmaz museum Deanna Im>oam 81 omem bmmH mmmm momma maeom omm MmHIzoaam .mma IIII omom mamm coma ammom mom MmHIZeImm .Hma chem cmma comm «mmm mmmmm mom mmHIZcImm .oma meom mcom ommm mmma ncmHm mam mmaazvamm .mma cmom cmom mmmm smma mnmam omm mmHIchmH .mmH IIII mama mmom coca mmmom mmm mmHIZmImm .mmH mmmm mmma mmmm coed vamom mmm mmHIzvumH .mma chem IIII comm mama mmmam mmm moaazoam .mma IIII mmom mvsm coma me omm mmHIzcam .ema mmmm mmma mmmm mmva ammo mmm moHIchH .mma meam coma chem mmva mmmam omm umanzouma .mmH IIII coma mmmm mmva IIIII vac umHIzwnm .Hma m2 m2 ooom Hamm ommam mmm BmHIZmacm .cma IIII oz omam mmom mmmam mom zmHIZmIHH .mHH IIII doom ommm comm mmmmm mmm 3¢HIZmIm .maa mz m2 IIII mamm shoam mam 3¢HI2mImm .saa m2 m2 mmcm comm ccmom mom ZSHIZmImm .maa m2 m2 msmm memm momom mam BvHIZmIHH .maa m2 m2 IIII ommm mmmam mmm BmHIZmIom .vHH m2 m2 IIII mmnm oemom mmm SMHIZmImm .mHH mmmm dz Hmmm mmnm mmmcm Hon ZHHIZmInH .mHH IIII hmom mmmm camm IIIII mmm chIZmIHm .HHH mmmm maom ommm comm comma mmm zoaIZmIHm .oaa mnmm monm IIII mmmm omham mmm ZmIZmIm .moa IIII Hacm IIII Hmmm mmmefl omm BmIZmIm .moa mmmv mode moan comm ommm mmm 3MIZmI¢H .noa mos mum mos one mos mos .02 cows cOaumooq .oz Iuomm>m mIm Iuomm>mIm smummmaz mceamm Dessom Im>wam f) 82 coma :21in .2. - (“no-I II.III. I. [Ill mmmm chem cmca cmcam mom umHIZMIHH .mma mamm coma Hamm cmoa mnema Hmm MmHIZmIm .mma momm mmma comm cmca mmmma mam mmHIZmIH .mma IIII mmma IIII cmma mcmam mmm MmHIZMIH .mma scam mmma cmmm cmma mmmma mmm mmHIZMIHm .mma omcm coma cmmm cmma mmccm mmm mmHIZmImH .cma mmam Hmha moccm cmma mmmcm com mmHIZMIm .mma mcma mmmm Hmcm cmma mvmam mmm mmAIzMIm .mma omam Hmma mmmm mmma mocam omm mmHIZMIm .HmH m2 m2 mmmm mmmm mhmcm «mm SoHIZcImm .cma IIII IIII IIII msmm mmoam Hmm SeaazoIm .mca m2 m2 cmcm IIII Hmmma mmm ZMHIZcIom .mca m2 m2 mmmm cmmm cmcm mmm KmHIZcImm .hca m2 m2 mcmm mmmm smmcm omm SHHIszmm .mca IIII mz IIII mmmm menam com SHHIchm .moa mmmm IIII comm cmmm smeam mmm umazvamm .coa mmmm IIII hmac ommm mommm ccm mmlzolmm .mca cmmm mhmm mmmo mmmm momma mam mmIzoImH .mca mmvv mmmm mama cmcm mmmmm coca unIzoIm. .Hoa mode mmmm mHmm mcmm mhcma cmca mmIzoImm .ch IIII comm mmmo mmcmm cmvm mmca umIZvIea .mmH «mam mmmm camm mmcm mcham mmm mHHIzoImm .mma mmmm maam Hmmm cmmm mmmma mom mHHIzoIHH .hma mmcm mmom mmmm mama mmmam omm amalzola .mma comm vmam comm mmha