w“ W 'w . «‘4. .1 0-- ~v . ”A. ..1.-"s(-‘ ga-,...,v . ,,. f, .h, . - .~wu‘rM-wI.I‘-.¢,-x:.-:-_ -: .. - .. _.Il~| ‘ I‘. .,,‘_4“, ' - -. ‘”"4“..L'IIJVV'IItII u H... SUBSURFACE GEOLOGY AND STRATIGRAPHIC ANALYSIS OF THE BAYPORT FORMATION IN THE “MICHIGAN BASIN Thesis for the Degree of M. S. MICHIGAN STATE UNIVERSIIY YAGHOOB LASEMI 1975 IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII / 3 1293 10422 7693 ‘ 1 . SSSSSS LIB RA}: Y “ Michigan State ,3 University “w mm 0 5 I”? a 5 -. tlk M... tr QIOW 0,21,535 . ~ .' ‘ I ' 9 .. I XII" AA? ' K » .y' 7. i ABSTRACT SUBSURFACE GEOLOGY AND STRATIGRAPHIC ANALYSIS OF THE BAYPORT FORMATION IN THE MICHIGAN BASIN BY Yaghoob Lasemi Rocks of the Bayport formation have been analyzed to determine the sedimentation and stratigraphic relation of this almost unexamined formation of the Michigan Basin. Samples from 202 wells, which are the basic tools for the analysis of this formation, were studied to present a picture of the environments of deposition. The formation is subdivided into three units on the basis of lithology and fossil-rich zones. Isopach and lithofacies maps of the formation and isopach-limestone/dolomite ratio maps of the subdivisions are bases for determining the sedimentation processes. The rocks of the upper and lower units were deposited in intertidal or lower supratidal environments. These two units are composed of predominantly microcrystal- line dolomite which is deposited under a warm climate with high evaporation. Dolomitization occurred shortly after ‘deposition of the lime or aragonite muds. The middle unit was deposited after a major trans- gression and is characterized by ostracodal biomicrosparite Yaghoob Lasemi or calcareous sandstone in the lower and upper parts and by a biosparite with normal marine fossils in the middle. Secondary dolomitization in a few places has produced medium-coarse crystalline dolomite with clear crystals. The lithology indicates that the formation was deposited in a stable environment. SUBSURFACE GEOLOGY AND STRATIGRAPHIC ANALYSIS OF THE BAYPORT FORMATION IN THE MICHIGAN BASIN BY Yaghoob Lasemi A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Geology ACKNOWLEDGMENTS The writer wishes to express his most sincere gratitude to Dr. C. E. Prouty, who gave of his time freely for invaluable advice, assistance, and consul- tation. Thanks are extended to Dr. Robert Carmichael and Dr. Duncan Sibley, the other members of the Committee, for helpful suggestions and criticism. Special thanks are extended to the Michigan Geo- logical Survey who furnished some of the samples used in this study. ii TABLE OF CONTENTS LIST OF FIGURES . LIST OF TABLES INTRODUCTION PREVIOUS WORK REGIONAL STRATIGRAPHY DETAILED STRATIGRAPHY Description of Unit A (Lower) Description of Unit B (Middle) Description of Unit C (Upper) DISTRIBUTION AND THICKNESS Unit A Isopach . Unit B Isopach . Unit C Isopach . Bayport Isopach LATERAL RELATIONSHIPS Bayport Facies . Unit A Facies Unit B Facies Unit C Facies GEOLOGIC HISTORY AND ENVIRONMENTAL INTERPRETATION Unit A . . . . . . . . Unit B . Unit C . . Bayport Clastics iii Page vi 10 11 13 13 16' 18 18 22 22 24 27 27 31 32 35 39 40 STRUCTURE SUMMARY AND CONCLUSION BIBLIOGRAPHY APPENDIX A APPENDIX B APPENDIX C iv Figure 1. Figure 2. Figure 3 Figure 4. Figure 5. Figure 6. Figure 7. Figure 8. Figure 9. Figure 10. Figure 11. Figure 12. LIST OF FIGURES Index map of the study area Isopach map of the lower (A) unit ISOpaCh map of the middle (B) unit Isopach map of the upper (C) unit Isopach map of the Bayport formation Lithofacies map of the Bayport formation Regressive-transgressive cycles -- Bayport formation . . . . Limestone-dolomite ratio map of the lower unit Limestone-dolomite ratio map of the middle unit . . . . . Limestone-dolomite ratio map of the upper unit Restored section of the Bayport formation Structure contour map 25 26 28 29 43 45 LIST OF TABLES Page Table 1. Correlation table of the Bayport formation . 7 vi INTRODUCTION The Bayport formation is of Upper Mississippian age and forms a part of the Grand Rapids Group in the Michigan Basin area. Studies to date regarding the formation either have been restricted geographically or covered regionally in very little detail as part of a broad stratigraphic interval. None of the studies gives adequate information of the regional picture and depositional environment of this formation. The present study attempts to analyze the lithology and distribution of the Bayport formation to identify and describe any facies present and their deposi- tional environment. Observations have been made concerning rock types, contact relationships with adjacent units, dolomite distribution, clastic ratios, sand-shale ratios, and facies relationships. Well cuttings from the Department of Geology, Sample Library and the Michigan Geological Survey have been the basic data source. Very few mechanical logs exist for this stratigraphic interval and none was available for the wells for which there are samples. Also because the stratigraphic position of the Bayport is higher than most oil and gas targets, no coring has been done and cuttings have not been collected for most of 1 2 the wells. However, the writer examined samples from 202 wells which served as a reasonable data base for a structural and stratigraphic regional framework study of the Bayport formation. PREVIOUS WORK Rocks of the Bayport formation have been described by several early workers including Lane (1899, 1906, 1908), W. M. Gregory (1912), Smith (1914), Alen et al. (1917), Newcombe (1933), Eddy (1936), and Martin (1937). Lane (1906) defined the Bayport as being the upper part of the Grand Rapids Group, and consisting of light- colored high-grade limestone and white sandstone. New- combe (1933) indicated that the Bayport formation includes alternating limestone, dolomite, sandy limestone and sand- stone, with a thickness range of 0-100 feet. Cohee (1951) displayed iSOpach and structure maps of the Carboniferous System of the Michigan Basin including the Bayport formation. McGregor (1953) described the general lithology of the Bayport formation as light to dark gray shale, bluish lime- stone and dolomite with some chert and a few lenses of sandstone. He displayed isopach, sand-shale ratio, percent carbonate and percent evaporite maps of the Grand Rapids Group (Michigan plus Bayport formations) but did not treat the Bayport individually or in detail. Bacon (1971) made the most detailed study to date of the Bayport formation but restricted his study to the 4 Wallace Stone Company Quarry at Bayport where he concluded that the formation was deposited in a sabkha environment. REGIONAL STRATIGRAPHY The Bayport limestone1 (referred to as "formation" herein) was named by Lane (1899) for outcrops at Bayport, Huron County,where it is quarried. It lies locally with disconformity upon the Michigan formation which consists of shales, anhydrite, gypsum, sandstone and dolomite. Rocks of Pennsylvanian age (Parma sandstone and Saginaw formation) unconformably overlie the formation and fill the irregular surfaces which are the result of the post-Bayport erosional unconformity. ‘The formation was divided by the writer into three units throughout the Michigan Basin. The lower unit (A) is very irregular in thickness and is predominantly dolomite with chert and interbedded sandstone. The middle unit (B) is a fossil- iferous limestone with diverse fossils and can be traced in all places in the Basin. It has been used as a marker bed to correlate the rock units of the formation. The upper unit (C) is similar to the lower unit, consisting of dolomite, chert and sandstone lenses. Details of these units will be considered later. 1This study shows that the Bayport limestone (as described by Lane) contains considerable amounts of dolomite, sand- stone, and shale also. Therefore the name formation has been used herein. 6 The Bayport formation is believed (Newcombe, 1933, and Weller et aZ., 1948) to be Meramecian in age and equivalent to the lower part of Maxville limestone of Ohio, St. Genevieve and St. Louis limestone of the Miss- issippi Valley section. Oden (1952) studied the brachio- pods of the Bayport and pointed out that they are the same species that have been found in the St. LOuis and St. Genevieve limestones (chert is also present in the St. Louis limestone). According to Kay et a1. (1965, p. 240-244), the Meramecian Sea spread over the Cincinnati Arch and warm, shallow water extended from West Virginia to the Mississippi Valley area and Michigan. The fossil- iferous limestone of the middle (B) unit is present along the margin of the Basin inferring that this unit of the Bayport at least, was connected to correlates in Ohio, Indiana and Illinois. The Chester Series is not believed to be represented in the Basin because of non-deposition or post-Mississippian erosion. The correlation table of the Bayport formation is shown on page 7. Correlation table of the Bayport formation Table 1. (Modified from Weller, J. M. et al., 1948). Standard Sec. . . . . - . 