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Appendix A
Procedure
Field study of Greenhorn rocks in Kansas was accomplished during, part of each summer from 1962 to 1968, and 1971. For comparative purposes, sections in Oklahoma, Colorado, and Iowa were examined during the field seasons of 1963, 1964, and 1968. In Kansas, exposures were located by reference to published work and by systematic traversing of the outcrop area. The latter was based on study of the Geologic Map of Kansas (Moore and Landes, 1937), maps accompanying bulletins of the Kansas Geological Survey, State Highway Commission county plat maps, maps in U.S. Geological Survey construction-materials circulars, and U.S. Geological Survey topographic maps.
Stratigraphic sections were measured with a hand level, steel tape, and stadia rod. Most measurements were made to the nearest hundredth foot because of small and relatively uniform thickness of many shaly chalk, bentonite, and chalky limestone beds. For beds having undulatory-surfaces or non-uniform thickness a range of thickness was determined. In most measured sections the described units were defined on the basis of homogeneous lithology but some intervals comprising an alternating sequence of only two rock types were treated as a single unit. The limits of individual units, or homogeneous bundles of strata, are based on sharp changes in lithology or stratal characteristics that can be distinguished readily in the field. At many places poorly exposed or extensively weathered rocks were ditched with a trench pick so as to permit study of a continuous stratigraphic section.
Representative rock samples were collected from, each measured section and at key sections, scattered across the entire outcrop, samples were collected from every lithic unit. Detailed descriptions of four key sections are included in the appendix. At all key sections each lithic unit was searched systematically for fossils. Beds of limestone were examined surficially and broken up with a hammer. Shaly chalk units were searched virtually on a lamina-by-lamina basis in each key section. In addition to the measured sections, 46 sections were examined, but not measured in detail. At these sections notes were made on bed continuity, variations in bed thickness and lithology, unusual stratigraphic features such as scour features and concretions, and fossil content. Many of the fossils illustrated in this report and much additional data on fossil distribution were taken from these supplementary sections.
Although few beds contained a sufficient number of fossils or were suitably exposed, quadrat and meter-long counts of specimens were made at several horizons. Data on orientation, articulation of bivalves, and degree of breakage were also gathered. Crossbedded strata are not common in the Greenhorn of Kansas but a few measurements were made of crossbed dip direction and dip angle.
Laboratory work consisted of fossil identification, thin section study, insoluble residue study, chemical analysis of representative rock specimens, X-ray determination of major mineral components, and scanning electron microscopy of shaly chalk and chalky limestones. Fossils were freed from matrix using hammer and chisel, a Gravermeister pneumatic chisel, and an S. S. White Airbrasive unit. Thin sections were cut normal to stratification and prepared by vacuum impregnation techniques. Many of the thin sections were X-rayed before being covered. Insoluble residues were prepared from the unweathered or little-weathered parts of four key sections including one in Pueblo County, Colorado. Samples weighing approximately 20 grams were digested in HCI, filtered, through pieces of No. 40 filter paper, dried, and weighed to the nearest tenth gram. Most of the residues were examined microscopically and selected samples were analyzed with an X-ray unit. In addition to analyses of the thin sections and insoluble residues, powdered samples of shaly chalk, bentonite, and skeletal materials were analyzed by X-ray diffraction. Samples of shaly chalk and chalky limestone were subjected to partial chemical analysis in order to determine percentages of organic carbon, pyrite, and gypsum. Percentages of these components were used in interpreting the chemical environment below the depositional interface and as a rough index to amount of weathering. Scanning electron microscopy of shaly chalk and chalky limestone samples was used to distinguish ultramicroscopic textures and structures that reflect primary and diagenetic-epigenetic differences between these major kinds of carbonate rock.
Results of insoluble residue study, thin section analysis, chemical analysis, electron microscopy, and trace fossil study of the Hartland and Jetmore Members has been reported, in part, by Hattin (1971).
Appendix B
Description of Measured Sections
Explanation
This appendix includes descriptions of four measured sections that characterize the Greenhorn Limestone in the Kansas outcrop. The colors used are from the Rock Color Chart (Goddard et al., 1948) and are given for wetted rock unless specified otherwise. Alphanumeric color codes are used only with color names that appear more than once in the color chart and with color names that are not included in the chart.
Virtually all shaly chalk units are speckled by minute, nearly white, ellipsoidal fecal pellets; most shaly chalk units contain abundant calcareous silt and fine sand made up of foraminifer tests, Inoceramus prisms, etc.; most shaly chalk units are more or less laminated; shaly chalks are tough and blocky where freshly exposed and weather into small soft chips. Repetitious description of these features is deemed unnecessarily monotonous; therefore, mention of these fairly uniform characteristics is omitted from the descriptions that follow.
Nearly all Greenhorn rocks contain tests of planktonic foraminifera, but in the descriptions of key sections mention of these fossils is made only when they are especially conspicuous in the field.
Chalky limestones commonly contain evidence of burrowing by infaunal organisms. Except where otherwise specified the "burrow structures" or "burrow mottles" of the described sections are chalk-filled features that differ from the surrounding rocks chiefly in color or degree of staining by limonite.
| Key Section 1--Composite section in Republic and Washington counties. Upper part of section is in road cut on north side of U.S. Hwy. 36, in SW SW sec. 4, T. 3 S., R. 1 W., Republic County, Kansas (Locality 7). | Thickness, feet |
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| Greenhorn Limestone | ||||
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Pfeifer Member | |||
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47. | Chalky limestone, Fencepost limestone bed, weathered grayish orange to dark yellowish orange, resistant, ledge forming, weathers into three beds. FOSSILS: Mytiloides labiatus, Inoceramus cuvieri, Collignoniceras woollgari | 0.55 |
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46. | Shaly chalk, very light gray in basal foot becoming grayish orange to dark yellowish orange in upper part; soft, breaks blocky but is apparently thinly and evenly laminated; several very thin chalk layers in upper foot project from weathered surface; unit contains layer of chalky limestone concretions, light olive gray (5Y6/1) to yellowish gray (5Y8/1), speckled throughout, middle part thinly and evenly laminate , central part stained by limonite; bentonite seam 0.08 foot thick, slightly silty, light olive gray (5Y6/1) lies 0.5 foot below top; very thin bentonite seam, 0.01 foot thick, lies 0.65 foot below top of unit. FOSSILS: in shaly chalk, Mytiloides labiatus | 2.8 |
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45. | Chalky limestone, very light gray to dark yellowish orange, resistant, ledge forming, thinly and evenly laminated, speckled throughout, lower half in part visibly crystalline, with conspicuous tests of planktonic foraminifera. FOSSILS: Mytiloides labiatus | 0.2 |
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44. | Shaly chalk, weathered grayish orange to dark yellowish orange, soft, nonresistant; extremely thin seam of light bluish gray bentonite lies 0.6 foot above base. FOSSILS: Mytiloides labiatus, fish scales | 2.0 |
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43. | Bentonite, "sugar sand" seam, bluish white, very slightly silty, with sparse flakes of biotite? | 0.08 |
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42. | Shaly chalk, weathered yellowish gray (5Y8/1) to grayish orange, soft. FOSSILS: Mytiloides labiatus, fish scales | 0.15 |
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41. | Chalky limestone, weathered pale dusky yellow (5Y7/4) to dark yellowish orange, concretionary, resistant, ledge forming, speckled; lower part of bed pinches and swells from 0.15 to 0.35 foot, upper 0.15 foot is thinly and evenly laminated, bed has two ferruginous bands parallel to bedding; contains scattered Inoceramus fragments and sparse, soft limonite nodules. FOSSILS: Inoceramus cuvieri, fish bones. Equivalent bed forms top of companion section (Loc. 6) and contains Baculites cf. B. yokoyami | 0.35 |
| Road cut on north side of U.S. Hwy. 36, in SW sec. 5, T. 3 S., R. 1 E., Washington County (Locality 6). | ||||
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40. | Shaly chalk and chalky limestone; shaly chalk predominant, weathered yellowish gray (5Y7/2) to grayish orange, all but uppermost part filled with inoceramid valves and fragments that interrupt evenness of lamination, lower part contains very small lenses of brittle, dark yellowish brown, calcite-cemented skeletal limestone containing abundant inoceramid, prisms and/or tests of planktonic foraminifera; unit contains at least nine irregular, discontinuous beds of nodular chalky limestone, weathered yellowish ray to pale grayish orange, resistant, project from weathered slope, speckled, with abundant valves and fragments of Mytiloides; parts of some limestone nodules are cemented by visibly crystalline calcite and have a petroliferous odor; upper part of nodules in 6th bed is very thinly laminated and cemented by sparry calcite; bentonite, 0.08 foot thick, light gray, weathering dark yellowish orange, lies 0.1 foot below top of unit. FOSSILS, in shaly chalk, Mytiloides labiatus; in chalky limestone, M. labiatus. At Locality 7 the 3rd limestone bed contains Baculites cf. B. yokoyamai | 5.7 |
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39. | Chalky limestone (PF-1) weathered light olive gray (5Y6/1) to grayish orange, with ferruginous stain along center of bed; unit resistant, ledge forming, speckled, well cemented, with very flat top and base; contains many very thin inoceramid valves and fragments, some of which are oblique to bedding. FOSSILS: Mytiloides labiatus | 0.17 |
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38. | Shaly chalk and chalky limestone; shaly chalk predominates, lower 1.4 feet yellowish gray (5Y8/1), remainder light gray, yellowish gray (5Y8/1) or pale grayish orange owing to limonite staining; mostly contains abundant inoceramid valves and fragments that interrupt evenness of lamination or bedding and that in part are imbricated so as to form small limestone lenses; contains scattered small lenses of skeletal limestone consisting largely of Inoceramus prisms and/or tests of planktonic foraminifera; unit contains at least 7 irregular, discontinuous beds of nodular chalky limestone, weathered yellowish gray (5Y8/1) to dark yellowish orange, all relatively resistant, project from weathered slope, contain abundant inoceramid valves and fragments that are mostly parallel to bedding; limestone in uppermost bed in part cemented with visibly crystalline calcite and has petroliferous odor. FOSSILS: in shaly chalk, Mytiloides labiatus, fish scales, phosphatic coprolite; in chalky limestone, M. labiatus | 6.3 |
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Total thickness (composite) of Pfeifer Member | 18.3 | ||
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Jetmore Member | |||
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37. | Chalky limestone (Shellrock limestone bed), lower part pale grayish orange; upper part yellowish gray (5Y8/1) and slightly softer than lower part; resistant, ledge forming, upper part of unit concretionary; weathers to form several slabby beds, all speckled, inoceramid valves and fragments common throughout, especially in lower half, oriented parallel to bedding, base of lower part plastered with in-the-round Mytiloides valves. FOSSILS: M. labiatus, Baculites cf. B. yokoyamai, fish bones and scales | 0.95 |
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36. | Shaly chalk and chalky limestone; shaly chalk predominant, yellowish gray (5Y7/2) to grayish orange, not visibly speckled; uppermost 0.3 foot very thin bedded soft chalk; all but upper 0.8 foot contains abundant inoceramid valves and valve fragments together with very thin irregular beds of soft nonshaly chalk; discontinuous layer of oblate spheroidal chalky limestone concretions up to 0.2 foot thick, yellowish gray (5Y8/1), at least in part thinly and evenly laminated, with few fossils, lies at center of unit; lower half of unit contains at least two irregular, discontinuous beds of concretionary chalky limestone, light olive gray (5Y6/1) to grayish orange, contain abundant inoceramid valves and fragments some of which are crinkled because of compaction; limestones are resistant, project from slope speckled. FOSSILS: in shaly chalk, Mytiloides labiatus, fish scales, phosphatic coprolite; in chalky limestone, M. labiatus, Baculites cf. B. yokoyamai, fish scales | 2.55 |
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35. | Limestone (three hard beds) and shaly chalk; limestone separated by shaly chalk intervals, weathered yellowish gray (5Y7/2) to light olive gray (5Y5/2), brittle, resistant, ledge forming, speckled, with abundant in-die-round valves and fragments of Mytiloides, most shells parallel to bedding, beds weathered into sharp contact with adjacent rock; shaly chalk weathered light gray to yellowish ray (5Y8/1, 5Y7/2), with abundant Mytiloides valves and fragments that project conspicuously from surface, also contains small lenses of imbricated inoceramid valves; bentonite seam, 0.01 foot thick, dark yellowish orange to light gray, lies on lowest limestone bed. FOSSILS, in shaly chalk, Mytiloides labiatus, fish scales; in lime- stone, M. labiatus, Baculites cf. B. yokoyamai, calcite and limonite cylindrical burrows, limestone-filled Planolites-like burrow structures | 2.65 |