mmmam mmm moalzclmm .mma mmhm mmmm mmam mmma Hemam omm moaI2¢Ina .cma mmmm mcmm cmmm mmmma chmam mam MmHIZcImm .mma mos mum mos one moa mos .02 soap coaumooq .oz Iuoamem mI< Iuomm>mIm cmummmmz mcaamm peeumm Im>mam 83 “AH-l" omam mmom cccm momma mmm weIZmImm .mma IIII cmHm cmHm mmma mmca mmm mmHIZmIm .ema m2 m2 mmmm moam mmmmm mas SmHIZmImm .mma m2 m2 Hmmm mmmm mommm mam 3maIZmIm .mma m2 m2 mmmm mcmm cemcm omm ZeHIZmIH .Hma m2 m2 cmcm mmcm mmcam omm zmaIZmImm .cma m2 m2 cccm cmmm emacm mmm 3maIZmImH .mea oz mz mmam mmam mcaam has SmHIZmIc .mma m2 m2 IIII cccm mmaam mam ZNHIZmIm .bba m2 dz mmmm mcmm namcm mmm 3HHIZmImm .mma m2 m2 IIII Hamm mmmmm mmm SHHIZmImH .mha mean mcmm momm mmmmm meme mmm BmIZmIm .cma mmam IIII mcem mccmm mmmma mam SmIste .msa mmcc mmcc come comm Hacca mcm mHIZmuca .mma IIII IIII some IIII mmcma mom MmIZMImm .HSH mmmm emam cemm comm meam cam mcIZMImm .cha mcmm camm mHmm cmmm mmmma mam meIZmIcm .mma IIII «mam mmmm ommm momma cam McIZMIm .mma comm mmmm Hmac Hmvm momma mmm m¢IZmIm .hma IIII comm cede «mmm mmmmm mmm mmIZmImm .mma mmom cccm mmmm mmea mmmma mmm mMHIZmImm .mma cmom coma comm IIII IIIII mmm umHIZmImm .oma IIII mmhmm mmmm comm momma mom mmHIZMImm .mma comm ceam mccm cmma mmmH mmm moaIZMImm .mma IIII mmma cmmm mama Homam mmm moaIZmImm .HmH «mom mmmm cmmm momma Hammm mmm mcHIZmImH .cma mos one mos one mos moa .oz soap, coaumoon .oz Iuomm>m mI¢ Iuomm>mlm cmnmmmmz meadow assume Im>mam 84 ommm “Mu-338 caom mmmm mmm mmm SmIzHImm .cam IIII IeII mmom comm Hemmm mmm SmIzHIma .mcm cmmm cmmm cmmm cmmm mmeam ccm zmazHImH .mcm IIII IIII smcm cmmm mcmmm Hem umIzHIma .mcm mHmm mmmm mmmm «cmmm mmmma cam MmIzHImm .mcm comm comm cmmm mmcm mmcma mmm mmIzHImH .mcm cmmm mmcm moon maam manna mom mmIzHIm .mcm cmmm cmHm Hemm mcmm mnmma mmm mmIzHIm .mcm mmmm cmmm cmmm mmma mmcmH cmca MmIzHImm .mcm mamm comm mmmm cmmH nmcma Hmcm meazHImm .Hcm mmmm mmmm mmmm IIII momma mmm mmIZHImm .ccm cmmm mcmm IIII momma ammo mmm mhIzHIHm .mmH mmmm mcmm comm mcmm mmmma mmm mmIzHIcm .mma mmmm cmmm hmom cmma cmcma mmm mmIzHImm .bma comm mmmm mcamm IIsI mmema mmm mmIzHImm .mmH IIII mHHm IIII momma IIIII mmm mHaIszHm .mma oz mz cmam mmmm eocam omm SmHIZmIm .oma m2 m2 IIII cmmm memcm mmm BOHIZmImm .mma mmcm mmmm cmmm mmcm mmhcm omm ZmIZmIom. .mma IIII IIII mmmm mmmm msmmm mmm SmIZmImH .ama mcmm comm mmmm cmmm mamma mom m¢IZmIH .cma IIII mmmm