1111n01s Oth VUpapllezyMlss. Michigan Monroe Co. South Central Chesterian Chesterian Series W Maxville 15. Is. ‘3 Bayport 15. St. Louis ls. Meramecian 'g Salem ls. 3‘ M' h' a: 1cF1gan» Warsaw ls. m vu g Keokuk- (S IMthgtmnls. Osaglan Marshall Gr. Fern Glen fm. Goldwater Sh. Waverly Gr. Kinderhookian Sunbury 3*" Bera 55. Bedford Sh. Ohio Sh. Antrim Sh. DETAILED STRATIGRAPHY The Bayport formation was subdivided into three units with control based on the middle unit (B) fossiliferous limestone. This limestone is traceable throughout the Michigan Basin. Description of Unit A (Lower) The A-unit consists of brown to light brown and buff microcrystalline dolomite. It contains a few anhydrite nodules at the base and some pore-filling gypsum crystals present in the dolomite. The dolomite is cherty in most places and quartzose sand grains are embedded in the dolomite in some localities. Occasionally near the center of the Basin, the unit is composed of a gray-dark gray lime- stone (micrite). The dolomite is interbedded with quartzose sandstone which is in the range or zero to several feet in thickness. The sandstone is grayish white, fine to medium grained, sub-angular to rounded with some frosted quartz grains. It is mostly friable but in some places cemented by dolomite or earthy gypsum. The sandstone is lenticular and the thickness changes rapidly from a few inches to several feet in a few miles. Both sandstone and dolomite 9 have spots filled locally by glauconite. Thin beds of greenish gray to gray and dark-gray shale are also present in the unit, mostly in the western part of the Basin. In the south, east and a few places in the north, the middle or lower part of the unit is replaced by a sequence with upward decreasing grain size from medium- coarse grained, sub-angular-rounded quartzose sand, to fine-grained sand, silt and finally blue-gray silty clay. This is a very local feature and may change to dolomite in the adjacent section or township. Greenish-gray clay- stone is also present in a few places interbedded with dolomite. Except for a few silicified ostracods and some stromatolites in the dolomite, no other fossils have been found in the unit. In a few places near the base of the unit are quartz pebbles and dolomite pebbles or coarse- grained sandstone, possibly indicative of a disconformable relationship with the underlying Michigan formation. The contact is usually readily chosen and A-unit lithology is contrasted to the anhydrite, gypsum and micaceous shale of the Michigan formation. In a few places the unit is absent and the middle unit rests with clear disconformity on the Michigan formation. The upper contact is conformable and sharp and is overlain by the fossiliferous limestone of the middle unit. 10 Description of Unit B (Middle) This unit in most places starts with fine sandy gray- ish-brown to tan, finely crystalline limestone with an assemblage of fossils. Other than for a few fine-grained, angular quartz grains the limestone is quite pure in most places showing little insoluble residue. However, it does become shaly to the west and northwest in the Basin. Near the top of the unit fine quartz sandy limestone reoccurs and thin beds of gray to dark gray shale are also present as tongues comprising up to 20 percent of the unit. The limestone is interbedded with light brown medium sucrosic dolomitic limestone or dolomite in some localities. In the latter instance the criterion for distinguishing the B-unit from the A- and C-units would be the occurrence of a few undolomitized crinoidal stems in the B-unit. The limestone contains a fossil zone, persistent throughout the Basin, consisting predominantly of crinoids, ostracods, foraminifera (Endothyra), echinoid spines, occasional bryozoan brachiopods and corals. There is no evidence of transportation of the fossils. These fossils which form the framework of the rock are cemented by a gray brown, finely crystalline sparry calcite (biosparite of Folk, 1959). Chert is less than in the lower unit and when present consists of white-gray and gray-brown nodules which, on outcrop, often show fossil fragments or bulbous entities ll (algal according to Bacon, 1971) which serve as nuclei. Also burrow-like tubes often penetrate the nodules as well as the host rock and the possibility of worm borings being present also cannot be ruled out. Glauconite also is present in the limestone and frequently in the center of the chert nodules, where vugvlar at the center, or in the tubes, suggesting a reducing condition provided by the organic nuclei. The unit in other places, mostly in the north, south and east parts of the Basin, starts with a grayish¥brown to light brown, finely crystalline sparry calcite facies with ostracods (biosparite). This facies changes to crinoidal limestone upwards. At the top of the unit, the isame ostracodal limestone as at the bottom of the unit is present (for example, T19N-R7W-24). In a few places, there is no middle fossiliferous limestone and the whole unit is composed of ostracod limestone which is quite pure, yield- ing only traces of insoluble residues. Description of Unit C (Upper) The C-unit is partially or entirely eroded along a post-Mississippian erosional unconformity (Fig. 4). When present, it is composed of gray to dark gray limestone (micrite) interbedded with brown to light brown dolomite micrite (landward) and finally grading into light brown to buff limy dolomite or dolomite micrite. The dolomite is 12 partly quartz sandy and pyritic and has a few pore-filling gypsum crystals. Both dolomite and limestone are cherty but most of the chert is present in the dolomite. Lenses of gray to gray brown, fine to medium grained subangular to subrounded quartzose sandstone are present in the unit and are mostly friable and in some places cemented by dolomite, calcite or earthy gypsum. There are also some frosted quartz grains in the sandstone. Thin beds of gray to greenish gray and brownish red shale are also present as tongues in the unit. The lower contact is conformable with the middle unit, and the upper contact occurs at the pronounced pre-Pennsylvanian disconformity. The Parma $5. or Saginaw formation of Pennsylvanian age fills the irregular surface of the Bayport and quartz, chert and dolomite pebbles occur at the contact in most places. DISTRIBUTION AND THICKNESS The irregular pattern of the total Bayport isopach (Fig. 5) distribution is partly because of post-Mississ— ippian erosion. Attempts were made to use the wells which had at least parts of Unit C in the construction of the isopach map. However, those wells showing clearly anomalous thicknesses for Unit C along the disconformity were eliminated and the isopach maps for Unit C and total Bayport were reconstructed from more meaningful data. In order to assure full thickness development in Units B and A, only those wells showing Unit C as present were used to generate these maps. Unit A Isopach The isopach of A-unit (Fig. 2) indicates several local basins which were present at the time of deposition, or produced by subsidence at the time of deposition. These basins are in approximate north-south and east-west directions, and in both ovate and elongate shapes. The thickest parts of the unit show the area of maximum sub- sidence in respect to adjacent shallow shelf area at the time of deposition. The isopach lines show that the 13 M I C H I G A N E L A K Figure l. ___)d== I N D I A N A a.-.- 14 O H I O — - —--—-- - Index map of the study area. —T—-—t—-r -‘—+- - 4— Figure 2 Isopagb Map Unit A Of Bayport Formation Int 9 Michigan Basin scale 5 0 10 20 30 n n I l Jmi. Contour interval 2 O“- Y. Lasemi JulY l9 7 5 15 016 Control well Thickness line 4 0/ / /' Bayport subcrop I l6 thickest areas are to the north, northeast and northwest. The unit thins to the south, southeast and east in the Basin. These were the high areas in respect to negative areas of the subsiding local basins. In some places, the unit thins and finally is absent (e.g., wells 5, 7, 38, 71, 72, Appendix A), indicating that there was either local upwarping contemporaneous with the subsidence of the adjacent areas, or simply differential settling. Unit B Isopach The isopach pattern of the B-unit (Fig. 3) shows that the thickest parts of the unit are in the north central part of the Basin, indicating the shifting of the major area of subsidence to the north central part where it was more of a shelf area at the time of deposition of the lower unit. While some of the subsiding areas maintained sub- sidence after A-unit time others shifted to areas which were shallow at the time of deposition of the A-unit. The local basins show generally north-south and east-west elongation. The major "highs" were similar to those of the A-unit, to the south, the southeast, east, northeast and northwest. The same general randomness of isopach closure is apparent here as in Unit A. Figure 3 l$0pach M a p of Unit B of BOYPOI't Formation in the Michigar Basin scale 9 .0 12 22 1°... Contour interval 20? t. Y. Lasemi July 1 9 7 s / 0 lb Control well 4 O / Thickness line . ’ Bayport SubcrOp 18 Unit C Isopach The C-unit isopach (Fig. 4) shows a very irregular isopach pattern obviously as a result of pre-Pennsylvanian erosion. The isopach shows that the thickest parts of the unit are in the north and center of the Basin. The zero isopach indicates patterns highly suggestive of streams which appear to radiate from a central Basin position. The C-unit is absent in the "positive" areas to the south, east, northeast and west, where erosion was apparent- ly more pronounced. Bayport Isopach The total Bayport isopach map (Fig. 5) shows that the thickest areas are in the north, northwest and in the center of the Basin, indicating the major subsidence of the formation at the time of deposition. The subsiding areas are almost in the north-south direction. The "positive" areas are in the same areas displayed on the isopach maps of the individual units. The total Bayport isopach does not compare favorably with any one of the subdivision isopach maps, pointing to the general randomness of the general thickness patterns. Thus it appears that there is no definite reflection of any pre-existing intrabasinal structures, faults or folds, that are believed (Prouty, 1972) to have developed earlier in about pre-Meramecian time. The isopach maxima (two) figure 4 l h sopaacf Map Unit C of “War! Formation m the MICDIQO n Basin 5 e o .5 16' go 29“,. Contour interval 20 It. Y. lasemi July 1 9 7 5 19 016 Control well 0 ’- Thickness line .’ .Bayport subcrOp Figure 5 Isopach Map of 8‘:')'P0”. Formation . . I e Michigan Basin scale 9 a" 30 2.0 30 Contour interval 25ft. Y. lasemi July 19 7 5 20 /5 ’0 016 Control well 0 /Thicl 1). The map also shows that the major area of shale deposition is in the northwest central part of the Basin, where the shale percentage is mostly between 50-80, with few places showing less than 50 percent shale. The major clastic influx apparently was from the high areas to the south, east and possibly northwest of the Basin. 4 Thin shale alternations occur in the carbonates, indicating small cycles of deposition. Major cycles based on regression—transgression-regression (Fig. 7) define the three facies of the Bayport (Fig. 11), referred to also under Geologic History and Environmental Interpretation. Unit A Facies Figure 8 shows the facies relationship of carbonates of this unit. The map indicates that the unit is mainly dolomite forming broad unbroken areas near the periphery of the Basin. More basinward and occurring in a number of disconnected "pockets," the dolomite interbeds with lime- stone and becomes mainly or entirely limestone at the center of these pockets, a relationship to be discussed later. At some shoreward localities to the east and south in 25 6- Deepening Shallowing -—) Saginaw fm. C-Unit B-Unit A-Unit Michigan fm. Figure 7. Regressive-transgressive cycles--Bayport formation. Figure 8 Is, _dol. ratio map Un‘It A of BayportFormation . in the Mlcl'igan Basin scale 5 0 110 20 30 Y- lasemi July 1 9 7 5 016Control well I Ratio line ’.— Bayport subcrop a 1 1/8 '8 I dol ratio »3 Is 11: ls—dol. 1— 1/edol.— Is. ‘ 1/8 dOl 27 the Basin, typical A-unit lithology grades sharply into a clastic sequence showing upward decreasing grain size. The meaning of this sequence in environmental interpretation will be described later also. Unit B Facies The lithofacies map of Unit B (Fig. 9) indicates that the unit is mainly limestone, composed of less than 50 per- cent dolomite. The dolomite/limestone ratio increases, though in isolated areas, towards the southeast, northeast, northwest and east central part of the Basin; and finally grades to dolomite in a few places. There are some suggestions of structural control of the dolomite distribution, especially in the somewhat linear strip occurring from TlN-R3E to T6N-R1W, essentially astride the Howell Anticline. Several other dolomite or lime-dolomite areas show linear trends, as from TlON-RSW to T12N-R1E, and TlON-RSE to TllN-R3E, suggestive of fault control. Some other occurrences as from Tl8N-R12W to T18N- RllN, and TlQN-RlW to T19W to Tl9N-R2E are suggestive of plunging fold axes, but could be coincidental. Unit C Facies Figure 10 shows the facies distribution of the C-unit as it relates to the post-Bayport pre-Pennsylvanian dis- conformity. The blank area of the map shows the places Figure 9 ls.— dolf. ratio map 'l6ControI well a Unit Bot .JRatiolino Bayport Formation --OBayport subcmp in the Michigan Basin Scale ‘ dol. 5 0 10 20 30 . #4 l I J an. I; / dol ratio 93 s. 1— a Is. -—d0l. Y Lasemi July 1 9 7 5 1—1/8 dot—ls. ‘1/8 dOL Figure l 0 I3. Idol- rptio map a Unit C of Bayport Formation in the Michigan Basin scale 30 12 2.° Y. Lasemi July 1 9 7 s .16 Control well ’ROHO “n. '0‘! Bayport su bcrop ls. Is. I doI.ratio Is it 8 - 1 -8 ls.—dol. l -1/3dol. —lS. ¢ 1/8 dol- 30 where the unit is eroded. This unit is similar to the A- unit in being composed principally of dolomite, although, erosion has had some effect on the facies distribution of this unit. The map indicates that in a few small pockets of the north central and western part of the Basin the dolomite interbeds with limestone and at the center of some pockets the unit is all limestone, an occurrence noted in Unit A, and considered of similar origin, dis- cussed under Environmental Interpretation later. In general these pockets, in both Units A and C, are clustered nearer the central Basin area as opposed to the broad relatively continuous peripheral dolomite area. It may be more than coincidental that some of the limy pockets of A and C occur in the same areas as Tl7N-R3-4W and Tl9N-R5-6W. The clastic content of Unit C (Appendix A) rarely exceeds 50 percent. GEOLOGIC HISTORY AND ENVIRONMENTAL INTERPRETATION The sedimentologic association of the Bayport form- ation would appear to represent the condition of a stable shelf, as proposed by 81055 et a2. (1948). Lithologic associations of the formation reveal the types of environ- ments that were present during Bayport time. Bacon (1971) studied the 18-foot section of the Bay— port formation in the Wallace Stone Company quarry at Bay- port, Michigan. It appears that this section is composed of the upper part of Unit A and part of Unit B of the Bay- port subdivisions used herein. Bacon apparently applied the model of Butler (1969) for sabkhas of the southern Persian Gulf, concluding that the entire Bayport has been .deposited in a sabkha environment, based on the single section. The study herein is directed towards a sediment- ary environmental study of the total Bayport formation in the regional sense and will test several models by differ- ent investigators in search of a clear picture of the depositional history of the formation. 31 32 Unit A Deposition of the lower unit began with a slightly less restricted environment in the Michigan Basin area. This terminated the gypsym deposition of the hypersaline lagoon of the Michigan formation. The environment of deposition is suggestive of a tidal flat. Clastics of decreasing grain size upward grade laterally into carbon- ates. This is particularly noticeable in the south, east and northeast part and into the central Basin area. This type of sequence, referred to as intertidulite by Klein (1971) are deposited in the intertidal environment by tidal processes. The clastic sequence when present is about 5 to 30 feet thick, and has a sharp contact with the Michigan formation or occurs within lower or upper part of the unit. The sequence starts below with fine to medium and coarse quartzose sand and grades upward to fine sand, very fine sand, silt and finally to silty clay. The upper contact is sharp with Unit B or upper part of Unit A. According to Klein, a gradation into finer sediments across the tidal flat shoreward and the textural distribution occurs as a result of high and low tide level. If the tidal flat environment progrades seaward upward gradation to finer will occur. Paleotidal range can be determined from the upward fining sequence of tidal flat clastics. The sand at the bottom represents the low tide; the transition sedi- ment, which is from suspended load and bedload, represents 33 mid-tide; and the clay indicates high tide (Klein, 1971). The sequence shows local progradation of the sea at the time of deposition. The carbonate of Unit A also represents deposition mainly in a tidal flat environment. The dolomite is micritic and in the most part associated with pore—filling gypsum crystals. Quartz sandstone beds are generally cemented by earthy gypsum. Except for occasional ostra- cods, fossils are rare in the dolomite. Bacon (1971) recognized algomat associated with dolomite in the Wallace Stone Company Quarry at Bayport. Investigations in recent tidal flat environments by Illing et al. (1965), Curtis et al. (1963), Lucia (1968), Butler (1969), Shinn (1965) and Deffeyes et a1. (1965) indicate similar sedimentation in intertidal and lower supratidal environments. Dolomites of intertidal and supratidal origin have been recognized in ancient records by several investigators including Lucia (1972), Laport (1967), Armstrong (1970), Fisher and Rodda (1969), Campbell (1962), Gardner (1971) and many others. Micritic dolomite of A-unit of the Bayport formation is also interpreted as intertidal or lower supratidal carbon- ate, as does Bacon (1971) at Bayport. The amount of chert increases in this unit which is additional likely evidence of tidal flat sedimentation of the dolomite. The silica may have been deposited either inorganically from the quartz sands brought