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34. | Shaly chalk and chalky limestone, shaly chalk predominates, medium olive gray (5Y5/1) where nearly fresh, mostly weathered yellowish gray (5Y7/2), in part not laminated, Mytiloides valves and fragments scattered throughout and very abundant in upper 1.5 feet; chalky limestone all partly weathered light olive gray (5Y6/1) to light ray and partly stained dark yellowish orange by limonite, occurs as nine uneven, mostly continuous, subequally spaced beds separated by shaly chalk; limestone relatively resistant, ledge-forming, breaks blocky, most beds speckled and burrow mottled, with nearly homogeneous texture; burrow structures most evident in beds 1, 6, 7, 8, and 9; basal limestone bed contains small pyrite nodules; skeletal limestone, 0.02 foot thick, very pale yellowish brown, well cemented, thinly laminated to gently cross laminated, composed mostly of planktonic foraminiferal tests, lies 0.32 foot above JT-1; lenses of skeletal limestone composed of inoceramid fragments occur above JT-9. FOSSILS: in shaly chalk, Mytiloides labiatus, Pycnodonte sp. A (above JT-9); in chalky limestone: M. labiatus, Watinoceras reesidei (JT-1, JT-6, JT-8?), Baculites cf. B. yokoyamai (JT-8, JT-9), Mammites nodosoides wingi (JT-9 and as float), Tragodesmoceras? sp. (JT-8) | 9.3 |
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Total thickness of Jetmore Member | 15.5 | ||
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Hartland Member | |||
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33. | Bentonite and bentonitic shaly chalk; bentonite 0.12 foot thick, medium olive ray (5Y5/1) to light olive gray (5Y6/1), weathering dark yellowish orange, slightly silty, biotitic, grades up into bentonitic shaly chalk, weathered yellowish gray (5Y7/2) | 0.25 |
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32. | Shaly chalk, olive black, dries medium light gray, in part very tough; inoceramid fragments common throughout, lie parallel to bedding; planktonic foraminiferal tests abundant, stud weathered surfaces; yellowish brown (10Y5/ 2) zone 0.2 thick and lying 1.8 to 2.0 feet above base contains very thin (<0.01 foot) seam of light olive gray bentonite; grayish orange to yellowish brown zone 0.35 foot thick (5Y6/1) bentonite seam | 6.0 |
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and lying 1.9 feet below top contains 0.02 foot-thick medium light gray to light olive gray | ||
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31. | Bentonite, medium gray, weathering dark yellowish orange, brittle, slightly silty | 0.55 |
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30. | Chalk (HL-3), weathered yellowish gray (5Y8/1) to very pale orange, highly fractured, soft, almost punky, speckled; moderately bioturbated, burrow structures weather to lighter color than rest of rock; tests of planktonic foraminifera common to abundant | 0.3 |
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29. | Shaly chalk, olive black, dries medium light gray, with abundant tests of planktonic foraminifera; contains thin, large valves of inoceramid bivalves, some valves and fragments project from weathered slope; unit contains a few very thin layers of soft olive gray chalk and a very thin lens of hard, thinly laminated, light olive gray (5Y5/2) calcisiltite. FOSSILS: Inoceramus prefragilis | 2.2 |
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28. | Ferruginous-bentonitic unit; partly soft, olive black shaly chalk, partly limonite, basal 0.02 foot is pale gray bentonite; unit forms reentrant. FOSSILS: Allocrioceras annulatum at extreme base of unit | 0.4 |
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27. | Chalky limestone (HL-2), olive gray (5Y4/1), dries light gray, very resistant, ledge forming, speckled, bioturbated throughout, Inoceramus valves and fragments common, thickness of bed ranges from 0.2 to 0.6 foot, base undulatory; FOSSILS: Inoceramus prefragilis, Sciponoceras gracile, Metoicoceras whitei, Cerithiella sp. A | 0.35 |
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26. | Chalky shale, medium gray, blotched with green, plastic when wet, slightly silty, speckled, bioturbated locally; burrow fill dark gray; basal 0.4 foot bentonitic; bentonite seam, 0.12 foot thick, pale grayish yellow, stained dark yellowish orange, moderately silty, lies 0.4 foot above base of unit | 1.1 |
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25. | Chalky limestone, (HL-1) light olive gray to dark olive gray (5Y6/1 to 5Y3/1), weathering yellowish gray (5Y8/1), not as hard as HL-2, not very resistant, crumbly, sparsely speckled burrow mottled throughout, with scattereda blebs of limonite; contains abundant tests of planktonic foraminifera, sparse Inoceramus fragments, and conspicuous limonite-filled Trichichnus | 0.9 |
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24. | Shaly chalk, olive black, dries medium light gray [)orly laminated; contains numerous small, very thin lenses of well-cemented, light olive gray (5Y6/1), fine-grained skeletal limestone. FOSSILS: Inoceramus prefragilis, fish scales | 2.4 |
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23. | Bentonite, yellowish gray (5Y8/1) to grayish orange with dark yellowish orange limonite stains, slightly silty, with sparse biotite flakes | 0.12 |
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Total thickness of Hartland Member | 14.6 | ||
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Lincoln Member | |||
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22. | Shaly chalk, olive black, dries medium light gray, at least in part thinly and fairly evenly laminated; contains numerous small, very thin lenses of well-cemented, light olive gray (5Y6/1, 5Y5/2) fine-grained skeletal limestone consisting of planktonic foraminiferal tests, Inoceramus prisms and small fragments, and sparse fish remains. FOSSILS: Inoceramus prefragilis, fish bone fragments and scales | 1.15 |
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21. | Bentonite, grayish yellow, stained dark yellowish orange by limonite, locally up to 0.2 foot thick | 0.15 |
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20. | Shaly chalk, olive black, dries medium light gray, at least in part thinly laminated, hard where freshly exposed, breaks blocky but not along bedding; upper half contains numerous small thin to very thin irregular lenses of well-cemented, light olive gray (5Y6/1, 5Y5/2) fine grained skeletal limestone; some limestone almost wholly composed of planktonic foraminiferal tests, some is almost wholly Inoceramus prisms, and some is a mixture of these grain types; bottoms of limestone lenses marked by fecal casts; bentonite seams, 0.03, 0.03, 0.01 to 0.03 and 0.06 foot thick, respectively, pale olive to light olive gray (5Y5/2), weathering dark yellowish orange, lie 0.6, 1.0, 5.1, and 6.5 feet above base of unit, respectively. FOSSILS: Inoceramus prefragilis | 6.7 |
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19. | Bentonite, yellowish gray (5Y8/1), weathering dark yellowish orange, slightly silty, very slightly biotitic | 0.07 |
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18. | Shaly chalk, olive black, dries medium light to light gray, not well laminated, with numerous Inoceramus valves projecting from slope; contains sparse, very thin lenses of well-cemented, light olive gray (5Y6/1) fine grained skeletal limestone composed mostly of Inoceramus debris. FOSSILS: Inoceramus prefragilis | 3.6 |
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17. | Chalk, olive gray (5Y3/2), thinly laminated, soft, discontinuous, speckled, with fragments and valves of Inoceramus. FOSSILS: Inoceramus sp., fish scales | 0.25 |
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16. | Bentonite, yellowish gray (5Y8/1), slightly silty, stained by jarosite and limonite, weathers mealy, thins laterally to 0.05 foot | 0.23 |
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15. | Shaly chalk, olive black, dries medium light gray; contains scattered very thin, small lenses of skeletal limestone, light olive gray (5Y6/1), weather medium light gray. FOSSILS: in limestone, Inoceramus debris, fish scales, teeth and bones | 0.5 |
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14. | Chalk, olive gray, granular, soft, with limonite nodules near base. FOSSILS: Fish scales | 0.2 |
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13. | Bentonite, lower half light gray, weathering dark yellowish orange, mealy, biotitic; upper half light olive gray (5Y5/2), slightly silty | 0.25 |
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12. | Shaly chalk, olive black, dries medium light gray; contains numerous lenses of skeletal limestone, light olive gray (5Y6/1), generally lumpy on tops and bases, composed largely of inoceramid debris; also contains very thin, laminated layers of foraminiferal limestone, olive gray (5Y4/1). FOSSILS: Inoceramus prefragilis, fish scales and bones | 5.0 |
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11. | Chalk, shaly chalk, and bentonite; chalk. lies at top and base of unit, olive gray (5Y4/1), soft, granular, upper chalk bed with fresh to partially decomposed nodules of pyrite that weather to form masses of limonite, nodules surround large Inoceramus fragments; chalks are separated by 0.15 foot of olive black shaly chalk. FOSSILS: Inoceramus sp. | 0.4 |
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10. | Bentonite, very light gray, weathering dark yellowish orange, slightly silty, very slightly biotitic | 0.1 |
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9. | Shaly chalk, olive black, dries medium light gray, with many large thin valves of Inoceramus lying parallel to bedding and in part projecting from slope; contains numerous small very thin lenses of skeletal limestone, light olive gray (5Y6/1) to yellowish gray (5Y7/2), composed mostly of inoceramid debris, one lens contains abundant coprolites; bentonite, 0.02 foot thick, light olive gray, weathering dark yellowish gray, lies 2.5 foot above base; soft, granular chalk, maximum 0.15 foot thick and discontinuous, containing decomposed pyrite nodules, lies on bentonite seam. FOSSILS: Inoceramus prefragilis, Exogyra aff. E. boveyensis | 3.8 |
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8. | Chalk, olive gray (5Y4/1), soft, nonresistant, crumbly, with a few faint laminae; lensing zone of soft limonite, 0.05 to 0.1 foot thick, lies in lower part of bed; upper part contains small fragments of Inoceramus | 0.2 |
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7. | Bentonite, light gray, weathering dark yellowish orange, slightly silty, biotitic, lensing | 0.06 |
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6. | Shaly chalk, olive black, dries medium light gray, with very thin laminae of skeletal calcisiltite; contains numerous very thin lenses of skeletal limestone, light olive gray (5Y6/1), composed largely of Inoceramus debris. FOSSILS: Inoceramus prefragilis, fish bones and scales | 2.25 |
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5. | Bentonite, light gray, weathering grayish yellow to dark yellowish orange, moderately silty, biotitic | 0.2 |
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4. | Shaly chalk, olive black, dries medium gray, only slightly speckled and with little calcareous silt; contains a lensing bed and numerous small, very thin lenses of skeletal limestone, light olive gray (5Y5/2) to olive gray (5Y4/1), well-cemented, brittle; one lens contains light brown phosphatic coprolite; lensing bed has fecal casts on underside. FOSSILS: Inoceramus prefragilis, fish scales and bones | 1.7 |
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3. | Chalk, olive gray (5Y3/2), soft, discontinuous, slightly speckled, with local ferruginous staining along center of bed | 0.25 |
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2. | Chalky shale, olive black, dries medium light gray, not well laminated, weathers flaky, not conspicuously speckled; unit transitional in lithology from typical Graneros shale to typical Lincoln shaly chalk; contains scattered small lenses of skeletal limestone, mostly well cemented, resistant, composed largely of Inoceramus debris, with most conspicuous lenses in upper part; limestones olive gray (5Y3/2) to light olive gray (5Y5/2), some lenses thinly laminated, some lenses have highly irregular cross sections; unit contains much ferruginous matter. FOSSILS: Inoceramus sp., Squalicorax falcatus, fish bones and scales | 3.2 |
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1. | Chalky shale, olive black, dries medium gray, thinly and faintly laminated, weathers flaky, speckled, unit transitional in lithology from typical Graneros shale to typical Lincoln shaly chalk; unit contains numerous thin lenses of skeletal calcisiltite, medium gray to olive gray (5Y4/1), weathering grayish orange, very thinly laminated, gently cross laminated, weather papery, with maximum thickness of 0.03 foot | 1.8 |
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Total thickness of Lincoln Member | 32.1 | ||
| Total thickness of Greenhorn Limestone | 80.5 | |||
| Rests conformably on Graneros Shale | ||||
| Key Section 2--Cuts on east side of Bunker Hill-Lura Road along center, westline, sec. 18, T. 13 S., R. 12 W., Russel County, Kansas (Locality 3). | Thickness, feet |
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| Greenhorn Limestone | ||||
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Pfeifer Member | |||
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36. | Chalky limestone, weathered, mostly grayish orange; upper 0.4 foot slabby, weakly resistant; lower 0.7 foot is massive Fencepost limestone bed, resistant, ledge-forming, with dark yellowish orange limonite stain along nearly central plane and with undulatory base. FOSSILS: Mytiloides labiatus, Inoceramus cuvieri, Baculites cf. B. yokoyamai, Collignoniceras woollgari, scalpellid cirriped (rare), Pseudoperna bentonensis, fish scales | 1.1 |
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35. | Shaly chalk, weathered, pale grayish orange; bedding fractures 0.04 foot apart in lower part, closer together above, mostly stained dark yellowish orange by limonite; 0.12-foot-thick very even bed of dark yellowish brown to grayish orange chalky limestone lies 0.8 foot above base of unit, base of bed criss crossed by linear burrow casts; weathered oblate spheroidal concretions of grayish orange to dark yellowish orange chalky limestone lie in two zones centering 2 and 4 feet above base, shaly chalk beds bend around concretions; concretions in lower zone are up to 0.2 foot thick, with thin strata of dark yellowish brown skeletal limestone passing through centers; bentonite seam, 0.03 foot thick, light gray, overlain by 0.02 foot of finely granular gypsum, lies beneath even bed of limestone. FOSSILS: in shaly chalk, molds of flattened Mytiloides labiatus, fish scales; in chalky limestone, M. labiatus, Inoceramus cuvieri, calcitic casts of juvenile hamitids, fish scales | 5.1 |
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34. | Bentonite and granular calcite (sugar sand); bentonite lies at base and top of unit, 0.05 and 0.03 foot thick, respectively, weathered, nearly white; granular calcite dark yellowish orange, sandy texture | 0.36 |