cmco comm coma com mmIZmIcm .mma cmmm comm mamm cmmm mcama mmm mmIZmIS .mma mamm mmmm IIII mcmm mmmma coca umIZNIma .mma IIII moan cmmm mmma mmmam mmm mhIZNImm .mma moa one mos mum mos mos .oz soap comumooq .oz Iuomm>u mld Inomm>MIm cmummMHz mcaamm passed Im>mam 85 4|"!!! .0. . .. cmmm cmmm cmmm mama cmmm mam umammuma .mmm IIII mesa mmcm mmm mamm mmm mmImmImm .mmm IIII mcmm mmmm momma Hmmm mmm mmImmIm .mmm IIII coma comm mmm IIIII mam McHImmImm .mmm m2 m2 mcmm mmma IIIII hem mHHImmImm .mmm IIII IIII IIII com mmmcm mmm mHHImmImm .mmm oz m2 cmcm mama mmmm omm zmaImHImm .amm m2 dz mmmm momma IIIII mmm smaamHImm .cmm m2 m2 mcmm mmmH IIIII mmm ZmHImHImH .mmm m2 m2 cmmm mmHm memcm mam ZcHImHInm .mmm m2 m2 cmmm cmmm smmam omm 3mImHI¢m .mmm m2 m2 Hnmm mmmm mmmam mmm SmImaImH .mmm m2 oz Hmam cmmm samam mmm SmImHImH .mmm oz mmcm mmmm mnmm momam mmm SmImHIHH .mmm m2 m2 mmmm mcmm cmcam mmm mmImHIm .mmm IIII mz mcmm cmmm Hmmma mmm mmImAImm .mmm emcm mmmm comm mmma mmmca mmm umImHIem .Hmm mmmm mHmm mmmm mama cmmma mmm MSImHImH .cmm cmmm mmsm mmmm momma Hoaca mam mmImHIma .mmm mcmm mcmm cmmm «mam mmoma mom mmImHIm .mmm IIII mmmm cccm coma momma mmm mmImHIam .mmm namm mnmm cccm cmma mmmma omm mmImHIma .mam mmcm mmom mmmm IIII mmmma omm mmImHIm .mmm HHmm IIII cmmm mmma acmma Hmm mmImHIm .oam IIII cmma mmmm cccm IIIII mmm mHHImHIma .mmm mz m2 mmmm mmma hmmma mmm smaleImm .mmm m2 m2 comm cmmm mommm omm BmHIzHIm .Ham mos one mos one mos mos .02 cows coaumooa .oz Iuomm>m mI< Iuomm>mlm commonaz meadow uHEumm Im>oam 86 ’ Ill -11).: m2 m2 mmmm mcmm mcmmm mace smemmum .mmm m2 m2 cmmm IIII mmmam omm 3mImmnma .mmm m2 m2 mcmm mcmm mmmmm mmm SHImmImm .mmm aIII IIII IIII mmm mmsma mmm MmImmImH .cmm IIII some mmmm mom IIIII mmm mmsmmIm .mmm m2 m2 mmcm mmcm Hmmmm mmm ucammam .mmm m2 m2 mcmm mccm mmmma mom moImmIm .mmm m2 m2 mmmmm cmmm mcmam mom mvnmmem .mmm m2 m2 cmmm cmmm momma omm umsmmua .mmm IIII mcmm sIII mmm IIIIII ham mcHImmImm .mmm IIII IIII IaII omm comma mmm mcHImmIn .mmm IIIQ cmcH IIII mmm IIIII omm MHHImmsmm .mmm m2 m2 mmmm mmma mmmm Hes Smaammumm .Hmm m2 m2 mmma mmma mmm mmm SmHImmImm .cmm m2 m2 eamm cmcm mmcma mmm SmHImmIHm .mmm m2 m2 cmmm mmcm omm mmm smammnca .mcm m2 m2 cmmm mmmm mmcmm mmm BmImmImm .mcm mz oz cmcm mamm mmmam mmm BmImmIm .mcm m2 m2 chm mmcm mmmmm com Scammnma .mcm m2 m2 mmmm mmmm mmmmm maca SmImmImH .mcm m2 oz mmcm mmcm