to the environment by the streams, or organi- cally by silica-precipitating organisms. Gardner (1971) 34 concluded that the chert in the Bois Blanc Formation of the Michigan Basin deposited extensively along the periphery of the Basin. Fisher and Rodda (1969) also showed that, like dolomite, chert is present in a belt marginal to carbonate evaporite lagoon in Texas. In several disconnected areas of the north central part of the Basin (Fig. 8) the dolomite is interbedded with a gray to dark gray micrite and finally grades to lime- stone. This limestone, which corresponds to the deeper part of the Basin, indicates conditions of subtidal (marine) environment, which remained undolomitized. The environment of deposition of the dolomite was likely in warm waters with high evaporation rate. The evaporation produced a fluid of much higher Mg-Ca ratio because of the formation of gypsum (Adams and Rhodes, 1960, Deffreyes et al., 1965, and Butler, 1967). The dolomitization may have occurred according to the seepage refluxion model proposed by Adams and Rhodes (1960). According to this model, the loss of water by evaporation increases the concentration and specific gravity of the remaining brine along with precipitationlof gypsum. The heavy hypersaline water seeps slowly downward through the slightly permeable carbonates. During this process the MG++ replaces Ca++ and high magnesium calcite recrystallizes as dolomite. The limestone of the lower unit and those interbedded with dolomite in the north central part of the Basin are similar to dolomite in having 35 micritic texture, inferring that the dolomite is pene- contemporaneous with the limestone and that dolomitization occurred shortly after deposition of the lime or aragonite mud. The hypersaline brine with high Mg-Ca ratio, either could not reach some parts of the lime mud, or evaporation was not high enough to produce high Mg++-Ca++ ratio, because of water depth. The latter possibility is strengthened by the occurrence of the limestone in isolated patches which may have been "pockets" or depressed areas of deeper water on the sea floor. This is supported by comparing the A-unit iSOpach (Fig. 2) to A-unit limestone/ dolomite ratio map (Fig. 8). Examples of reasonable correlations between isopach "highs" (low topography) and increased limestone content may be Observed in Tl3N-R3 and 4E, and TZON-Rl and 2W of both maps. ISOpach "lows" (high- er topOgraphy) correlates rather well with increased dolo- mite areas. Clastic deposition exceeds carbonate in some areas. The quartzose sand often has dolomite cement which may be the result of dolomitization of pre-existing calcite cement (Blatt et al. , 1972, p. 491). Unit B A major transgression occurred after a quick rise of sea level in early B-unit time. The B-unit, which is deposited in a marine environment, consists of dominantly 36 limestone with a diverse and normal marine fossil assemblage. At the beginning, quartz sand deposition was predominant in many places, and with additional transgression the en- vironment became suitable for carbonate deposition in which invertebrate forms flourished. In the other parts of the Basin sedimentation began more quietly with lime muds. The only fossil in this limestone is well preserved ostracods with thin shells and no ornaments,'indicative of a deeper marine environment (Heckel, 1969). This is now a biomicrosparite with the ostracods in a very finely crystalline sparry calcite cement. As there has been no transportation to wash away the microcrystalline ooze matrix, the sparry calcite cement may have been the result of recrystallization of the microcrystalline calcite or inversion of aragonite ooze (Folk, 1959). The ostracod biomicrosparite or calcareous sandstone of the lower part grades upward to a gray-brown-tan, generally finely crystalline fossiliferous limestone (biosparite). As there is no evidence of transportation and sorting of the fossils, the microcrystalline calcite ooze, primarily deposited as a cement, may also have altered to finely crystalline sparry calcite after recrystallization. In some localities recrystallization has affected both the cement and the fossils such that the entire rock is a medium to coarsely crystalline limestone in which, except for a few crinoid stems, all fossils have been destroyed. The fossil assemblage of this unit contains crinoids, 37 foraminifera (Endothyra) ostracods, echinoid spines, bryozoans, corals and brachiopods, all of marine habitat. The middle part of the B-unit indicates the time of ~maximum stand of the sea level which brought the circu- lation of normal sea water to other basins, as in Illinois, Indiana, Ohio and the Appalachian area. According to Matthews (1974, p. 257), rising water creates more living space between the bottom and surface of the water, while at the same time Clastic influx is ceased by trapping in the extuaries and alluvial environments. Since the rising water was not fast, the character of the carbonate deposi- tion did not change and the organisms could flourish along with rising sea level. The presence of thin beds of shale or quartz sand in the limestone indicates fluctuations at the time of deposition. The presence of ostracod limestone and calcareous sandstonenear the close of Unit B similar to those of the lower part of the unit, indicates gradual lowering of the sea level. Near the top of the unit in the Cheney Quarry at Bellevue, Michigan, is a zone of cup corals. The same coral zone, apparently, was recognized by Bacon (1971) in the quarry at Bayport, inferring a warm shallow marine environment near the end of Unit B. The presence of fossil fragment serving as nuclei in the chert nodules of Unit B infers a secondary origin for the chert. Glauconite is found also rather commonly with the organic nuclei of the chert and as casts in limestone, inferring a reducing condition for the environment. Both chert and 38 glauconite suggest a quiet environment with no elastic material at the time of deposition. In some places the limestone has been dolomitized (Fig. 9) resulting in a medium-coarse crystalline mosaic of saccharoidal dolomite or dolomitic limestone. In some localities the dolomite rhombs are large and can easily be seen under the binocular microscope (e.g., T4N—RlW-Sec. 22). The dolomite rhombs are yellowish brown, transparent and sometimes are interlocking medium-coarse sucrosic, sparry crystals. The transparent crystals are similar to those of limpid dolomite of Folk and Land (1975). Several observations can be made concerning dolomiti- zation in the B-unit. A few of the lime-dolomite beds have linear traces which may reflect some known structures (which may be faulted), as indicated earlier under Lateral Relations. Oil production from linear structures in the Ordovician and Devonian long have been attributed to fractures and dolomite porosity, with dolomitization clearly epigenetic in origin. Linear structures in Mississippian limestones similarly could be faulted with the faults serving as channelways for secondary dolomiti- zation. The isolated patterns of dolomite-rich (Mg++-rich) rocks of the B-unit, apparently are unrelated to thickness (Fig. 9) or proximity to the ancient shorelines and there- fore appear related to faults and fractures with dolomiti- zation being epigenetic. Some of the magnesium may be related to post—Bayport 39 erosion and descending groundwater. The localized dis— tribution of magnesium-rich areas (Fig. 9) could then be related to the loci of fault channelways and localization of high Mg++-charged descending groundwater. This high- magnesium water source could have originated in standing bodies of water, as lagoons, where fresh water may be mixed with sea water —- hypersaline or normal (Folk and Land, 1975), which causes the Mg/Ca ratios to remain high, but lowers the salinity and crystallization rate. This diluted solution is then transported to the limestone of the B-unit. The non-dolomitized area of Unit B indicates that either the magnesium-rich solution was not available, or by the time it reached the B-unit, the magnesium was already consumed, and the crystalline limestone was not dolomitized. Another possible source for the origin of the dolomiti- zing fluids could be groundwater/seawater mixtures (Folk and Land, 1975; Badiozamani, 1973). Such a process may have yielded the "limpid" dolomite that would appear to characterize the B-unit. Unit C Because of similarity of carbonate associations of the C-unit with that of the A-unit it is considered here that they were developed under similar conditions and had parallel histories. The only apparent difference in the two is the sucrosic dolomite (like that in Unit B) found 40 occasionally in Unit C. The sucrosic dolomite may have been formed by one or more of the methods described for dolomitization of the B-unit. Bayporthlastics As indicated before, the sandstone of the Bayport formation is quartzose and may be either well cemented or friable. The grains are usually subangular to rounded, but occasionally show high sphericity, indicating possible reworking of the grains prior to deposition, or they may have been derived from older formations. The infrequent highly spherical frosted