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33. | Shaly chalk and chalky limestone; shaly chalk dominant, olive black in lower part of unit where fresh, light olive gray (5Y6/1) to moderate yellowish brown to grayish orange where weathered, non-resistant, contains an abundance of chalky Inoceramus-fragment lenses that are mostly less than 0.01 foot thick and 0.2 foot across; chalky limestone nodules and concretions scattered throughout unit, arranged roughly in 11 zones, mostly resistant, forming discontinuous ledges, olive gray where fresh, weather light olive gray (5Y5/2) to yellowish gray (5Y7/2) to grayish orange and pale yellowish orange; limestone in zone 4 partly concretionary and in zones 9 and 11 entirely concretionary and poorly fossiliferous; remaining limestones mostly nodular, more brittle than concretions, with abundant whole and broken valves of Mytiloides labiatus; all limestones are white speckled; concretions in zone 9 are thinly laminated, laminae are contorted; shaly chalk beds bend around concretions and nodular limestones; bentonite, 0.12 foot thick, very light gray, weathering dark yellowish orange, slightly silty, lies 0.65 foot below top. FOSSILS: in shaly chalk, abundant scattered valves of M. labiatus; in chalky limestone, M. labiatus, Pseudoperna bentonensis, Baculites sp., fish scales | 6.6 |
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32. | Chalky limestone (PF-1), olive gray, weathering grayish orange to pale grayish orange, white speckled, resistant, forms prominent thin ledge with very flat top and base. Fossils: Mytiloides labiatus, whole and broken, Pseudoperna bentonensis | 0.25 |
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31. | Shaly chalk and chalky limestone; shaly chalk dominant, olive black where fresh, weathering light olive gray (5Y6/1) to medium yellowish brown, with abundant flattened valves of Mytiloides lying parallel to bedding; upper foot contains very thin lenses of pale yellowish brown skeletal limestone rich in Mytiloides debris and foraminifer tests; chalky limestone occurs as resistant nodular masses up to 0.2 foot thick and arranged roughly in 5 main layers, olive black speckled with white where fresh, weathering light gray to grayish- and pale grayish orange, very pale orange, and moderate- to dark yellowish brown with limonite-stained zones passing through centers of most nodules; fragments of Mytiloides valves are common in nearly all limestones, nodule surfaces are roughened by tests of foraminifera that weather into relief; bentonite, two seams, 0.01 to 0.02 foot thick, lie 0.6 and 0.1 foot below top of unit, respectively, dark yellowish orange, with upper bentonite separated from unit 32 by seam of dark yellowish orange granular calcite. FOSSILS: in shaly chalk, Mytiloides labiatus; in chalky limestone, M. labiatus, Pseudoperna bentonensis, fish scales | 7.0 |
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Total thickness of Pfeifer Member | 20.4 | ||
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Jetmore Member | |||
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30. | Chalky limestone, Shellrock limestone bed, olive gray, weathering dark yellowish brown to yellowish gray (5Y7/2) with dark yellowish orange limonite staining, white speckled throughout, resistant, forms prominent ledge, characterized by abundance of Mytiloides valves and valve fragments lying mostly parallel to bedding, with upper surface characterized by abundance of baculitid molds; upper half of unit tends to be concretionary. FOSSILS: Mytiloides labiatus, Baculites cf. B. yokoyamai, burrow structures, fecal? casts on upper surface | 1.15 |
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29. | Shaly chalk, olive black, weathering yellowish gray, lowest foot shelly with many Mytiloides valves and valve fragments lying mostly parallel to bedding and with very thin lenses of dark yellowish brown skeletal limestone rich in Mytiloides debris; unit contains two layers of relatively resistant chalky limestone that form minor ledges; lower limestone is discontinuous, concretionary, softer than beds in unit 28, weathering light olive gray (5Y5/2) to pale grayish orange, and containing many nonflattened valves and valve fragments of Mytiloides; upper limestone is continuous flat bed, pale grayish orange, white speckled, and composed partly of hard, pale olive calcilutite. FOSSILS: in shaly chalk, Mytiloides labiatus, fish scales and bones; in lower limestone, M. labiatus, Baculites cf. B. yokoyamai; in upper limestone, Anomia sp. A, Baculites cf. B. yokoyamai | 2.95 |
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28. | Limestone (three hard beds) and shaly chalk; limestones dark olive gray weathering light olive gray to pale grayish orange to pale grayish yellow, lowest two beds with limonite stained zones in upper half; all limestones hard, brittle, resistant, form prominent ledges separated by shaly chalk, punky on weathered edges, all with abundant disarticulated and many broken valves of Mytiloides most of which lie parallel to bedding and with some shell debris concentrated in thin lenses; burrow structures, some sediment-filled and some calcite or limonite filled, occur in all beds and especially in lowest bed; rock is white speckled and has slight petroliferous odor; shaly chalk is olive black where fresh, weathering to grayish orange, contains abundant flattened fragments and valves of Mytiloides and small, very thin lenses of dark yellowish brown skeletal limestone all of which project prominently from weathered exposures; shaly chalk relatively hard where filled with skeletal debris; bentonite, 0.01 foot thick, dark yellowish orange, lies on top of lowest limestone bed. FOSSILS: in limestone, M. labiatus, Pycnodonte sp. A, Baculites cf. B. yokoyamai, burrow structures (see species count in text); in shaly chalk, M. labiatus, Ptychodus (rare) | 3.2 |
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27. | Shaly chalk and chalky limestone, shaly chalk predominant, olive black, locally dark olive gray, weathering light olive gray, weakly resistant, blocky, weathers to small chips, in part well laminated, with abundant fragments and valves of Mytiloides and very thin lenses of skeletal limestone in upper 2.5 feet; chalky limestone, 8 subequally spaced mostly continuous thin to medium beds, dark olive gray to light olive gray (5Y6/1) or medium gray, weathering very pale orange or pale grayish orange, usually having dark yellowish orange limonite stain near centers of beds, sparingly white speckled; limestones mostly brittle, resistant, ledge-forming, break into blocks, all more or less burrow mottled, some beds with calcite-filled burrows; thin bed of softer, almost nonresistant burrow-mottled chalk lying 4.5 feet above base of unit is equivalent to marker bed JT-4 of other localities; cross laminated skeletal limestone bed, composed mostly of foraminifer tests, mostly grayish orange, 0.2 to 0.3 foot thick, lies 0.8 foot above base. FOSSILS: in limestone, M. labiatus, Baculites cf. B. yokoyamai, Watinoceras reesidei, Mammites sp., ostreid sp. (lower part); in shale, M. labiatus, Pycnodonte sp. A (upper part) | 13.5 |
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Total thickness of Jetmore Member | 20.8 | ||
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Hartland Member | |||
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26. | Shaly chalk and chalk, shaly chalk predominant, mostly olive black, dries medium light gray, weakly resistant, blocky, weathers to small chips; chalk is olive gray (5Y4/1) to light olive gray (5Y6/1), all burrow mottled, relatively harder than shaly chalk, not ledge forming, uppermost bed contains pyrite nodules; basal foot contains starved ripples composed of gently cross laminated foraminiferal limestone; bentonite seam 0.01 foot thick, grayish orange lies 4.0 feet above base; bentonite seam 0.02 foot thick, dark yellowish orange, marked by line of pyrite nodules, lies 8.1 foot above base; chalky bentonite, 0.4 foot thick, olive gray to grayish orange with dark yellowish orange limonite stains, lies 8.5 foot above base; bentonseam, 0.08 foot thick, light gray, weathering dark yellowish orange, lies 0.15 foot below top of member. FOSSILS: in shaly chalk, Inoceramus prefragilis (lower part), Mytiloides labiatus (in upper 3 feet), Isurus sp., fish scales and bones especially common in upper part | 13.3 |
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25. | Bentonite, nearly white, stained dark yellowish orange, biotitic?, slightly silty | 0.5 |
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24. | Chalk (marker bed HL-3), olive gray (5Y4/1) to light olive gray (5Y6/1), soft, crumbly, burrow-mottled throughout, weathers slabby, foraminifer tests stud weathered surface | 0.35 |
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23. | Shaly chalk, olive black to olive gray (5Y4/1), soft, weathers to small chips, whole and fragmentary valves of Inoceramus scattered throughout; bed of chalk 0.1 foot thick, like unit 24, lies 1.6 foot above base. FOSSILS: in shaly chalk, Inoceramus prefragilis, fish bones and scales | 2.25 |
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22. | Chalky limestone, olive gray (5Y4/1) to light olive gray (5Y6/1), much burrow mottled especially at base, speckled by nearly black fish? bone scraps, relatively resistant, not as hard as limestones in Jetmore Member; unit characterized by abundance of black stained molds of smooth slender baculitids; bed is in sharp contact with underlying unit. FOSSILS: Inoceramus prefragilis, Phelopteria sp. A., Worthoceras vermiculum?, Baculites sp., acrothoracian cirriped borings in Inoceramus | 0.3 |
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21. | Shaly chalk, olive black, tough, well jointed, weathers to small chips, ferruginous in lower 0.6 foot, contains scattered very thin lenses of hard, pale yellowish brown skeletal limestone; bentonite seam, 0.02 foot thick, grayish yellow (5Y7/2), lies 0.5 foot above base; discontinuous lensing bed of chalky limestone, 0.2 foot thick, olive gray, dries to light gray, speckled with fine black grains of possible fish-bone fragments, lies 0.6 foot above base. FOSSILS: in shaly chalk, Inoceramus prefragilis; in chalky limestone, Baculites sp., Worthoceras vermiculum, W. gibbosum, Inoceramus prefragilis, Cerithiella sp. A | 2.6 |
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20. | Chalky limestone (marker bed HL-2), olive gray, dries very light gray to yellowish gray (5Y8/1), hard, resistant, prominent ]edge formed in weathered part of outcrop, speckled, bed contains abundant burrow structures some of which are weathered to low relief on weathered slabs, body fossils and small fragments of fish bones are conspicuously aligned parallel to bedding, bed swells downward locally to produce bed 0.6 foot thick. FOSSILS: Inoceramus prefragilis, I. cf. I. tenuistriatus, I. flavus, Phelopteria sp. A, Metoicoceras whitei, Worthoceras vermiculum, Kanabiceras septemseriatum, Sciponoceras gracile, Allocrioceras annulatum, Baculites sp., Cerithiella sp. A | 0.2 |
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19. | Shaly chalk and bentonite, shaly chalk olive black, medium gray to dark olive gray (5Y3/1) at top and base, has ferruginous streak near top; bentonite seam, 0.3 foot thick, light brownish gray, weathers yellowish gray (5Y8/1), stained dark yellowish orange by limonite, lies 0.3 foot above base | 2.0 |
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18. | Chalky limestone (marker bed HL-1), light olive gray (5Y6/1), to medium gray, moderately hard, resistant, highly fractured, with abundant burrow structures; burrow fill is both lighter and darker than surrounding rock; unit contains some open horizontal burrows that are lined with limonite; also sparse, vertical, cylindrical pyrite-filled burrows. FOSSILS: Inoceramus prefragilis | 0.7 |
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17. | Shaly chalk, olive black, lower 2 feet contains very thin, small lenses of pale yellowish brown skeletal limestone; thin lenses of olive gray (5Y4/1) chalk, composed largely of foraminifer tests, lie 2.1 feet above base; upper half of unit contains two thin, nonshaly layers of olive gray (5Y4/1) to light olive gray (5Y6/1) chalk that are gradational with adjacent rock, upper layer is burrowed extensively. FOSSILS: Inoceramus prefragilis, Plicatula? sp. (near top)14.9 | |
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16. | Bentonite, yellowish gray (5Y8/1) weathering grayish yellow and stained dark yellowish orange | 0.22 |
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15. | Shaly chalk, olive black, contains many valve fragments of Inoceramus; bentonite seam, less than 0.01 foot thick, yellowish gray (5Y7/2), stained dark yellowish orange, lies 0.4 foot below top; unit contains very thin scattered lenses of hard, brittle, pale yellowish brown skeletal limestone. FOSSILS: Inoceramus prefragilis | 1.3 |
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Total thickness of Hartland Member | 28.6 | ||
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Lincoln Member | |||
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14. | Shaly chalk and skeletal limestone, shaly chalk olive black, with numerous very thin, discontinuous laminae of limestone and fragments of Inoceramus; skeletal limestone, abundant but not predominant, mostly pale yellowish brown, hard, brittle, resistant, has petroliferous odor, occurs as thin to very thin mostly discontinuous beds and as lenses composed predominantly of Inoceramus debris and/or tests of planktonic foraminifera and lesser amounts of bone fragments; some of limestone is cross laminated; uppermost bed convoluted locally and with well preserved casts of thalassinoid burrows; layer of limonitized and gypsiferous pyrite nodules lies 0.5 foot above base. FOSSILS: Inoceramus prefragilis, Calycoceras? sp., Squalicorax falcatus | 2.0 |
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13. | Shaly chalk and skeletal limestone, shaly chalk olive black, weathering dark yellowish brown to grayish orange; skeletal limestone as scattered lenses, olive gray, weathering moderate yellowish brown to grayish orange, hard, brittle, mostly with sand-sized grains, composed predominantly of Inoceramus prisms and/or tests of planktonic foraminifera; in lower 2.2 feet the unit contains 3 thin or very thin seams of dark yellowish orange bentonite and one seam of grayish olive bentonite that is overlain by 0.2 foot of olive gray granular chalk. FOSSILS: Inoceramus sp., vertebrate bone fragments | 4.5 |
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12. | Shaly chalk, olive black, weathering dark yellowish brown, with some whole and fragmentary remains of Inoceramus; contains sparse, scattered very thin small lenses of hard, brittle, skeletal limestone, olive gray (5Y4/1), weathering pale yellowish brown, with bone fragments and local worm? castings; very thin dark yellowish orange bentonite seams lie 1.3 and 4.5 feet above base. FOSSILS: Inoceramus sp. | 5.0 |
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11. | Bentonite, dark yellowish orange | 0.2 |
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10. | Shaly chalk, olive black, dries medium light gray; unit contains very thin, small lenses of hard, brittle, skeletal limestone, pale yellowish brown, with petroliferous odor, composed largely of tests of planktonic foraminifera. FOSSILS: Inoceramus sp. | 0.8 |