Hmaam mccH smummImm .mcm m2 m2 mcmm mcmm mmmam mmm zmImmIm .mcm m2 m2 cmmm mmnam Hmmma mmm mmImmIvH .mcm m2 m2 comm mmcm mmmH mam vammImm .com m2 m2 mmmm cmma momma omm MmImmImm .mmm om mnHm Hmmm mama mmmm mmm umImmImm .mmm moe mum moe mum mos moa .oz soap coeumooq .oz Iuomm>m mlm Iuomm>MIm commonez mcaamm uaauom Im>mam fl ll-i 87 m cmmm m2 m2 mmma cmmmm mam ZnumcIv .mmm m2 m2 comm mama mmcmm mom ZmImcamm .mmm m2 m2 mmmm mmma mmcmm omm ZmImcIma .mmm m2 m2 mmom mcma mmmmm mmca anmcImm .mmm oz mz comm mcmm cmmcm Hmca zmsvam .mmm m2 m2 comm mmcm mmmam chH Bmavah .mmm m2 m2 cmmm mHHm ommam cmcm BmIvam .mmm m2 m2 cmmm cmcm mmmmm mmca ZHImMImm .mmm m2 m2 mmmm cmmm momma IIII zHImcImH .mmm mz mz mHmm mmHm mmmam mmm mHImenm .cmm mz mz cccm IIII mhmH mmm monmvumm .mmm m2 m2 mmma momma mmmma mmm mmIvamm .mmm m2 m2 cmmm mava mmcmm mmm umIvacH .mmm m2 oz mmma IIII omm omm umIvamm .mmm m2 m2 mmam mmm oammm mmm mmIvamm .mmm m2 m2 mcmm moon mcmm mmm mmIvamH .cmm dz oz mcmm moon cmmmH mmm mmlmoIH .mmm m2 m2 cmmH cmo IIIII mmm mcHImcImm .mmm IIII cmcm IIII IIII IIIII mmm mHHIvam .Hmm mz m2 mmvm mmma Homcm mmm SmImmIcH .cmm m2 dz cmmm cmmm mmcmm moca BoImmImm .mmm m2 m2 mmmm mmmm mHmHm mmm BoImmIm .mmm m2 m2 cmmm comm mmva mmca 3¢ImmImH .mmm mz mz mmmm comm mcmam mmm ZolmmIo .mmm m2 m2 mmmm mmmm mmmam mmca 3¢Immlmm .mmm m2 mz mmhm Hmmm thmm Hmm 3mlmmI¢H .cmm QOB mum QOB mud moa mos .02 com“ comumooq .02 Iuomm>mhmI¢ Iuomm>mlm cmummmaz mcmamm uHEuom Im>oam 88 Maw Iuomm>m mI4 Hail) Il’ (ll oz oz snow mmma mmcmm mam smammamm .mmm mz mz omen mmm mamas mmm mmcmmns .enm mz as some mmm momma mmm menmmua .mam. oz mz nee omm mmcmm mmm mmnmmams .mmm mz oz mean mmos amnms mmm senammnmn .mmm mz mz moan «coma Hams omm zansmmama .cmm mz oz cmmm moms memmm mam smammeam .mcm az mz mcmm mama «mcmm mmm zsummuom .mcm mz mz msmm oops mmmom mmm saummam .som oz mz cmmm moms mmmma mam smummue .mcm oz oz mama moss mmmom amen smummumm .mcm mz oz Hmmm anon mmmsm mmm smummam .ecm mz mz mcmm coma mamnm mmos seammunn .mcm mz mz mmmm ohms mamam mmoH smammam .mcm mz oz mmmm cmmm mmcmm Haas smammums .Hom mz mz cmmm mama Hmmmm mama smammsmm .oom mz mz IIII cmmm mmmom moms amnmmamm .mmm mz mz ammm cmmm vmmam ends smammaam .mmm mz oz mcmm mmma mesmm cmmm sHImmImm .mmm m2 m2 mmmm IIII mmama mmca SHImmIH .mmm mz oz cmmm mmm cmmm Hos emammnmn .mmm mz mz ooom smma mmoom mmm mvammaea .emm mz mz cmmm mmm mmmmn one smImmImH .mmm oz mz mmma «om maema mmm saummIoa .mmm oz mz «mes mam amass mam waImm.a .mmm oz oz moan amen mmos mmm smmumaImm .cmm men one mos mun mos mos .oz coop coaumooa .oz Iuomm>mam cmummmaz madame passed Im>mnm i I liillllti Dill If .1'.1l|\."l”i’l.4n inugunfld.