quartz grains probably were handled by wind at some stage in their history. Typically the Bayport quartzose sands vary appreciably in their concentration. When sand grain movement was in the form of collective movement, carbonate sedimentation ceased; on the other hand the individual movement of sand grains might not haVe any effect on carbonate deposition (Payne, 1942). The quartz grains of the B-unit are in the form of angular, very fine grained sand or silt, indicating that the grains could be carried by suspension or by saltation during stormy seasons. The shale of the Bayport is greenish gray, dark gray and black. Though the clay minerals were not investigated qualitatively, the green color could well reflect the 41 rather common glauconite in the Bayport, or simply the inferred reducing conditions with iron in the ferrous state. The dark to black color of the shale represents finely disseminated carbonaceous material, or otherwise finely disseminated pyrite or marcasite observed commonly as fine euhedral crystals in the carbonate groundmass. Also, secondary crystal masses are found commonly through- out the carbonates as fillings of vugs and other porosity. For the thin shale partings in the limestone, Heckel (1969) suggested either a rapid influx of fine clastics to the environment, where both carbonate and skeletal material were depositing slowly, or a cessation of carbon- ate deposition for a longer period of time. Of the two the latter might more closely fit the situation for the shale in the Bayport, as the carbonate is shaly in some areas, especially to the west in the Basin. The shale- limestone alternations may also reflect sea level fluc- tuations as a part of smaller cycles within the major cycles inferred by the transgressions and regressions that defined the three units of the Bayport formation (Fig. 7). The lagoonal environment of the Michigan formation gave way to the tidal flat deposition of the A-unit. Then after a local progradation, the major transgression occurred and resulted in the more open, marine B-unit. At the end of B-unit time progradation (recession) occurred with a return to a similar condition to the A-unit in C-unit time. 42 The source of the clastics in the Bayport poses a problem because of the patchy occurrence of some of the shale and sand bodies. The sand-shale ratio of the Bayport lithofacies map does not show a clear regional directional trend, inferring irregular distribution by currents along tidal flats. Unit A sandstone near the base (Fig. 11, A-A') represents one of the more continuous bodies indicating likely a sheet sand along the recessive shorelines, with the source to the east. Probably the same sand crosses the basin along the north-south profile (B-B'). Concentrations of sandstone and the principal shale body occurs near the west side of the structural basin, suggesting a possible source from that direction. The north-south section (B-B') shows similar clastic concentrations to the north and south. Thus it would appear that the clastics may have been derived ultimately from peripheral highlands. This departure from the more typical eastward source in earlier Mississippian time probably represents the general uplift of the Basin that culminated in the post-Bayport dis— conformity. «no, sane .1-«14 » ~ 12,1. 110...?! «2.1. at. .a-< OZOH< :0..3. .r ~wd J. bled/st! 8 .< afillinliowlllszjflnl oi moutcu. r 2.01 rd-UttssQ: .5 01 Tall—die! tarts... a. 1muilnrr < .351 e: 08 .Q|Ifi ‘ l}.* STRUCTURE The presence of an erosional unconformity on top of Bayport formation is well-recognized by residual chert, quartz pebbles, coarse sand and occasional dolomite pebbles at the base of Pennsylvanian rocks. In most places, the upper unit is all eroded (Fig. 4). This figure shows the zero isopach of the upper unit, which is suggestive of stream channels radiating from the center of the Basin. In some localities the entire Bayport is missing along the erosional unconformity. A local erosional unconformity is suggested for the lower contact with the Michigan formation, as in a few places (such as in the northeastern part of the Basin) the Bayport formation rests on the Marshall sandstone. Figure 12 is a structure contour map constructed on the base of the Bayport. The map shows that the deepest part of the Basin is in the north central area where three synlines are elongate in a northwesterly direction. It is of interest to note that the Bayport formation in its entire distribution conforms with the general northwest elongation characteristic of all the previous Paleozoic systems in the Basin -- despite the obvious shifting of the Basin structural center in post-Osage time (Prouty, 1972) from the general Saginaw Bay area to the present 44 Figure 12 Structure Contour Map of base of Bayport Formation 016 Control well In the Michigan Basin scale 2 3 15—2 l‘oL lo #121". / Contour line Contour interval 50 ft. Y. Lasemi July 19 7 5 46 structural center of the Basin. The Bayport depocenter as defined by the isopach high (Fig. 5) conforms generally to the structural center. The Howell Anticline is defined by sharp offset of the isopleths in T3N—R4B to TSN-RZE where a fault (perhaps in the left lateral sense) is inferred. It is noteworthy that this structure does not show pronounced anticlinal form in Bayport time. Ells (1969) has shown in a north- east-southwest section across the fold the offlapping nature of the Coldwater, Marshall and Michigan formations, presumably because of post-Marshall erosion. Bayport sedimentation occurred in a structure that apparently had been largely, but not entirely, truncated such that pro- 'nounced structural relief does not show in the Bayport formation. Evidence has been presented (Prouty, 1972) that the anticline was likely formed, and perhaps faulted, in post—Osagean (Mississippian) time. The post-Marshall pre-Bayport erosion interval apparently resulted from this uplift. Another observation from the structure map shows the steeper east side of the Michigan Basin. This could .well be one of the better lines of evidence to support the contention of Prouty (op.cfit.) that the principal stresses forming the faulted structures such as the Albion- Scipio, Howell, Pinconning, North Adams, Deep River and other dolomite and fracture producing oil fields, as well as the shifting of the Basin center from the Saginaw Bay general area westward to its present central position, 47 resulted from stresses from the east to southeast (presumably orogenic stresses from the developing Appalachians) in post«Osagian time. The marginal area of the Bayport basin shows a number of gentle folds plunging generally towards the basin center. A rather pronounced exception is a relatively sharp northeast structure near the central basinal area from T10N-R4W to T13N-R2W. SUMMARY AND CONCLUSION The Bayport formation is subdivided into three units, for more detailed stratigraphic, sedimentologic and en- vironmental interpretation. The lithologic observations indicate that the formation was deposited in a rather stable tectonic environment. Deposition of the lower unit (A) began after cessation of the predominantly evaporite deposition of the Michigan formation. The evaporite lagoons gave way to carbonate flat deposition by a slight rise of sea level, which caused more circulation of the sea water over wide areas. Hypersaline conditions returned occasionally to the point of gypsum precipitation as crystals, pore fillings or very thin beds. In this case the brine of high Mg/Ca ratio caused dolomitization of already deposited lime or aragonite muds. The major transgression at the beginning of the middle unit (B) provided an excellent environment for development of organisms. This was the time when the Basin was probably connected to the adjacent basins and open circu- lation of sea water produced essentially similar environ— ments regionally. The gradual regression at the close of the B-unit provided almost the same environment of deposition as the lower unit. Thin beds or lenses of 48 49 sandstone and shale in the carbonate indicate that there have been occasional fluctuations at the time of deposition. The penecontemporaneous (stratigraphic) dolomite of the A- and C-units was distributed mostly throughout the Basin, interrupted by a few isolated limestone areas, which are believed to reflect pockets of deeper, less saline waters. Dolomitization in the B-unit is the converse of the A and C units in that the dolomite represents localized areas in a wide-spread limestone unit. These isolated, but somewhat geometric, patches strongly suggest fault and fracture control. The dolomitizing process in this case was epigenetic, and the magnesium-rich replacing fluid is believed to have its origin in a fresh water-sea water mixing environment, such as a lagoon, or perhaps where groundwater and sea water could admix. After deposition of the C-unit, the entire area rose above sea level by positive epeirogenic movements or negative eustatic movement and then was sugjected to severe erosion. Streams cut through the formation and eroded the upper unit in most places. It is not resolved whether the entire Chesterian series was eroded along this disconformity or whether