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9. | Bentonite, dark yellowish orange | 0.27 |
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8. | Shaly chalk, olive black, dries medium light gray and weathers dark yellowish brown. FOSSILS: Inoceramus prefragilis, fish bones, one large fish skeleton | 1.7 |
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7. | Bentonite, yellowish gray (5Y7/2), stained dark yellowish orange | 0.15 |
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6. | Shaly chalk, olive black, weathering light gray to grayish orange, very soft where weathered; contains local lenses of skeletal limestone, pale yellowish brown, hard, brittle, petroliferous odor, composed mainly of Inoceramus debris together with oyster and bone fragments. FOSSILS: Inoceramus prefragilis, Stramentum sp. A, ostreid, sp., vertebrate bone fragments | 1.2 |
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5. | Chalk, light brown (5YR5/6) to grayish orange, weathering to form thin layers. FOSSILS: Inoceramus prefragilis, Eucalycoceras? sp., fish bone fragments | 0.3 |
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4. | Shaly chalk, olive black (part), mostly weathered dark yellowish brown to grayish orange, very soft where weathered, Inoceramus fragments common. FOSSILS: Inoceramus prefragilis | 3.1 |
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3. | Chalk, light olive gray, weathering dark yellowish orange, granular, discontinuous, with ferruginous band along center; underlain by 0.04 foot thick seam of nearly white bentonite that weathers dark yellowish brown; also very thin seam of bentonite at top of chalk. FOSSILS: fish bone fragments | 0.5 |
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2. | Shaly chalk, weathered grayish orange; contains numerous very thin, small lenses of hard, brittle, skeletal limestone, pale yellowish brown, with abundant fish bone fragments | 0.7 |
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1. | Skeletal limestone, medium dark gray, weathering light olive gray to pale yellowish brown with dark yellowish orange limonite staining, mostly hard, brittle, resistant, ledge former, medium to very thin bedded, in part thinly laminated to cross laminated, has petroliferous odor, composed mostly of Inoceramus prisms; basal 0.25 foot coarser, contains much quartz sand, oyster fragments, fish tooth and bone fragments, coprolites, fish scales and is crumbly where weathered. FOSSILS: Inoceramus prefragilis, Calycoceras? canitaurinum (float), Stomohamites cf. S. simplex, Exogyra aff. E. boveyensis, Ostrea beloiti, cirriped valves, shark teeth, fish bones | 0.9 |
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Total thickness of Lincoln Member | 21.3 | ||
| Total thickness of Greenhorn Limestone | 91.1 | |||
| Rests conformably on Graneros Shale. | ||||
| Key Section 3--Composite section in Hodgeman and northern Ford counties. Pfeifer Member exposed in bluff and abandoned fencepost quarry on south side of Pawnee Creek, NE SE sec. 25, T. 21 S., R. 26 W., Hodgeman County, Kansas (Locality 10). | Thickness, feet |
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|---|---|---|---|---|
| Greenhorn Limestone | ||||
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Pfeifer Member | |||
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103. | Chalky limestone, Fencepost limestone, weathered grayish orange to very pale orange, resistant, ledge-forming, speckled, with ferruginous zone along center of bed; contains abundant valves and fragments of inoceramids, including molds; lower 0.1 foot is softer, very thin bedded. FOSSILS: Mytiloides labiatus, Collignoniceras woollgari | 0.9 |
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102. | Shaly chalk and chalky limestone; shaly chalk predominant, all weathered pale grayish orange; contains a few lenses of shelly foraminiferal chalk and soft grayish orange chalk that project from slope; chalky limestone is concretionary, weathered grayish orange to pale grayish orange, resistant, occurs as oblate spheroids in three layers centering 1.2, 1.8, and 2.1 feet above base, lowest group reach maximum thickness of 0.65 foot; one concretion is 23 feet long, up to 1.1 feet wide, 0.65 foot thick and encloses a log through most of its length; concretions contain relatively few fossils, including whole and fragmentary inoceramid valves, and commonly have ferruginous zone along central plane; bentonite seam, 0.01 foot thick, light olive gray, weathering dark yellowish orange, lies 0.5 foot below top of unit. FOSSILS: in shaly chalk, Mytiloides labiatus; in chalky limestone, M. labiatus, Pseudoperna bentonensis | 3.6 |
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101. | Chalky limestone, weathered grayish orange to light brown (5YR5/6), moderately resistant, forms small ledge, speckled, contains lenses of pale yellowish brown, well cemented, brittle limestone; bed underlain by bentonite seam, 0.01 foot thick, olive gray, weathering dark yellowish orange, silty. FOSSILS: Collignoniceras woollgari | 0.18 |
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100. | Shaly chalk, weathered pale grayish orange | 0.6 |
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99. | Chalky limestone, weathered yellowish orange (5Y7/2) to dark yellowish orange, moderately resistant, forms small ]edge, speckled, much stained by limonite, poorly fossiliferous, with many calcite-lined joints. FOSSILS: ammonite mold | 0.15 |
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98. | Shaly chalk, dark yellowish orange | 0.09 |
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97. | Bentonite and granular calcite (sugar sand), bentonite 0.09 foot thick, dark yellowish orange, very slightly silty, overlain by 0.32 foot of dark yellowish orange granular calcite | 0.41 |
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96. | Shaly chalk, grayish orange to pale yellowish orange. FOSSILS: Mytiloides labiatus | 0.4 |
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95. | Chalky limestone, yellowish gray to grayish orange, speckled, poorly fossiliferous | 0.1 |
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94. | Bentonite, dark yellowish orange | 0.12 |
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93. | Shaly chalk and chalky limestone; shaly chalk predominant, dark olive gray (5Y3/1), mostly weathered grayish orange to very pale orange, with inoceramid valves abundant in lower part becoming less common upward; lower 2.3 feet of shaly chalk contains abundant lenses of well cemented fine-grained skeletal limestone composed of foraminiferal tests and inoceramid debris and with some chalky matrix, lenses project from weathered slope; chalky limestone, light olive gray (5Y5/2), light brown (5YR5/6) grayish orange or dark yellowish orange, all speckled, resistant, ledge forming, most limestone (5 beds) occurs in irregular, continuous to discontinuous, subequally spaced concretionary beds that contain abundant fragments and valves of inoceramids, second bed from base has sparry calcite cemented laminated zone along center of bed; large chalky limestone concretions, flat on top, hemispheroidal below, poorly fossiliferous, with limonite stains along center, lie 2.9 feet below top. FOSSILS: in shaly chalk, Mytiloides labiatus, Pseudoperna bentonensis, scalpellid plates (lower 2.3 feet); in chalky limestone, M. labiatus, P. bentonensis | 4.7 |
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92. | Chalky limestone (PF-1), grayish orange to very pale orange, resistant, ledge forming, speckled, valves and fragments of inoceramids common, top and base uneven. FOSSILS: Mytiloides labiatus | 0.2 |
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91. | Shaly chalk and chalky limestone; shaly chalk predominant, olive black, weathering yellowish gray (5Y7/2) to grayish orange; in upper foot contains lenses of skeletal limestone composed of foraminifera and inoceramid fragments and prisms, with some chalky matrix, project conspicuously from slope; chalky limestone, olive gray (5Y4/1) to light olive gray (5Y6/1) weathering grayish orange to dark yellowish orange, resistant, ledge forming, speckled, in three irregular concretionary beds containing common to abundant fragments or valves of inoceramids, middle bed has ferruginous stain along center; bentonite seam, overlain by granular calcite, dark yellowish orange, 0.01 foot thick, lies at top of unit in contact with PF-1. FOSSILS: in shaly chalk: Mytiloides labiatus, fish scales; in chalky limestone, M. labiatus, Baculites cf. B. yokoyamai (lowest bed) | 6.4 |
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Total thickness of Pfeifer Member | 17.9 | ||
| Cut bank on intermittent stream, NW sec. 13, T. 23 S., R. 24 W., Hodgeman County, Kansas (Locality 9). | ||||
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Jetmore Member | |||
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90. | Chalky limestone, Shellrock limestone bed, weathered yellowish gray (5Y7/2) to light brown (5YR5/6) or grayish orange, resistant, major ledge former, speckled, in part composed of visibly crystalline calcite, valves and fragments of inoceramids abundant throughout, mostly preserved in-the-round. FOSSILS: Mytiloides labiatus | 0.55 |
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89. | Chalk, yellowish gray (5Y7/2) to grayish orange, very thin beds project from weathered slope, brittle, represents lower part of Shellrock limestone bed of other localities | 0.45 |
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88. | Shaly chalk, weathered yellowish gray (5Y7/2) to grayish orange, soft, poorly laminated, contains many small fragments and lenses of fragments of inoceramids; contains two beds of chalky limestone weathered yellowish gray to grayish orange; lower bed continuous, flat on bottom, irregular on top, maximum of 0.23 foot in thickness, highly speckled, contains abundant valves and scattered prisms and fragments of inoceramids; upper limestone bed consists of oblate spheroidal concretions, some coalesced, maximum of 0.3 foot in thickness, highly speckled, with liesegang banding along centers of concretions. FOSSILS: in shaly chalk, Mytiloides labiatus; in chalky limestone, M. labiatus, ?Pseudoperna bentonensis | 2.65 |
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87. | Limestone (3 hard beds) and shaly chalk; limestone light olive gray (5Y6/1), weathering grayish orange, three subequally spaced beds separated by shaly chalk, resistant, ledge forming, sparingly speckled, composed in part of visibly crystalline calcite, with many whole and fragmentary valves of inoceramids; inoceramids preserved mostly in-the-round; bentonite seam, 0.01 foot thick, dark yellowish orange, lies on basal limestone bed; shaly chalk predominant, weathered yellowish gray (5Y7/2) and dark yellowish orange, irregularly laminated, soft, with many valves and fragments of inoceramids that project from weathered slope; contains a few lenses of gritty chalk; FOSSILS: in shaly chalk, Mytiloides labiatus; in chalky limestone, M. labiatus, Baculites cf. B. yokoyamai | 3.3 |
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86. | Shaly chalk and chalky limestone; shaly chalk predominant, in part dark olive gray in lower 3.5 feet, remainder is weathered yellowish gray (5Y7/2) to grayish orange; in uppermost 2.5 feet the shaly chalk beds are crowded with inoceramid valves and fragments that project from weathered slope; chalky limestone, 8 uneven beds, subequally spaced, separated by shaly chalk intervals, relatively hard, resistant, form minor ledges, = JT-1 to JT-8, lowest bed in part olive gray (5Y4/1), remainder of chalky limestone is weathered yellowish gray (5Y7/2) and is dark yellowish orange where stained by limonite; most beds sparingly speckled by fecal pellets; all beds lack laminations, beds 1, 2, 4, 6, and 7 are conspicuously burrow mottled, beds 1, 3, 6, and 7 contain abundant slender, tubular, calcite and/or limonite-filled burrows; position of JT-9 is occupied by soft chalk bed; shaly chalk between JT-6 and JT-7 contains 0.3 foot thick bed of soft, nonresistant chalk; lens of chalk, 0.02 foot thick, thinly laminated, lies 0.5 foot above top of JT-1. FOSSILS: in shaly chalk, Mytiloides labiatus, Pycnodonte sp. A (above JT-8), fish bones and scales; in chalky limestone, M. labiatus, Baculites cf. B. yokoyamai (JT-3), ostreid, sp. (JT-1, JT-2) | 15.6 |
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Total thickness of Jetmore Member | 22.6 | ||
|
Hartland Member | |||
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85. | Shaly chalk, dark olive gray (5Y3/1), dries medium light gray; lens of soft chalk, up to 0.25 foot thick, lies 1.0 foot above base; bentonite seam, 0.06 foot thick, dark yellowish orange, lies 0.15 foot below top. FOSSILS: Mytiloides labiatus | 2.25 |
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84. | Chalky limestone, weathered yellowish gray (5Y7/2), forms minor ledge, burrow mottled, with zone of limonite nodules near top | 0.35 |
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83. | Shaly chalk, dark olive gray (5Y3/1), dries medium light gray, bedding fractures pitted | 1.0 |
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82. | Chalky limestone, olive gray (5Y4/1), weathering yellowish gray (5Y7/2), forms minor ledge, burrow mottled, with tests of foraminifera studding weathered surface | 0.4 |
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81. | Shaly chalk, dark olive gray (5Y3/1), dries medium light gray | 1.3 |
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80. | Chalky limestone, olive gray (5Y4/1), weathering yellowish gray, swells locally to 0.3 foot, forms prominent minor ledges, burrow mottled | 0.15 |
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79. | Shaly chalk, olive black, dries medium light gray; contains two seams of bentonite, dark yellowish orange, 0.05 and 0.01 foot thick, lying at base and 0.5 foot above base of unit, respectively | 0.7 |
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78. | Chalky limestone, olive gray (5Y4/1), weathering very pale orange, forms minor ledge, weathered slabby, sparingly speckled, faintly burrow mottled, with conspicuous tests of foraminifera. FOSSILS: Inoceramus prefragilis | 0.8 |
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77. | Shaly chalk, olive black, dries medium gray, weathering grayish orange; unit has zones of soft, laminated, weathered rock that alternate with harder, nonlaminated, little-weathered rock resulting in irregular profile on exposure; where least weathered this unit does not show alternation of harder and softer layers and is uniformly olive black. FOSSILS: Inoceramus prefragilis, Syncyclonema? sp., lignitized wood (fragment) | 3.5 |
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76. | Chalky limestone, weathered yellowish gray (5Y7/2), weathers into very thin uneven beds, weakly resistant, with scattered valves and fragments of inoceramid bivalves. FOSSILS: Inoceramus prefragilis | 0.4 |