‘ "II. mz mz Hmmz amoz wzvmz qom zwzgmmnom ozwm mz mz mama ommz ohm mmm zmzsmmam oo¢m mz mz mnnz mzwz mmmmz moo snumnaoz cmmm mz mz moon mood ozmzm wozz swumnum cmmm mz mz omom mmoz Hnmzm Hmzz zmammum onmm mz mz onmz ommz nmmmm wooz swamnawm .mmm mz mz mzzm whoa mmnzm «mad zzcmnum .mmm mz mz mesa mmmz oznmm Ham manmnsmm .wmm mz zz mmmz ommz comm mmm mzamnan cmmm mz mz mmmz momn mmm mom mmamnam cmmm mz mz ozm omz momma who moamnu¢m ozmm mz ‘mz «moz omm mmmmz mmw mngmnaw °omm mz mz oznz ozmz mmoom new zmammamz cmmm mz mz omm oom mmmmz omm gaznmoa¢ cmmm mz mz o¢¢z momzz q aaaaa omm zozumoez ohmm mz mz mmoz omzz mmzzm mmm zHHamoun~ cmmm mz mz Anna hwmz mmmm mam zzzamoumz cmmm mz mz momz mz¢z momma ohm zozsmoan .¢~m mz mz owmz son» oonom mom zmnmoaom .mmm mz mz mmmz mo¢z mzmzm mom amamoamm .mmm mz mz mvzm «nod nomad mooz zmummsa .Hmm mz mz mmzm mend m¢nz~ mwoz z¢amoaz .cmm mz mz swam Mona Huhzm omzz guamoumm .mzm mz mz cmmm omnz wmmzm wmzz {3mumouom .mzm mz mz mmmm coma omzmm HmHH smumouw .nam mz mz m¢m~ momz madam omzz .3H-moumH .ozm mos mua moa mua mos mos .oz cozy cofiumooq .oz luomm>m mud Iuomm>mlm :mummmfiz maHHmm uHEhmm um>mHm 9G mans Oman cmmm omao auaug mwo mmuzzzuom cmmm m2 m2 mmoa mwaa mammm woo Basmwsam cmmm mz mz omna moma Hmmmm mam azamwazz oomm mz mz o¢>a ommz swam” «vm zaammam cmmm mz mz mama wooz mamam mam maammUNN °¢mm m2 m2 mafia mmm mmooa ham mwsmmlma ommm m2 m2 omaa omm mvvoa «an m¢ammumm cmmm m2 m2 omm om mmnma Nvo mbnmwam .Hmm m2 m2 mmm om Hmom omm monmmnmm comm m2 m2 Han nma mmnmm moo whammam .mvm m2 m2 mNNH mooa mnmma mob Shalmbom .mwm m2 m2 05mm omam owbam Hmoa Smlmfilmm .hfim mz m2 coma omma mnham whoa 3¢Immlm .wvm m2 m2 «mud NNMH mmowa omoa 3mlmm1¢ .mfim m2 m2 vvm mmm womo hwo SomImmIm .qwm m2 m2 mmma mnaa whom Hmh Smalmmlma .mfim mz .mz mmoz mama ommzm mmoz z¢ummumH .Nvm mos mug moa ova mos mos .oz coau coaumooq .oz luomm>m m|¢ luomm>mum amummmaz mcaamm paEumm im>mam g hL ifinfllflflflufl luff! "a. MICHIGAN STQTE UNIV. LIBRQRIES lllllllllll‘lllll lillllll II III lllllllll ll! NIHI 3129 1 3 01325243