it was deposited at all. In some areas, the entire Bayport was eroded away. The major area of subsidence apparently was in the north central part of the Basin, while the major positive areas were located in the south, east and northwest. These higher marginal areas may have accounted for the somewhat 50 peripheral occurrence of the Bayport clastics. The structural center and depocenter of the Basin conform rather closely to the present Basin center, suggesting relatively stable conditions since directly post-Osagian structural changes. The Bayport structure contour and isopach maps reveal evidence of these earlier movements, including the likelihood of extrabasinal stresses. BIBLIOGRAPHY BIBLIOGRAPHY Adams, J. E., and M. L. Rhodes, 1960, Dolomitization by seepage refluxion: Am. Assoc. of Petroleum Geologists Bull., v. 44, p. 1912-1920. Alen, R. C., R. A. Smith and L. P. Barrett, 1917, Mich. Geol. Survey, pub. 23. Armstrong, A. K., 1970, Mississippian Dolomites from Lisburne Group, Killik River: Am. Assoc. of Petroleum Geologists Bull. v. 54, p. 251-264. Bacon, D. J., 1971, Chert genesis in a Mississippian sabkha environment: M.S. Thesis, Michigan State University. Badiozamani, K., 1973, The Dorag dolomitization model -- application to the Middle Ordovician of Wisconsin: Jour. Sed. Petrology, v. 43, p. 965-984. Blatt, H., G. Middleton, and R. Murray, 1972, Origin of sedimentary rocks: Englewood Cliffs, New Jersey, Prentice-Hall, 634 p. Butler, G. P., 1969, Modern evaporite deposition and geo- chemistry of coexisting brines, the sabkha, Trucial Coast, Arabian Gulf: Jour. Sed. Petrology, v. 39, p. 70-89. Campbell, C. V., 1962, Depositional environments of Phosphoria Formation, Wyoming: Am. Assoc. of Petro- leum Geologists, v. 46, p. 478-503. Cohee, G. V., 1951, Thickness and lithology of Upper Devonian and Mississippian rocks of Michigan: U.S.G.S. (Co-op. Mich. Geol. Survey. Univ. Mich. Dept. Geol.) Oil and gas investigation chart 41. Curtis, R., G. Evans, D. J. Kinsman and D. J. Sherman, 1963, Association of dolomite and anhydrite in the Recent sediments of the Persian Gulf: Nature, v. 197, p. 679-680. 51 52 Dapples, E. C., W. C. Krumbein, and L. L. 51055, 1948, Tectonic Control of Lithologic Associations: Am. Assoc. of Petroleum Geologists Bull. , v.32, p. 1924- 1947. Deffeyes, K. S., F. J. Lucia, and P. K. Wehl, 1965, Dolomitization of Recent and plio-Pleistocene sediments of marine evaporite waters on Bonaire, Netherlands Antilles: Soc. of Econ. Paleontologists Mineralogists Spec. publ. 13, p. 71-88. Eddy, G. E., 1936, Geology of the crystal oil fields: Oil and Gas Jour., v. 35, p. 32-38. Ells, G. D., 1969, Architecture of the Michigan Basin: In Michigan Basin Geol. Soc. Ann. Field Excursion, by H. B. Stonehouse, p. 60-89. Fisher, W. L. and P. U. Rodda, 1969, Edwards Formation (Lower Cretaceous), Texas: Dolomitization in a carbonate platform system: Am Assoc. of Petroleum Geologists Bull., v. 53, p. 55-72. Folk, R. L., 1959, Practical petrographic classification of limestones: Am Assoc. of Petroleum Geologists Bull., v. 43, p. 1-38. and L. S. Land, 1975, Mg/Ca ratio and salinity: Am. Assoc. of Petroleum Geologists Bull., v. 59, p. 60-68. Gardner, W. C., 1971, Environmental analysis of the Middle Devonian of the Michigan Basin: Ph.D. Dissertation, Northwestern University, 109 p. Gregory, W. M., 1912, Geol. Rep. on Arenac County: Mich. Geol. and Biol. Survey, pub. 11, 146 p. Heckel, P. H., 1969, Recognition of ancient shallow marine environments: Soc. Econ. Paleontologists Mineralogists Spec. Publ. 16, p. 226-286. Illing, L. U., A. J. Wells, and J. C. M. Taylor, 1965, Penecontemporary dolomite in the Persian Gulf: Soc. Econ. Paleontologists and Mineralogists, Spec. Publ. 13, p. 89-111. Kay, M. and E. H. Colbert, 1965, Stratigraphy and life history: .John Wiley and Sons, Inc., New York, 736 p. 53 Klein, C. DeV., A sedimentary model for determining paleo- tidal range: Geol. Soc. America Bull., v. 82, p. 2585-2592. Krumbein, W. C., 1948, Lithofacies maps and regional sedimentary-stratigraphic analysis: Am. Assoc. Petro- leum Geologists Bull., v. 32, p. 1909-1923. and L. L. 51055, 1963, Stratigraphy and sedi- mentation: 2nd ed., Freeman and Co., San Francisco, 660 p. Lane, A. C., 1899, Water resources of Lower Peninsula of Mich.: Water supply paper 30, 97 p. , 1906, Ann. Rep. of Mich. Geol. Survey. , 1908, Ann. Rep. of Mich. Geol. Survey. Laport, L. F., 1967, Carbonate deposition near mean sea- level and resultant facies mosaic: Mahluis Formation (Lower Devonian) of New York State: Am. Assoc. Petroleum Geologists Bull., v. 51, p. 73-101. Lucia, F. J., 1968, Recent sediments and diagenesis of South Bonaire, Netherlands Antilles: Jour. Sed. Petrology, v. 18, p. 845-858. , 1972, Carbonate shoreline sedimentation: Upper Clearfork (Leonard), Flanagan and Robertson Fields, West Texas: in Soc. Econ. Paleontologists Mineral- ogists Spec. publ. 16, p. 160-191. Martin, H. M., 1937, Legend Geol. Map: Mich. Geol. Survey, pub. 39. Matthews, R. K., 1974, Dynamic Stratigraphy: Prentice-Hall, Inc., Englewood Cliffs, New Jersey, 370 p. McGregor, D. J., 1954, Stratigraphic analysis of Upper Devonian and Mississippian rocks in Michigan Basin: Am. Assoc. Petroleum Geologists Bull., v. 38, p. 2324- 2356. Newcombe, R. B., 1933, Oil and gas fields of Michigan: Michigan Geol. Survey Div. pub. 38, Geol. Ser. 32. Oden, A. L., 1952, The occurrence of Mississippian Brachio- pods in Michigan: M.S. Thesis, Michigan State College. 54 Payne, T. G., 1942, Stratigraphical analysis and environ- mental reconstruction: Am. Assoc. Petroleum Geologists Bull., v. 26, p. 1697-1770. Prouty, C. E., 1972, Michigan Basin Development and the Appalachian foreland: (abst.), International Geologi- cal Congress, 24th Annual Session, Montreal, Canada, Aug. 1972, p. 97. Shinn, E. A., R. N. Ginsburg, and R. M. Lloyd, 1965, Recent supratidal dolomite from Andros Island, Bahamas: Soc. Econ. Paleontologists Mineralogists Spec. publ. 13, p. 112-123. 81055, L. L., W. C. Krumbein, and E. C. Dapples, 1949, Integrated facies analysis: Geol. Soc. of America, Memoir 39, p. 91-123. Smith, R. A., 1914, Mich. Geol. Survey, pub. 14. Weller, J. M. et al., 1948, Mississippian Formation of North America: Geol. Soc. of America Bull., v. 59, p. 91-188. APPENDICES APPENDIX A -- Unit not present Blank Units are not differentiated APPENDIX A Well data used for mapping of the total Bayport fm. and subdivisions. (D :4 g 0% <5 Location Un1t C Un1t g g2 0,2 TP-RG-S ls/dol Clasfic ss/sh thiav ls/dol clastic m 9* ratio ratio ratio ness ratio ratio 1 5222 22N-2W-36 -- -- -- -- .37 .08 ne ne se 2 9210 22N-7W-29 -- -- -- -- 9 .11 c s/2 se ne 3 9968 22N-6W-35 0 .8 w 55 w 0 c s/2 nw nw 4 997 22N-9W-28 -- -- -- -- m .6 ne ne ne 5 8726 21N-7W-16 1.5 1 8 52 w .9 - c S w 6 8468 21N-7W-23 .3 2.7 6.3 15 4.2 .03 c s/2 se ne 7 7381 21N-9W-24 2.2 .6 m 26 m .05 sw se se 8 4595 21N-2W-32 -- -- -- -- 1.4 .27 cnw nw 9 8014 21N-6W-l6 -- -- -- -- w .2 cs/2 sw sw 10 145W) 20N-1W-8 -- -- -- -- m .16 nw nw ne 11 8587 20N-1W-33 -- -- -- . -- m .25 ne se ne 12 5065 20N-2W-28 sw se se 13 8438 20N-6W-36 3 1.5 1.4 20 m .14 cn/Z ne SW 14 12648 20N-lOW-27 2.5 .9 0° 20 °° .38 se se nw 15 7473 20N-7W-25 1.1 1 4 30 m 0 n/2 ne ne 16 16231 20N-3W-26 .52 .61 3 84 17.5 .05 se se 17 114¢4 20N-5W-7 .27 1.6 4.5 36 w .54 cs/2 se nw 18 124 20N-llW-ll -- -- —- -- m 3 nw nw 19 3856 19N-lW-34 nw ne ne 20 14123 19N-2W-15 -- -- -- -- 3.2 .52 se 58 ne Elev. ss/sh thick-ls/dolclastic ss/sh thick-ls/dol Clastic 5575h thiCk- 3:5: ratlo neSS rat 10 ratlo ratlo 1165 S rat 10 rat 10 ratio neSS m 13 57 .13 1.4 1.4 70 +394 1 10 40 .5 .9 m 50 +225 0 25 -- .3 .45 m 30 +320 m 24 31 2 1.5 .74 55 +335 7.3 51 15 4.4 .96 7.6 113 +139.7 .5 46 19 1.3 .3 1 30 +203.3 0 40 0 9.3 .2 5 66 +277.3 2.7 34 46 .7 4 .7 30 +43 .5 20 so .5 .37 .6 70 --- 1.3 12 27 3.2 .46 4.4 39 +239 1 11 63 .6 2.5 30. 79 +113.4 -- -- -- .02 1.4 9 130 -29.7 .3 31 39 4.7 1.25 3.5 90 +71.6 2.5 50 15 14.5 .5 4.3 35 +242.7 0 33 12 2.9 .29 3.5 30 +134.4 0 39 27 1.1 .5 4.1 150 +42.5 .62 37 17 1.63 1 1.93 90 +205 m 12 26 .3 2 m 33 +325 0 1.1 3 69 -46 2.4 20 46 .46 .62 2.3 66 -50.5 21 22 23 24 25 26 27 23 29 30 31 32 33 34 35 36 37 33 39 40 41 42 43 45 46 47 43 4265 14627 3666 8365 10009 5740 16286 15193 16884 3885 3781 12658 2372 3591 1449 11625 5200 10336 17086 13403 4424 3690 4796 16197 8738 10046 16695 l9N-2W-12 se se ne 19N-2W-34 se ne ne 19N-3W-15 ne nw nw 19N-6W-29 cs/2 nw sw ' 19N-7W-24 c n/2 ne ne 19N-lW-23 se se nw l9N-10W-20 nw nw ne l9N-9W-8 se ne se 19N-5E-26 se se nw l8N—lW-36 nw sw nw 18N-lW-ll se sw se l8N-2W-12 sw sw se 18N-3W-2 c se se l8N-5W-3 c sw sw 18N-5W-24 nw se sw l8N-5W-5 c ne l8N-6W-2 nw ne nw 18N-8W-29 cn/Z nw nw l8N-4W-28 nw nw sw 18N-12W-l3 se se sw l8N-12W-25 sw sw sw l7N-4E-12 sw nw ne 17N-2E-28 nw nw nw l7N-lW-15 se se se l7N-2W-28 se se se 17N-3W-ll s s/2 sw se l7N-4W-24 sw sw sw 11. 12. 12. 11 .76 17 40 22. 30. 51. 