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75. | Shaly chalk, olive black, in part weathered grayish orange. FOSSILS: Inoceramus prefragilis | 1.1 |
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74. | Chalky limestone, weathered yellowish gray (5Y7/2), weathers to very thin beds, weakly resistant | 0.23 |
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73. | Shaly chalk, olive black, dries medium light gray with bluish tinge, in part weathering to grayish orange; ferruginous zone, 0.02 foot thick, dark yellowish brown, lies 0.4 foot below top. FOSSILS: Inoceramus prefragilis | 1.1 |
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72. | Chalky limestone, weathered pale yellowish brown to grayish orange, partly stained by limonite, speckled, moderately resistant, single bed of uneven thickness | 0.5 |
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71. | Shaly chalk, dark olive gray, in part weathered to grayish orange. FOSSILS: Inoceramus prefragilis | 1.1 |
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70. | Chalky limestone, weathered yellowish gray (5Y7/2) with dark yellowish orange limonite stains, moderately resistant, burrow mottled, white speckled. FOSSILS: fish scale | 0.3 |
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69. | Shaly chalk, olive black, mostly weathered dark yellowish brown to pale yellowish brown. FOSSILS: fish scales and bones | 0.8 |
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68. | Chalky limestone, olive gray (5Y4/1), weathering very pale orange, in part stained dark yellowish orange by limonite, very uniform texture, sparse inoceramid bivalve fragments, abundant foraminifera. FOSSILS: Inoceramus sp. | 0.3 |
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67. | Shaly chalk, olive black, weathering grayish orange. FOSSILS: fish bones | 1.85 |
| Draw in south wall of Buckner Creek valley, NE sec. 10, T. 23 S., R. 23 W., Hodgeman County (Locality 11) | ||||
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66. | Bentonite, weathered nearly white to dark yellowish orange | 0.3 |
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65. | Chalky limestone (HL-3), weathered very pale orange (10YR8/2), relatively soft, weathers into very thin irregular beds, weakly resistant, sparsely burrow mottled, some laminae preserved. FOSSILS: Inoceramus prefragilis, fish vertebra | 0.25 |
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64. | Shaly chalk, weathered light gray with dark yellowish orange limonite stains on bedding fractures and joints, with scattered whole and fragmentary inoceramid valves; contains very thin bed of soft, partially burrow mottled chalk 1.6 feet above base. FOSSILS: Inoceramus prefragilis, fish scales | 2.8 |
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63. | Chalky limestone, mostly weathered pale grayish orange (10YR8/4), locally almost white, brittle, weathers blocky and crumbly, minor ledge former, much burrow mottled, with abundant spheroidal to vermiform bodies of limonite that may be burrow fillings; contains whole and fragmentary inoceramid valves. FOSSILS: Inoceramus prefragilis, Phelopteria sp. A., Baculites sp. (smooth), Worthoceras vermiculum | 0.3 |
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62. | Shaly chalk, olive black, weathering medium light gray, some bedding planes made very light gray by abundance of fecal pellets (white specks). FOSSILS: Inoceramus prefragilis, fish bones and scales | 2.15 |
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61. | Chalky limestone (HL-2), weathered light gray to pale grayish orange (10YR8/4), hard, brittle, resistant, major ledge former, faintly burrow mottled, uppermost part very thinly laminated, fossils abundant relative to other Hartland beds, commonly preserved in-the-round; contains slender calcite-filled burrows: FOSSILS: Inoceramus prefragilis, Cerithiella sp. A., Baculites sp. (smooth), Kanabiceras septemseriatum, Worthoceras vermiculum, W. gibbosum, Pseudocalycoceras dentonense, Allocrioceras annulatum, Hemiptychoceras reesidei, articulated teleost skeleton | 0.3 |
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60. | Shaly chalk, weathered light gray mottled with dark yellowish orange; bentonite seam, 0.07 foot thick, dark yellowish orange, lies 0.8 foot below top | 1.45 |
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59. | Bentonite, yellowish gray (5Y8/1) to white with dark yellowish orange staining, very slightly silty | 0.35 |
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58. | Shaly chalk, weathered light gray to grayish orange | 0.7 |
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57. | Chalky limestone (HL-1), weathered very light olive gray (5Y7/1) to very pale orange (10YR8/1), brittle, resistant, ledge forming, weathers into very thin irregular beds, thoroughly burrow mottled; contains calcite-filled burrows and threadlike, limonite-filled burrows. FOSSILS: Inoceramus sp. (frags.), ostreid (indet.), Trichichnus | 0.4 |
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56. | Shaly chalk and chalk, weathered pale orange (10YR7/2); lower part is tough chalk, fractures irregularly subparallel to bedding, burrow mottled, transitional upward from bed below, may grade laterally into upper part of bed below | 0.7 |
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55. | Chalky limestone, very light gray to nearly white, very thinly bedded, thickens locally to 1.0 foot thickness, main part burrow mottled, upper part thinly and evenly laminated where bed is thicker than normal; brittle, moderately resistant. FOSSILS: ammonite mold (indet.), Trichichnus | 0.5 |
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54. | Shaly chalk, dark olive gray (5Y3/1), dries light gray, in part weathered brown (10YR5/4), upper part weathered moderate grayish orange (10YR6/4), soft at top, remainder very tough and blocky; burrow mottled chalk, 0.2 foot thick, lies 1.5 foot below top; limonite seam, 0.01 foot thick, lies 3.1 foot below top | 8.0 |
| Cut bank and pasture on south side of Sawlog Creek, SW sec. 5, T. 25 S., R. 24 W., Ford County (Locality 8). | ||||
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53. | Bentonite, pale yellowish gray (5Y8/2) to dark yellowish orange, very slightly silty | 0.32 |
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52. | Shaly chalk, weathered grayish orange | 0.16 |
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51. | Skeletal limestone, yellowish brown (10YR5/2), weathering very pale orange, well cemented, brittle, mostly very fine grained with some coarse shell fragments, has strong petroliferous odor | 0.05 |
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50. | Covered interval | 2.1 |
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49. | Skeletal limestone, light brown (5YR6/4) to grayish orange pink, well cemented, brittle calcisiltite with sparse shell fragments | 0.05 |
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48. | Shaly chalk, weathered grayish orange to very pale orange, with sparse inoceramid valves and fragments; with scattered very thin, small lenses of foraminiferal limestone, very pale yellowish brown, well cemented, brittle, project from weathered slope; Inoceramus-rich limestone, 0.15 foot thick, well cemented, brittle, forms local lens 0.5 foot above base; bentonite seam less than 0.01 foot thick, dark yellowish orange, lies 0.35 foot above base. FOSSILS: Inoceramus prefraglis, fish bones and scales | 1.9 |
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47. | Chalky limestone, weathered grayish orange to pale grayish orange (10YR8/4), relatively resistant, faintly laminated, speckled, with inoceramid shell fragments on upper surface | 0.12 |
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46. | Shaly chalk, weathered grayish orange to very pale orange, with scattered inoceramid valves and fragments and sparse small, very thin lenses of skeletal limestone composed of Inoceramus debris; bentonite seam, 0.02 foot thick, light olive gray (5Y6/1), slightly silty, lies 0.4 foot above base; bentonite seam, 0.06 foot thick, grayish orange, lies at top of unit. FOSSILS: Inoceramus sp., fish bones and scales | 1.1 |
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45. | Bentonite, dark yellowish orange, slightly silty | 0.17 |
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44. | Shaly chalk, weathered yellowish orange (10YR7/6) to very pale orange, unevenly laminated, filled with inoceramid valves and fragments; contains numerous small, very thin lenses of well cemented, brittle, skeletal limestone composed of Inoceramus debris | 0.9 |
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43. | Skeletal limestone,. pale, yellowish brown, weathering grayish orange, well cemented, brittle, composed of very fine to coarse Inoceramus debris, has petroliferous odor. FOSSILS: Inoceramus sp. | 0.05 |
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42. | Shaly chalk and bentonite; shaly chalk mostly weathered dark yellowish orange to very pale orange; weathered slope littered with Inoceramus valves and fragments and lenses of inoceramid debris; skeletal limestone, pale yellowish brown, as scattered small, very thin lenses, well cemented, brittle, has petroliferous odor; bentonite, 4 seams 0.06, 0.05, 0.05, and 0.15 foot thick, dark yellowish orange, lie 0.2, 1.0, 2.35, and 2.6 feet above base, respectively; unit contains sparse very thin, small lenses of relatively resistant chalk. FOSSILS: Inoceramus prefragilis | 3.6 |
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41. | Chalky limestone, weathered grayish orange, moderately resistant, minor ledge former, faintly laminated, white speckled, lenticular, wedges out laterally. FOSSILS: fish bones and scales | 0.17 |
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40. | Shaly chalk, weathered pale yellowish brown to very pale orange; slope littered with inoceramid valve fragments; unit contains sparse lenses of skeletal limestone, pale yellowish brown, well cemented, brittle, composed mainly of Inoceramus debris; bentonite, 0.03 foot maximum thickness, wedges out laterally beneath unit 41, lies at top of unit | 1.2 |
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39. | Bentonite and limonite; limonite powdery, yellowish orange (10YR7/6), predominates; bentonite is light brown (5YR5/6) | 0.13 |
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38. | Shaly chalk, weathered dark yellowish orange to very pale orange, with abundant Inoceramus valves and fragments; contains many small, very thin lenses of skeletal limestone, pale yellowish brown, well cemented, brittle, with petroliferous odor, composed largely of Inoceramus debris, very fine to coarse grained, project from weathered slope. FOSSILS: Inoceramus prefragilis, fish bones and scales | 3.2 |
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37. | Bentonite, pale yellowish brown to very dark yellowish orange (10YR5/6) | 0.15 |
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36. | Shaly chalk, weathered grayish- to pale grayish orange (10YR8/4) to pinkish gray; contains small, very thin lenses of skeletal limestone, pale yellowish brown, well cemented, brittle, have petroliferous odor, composed predominantly of tests of foraminifera or Inoceramus debris, range from very fine to coarse grained. FOSSILS: Inoceramus prefragilis, fish bones and scales | 0.9 |
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35. | Bentonite, weathered light brownish gray (5YR6/1) to very dark yellowish orange (10YR5/6) | 0.15 |
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34. | Shaly chalk, weathered very pale orange to dark yellowish orange, in part harder than usual and projecting from slope; contains sparse very thin, small lenses of skeletal limestone. FOSSILS: Inoceramus prefragilis, fish bones and scales | 0.4 |
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33. | Bentonite, very light olive gray (5Y7/1) to very dark yellowish orange (10YR5/6) | 0.27 |
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32. | Shaly chalk, weathered grayish- to pale grayish orange (10YR8/4) and pinkish gray, with numerous Inoceramus valves and fragments that litter weathered slope; upper foot contains thin to very thin lenses of skeletal limestone, well cemented, brittle, project from slope, fine to coarse grained, composed largely of Inoceramus debris; local lens of chalky limestone, 0.01 foot thick, lies 1.7 feet above base; bentonite seam, 0.01 foot thick, lies 0.5 foot above base. FOSSILS: Inoceramus prefragilis, fish bones and scales | 3.0 |
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31. | Bentonite, mostly weathered very dark yellowish orange (10YR5/6), limonitic | 0.04 |
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30. | Shaly chalk, weathered grayish orange to very pale orange, very flat bedding planes, with abundant Inoceramus valves and fragments that litter weathered slope. FOSSILS: Inoceramus prefragilis | 2.3 |
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29. | Chalky limestone, weathered pale orange (10YR7/2) to pale grayish orange (10YR8/4), relatively resistant, forms minor ledge, white speckley, basal part faintly laminated, weathers platy, with whole and fragmentary Inoceramus valves. FOSSILS: Inoceramus prefragilis | 0.25 |
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28. | Shaly chalk, weathered grayish orange to pale orange (10YR7/2), with common Inoceramus valves and fragments; discontinuous bentonite seam, 0.03 foot thick, dark yellowish orange, lies 0.01 foot below top of unit. FOSSILS: Inoceramus prefragilis, fish bones and scales | 4.3 |
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27. | Chalky limestone, weathered pale grayish orange, moderately resistant, forms prominent bench, weathers into three very thin beds, speckled. FOSSILS: Inoceramus prefragilis | 0.3 |
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26. | Shaly chalk, weathered light brownish gray to pinkish gray and grayish orange, with many harder-than-usual laminae that project from weathered slope locally; discontinuous bentonite seam, dark yellowish orange, maximum 0.08 foot thick, lies at top of unit. FOSSILS: fish bones and scales | 1.6 |
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25. | Bentonite, very light gray to dark yellowish orange, with associated coarsely granular gypsum; contains sparse limonite nodules | 0.16 |
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24. | Shaly chalk, weathered pale orange (10YR7/2) to grayish orange, limonite stained, with much powdery gypsum on bedding planes; soft, non-laminated chalk bed, 0.2 foot thick, pale yellowish brown to dark yellowish orange, lies 0.3 foot above base. FOSSILS: Inoceramus prefragilis?, fish scales and bones | 3.25 |
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Total thickness of Hartland Member | 68.3 | ||
|
Lincoln Member | |||
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23. | Skeletal limestone, pale orange (10YR7/2), well cemented brittle, very fine grained with some coarse and pebble size grains, resistant. FOSSILS: Inoceramus prefragilis, Exogyra aff. E. boveyensis, fish bones | 0.1 |