45 16 20 25 1.3 .06 .79 .05 .04 .13 .14 .03 .15 .08 .25 .14 0.1 1.1 .14 .12 .15 1.3 16 11 1.1 .22 16.5 3.3 16.25 0 7 0 40 .02 33 m 30 w 50 0 15 0 28.5 .36 18 .07 -- 0 -- 1.4 6.4 0 22.3 0 17.8 1 40 0 35 w 20 0 10 -- 20.25 .33 -- 0 11 0 25 0 35 0 35 0 36 0 39 0 .43 26 .37 1.5 1.6 .49 2.5 .26 5.6 .73 1.5 6.5 3.9 4.9 .74 .05 .42 .A-2 8.4 7.6 1.2 5.8 1.47 3.5 1.7 22.75 53 .66 34.75 .76 10 .28 27 1.6 27 w 20 31 90 .22 40 .93 19.5 2.6 13 .3 35 0 25 14 .35 21 .59 35 3 10 1 40 w 49 4 0 1 29.75 2.6 65 0 29 .16 43 .46 20 1.3 4 .06 20 2.5 15 .27 20 w .62 .78 .17 .93 .25 .01 .77 .62 .35 2.5 .34 1.7 .53 1.3 .87 .54 4.9 1.7 4.8 .11 2.78 1.2 .37 31 13 44.6 9.5 11.2 3.4 21 .13 1.5 .75 10.7 1.7 15.7 58 57 67 60 60 141 55 125 31 35 25 43 104 -68.8 +423.5 +58 -12.6 -83 -235 -90 -99.4 -93.3 -75 -21.7 -143.6 +261 +182.7 +270 +12.4 -282.3 -248.4 -153.6 49 50 51 52 53 S4 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 3662 2474 4637 12066 12865 2419 12469 4724 2977 7225 3900 16665 5090 3677 3676 5109 17018 9924 10387 15300 4890 3247 5201 4606 4932 12335 13673 17N-4W—31 sw sw sw 17N-5W-26 nw se se 17N-6W-18 c n/2 sw nw 17N-9W-25 c ne 17N-9W-16 ne sw se 17N-10W-20 c ne se l7N-1lW-28 sw ne se 16N-1W-27 nw sw ne l6N-lW-7 sw sw nw 16N-3W-8 se nw nw 16N-3W-6 E/2 ne 16N-3W-13 se se ne 16N-3W-28 se se nw 16N-4W-23 sw ne nw 16N-4W-5 sw nw ne l6N-7W-25 sw nw se 16N-10W-33 nw nw ne 16N-6W-25 se se se l6N-8W-l3 c N/2 nw sw 16N-11W-S sw se sw 16N-2E-11 ne se nw 16N-3E-35 se se se lSN-ZE-23 nw nw sw 15N-2E-29 lSN-lW-Z ne nw nw lSN-3W-3 sw ne ne 15N-4W-33 ne se nw 25 35 47 42 34.15 14.2 .25 .37 .73 .28 .15 .04 .33 .18 .09 3.6 .57 23.8 10 20 52 47 36 48 52 16 70 25 15 24 25 21 31 16 .59 1.3 2.3 1.5 .03 .96 1.8 6.5 1.1 1.3 .25 .52 2.33 2.4 .08 .84 1.7 1.3 .66 16.4 3.68 39 39 14 15 50 20 37 28 30 42 27 30 30 24 20 37 16 .36 2.7 9.3 .14 1.2 .46 1.58 1.5 .08 2.6 1.8 5.2 31.5 .84 .27 1.35 1.32 .05 2.2 2.2 .44 .74 .74 .92 .32 .97 .47 .97 .84 1.3 .35 .52 1.1 .42 1.8 10.6 16.2 2.85 .94 5.6 5.7 53 18.4 5.4 3.8 63 107 27 100 25 45 65 120 70 120 84 111 90 82 92 27 100 55 40 -203 -201.9 -98.7 -76.8? +128.8 +126 +102.6 -288 -286.7 -191 -183 -224. -l64. -l7l. @0154:- -196. -44.6 +103 -210 -93.6 +91.3 +74.7 -253.7 -203.7 -288.3 -188.5 -19.4 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 12124 6038 5495 13654 3713 19098 2060 19515 3664 18882 16696 13044 16520 4540 11199 11930 16678 17738 11864 11955 2916 11305 2962 7086 3095 13005 13414 15N—4W-12 c N/2 nw sw lSN—SW-23 ne se nw lSN-6W-32 se sw ne 15N-7W-35 nw se nw 15N-6W-28 se se nw lSN-ZW-33 lSN-lE-ll sw se 15N-9E-31 se se nw l4N-2E-27 ne sw nw l4N-9E-10 nw ne sw l4N-lW-20 ne sw sw l4N-2W-8 nw sw ne 14N-4W-1 nw ne ne 14N-4W-25 nw nw ne 14N-5W-3 sw nw sw l4N-5W-l4 sw ne nw l4N-5W-l nw ne ne l4N-6W-33 ne sw sw l4N-6W-l3 se sw nw 14N-9W-35 c sw l4N-llW-29 l4N-7W-7 se nw ne l4N-3W-3 ne ne nw l4N-5E-l7 nw nw nw l3N-10W-35 c se nw l3N-8W-ll se ne se l3N-6W-28 nw se sw 0 .54 1 .36 2.5 .87 .11 .11 .56 .36 52.5 3.7 .04 44 20 29 40 49 25 37. 20 13 m .1 1 1 .01 m .18 1.9 8 2 3 .13 5 .24 4 5 .09 m .18 w .15 w 0 6.9 0 w .1 w 0 m .66 w .1 w .77 m .36 .24 .26 17.2 1.4 4 7.4 w 0 1.8 2.9 .58 68 1.75 1.68 1.2 3.3 40.5 25.8 24 44 37.5 22.4 36 30 36.2 30 25.2 46 39.5 36 27.5 10 23 15.5 .02 1.6 .37 .22 COCO 10 1.1 3.2 .49 .56 12.5 1.26 4.4 .16 .74 2.5 1.6 .85 .47 24 1.9 8.6 1.7 1.24 .76 1.4 8.3 3.4 2.2 .07 23 21.2 18.5 21 85 28 23 33.8 19 39.8 65 25 15 33.3 29 21 1.3 1.44 H .54 1...: H 1.67 11 .17 oo .06 1.33 1 .4 1 .5 .05 .68 .34 1.5 .25 .82 .82 .04 .23 .58 .68 .37 .78 1.5 1.6 .3 1.6 7.8 .77 2.8 29.9 20 3.8 11.3 3.4 1.2 8.4 1.7 3.2 23.4 116 44 44 85 52 85 64 160 53 110 51 114 63 55.5 100 95 -179.5 -186 -53 -116.4 -54.8 +456 -279 441.7 -197.6 -234 -259 -142.4 -l30.6 -151 -53 -57.6 +23.6 +194.6 -99.6 -l42.5 +196.5 +134 +3 103 104 105 106 167 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 7450 12679 3654 3935 12634 8751 3423 12532 3231 6156 4694 1303 S422 3133 20114 17295 3519 3729 5037 1403 3439 17752 8417 12783 5472 774 13N-5W-21 c E/2 ne ne 13N-5W-32 nw nw se 13N-4W-l9 w/2 S nw l3N-4W-l nw ne nw 13N-4W-36 nw sw ne l3N-3W-20 c w/Z nw se 13N-3W-16 se se ne 13N-3W-12 sw nw sw 13N-lW-ll se nw se l3N-lE-15 c s/2 nw nw l3N-2W-12 c nw se se 13N-3E-15 ne sw 13N-2E-9 sw sw ne 13N-7W-32 C so ne 13N-4E-4 ne ne sw 12N-12W-10 se sw sw 12N-9W-20 sw sw se 12N-7W-2 c ne se 12N-6W-14 c sw 12N-4W-15 c se nw 12N-2W-8 nw ne nw 12N-lE-4 se se sw lZN-lE-ll c E/2 ne nw 12N-2E-34 se se se 12N-3E-31 nw nw sw 12N—1W-27 E/2 sw .17 .44 34.5 50 101 53 49 20. 25 9 .41 .7 .05 .02 .06 .06 .18 .15 8.4 .06 .59 .31 .05 .26 .31 .27 2.6 4.4 31 22. 32 32 25 16. 32 20. 30. 31 30 34 42 44 51 12 44. 29 42 34 24. 31 .8 16 O O O O O O I—‘ O O O O O F-' 0000 8 .75 1.5 .63 2.1 7.3 1.7 .81 2.25 1.3 5.2 4.1 .47 .82 .86 3.8 5.6 A-5 3.65 6.6 2.8 2.8 17.7 1.25 1.47 11 17 14 13.9 20 12 25 19.6 12 18.1 18.8 25 29.8 71 13 25 34 19 30 18 23.5 42.4 12 58 23.4 40 2.6 .97 2.4 7.6 .89 .88 .87 1.2 3.8 22.5 1.1 6.2 .26 2.6 .64 15.7 2 .66 .55 .46 .24 .58 .54 .34 .78 .38 8.8 .91 .37 .26 .68 .42 .74 .64 .17 .69 .23 1.3 .54 11.4 10 2.8 2.7 .98 4.1 14.6 52 25 2.7 1.2 7.8 1.37 16 10 31.2 15 1.1 45 71 102 145 126 65 46 63 48 120 —79.4 -20 -118 -196 -l33 -159 -l79.7 -213 -l37 -l70.6 -95 -113 -l74 +33 -67.6 +392 +150 +24.3 +9.7 -96 -109 -43.4 +6.9 +3 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 400 17332 37 2315 16315 15199 5005 3680 12394 4439 3739 4769 4565 8149 13168 13044 4569 3722 7688 16957 12688 3496 12864 12N-8W-20 ne sw 12N-10W-7 sw se se 12N-5E-33 se ne 12N-8E-8 ne sw sw 12N-5W-28 ne sw ne 11N-4E-20 ne ne ne 11N-4E-29 sw sw nw 11N-1E-11 ne ne 11N-2W-7 nw nw nw 11N-4W-2 ne nw ne 11N-5W-10 se ne nw 11N-SW-27 ne ne ne 11N-6W-11 c nw sw 11N-7W-17 sw sw se 11N-8W-29 se nw ne 11N-10W-23 sw se se 11N-12W-25 se se sw 11N-8E-21 ne ne ne 11N-3W-5 c N/2 nw 11N-6E-10 se sw nw 11N-2E-26 ne se se 10N-12W-3 ne ne sw 10N-11W-34 ne nw se 10N-9W-3 nw ne ne 10N-7W-3 nw se nw 10N-6W-20 se se nw .16 .78 .16 .05 28 16 18 60 26 75 32 73 30 59 34 15 ‘.44 .93 .56 13 6.5 13.3 9.3 12.8 34.6 15.2 .04 1.2 .03 .06 .45 .16 .28 .03 .52 0 .09 .89 .37 .75 17 14.7 22 44 40 31 50 50 23.6 29 25 19 50 21 48 53 37 20 17.8 32 OOOOOOO .22 1.25 .25 .17 1.48 1.4 .96 .77 27.3 15 8 27.6 8.1 3.5 30 6.3 30 46 16 44 34 27 48 33 10 17 24 33 35 20 39. 26 6.8 .02 .19 .66 .31 .43 .11 3.8 2.5 3.9 .38 1.8 .04 .73 3.7 9.3 1.3 .36 1.47 .62 1.4 .05 .33 .51 .16 .27 .52 .67 .43 .85 .41 .94 .45 .48 1.2 1.13 .5 .44 .27 18.1 1.9 9.3 14 8.4 27.3 10.4 23 47.5 .19 33.7 4.2 25 77 65 37 70 46 60 90 57 132 94 50 95 125 97 83 70 61 55 70 61 33 44 99 91 73 +82 +170 146.5 +259 -46.4 +80.4 +56.6 +19.7 -157 -19.3 -l4.7 +35 -42.7 +56 +121 +163 +320.8 +469 -11 +229 +47.4 +356.7 +363.5 +194.6 +73.6 +70 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 3819 12041 13120 4707 11700 19998 1954 19639 12536 13237 7992 3104 4834 9776 13554 11939 13906 11587 9669 2331 10N-4W-2 c sw sw 10N-4W-22 se sw se 10N-3W-14 c n/2 nw lON-3W-26 sw sw nw 10N-2E-3 nw nw nw 10N-3E-7 nw nw nw 10N-6E-26 sw ne sw 10N-5W-8 nw nw ne 10N-4E-29 c n/Z nw ne lON-lW-3 c nw nw 10N-10W-15 ne ne nw 10N-5E-19 nw nw sw 9N-llW-35 se sw se 9N-10W-l4 c N/2 ne ne 9N-7W-7 se sw nw 9N-5W-9 nw nw ne 9N-6W-30 ne se nw 9N-7W-21 ne sw sw 9N-7E-ll sw se ne 9N-3W-9 nw sw sw 8N-2W-22 nw nw nw 8N-6W-l3 se se nw 8N-9W-4 sw ne se 8N-llW-l6 sw sw nw 8N-llW-34 sw sw ne 8N-5W-29 nw nw se 8N-7W-l4 ne se se 32.6 2.4 19.9 oo 73 oo -- 5.5 40 .. -- 4.5 -- 4 13.5 1 2 -- .9 23 2.6 29 .. 30 oo 31 oo 17 7 1 12.5 9 6 3 1.3 -- 3 .38 .04 .25 .16 .37 .83 .06 .27 40.4 21.1 18 28 39 14 21.9 35 OOOOOOOOO 34.8 18.5 -- 29 .06 25 0 34 0 25 22.2 .66 18 53? t i O O O O 30 15.4 .08 17.5 0 27 0 34 0 30 0 .19 2.26 1.4 6.5 .95 3.7 .09 1.2 1.3 .79 3.9 4.9 .98 .33 25.3 2.3 6.5 1.4 2.3 6.9 2.4 37 .64 4.5 1.1 48 33 25 20 28 .93 .95 .28 1.64 1.1 1.2 .83 2.8 .54 .34 6.3 .05 .64 .91 2.5 .55 2.2 1.4 1.6 1.35 .15 2.5 .58 .05 .77 .95 3.5 .42 1.6 1.46 .18 .13 .52 .38 .14 .98 .53 109 44 117 60 105 56 56 45 66 57 32 77 58 83 97 70 53 65 44 117 59 73 35 52 62 62 58 -10. +10. +11 +7.6 +15. +78 +420 +140 +4 +262 +152 +404 +297 -19. +145 +147. +352 +440 +485. 7 6 6 .3 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 2341 13586 12514 11803 17980 11027 3090 20200 9869 3154 3390 5042' 3376 1198 14034 9987 792 20566 564 9477 4837 8N-lW-4 nw nw ne 8N-3W-9 nw nw se 8N-4W-28 nw ne sw 7N-2W-2 ne sw nw 7N-3W-l3 se se nw 7N-7W-6 ne nw se 7N-9W-35 7N-5W-16 sw sw ne 7N-4W-21 c S/2 se 6N-7W-12 6N-5W-19 ne ne nw 6N-3W-19 se se 6N-1W-29 ne sw ne 5N-1E-1 ne nw se 5N-2E-34 se se se 4N-1W-22 c N/2 sw 4N-2E-21 ne nw nw 4N-1E-2 se sw nw 3N-5W-28 sw sw 2N-1E-1 sw se sw 2N—1W-28 ne se nw SW SW 0 .59 0 0 43 5 71 1.4 0 .03 0 .32 0 ' 0 2 .65 0 .43 0 2.2 0 .07 0 1 62 3.5 -- 3.6 9.6 .32 30 18 28.5 m 26.5 1.3 32 m 17 1.1 56 0 20 1.8 24 .04 7 5 2 7 13 3 .44 .78 .13 .03 .72 .62 .07 .23 1.2 .14 13 0 25 .03 26.4 .05 -- 0 40 0 24 23 17 .03 -— o 15.5 0 20 0 13 0 -- 0 17.5 0 20 .5 21.7 0 7.5 ~- 10 .14 .23 1.3 .36 3.6 .18 .67 5.6 1.5 1.4 0.6 .A-8 .66 .22 3.5 1.64 .66 2.5 20 40 47 20 50 34. 18. 35 .38 .15 .73 .17 .55 .15 .16 .49 .47 .55 .57 .93 .44 .24 .88 .83 .56 .28 .74 .35 .03 .88 14.5 .47 14.3 .89 46 31.8 8.7 15.2 1.7 27.4 95 65 83 77 40 85 69 45 72 59 50 50 108 45 64 42 15 58 +127. +77 +127 +190 +181. +256 +458. +222. +192. +301 +348 +239 +279 +229 +346 +342. +342. +292 +646 +483. +575 APPENDIX B APPENDIX B Data from geologist log, only used for total isopach and structure contour maps. 0 F43 fl . Elevation . 