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22. | Shaly chalk, weathered medium light gray to light brown (10YR6/4), with powdery gypsum on bedding planes; contains scattered small, very thin lenses of skeletal limestone, pale yellowish brown, well cemented, brittle, have petroliferous odor, mostly very fine grained, composed largely of Inoceramus prisms or foraminifer tests, some lenses composed of large fragments of Inoceramus. FOSSILS: Inoceramus prefragilis, Exogyra aff. E. boveyensis | 0.9 |
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21. | Bentonite, moderate olive brown, calcareous | 0.24 |
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20. | Shaly chalk, weathered grayish orange; contains many small, very thin lenses of skeletal limestone, well cemented, brittle, pale yellowish brown, weathering grayish orange, has petroliferous odor, mostly fine to very fine grained, composed of foraminiferal tests and/or Inoceramus debris, very fine to coarse grained; burrow casts occur on soles of some limestones; bentonite seam, 0.01 foot thick, moderate yellowish brown, lies at base. FOSSILS: Inoceramus prefragilis, Exogyra aff. E. boveyensis, scalpellid barnacle plates, Calycoceras? cf. C? canitaurinum, Isurus, fish bones and scales | 2.4 |
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19. | Chalk, weathered dark yellowish orange with some manganese oxide staining, granular, probably secondary | 0.32 |
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18. | Bentonite, grayish orange to dark yellowish orange | 0.22 |
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17. | Shaly chalk, weathered light olive gray (5Y6/1) to grayish orange and dark yellowish orange; contains scattered very thin, small lenses and two very thin lensing beds of skeletal limestone, pale yellowish brown, very fine grained, well cemented, brittle, composed mainly of foraminifer tests or Inoceramus prisms; contains two bentonite seams, 0.05 and 0.04 foot thick, moderate olive brown and dark yellowish orange, lying 0.05 and 0.7 foot above base, respectively. FOSSILS: Inoceramus prefragilis, fish scales 1.2 | |
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16. | Bentonite, medium light gray weathering dark yellowish orange, very slightly silty | 0.3 |
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15. | Shaly chalk, as in unit 17, with only sparse lenses of skeletal limestone | 1.1 |
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14. | Bentonite, yellowish gray (5Y7/2), weathering dark yellowish orange | 0.25 |
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13. | Shaly chalk, as in unit 15; bentonite seam, 0.05 foot thick, dark yellowish orange, lies 0.2 foot above base | 1.53 |
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12. | Chalky limestone and shaly chalk; chalky limestone predominant, four thin to very thin lensing units, all very thin bedded, separated by shaly chalk beds, beds at base and top of unit are most conspicuous, resistant, form minor ledges, speckled, weathered grayish orange to dusty yellow, in part cemented or recrystallized to visibly crystalline calcite, in part laminated, in part burrowed; small, very thin lenses of skeletal limestone pale yellowish brown, very fine grained, well cemented, occur in the two main limestone beds; uppermost chalky limestone bed contains fragments of Inoceramus valves; fecal castings on soles of some limestone beds; bentonite seam, 0.07 foot thick, light olive gray (5Y6/1), lies 0.35 foot below top. FOSSILS: Inoceramus prefragilis, Exogyra aff. E. boveyensis, Eucalycoceras sp. A | 1.7 |
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11. | Shaly chalk and chalky limestone; shaly chalk predominant, weathered grayish orange to light brown (5YR6/4); chalky limestone, as scattered very thin beds, weathered grayish orange to dark yellowish orange, moderately resistant, contain abundant Inoceramus prisms and foraminifer tests, speckled, locally well cemented; lower part of unit contains small, very thin lenses of skeletal limestone, pale yellowish orange, cross laminated, very fine grained, well cemented, brittle, with petroliferous odor. FOSSILS: Inoceramus prefragilis | 1.2 |
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10. | Chalky limestone, weathered grayish orange, single lensing bed, moderately hard, forms prominent ledge. FOSSILS: Inoceramus prefragilis, fish scales | 0.12 |
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9. | Bentonitic shaly chalk, all weathered dark yellowish orange to moderate yellowish brown; contains a layer of nodular chalky limestone masses, up to 0.8 foot thick, grayish orange, with contorted laminae, resulting from disruption of a single bed, exhibits ball and pillow structure. FOSSILS: Inoceramus prefragilis | 0.8 |
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8. | Bentonite, light greenish gray, weathering dark yellowish orange, very slightly silty, grades upward into overlying unit | 0.5 |
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7. | Shaly chalk, weathered dark yellowish orange, bentonitic in upper 0.75 foot; contains 0.15 foot thick lens of soft chalk, grayish orange, laminated, limonite streaked, with fragments of Inoceramus valves, lies 0.35 foot above base. FOSSILS: Inoceramus prefragilis | 1.46 |
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6. | Bentonite, medium gray to nearly white, very slightly silty | 0.14 |
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5. | Shaly chalk, weathered dark yellowish orange 1.65 | |
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4. | Bentonitic chalk, weathered dark yellowish orange to moderate yellowish brown thinly laminated, speckled, contains calcareous silt and some light gray streaks of bentonite. FOSSILS: fish bones | 1.05 |
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3. | Chalk, mostly weathered to grayish orange, in part thinly laminated, all thin to very thin bedded, locally shaly; bentonite seam, 0.01 foot thick, light gray, lies 0.85 foot below top. FOSSILS: Ostrea beloiti, fish bones, teeth and scales | 2.0 |
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2. | Bentonite, dark yellowish orange | 0.02 |
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1. | Skeletal limestone, olive gray, weathering dark yellowish orange with much limonite staining, single well-cemented bed, composed of Ostrea beloiti valves set in "matrix" composed largely of Inoceramus prisms, has petroliferous odor, locally pyritic; uppermost 0.02 foot locally lacks Ostrea valves, is pale yellowish brown; unit forms conspicuous, projecting ledge. FOSSILS: Ostrea beloiti, ammonite mold (indet.) coprolites, bone pebbles, Inoceramus sp. (frags.), Lispodesthes? sp., Ptychodus, Isurus | 0.25 |
|
Total thickness of Lincoln Member | 19.4 | ||
| Total thickness of Greenhorn Limestone | 128.2 | |||
| Rests disconformably on Graneros Shale | ||||
| Key Section 4--Composite section in Hamilton and Kearny counties. Upper part in cut banks along East Bridge Creek, SW sec. 14, NE sec. 22, T. 23 S., R. 42 W., Hamilton County, Kansas (Locality 14). | Thickness, feet |
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|---|---|---|---|---|
| Greenhorn Limestone | ||||
|
Bridge Creek Member (Pfeifer equivalent) | |||
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116. | Chalky limestone, weathered very pale yellowish brown to pale grayish orange, tough, less resistant than unit 114, breaks blocky; represents upper part of Fencepost limestone bed. FOSSILS: Collignoniceras woollgari | 0.55 |
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115. | Shaly chalk, weathered pale grayish orange | 0.22 |
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114. | Chalky limestone, olive gray (5Y4/1), mostly weathered grayish orange, stained dark yellowish orange locally by limonite, hard, brittle, resistant, ledge forming, in part thinly laminated, locally cross laminated, sparsely speckled, represents lower part of Fencepost limestone bed. FOSSILS: Mytiloides labiatus, Collignoniceras woollgari, Baculites cf. B. yokoyami, Pseudoperna bentonensis, fish scales | 0.55 |
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113. | Shaly chalk, olive black to dark olive gray (5Y3/1); bentonite, dark yellowish orange, 0.01 foot thick, lies 0.07 foot below top. FOSSILS: Syncyclonema? sp., baculitid mold, fish scales | 2.75 |
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112. | Bentonite, dark yellowish orange, slightly silty | 0.14 |
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111. | Shaly chalk, dark olive gray (5Y3/1); limestone, dark olive gray (5Y3/1), weathering grayish orange, hard brittle, resistant, massive, sparsely speckled, unfossiliferous, concretionary, breaks with smooth vertical fractures, passes laterally into shaly chalk, maximum thickness 0.35 foot, lies 0.15 foot above base; limonite and gypsum nodule, 0.15 foot thick, centers 0.7 foot above base. FOSSILS: Snycyclonema? sp., Mytiloides labiatus, fish scale | 1.1 |
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110. | Bentonite, dark yellowish orange, gritty | 0.14 |
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109. | Shaly chalk, olive gray (5Y4/1), crowded with whole and broken inoceramid valves; FOSSILS: Mytiloides labiatus | 0.65 |
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108. | Chalky limestone, olive gray (5Y4/1) weathering yellowish gray (5Y7/2), tough, resistant, conspicuous on slope, homogeneous, partially cemented by visibly crystalline calcite, inoceramid valves and fragments abundant, weathered surfaces studded with foraminifera. FOSSILS: Mytiloides labiatus | 0.15 |
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107. | Shaly chalk, dark olive gray (5Y3/1); limestone, olive gray (5Y4/1), speckled, homogeneous, concretionary, with abundant whole and fragmentary inoceramid valves, 0.35 foot thick, lies 1.4 foot above base; unit contains very thin discontinuous beds of well-cemented skeletal limestone, yellowish brown, laminated to gently cross laminated, composed of inoceramid prisms or a mixture of prisms and planktonic foraminiferal tests; selenite seam, 0.01 foot thick, marked by limonitized marcasite nodules, lies 3.2 feet above base, probably marks weathered seam of bentonite. FOSSILS: Mytiloides labiatus, Syncyclonema? sp. | 4.5 |
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106. | Chalky limestone, olive gray (5Y4/1), weathering yellowish gray, tough, brittle, resistant, homogeneous, with abundant Mytiloides valves, surface studded with tests of planktonic foraminifera, base of unit contains concretionary masses up to 0.3 foot thick and 1.4 feet wide. FOSSILS: Mytiloides labiatus | 0.3 |
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105. | Shaly chalk, dark olive gray (5Y3/1), laminae bend downward beneath overlying concretions; unit contains abundant very thin small lenses of skeletal limestone, fine grained, composed largely of inoceramid valve prisms | 1.4 |
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104. | Chalky limestone, olive gray (5Y4/1) weathering pale grayish orange, discontinuous, ranges up to 0.35 foot thick, speckled, tough, resistant, partially cemented by sparry calcite, with very thin laminated zone in middle of bed and with sparse tests of planktonic forams studding surface; contains whole valves and fragments of Mytiloides, some valves with recrystallized nacreous layer preserved. FOSSILS: Mytiloides labiatus, fish scales | 0.2 |
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103. | Shaly chalk, olive black (5Y4/1), laminae bend around concretions; limestone, olive gray (5Y4/1), concretionary, as oblate spheroidal masses up to 0.2 foot thick and 1.0 foot in breadth, lie in zone centering 0.25 foot below top; in lower foot unit contains very thin lenses of well-cemented skeletal limestone, dark yellowish brown, composed mainly of inoceramid valve prisms; bentonite, less than 0.01 foot thick, dark yellowish orange, lies 1.2 foot above base. FOSSILS: Mytiloides labiatus, Pseudoperna bentonensis | 1.8 |
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102. | Chalky limestone, olive gray (5Y4/1), weathering grayish orange with dark yellowish orange limonite stains, tough, resistant, speckled, rock tightly cemented in lowest 0.02 foot, sole is load? casted, top of bed flat; contains whole and fragmentary valves of Mytiloides. FOSSILS: Mytiloides labiatus, Pseudoperna bentonensis, fish scale | 0.14 |
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101. | Shaly chalk, olive black, like unit 103; abundant whole and broken Mytiloides valves and very thin small lenses of pale yellowish brown skeletal limestone project conspicuously from slope. FOSSILS: Mytiloides labiatus, Pseudoperna bentonensis | 1.45 |
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100. | Chalky limestone, olive gray (5Y4/1), weathering grayish orange, homogeneous, speckled, partially cemented by sparry calcite, tests of planktonic foraminifera stud surface, unit weathers into very thin beds, marcasite fills sparse tubular burrows: FOSSILS: Pseudoperna bentonensis, Mytiloides labiatus | 0.35 |
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99. | Shaly chalk, olive black, like unit 103, with whole and broken valves of Mytiloides. FOSSILS: Mytiloides labiatus, fish scale | 1.0 |
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98. | Chalky limestone, dark olive gray (5Y3/1), weathering yellowish gray (5Y8/1) to pale grayish orange, homogeneous texture, partially cemented sparry calcite; Mytiloides valves in-the-round, many juveniles; contains sparse, large Planolites-type burrow structures. FOSSILS: Mytiloides labiatus, Baculites sp., Stomohamites sp. cf. S. simplex | 0.4 |
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97. | Shaly chalk, dark olive gray (5Y3/1), partly weathered dark yellowish brown to medium yellowish brown, like unit 103; unit contains abundant very thin, small lenses of pale yellowish brown skeletal limestone composed mainly of Mytiloides fragments and isolated prisms. FOSSILS: Mytiloides labiatus, fish scales | 2.5 |
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96. | Chalky limestone, dark olive gray, weathering yellowish gray (5Y8/1) to pale grayish orange, homogeneous, nonspeckled, partially cemented by visibly crystalline calcite, very fine grained, with sparse small limonitic nodules along center of bed; burrow structures not obvious, bed expands locally to 0.35 foot. FOSSILS: Mytiloides labiatus, fish scale | 0.2 |
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95. | Shaly chalk, dark olive gray, partly weathered to slightly brownish olive gray (5Y4/1), with abundant valves of Mytiloides projecting from slope; unit contains very thin lenses of hard, brittle, very fine grained skeletal limestone scattered throughout but mostly near middle and reaching 0.05 foot in thickness. FOSSILS: Mytiloides labiatus, Anomia sp. A, oyster (fragment), fish scales | 5.35 |
|
Total thickness of Pfeifer equivalent | 25.8 | ||
|
Bridge Creek Member (Jetmore equivalent) | |||
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94. | Chalky limestone, Shellrock limestone bed, olive gray (5Y4/1), weathering grayish, resistant, ledge-forming, less brittle than three beds in unit 92, massive, with shaly weathering in lower 0.3 foot, at top and base gradational to adjacent units, contains faintly defined burrow structures some of which are limonite stained or lined with marcasite, surface of bed studded with foraminifera and inoceramid valve prisms, lower 0.3 foot rich in whole specimens of Mytiloides. FOSSILS: Mytiloides labiatus, fish scales | 0.9 |
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93. | Shaly chalk, dark olive gray, laminae bend around concretions in lower part of unit; shaly chalk contains abundant Mytiloides valves, valve fragments, and lenses of fragments as well as numerous very thin, small lenses of chalky limestone; unit grades to very thin bedded chalk in upper 0.2 foot; at 0.9 foot above base unit contains layer of oblate spheroidal concretions of chalky limestone, olive gray, weathering grayish orange, brittle, resistant, in part cemented by visibly crystalline calcite, speckled, with abundant whole and fragmentary specimens of Mytiloides and with irregular masses of limonite scattered along middle part of concretion zone; individual concretions are as much as 0.3 foot thick and up to 1.2 feet in diameter but reach greater size where 2 such structures have coalesced. FOSSILS: in shaly chalk, Mytiloides labiatus, Pycnodonte sp. A; in chalky limestone, Mytiloides labiatus | 3.9 |
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92. | Limestone (three hard beds) and shaly chalk; limestones, three beds, separated by shaly chalk intervals, olive gray (5Y4/1) to medium olive gray (5Y5/1) or light olive gray (5Y6/1), weathering grayish orange, partly stained dark yellowish orange by limonite; all limestones hard, brittle, resistant, highly fractured, more or less speckled; all beds with burrow mottling and/or burrow structures and crowded with noncrushed valves of Mytiloides; shaly chalk dark olive gray (5Y3/1), contains abundant whole and fragmentary valves of Mytiloides and very thin lenses of skeletal limestone; bentonite, 0.14 foot thick, grayish orange, selenitic, lies on lowest limestone bed. FOSSILS: in limestone, M. labiatus, Baculites cf. B. yokoyamai, Pycnodonte sp. A, fish scales, Anomia sp. A, marcasite- and calcite-filled cylindrical burrows; in shaly chalk, M. labiatus | 4.0 |
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|
91. | Shaly chalk, dark olive gray (5Y3/1), partly weathered to dark yellowish brown, weathers more flaky than shaly chalks below, upper 0.5 foot rich in Mytiloides valves and fragments; 0.01-foot-thick seam of selenite and clay (bentonite?) lies 0.25 foot above base. FOSSILS: Mytiloides labiatus, fish scale | 1.3 |
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|
90. | Chalky limestone, light olive gray (5Y6/1) to olive gray (5Y4/1), partly weathered to light olive gray (5Y5/2), brittle, resistant, ledge-forming, speckled, upper part locally weathers slabby, lensing bed mostly 0.2 to 0.4 foot thick, locally discontinuous, many disarticulated and broken valves of Mytiloides, weathered surface studded with tests of planktonic foraminifera. FOSSILS: Mytiloides labiatus, ammonite mold fragment, fish scale | 0.35 |
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|
89. | Shaly chalk, dark olive gray (5Y3/1). FOSSILS: Mytiloides labiatus, fish scales | 1.3 |
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|
88. | Chalky limestone, light olive gray (5Y6/1) to olive gray (5Y4/1), brittle, resistant, weathers shaly, speckled, burrow mottled, some burrow fill dark olive gray (5Y3/1), with many broken and disarticulated valves of Mytiloides; tests of planktonic foraminifera stud weathered surface; bed pinches and swells, forms discontinuous ledge. FOSSILS: Mytiloides labiatus | 0.35 |
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87. | Shaly chalk, dark olive gray (5Y3/1); three thin beds forming reentrants 0.2, 0.45, and 0.75 foot above base are weathered light olive gray (5Y5/2) and are associated with very thin seams of gypsum. FOSSILS: Mytiloides labiatus, one phosphatic coprolite | 1.45 |
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86. | Chalky limestone, light olive gray (5Y6/1) to olive gray (5Y4/1), in part weathered yellowish gray (5Y8/1) to pale grayish orange, brittle, resistant, forms prominent ledge, speckled, extensively burrow mottled, some burrow fill dark olive gray (5Y3/1), some burrows weathered into strong relief, many burrows limonite stained, some burrows marcasitized; bed thickens locally to 1.6 feet where base extends lower in section, tests of planktonic foraminifera stand in relief on surface. FOSSILS: Discinisca sp. | 0.55 |
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85. | Shaly chalk, dark olive gray, in part weathered moderate yellowish brown; contains abundant Mytiloides valves and valve fragments; middle part with abundant planktonic foraminifer tests and less well speckled and laminated; limonitic and jarositic marcasite nodule 0.15 foot thick lies 0.8 foot above base. FOSSILS: Mytiloides labiatus, fish scales | 3.15 |
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84. | Chalky limestone, light olive gray (5Y6/1) with olive gray (5Y4/1) to dark olive gray (5Y3/1) burrow mottles, brittle, resistant, ledge-forming, sparsely speckled, with abundant tests of planktonic foraminifera weathered out on surface; rock extensively burrowed and burrow mottled; contains some marcasite- or calcite-filled burrows; sparse marcasite nodules lie near center of bed. FOSSILS: Mytiloides labiatus, Mammites sp. (fragment), Baculites sp. | 0.35 |
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83. | Shaly chalk, dark olive gray (5Y3/1), many tests of planktonic foraminifera, abundant whole and broken valves of Mytiloides. FOSSILS: Mytiloides labiatus | 1.1 |
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82. | Chalky limestone, light olive gray with dark olive gray (5Y3/1) burrow fill, mostly weathered pale grayish orange, relatively brittle, resistant, ledge-forming, very sparsely speckled, faintly burrow mottled, some burrows stained dark yellowish orange by limonite. FOSSILS: Mytiloides labiatus, Discinisca sp., Baculites sp. | 0.25 |
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81. | Shaly chalk, dark olive gray (5Y3/1), with prominent reentrants at levels of 3 very thin seams of bentonite. FOSSILS: Mytiloides labiatus | 1.0 |
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80. | Chalky limestone, weathered very pale orange, brittle, resistant, ledge-forming, sparsely speckled, faintly burrow mottled, scattered valves and fragments of Mytiloides, many tests of planktonic foraminifera weathered out on surface; sparse calcite-filled burrows; pyrite nodules in zone along center of bed are mostly weathered to limonite which stains much of bed dark yellowish orange. FOSSILS: Mytiloides labiatus, Baculites sp., Discinisca sp. | 0.44 |
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79. | Shaly chalk, all partially weathered to medium yellowish brown (10YR5/2); contains many whole and fragmentary valves of Mytiloides, abundant tests of planktonic foraminifera, unit weathers flaky. FOSSILS: Mytiloides labiatus | 1.25 |
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78. | Chalky limestone, partially weathered to light olive gray (5Y6/1 ) to very pale orange, brittle, resistant, ledge-forming, large burrow structures throughout that are locally stained dark yellowish orange by limonite, weathered surface studded with tests of planktonic foraminifera; sparse calcite-filled burrows; sparse marcasite nodules occur locally in center of bed. FOSSILS: Mytiloides labiatus, Discinisca sp. | 0.42 |
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77. | Shaly chalk, dark olive gray (5Y3/1), Mytiloides valves common throughout, abundant in upper 0.5 foot; dark yellowish orange bentonite seams, each less than 0.01 foot thick, lie 0.05 foot and 0.35 foot above base, respectively. FOSSILS: Mytiloides labiatus | 1.35 |
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76. | Chalky limestone, medium light gray, mostly partially weathered to light olive gray (5Y6/1) and yellowish gray (5Y8/1), brittle, resistant, ledge-forming, speckled, burrow mottled, in part stained dark yellowish orange by limonite, with scattered tests of planktonic foraminifera weathered out on surface. FOSSILS: Mytiloides labiatus, oyster sp. | 0.35 |
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75. | Shaly chalk, olive black, weathering locally to grayish orange, with many valves of Mytiloides; very thin (0.015 foot, maximum) lensing bed of foram-rich skeletal limestone lies 0.3 foot above base. FOSSILS: Mytiloides labiatus | 1.25 |
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74. | Chalky limestone, light olive gray (5Y6/1), weathering grayish orange, with olive gray (5Y4/1 ) burrow structures, brittle, resistant, ledge forming, very sparsely speckled, with abundant noncrushed valves (some paired) of Mytiloides. FOSSILS: Mytiloides labiatus, Watinoceras reesidei, Vasoceras birchbyi | 0.43 |
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Total thickness of Jetmore equivalent | 25.4 | ||
|
Bridge Creek Member (Hartland equivalent, part) | |||
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73. | Shaly chalk, dark olive gray (5Y3/1); bentonite, 0.05 foot thick, grayish orange to dark yellowish orange, lies 0.11 below top of unit. FOSSILS: Mytiloides labiatus | 2.4 |
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72. | Chalky limestone, weathered very pale orange, highly fractured, resistant, forms ledge, sparsely speckled, contains large limonite-stained burrow mottles and many slender burrows lined with limonite; unit in part laminated locally | 0.4 |
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71. | Shaly chalk and chalky limestone, shaly chalk all weathered grayish orange, soft and rich in foraminifer tests in lower part, brittle in upper part; chalky limestone bed 0.4 foot thick, weathered pale grayish orange, moderately resistant, forms minor ledge near middle of unit, contains abundant tests of planktonic foraminifera. FOSSILS: fish scales | 1.4 |
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70. | Bentonite, olive gray (5Y4/1), stained dark yellowish orange by limonite, gritty, not waxy like most bentonites | 0.11 |
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69. | Shaly chalk, all partly weathered light olive gray (5Y6/1) to grayish orange | 0.45 |
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68. | Chalky limestone, all weathered very pale orange to grayish orange, sparsely speckled, blotched with limonite that apparently reflects burrow mottling. FOSSILS: Mytiloides labiatus | 0.5 |
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67. | Shaly chalk, dark olive gray (5Y3/1), weathering yellowish gray (5Y8/1) to grayish orange or moderate yellowish brown, with some beds not well laminated; 0.3-foot-thick bed of chalk, dark olive gray (5Y3/1), thin bedded, speckled, burrow mottled, with abundant tests of planktonic foraminifera, lies 0.6 foot above base. FOSSILS: Mytiloides labiatus, Inoceramus prefragilis? | 2.2 |
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66. | Chalky limestone, light olive gray (5Y6/1), weathered grayish orange, brittle, resistant, ledge forming, highly fractured, speckled, extensively burrowed; burrows outlined by limonite | 0.4 |
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65. | Shaly chalk, dark olive gray (5Y4/1), weathering light olive gray (5Y5/2) to grayish orange or dark yellowish orange, thinly laminated, contains abundant tests of planktonic foraminifera; one foot above base is conspicuous 0.15-foot-thick lensing zone of very thinly bedded chalky limestone, weathered light olive gray, gradational with adjacent chalk. FOSSILS: Mytiloides labiatus | 2.05 |
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64. | Chalky limestone, olive gray (5Y4/1) to dark olive gray (5Y3/1), weathers grayish orange to very pale orange; speckled, extensive, burrowed, burrow fill mostly darker than adjacent matrix, contains abundant tests of planktonic foraminifera; scattered nodules of limonite, some with marcasite centers, lie near center of bed. FOSSILS: Mytiloides labiatus, Watinoceras reesidei?, Puebloites sp., Tragodesmoceras bassi? | 0.4 |
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63. | Shaly chalk, dark olive gray with some layers partly weathered to medium yellowish brown (10YR5/2); many tests of planktonic foraminifera visible on bedding planes; uppermost part poorly laminated, tougher than below, and burrow mottled; unit contains whole and fragmentary inoceramid valves. FOSSILS: Inoceramus prefragilis, Mytiloides labiatus | 1.1 |
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62. | Chalky limestone, olive gray (5Y4/1), mostly weathered light olive gray (5Y7/2) to light olive gray (5Y6/1), brittle, highly fractured, resistant, ledge-forming, sparsely speckled, apparently burrow mottled, weathered surface studded with tests of planktonic foraminifera | 0.3 |
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61. | Shaly chalk, dark olive gray (5Y3/1), very well laminated; local bed of chalk, 0.15 foot thick, pale grayish orange, lies 1.15 feet below top, forms conspicuous streak in unweathered exposures; scattered limonite nodules up to 0.05 foot thick and 0.4 foot wide occur in zone 0.3 foot above base. FOSSILS: Inoceramus prefragilis, Mytiloides labiatus, fish scale | 3.1 |
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60. | Bentonite, nearly white to grayish orange, in part stained dark yellowish orange by limonite; slightly silty; forms prominent reentrant | 0.25 |
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59. | Chalky limestone (HL-3), olive gray (5Y4/1), mostly weathered yellowish gray (5Y8/1), brittle, resistant, ledge forming, ranges from 0.35 to 0.5 foot, not speckled, abundant tests of planktonic foraminifera stud surface, faintly burrow mottled, burrows stained by limonite. FOSSILS: fish vertebra | 0.4 |
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58. | Shaly chalk, dark olive gray (5Y3/1), most is weathered yellowish gray (5Y7/2) to medium yellowish brown (10YR5//2); contains whole and fragmentary inoceramid valves. FOSSILS: Inoceramus prefragilis, Phelopteria sp. A | 1.75 |
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57. | Chalky limestone, mostly weathered grayish orange, sparsely speckled, brittle, resistant, ledge forming extensively burrowed, chalky burrow fill is light olive gray (5Y5/2) to light olive gray (5Y6/1), some slender burrows outlined by limonite stains. FOSSILS: Inoceramus prefragilis, Phelopteria sp. A., Worthoceras vermiculum, W. gibbosum, Baculites sp. (smooth), fish vertebra | 0.35-0.4 |
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56. | Shaly chalk, dark olive gray (5Y6/1), conspicuously laminated, contains sparse olive black burrow structures and whole and broken inoceramid valves; bentonite, 0.03 foot thick, dark yellowish orange, lies 0.7 foot below top. FOSSILS: Inoceramus prefragilis, fish scales, fish vertebra | 1.5 |