3 3% 5% Location of Bayport Thickness 3 a‘ o TP-RG- 8 Base 6 cm a) 203 967 4N-3E-28 se sw +507 50 204 --- 2N-4E-4 +77S.6 51 se se ne 205 24518 2N-2W-16 +524 50 ne ne ne 206 2767 2N-4W-l6 549 65 c se sw 207 7011 1N-7W-2 809.6 29 ne ne ne 208 24485 lN-6W-22 806 38 nw sw ne 209 24619 7N-8W-34 404 41 c se cw 210 24315 7N-lW-27 247 60 se se nw 212 21842 lS-3W-ll +747 50 c sw sw 213 248 6N-10W-15 546.3 41 se se ne 214 --- 9N-5E-35 348 50 se w/Z se 215 8746 l3N-6E-3 + 20.4 69 nw nw ne 216 5656 lSN-9W-l8 + 33 103 ne sw ne 217 10612 l6N-9W-8 + 65.3 90 c s/2 sw nw 218 11140 l8N-10W-19 +192.5 95 c n/Z ne sw 219 16158 20N-lE-l6 +273.4 40 ne ne nw 220 24239 20N-4W-20 + 68.8 80 c nw 221 24530 21N-4W-30 + 56.8 28 nw se nw 222 9063 21N-3W-34 +121.8 100 c s/Z sw nw APPENDIX C APPENDIX C Description of Wells Used in Restored Sections Depth (ft) 670-680 680-690 690-700 700-710 710-720 720-730 730-740 740-750 875-885 885-895 895-905 905-910 910-915 915-920 920—930 620-630 well Sequence NO. 119, T12N~R9W-20 SWSWSE Permit No. 3519 Limy dolomite, gray brown (some sandy), dense; lime- stone dark brown dense 30%; shale, red, silty 10%; few chert, white, gray and black. Limy dolomite, buff, dense; limestone as above 10%; some chert as above. Sandstone, white, fine—medium grained, sub-rounded to rounded; dolomite very finely crystalline; 10%. Limestone,dolomitic, brown, sucrosic, fine-medium grained, 80%; limestone, white-tan, fine-medium crystalline with ostracods and crinoids. Limestone as above, fine quartz sand with few white chert; dolomite as above 20%; sandstone, white fine grained 40%; shale, red and greenish gray 10%. Sandstone, white, fine-medium grained sub-angular- rounded; shale greenish gray 10%. Dolomite, buff-dark brown, dense, 90%; sand as above. Sandstone, white, medium-coarse grained, rounded- sub-rounded and some frosted grains, 90%;dolomite, as above 10%. well Sequence No. 121, TlZN-R6W-l4 C SW Permit No. 5037 Dolomite, light brown, v. finely sucrosic and dense with white gray chert; sandstone, gray, fine to medium grained, angular 40%; few grains gray and black shale. Same as above with 20% sandstone. Dolomite, light brown, sucrosic, sand 10% as above. Limestone, light brown-tan, medium crystalline with few crinoids. Limestone, as above, sandy 40%; sandstone, gray, fine-medium grained, sub-angular. Sand, as above; 50% dolomite, light brown, limey, v. finely crystalline. Sandstone, fine grained, sub-angular 90%; dolomite, light brown. well Sequence No. 128, TlZN-RlW-27 E/ZSW Permit No. 774 Dolomite, brown, very finely crystalline, dense with yellowish gray chert; sandstone, gray, well cemented in gypsum 10%; few gypsum crystals and pyrite. C-1 630-650 650-660 660-670 670-680 680-700 700-720 720-730 730-740 470-490 490-500 500-510 510-518 518-524 524-530 375-391 391—395 395-405 405-412 852-859 C-2 Same, with both cemented and friable sand. Dolomite, brown, very finely sucrosic, sandy; few white chert; sandstone, grayish white, medium grained, subangular-well rounded, cemented by dolomite 40%. Dolomite, brown, dense-very finely crystalline- dense; limestone, gray brown-tan, 10%; sandstone, gray, medium grained, sub-rounded 10%. Limestone as above, fine-medium crystalline with few crinoids. Limestone as above with crinoids, foraminifera (Endothyra), ostracods and echinoid spines. Clay, blue gray, soft, silty. Sandstone, white, fine grained, subangular-rounded, few frosted; dolomite, brown, dense, with few white chert, 30%. Dolomite as above, 30%; sandstone, gray, fine- medium grained, subrounded. well Sequence No. 135, TllN-R4E-29 SW SW NW Permit No.? Dolomite, light brown, limy, medium sucrosic. Dolomite, medium-coarse sucrosic 70%; limestone, gray-tan, very sandy 20% with few crinoids. Limestone, gray brown, very finely crystalline with ostracods; sandstone, gray, fine-medium grained, angular 40%. Limestone, as above, 50%; sandstone, white, fine- medium grained, some cloudy and rounded. Clay, gray-blue, soft. Sandstone, gray, fine-medium grained, sub-angular to sub-rounded, 40%; dolomite, light brown, micro- crystalline. well Sequence No. 132, TlZN-RBE-8 NE SW SW Permit No. 2315 Dolomite, brown, dense-very finely crystalline, few white chert; dolomitic limestone, light brown, finely sucrosic 20%; sandstone, medium-coarse grained, subrounded, 10%. Limestone, crinoidal, gray brown-tan, medium crystalline with eginoidal spines and crinoids; some chert, gray brown. Limestone as above, some finely sand. Sandstone, gray, fine-medium grained, angular- rounded, 50%; limestone, gray brown, dense, 10%; dolomite, brown, dense 40%. Well Sequence No. 21, TlQN-RZW-lZ SE SE NE Permit No. 4265 Dolomite, brown, dense-very finely crystalline, very cherty; some pyrite; shale, gray 5%; sand, gray, medium grained, angular 5%. 859-869 869-874 874-877 878-881 881-890 890-898 898-902 902-906 906-910 880-900 900-915 915-925 925-930 930-950 950-930 930-990 990-1000 900-920 920-930 930-940 940-950 950-960 C-3 Dolomite, as above, and buff sandy, dense; sand- stone, gray, fine-medium grained, subrounded to rounded, some frosted, 40%; chert, white. Limestone, gray-tan and gray brown, slightly crystalline, sandy, crinoidal, Endothyra, ostracod, and echinoid spines; some white chert. Limestone, as above; sand, gray, fine grained, ang- ular and cloudy 10%; shale, gray 5%. Limestone, as above, sandy, and gray brown, finely crystalline limestone with ostracods; sand, 10%. Limestone as above and gray 50%; dolomite, brown, dense 30%; sandstone, white, fine-medium grained, rounded and frosted. Sandstone, as above, 90%; dolomite, brown, dense. Sandstone, as above; dolomite, tan, dense 10%. Sandstone, white, fine-coarse grained, rounded, some frosted; dolomite, light brown, dense, sandy 10%; some black and gray shale. Dolomite, brown, dense, 80%; sand, as above. well Sequence No. 58, Tl6N-R3W-8 SE NW NW Permit No. 7225 Dolomite, light brown and buff, dense to finely crystalline, very cherty; shale, gray 30%; sand, white, angular 10%. Dolomite, limy, brown, dense with white chert; shale, black 20%; sand, as above 10%. Sandstone, yellow, fine-medium grained, angular-sub- angular; dolomite 10% as above; shale 10% as above. Sand as above 60%; limestone, gray brown-tan, finely crystalline with crinoid; little shale. Limestone, as above with Endothyra, crinoids, ostra- cod, echinoid spines. Same, finely sandy; sand, gray brown, angular, fine- medium grained 10%; some gray shale. Dolomite, limy, dense-very finely crystalline 50%; sand, white, medium grained, rounded. Same, with 80% sandstone. well Sequence No. 92, Tl4N-R5W-l NW NE NE Permit No. 16678 Limestone, light brown-gray brown, very finely crystalline; few chert; shale, gray-greenish gray 10%. Limestone, dark brown, finely crystalline; sand, white, fine-medium grained 10%; some greenish gray shale. Sandstone, white, medium grained, subrounded, 75%; limestone, gray to tan, sandy; grayish green shale, 5%. Sand as above 50%; limestone, as above; some shale. Limestone, white-tan, finely crystalline with crin- oids and other fossils; glauconite casts; sandstone, as above 20%. 960-965 965-980 980-990 870-880 880-890 890-910 910-920 920-930 930-940 630-640 640-650 650-660 660-670 670-680 680-690 365-375 375-385 385-390 390-417 well Sequence No. 133, well Sequence No. 170, c-4 Limestone, as above, sandy, 80%; shale, gray-green, gray and red. Limestone, microcrystalline, gray brown-light brown; sandstone, fine-medium grained, subangular- subrounded 40%; shale 10% as above. Same, limestone sandy; sand 60%; shale 20%. T12N-R5W-28 NE SW NE Permit NO. 16315 Dolomite, light brown-gray brown, finely sucrosic; white, sandy limestone 10%; shale, black 10%. Dolomite, brown, dense, very cherty with silicified ostracods; limestone, gray brown with crinoids, finely crystalline, 20%. Limestone as above, with crinoid, ostracod, specules; shale, black 10%. Dolomite, buff, microcrystalline with few ostracod in dolomite; shale, black 20%. As above, dolomite 30%; shale 20%; sandstone, gray, medium grained, cemented by dolomite and gypsum 50%. As above, 40% dolomite 30% shale, 30% sand. T9N-R5W-9 NW NW NE Penmit No. 11939 Dolomite, light brown, dense 40% with yellowish white chert; sandstone, white and gray, fine- medium grained, subangular-rounded, some cemented by gypsum. Dolomite, brown, finely crystalline, white and yellow chert; limestone, gray, dense 10%. Limestone, crinoidal, gray-tan, finely Crystalline; white-gray chert. Limestone, sandy as above, 20%, yellow brown, ostra- cods; limestone, very finely crystalline; sand, gray, medium grained, angular 30%. Limestone as above 40%; sandstone, white, medium grained, well rounded-subrounded, cemented by earthy gypsum. Sand as above, 30%, some earthy gypsum; dolomite, light brown, dense. well Sequence No. 192, T6N-R5W-19 NE NE NW“ Permit No. 3390 Dolomite, yellow brown, dense, some white chert. Sandstone, gray, medium grained, subangular to rounded; dolomite 10% as above. Dolomite, light brown, finely sucrosic; sandstone, white, medium grained, subrounded-well rounded 70%. Limestone, gray brown, fine sandy with few crinoids and ostracods 40%; sandstone, white, medium-coarse grained, subangular-well rounded, some cemented by calcite. C-5 417-424 Dolomite, light brown-buff, dense 50%; sandstone, gray, medium grained, subangular to subrounded, some cemented by earthy gypsum. "III11111111111114