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55. | Chalky limestone, olive gray (5Y4/1), weathers grayish orange to pale grayish orange, discontinuous lensing bed is brittle, ledge forming, locally contains oblate spheroidal chalky limestone concretions, limestone not speckled, contains whole and fragmentary inoceramid valves, basal 0.08 foot contains cylindrical chalk-filled burrow structures lying parallel to bedding, bed ranges from nothing to 0.55 foot in thickness. FOSSILS: Inoceramus prefragilis, Worthoceras vermiculum, Baculites sp. (smooth), ?Allocrioceras sp., fish scales | 0.33 |
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54. | Shaly chalk, dark olive gray (5Y3/1), weathers dark yellowish orange; contains 5 limonitic selenite seams the upper 3 of which merge laterally, these may be weathered bentonites; unit contains much jarosite | 0.85 |
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53. | Chalky limestone (HL-2), olive gray (5Y4/1) with weathered crust of dusky yellow, brittle, resistant, ledge forming, edge of ledge weathers rounded; part of bed contains faint laminae that contain visibly crystalline calcite; unit contains sparse, large, chalk-filled burrow structures. FOSSILS: Inoceramus prefragilis, Cerithiella sp. A, Worthoceras vermiculum, Pseudocalycoceras dentonense, fish scales, fish bone | 0.34 |
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52. | Shaly chalk, dark olive gray (5Y3/1) in lower part, medium dark gray and burrow mottled in upper 0.25 foot, poorly laminated, darker part not speckled; contains oblate spheroidal concretion of chalky limestone, medium gray, speckled, 0.25 foot thick, lying 0.5 foot above base; bed of chalky limestone, medium gray, 0.08 foot thick, lies 0.25 foot below top | 1.05 |
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51. | Bentonite, fresh color medium gray, most is weathered nearly white with dark yellowish orange limonite stains, gritty | 0.6 |
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50. | Shaly chalk, medium gray, not conspicuously speckled, poorly laminated, apparently clayey, upper part contains streaks of limonite and jarosite, rock contains fine grained selenite crystals | 0.4 |
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49. | Chalky limestone (HL-1), light olive gray (5Y6/1), brittle, extensively mottled by chalk-filled structures approximately 1 cm in average diameter, also contains calcite-filled burrows approximately 2 mm in diameter, rock speckled. FOSSILS: Sciponoceras gracile | 0.4 |
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48. | Shaly chalk, olive gray (5Y4/1), faintly speckled, soft | 0.13 |
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47. | Chalky limestone, dark olive gray (5Y3/1) mottled with light gray, crowded with chalk-filled burrow structures; equivalent to lower part of HL-1 | 0.8 |
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Total thickness of Hartland equivalent of Bridge Creek member | 24.0 | ||
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Total thickness of Bridge Creek member | 75.2 | ||
| Road ditch and bluff on north side of county road in NE sec. 32, T. 21 S., R. 38 W., approximately 2 miles east of Kendall, Kearny County. (Locality 13). | ||||
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Hartland Member | |||
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46. | Shaly chalk with some chalky limestone; shaly chalk mostly weathered to light olive gray (5Y6/1) to grayish orange; upper half contains scattered lenses and very thin beds of chalky limestone, light olive gray (5Y5/2) to grayish orange, that are rich in Inoceramus prisms; ferruginous streak lying 0.25 foot above base may be weathered bentonite; bentonite seam, dark yellowish orange, 0.06 foot thick, lies 0.8 foot above base. FOSSILS: Inoceramus prefragilis, fish bones and scales | 1.8 |
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45. | Skeletal limestone, pale yellowish brown to grayish orange, with both chalky matrix and sparry calcite cement, brittle, litters slope with slabs, petroliferous odor; rich in Inoceramus shells, prisms and fragments; sole of bed preserves large burrow casts. FOSSILS: Inoceramus prefragilis, mold of large ammonite, fish bones | 0.1 |
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44. | Shaly chalk, all partly weathered light olive gray (5Y6/1) to grayish orange or dark yellowish orange; skeletal limestone bed, pale yellowish brown, petroliferous odor, 0.02-foot-thick, lies 0.55 foot below top. FOSSILS: Inoceramus prefragilis, whole and as fragments, fish scales and bone fragments | 2.3 |
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43. | Bentonite, dark yellowish orange to very light gray, silty | 0.1 |
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42. | Shaly chalk, all partly weathered light olive gray (5Y6/1) to grayish orange or dark yellowish orange. FOSSILS: Inoceramus prefragilis, whole and as fragments, fish scales and bone fragments | 1.95 |
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41. | Limestone, pale yellowish brown, weathering grayish orange, brittle, ledge forming, with 0.05-foot-thick shaly chalk parting near middle, unit litters slope with slabs. FOSSILS: Inoceramus prefragilis, whole and as fragments, fish scales and bones | 0.22 |
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40. | Shaly chalk, mostly weathered grayish orange to yellowish gray (5Y8/1) | 0.15 |
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39. | Bentonite, dark yellowish orange, with shaly chalk parting 0.1 foot above base and about 0.04 foot thick | 0.25 |
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38. | Shaly chalk, mostly weathered grayish orange to yellowish gray (5Y8/1); lensing, skeletal limestone bed, 0.03 foot thick, pale yellowish brown, brittle, lies at top of unit. FOSSILS: Inoceramus prefragilis, whole and as fragments, fish scales and bones | 0.9 |
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37. | Bentonite, nearly white, stained dark yellowish orange by limonite, silty, with some granular selenite | 0.12 |
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36. | Shaly chalk, all weathered light olive gray (5Y6/1) to medium yellowish brown (10YR6/ 4) or grayish orange; selenite streaks, possibly representing weathered bentonite seams, lie 2.8 and 3.15 feet above base; bentonite seam, 0.02 foot thick, lies 0.04 foot below top. FOSSILS: Inoceramus prefragilis, whole and as fragments, fish scales and bones | 5.7 |
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35. | Bentonite and gypsum, dark yellowish orange, silty, gypsum concentrated in upper half; 0.05-foot-thick shaly chalk parting lies near middle | 0.45 |
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34. | Shaly chalk, all weathered light olive gray (5Y6/1) to dark yellowish orange, grayish orange, or pale grayish orange. FOSSILS: Inoceramus prefragilis, mostly whole, mold fragment of large, strongly ribbed ammonite, fish scales and bones | 2.7 |
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33. | Bentonite and gypsum, grayish orange, granular gypsum scattered throughout | 0.22 |
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32. | Shaly chalk, weathered light olive gray (5Y5/2) to grayish orange. FOSSILS: Inoceramus prefragilis, whole and as fragments, fish scales and bones | 1.15 |
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31. | Bentonite, dark yellowish orange, granular selenite prevalent in lower 0.1 foot | 0.2 |
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30. | Shaly chalk, partly weathered to light olive gray (5Y6/1, 5Y5/2) | 3.85 |
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29. | Bentonite, weathered dark yellowish orange, associated with granular selenite | 0.3 |
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28. | Shaly chalk, weathered light olive gray (5Y6/1) to grayish orange. FOSSILS: Inoceramus prefragilis, fish scales and bones | 2.3 |
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27. | Chalky limestone, all weathered grayish orange to dark yellowish orange, brittle, resistant, forms prominent bench, very thin bedded, speckled, crudely laminated. FOSSILS: Inoceramus prefragilis, whole and fragmentary, Inoceramus flavus, Stomohamites? sp. (molds), Eucalycoceras sp. B. (molds), Desmoceras (s.l.) sp. (molds) | 0.6 |
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26. | Shaly chalk, dark olive gray (5Y3/1), in upper half mostly weathered medium yellowish brown (10YR5/2) to grayish orange; 0.05-foot thick seam of granular gypsum lying 0.6 foot above base may represent weathered bentonite. FOSSILS: Inoceramus prefragilis, whole and fragmentary, Eucalycoceras? sp. (mold), Stomohamites? sp., Syncyclonema? sp., fish scales and bone fragments | 5.7 |
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25. | Chalky limestone, olive gray (5Y4/1), weathers grayish orange, thin to very thin bedded, brittle, resistant, forms small bench, speckled, specks aligned parallel to bedding. FOSSILS: molds of small ammonite, fish bone fragments | 0.35 |
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24. | Shaly chalk, dark olive gray (5Y3/1), in part weathered to medium yellowish brown (10YR5/ 2). FOSSILS: Eucalycoceras sp. B (molds), fish scales | 3.7 |
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23. | Chalky limestone, olive gray (5Y4/1), weathers grayish orange, brittle, resistant, forms small ledge, crudely laminated, speckled | 0.14 |
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22. | Shaly chalk, dark olive gray, mostly weathered moderate yellowish brown. FOSSILS: Inoceramus fragments, fish scales | 1.3 |
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21. | Chalky limestone, medium yellowish brown (10YR5/2), weathers pale yellowish orange, resistant, forms projecting ledge, all but middle bed are speckled, specks define crude laminae, unit thin to very thin bedded, grades into overlying shaly chalk; contains sparse limonite nodules scattered in band near middle of unit. FOSSILS: Inoceramus prefragilis, whole and fragmentary, mold of small ammonite, fish scales and bone fragments | 0.65 |
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20. | Shaly chalk, dark olive gray (5Y3/1), weathering medium yellowish brown (10YR5/2); bentonite seams, dark yellowish orange, 0.01 and 0.02 foot thick, lie 0.6 foot above base and 0.01 foot below top, respectively. FOSSILS: Inoceramus prefragilis, whole, Inoceramus fragments, mold of small ammonite, fish scales and bone | 3.2 |
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19. | Bentonite, dark yellowish orange, slightly silty | 0.11 |
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18. | Shaly chalk, dark olive gray, weathers dark yellowish brown; FOSSILS: Inoceramus sp. (juvenile), Syncyclonema? sp., fish scale | 0.6 |
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17. | Bentonite, dark yellowish orange, with associated granular gypsum | 0.1 |
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16. | Shaly chalk, dark olive gray (5Y3/1). FOSSILS: teleost vertebrae (articulated), Syncyclonema? sp. | 0.35 |
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15. | Covered interval, probably shaly chalk | 2.9 |
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Total thickness of Hartland Member (type) | 44.5 | ||
|
Lincoln Member | |||
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|
14. | Chalky limestone, dark olive gray (5Y3/1), weathering grayish orange to dark yellowish orange, brittle, resistant, ledge forming, speckled, has faint petroliferous odor; same unit lies at top of section at Locality 12. FOSSILS: Inoceramus prefragilis, Eucalycoceras sp. B. (juveniles); Stomohamites cf. S. simplex | 0.5 |
| Cut bank on tributary to Arkansas River in sec. 12, T. 25 S., R. 38 W., Kearny County (Locality 12). | ||||
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13. | Shaly chalk, all weathered grayish orange; filled with small very thin lenses of skeletal limestone, pale yellowish brown, sparry calcite cemented, composed mostly of Inoceramus debris; bentonite, 0.07 foot thick, grayish orange, lies at top (also seen beneath unit 14 at Locality 13); bentonite, 0.02 foot thick, nearly white to grayish orange, lies 0.4 foot above base. FOSSILS: Inoceramus prefragilis, whole and as fragments, Syncyclonema? sp., Exogyra aff. E. boveyensis | 4.05 |
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12. | Bentonite, nearly white to dark yellowish orange, flaky | 0.18 |
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|
11. | Shaly chalk, chalky limestone, and skeletal limestone; shaly chalk weathered yellowish gray (5Y8/1) to grayish orange with abundant very thin lenses of light olive gray (5Y6/1) skeletal limestone in upper part; chalky limestone, 0.17 to 0.25 foot thick, lies 0.5 foot below top; chalky limestone, maximum 0.3 foot thick, lenticular light olive gray (5Y5/2) and banded dark yellowish orange by limonite stains, lies 0.2 foot above base; skeletal limestone, light olive gray (5Y6/1) to grayish orange, 0.1 to 0.17 foot thick, arches above lower chalky limestone; 0.1 foot thick lens of similar skeletal limestone lies 0.1 foot above base. FOSSILS: Inoceramus prefragilis, fecal castings on sole of skeletal limestone bed | 1.3 |
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10. | Bentonite, grayish orange to dark yellowish orange, punky, with seams of coarsely granular calcite at top and base | 0.26 |
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|
9. | Shaly chalk, weathered grayish orange to dusky yellow; contains discontinuous seams of granular gypsum less than 0.02 foot thick; up- per 0.4 foot contains very thin lenses of skeletal limestone. FOSSILS: Inoceramus prefragilis, whole and fragments | 1.15 |
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|
8. | Bentonite and gypsum, bentonite nearly white to dark yellowish orange, punky, with seams of selenite at top and base | 0.1 |
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7. | Shaly chalk, weathered grayish orange to dusky yellow; contains 3 seams of gypsum each about 0.01 foot thick; skeletal limestone bed, 0.15 foot thick, thinly cross laminated, well cemented, in part with chalky matrix, and with petroliferous odor, lies 0.2 foot above base. FOSSILS: Inoceramus fragments, fish bones and scales | 0.85 |
|
|
6. | Chalky limestone, mostly weathered grayish orange but in part mottled with medium light gray, brittle, resistant, ledge-forming bed ranging from 0.17 to 0.35 foot thick, speckled, with Inoceramus fragments common; contains large (0.2 foot wide) elliptical masses of calcite that may be recrystallized fossils. FOSSILS: Inoceramus prefragilis, whole and as fragments, fish bones and scales | 0.35 |
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|
5. | Shaly chalk, chalk, chalky limestone, and bentonite, all weathered, mostly grayish orange; chalk bed 0.08 foot thick, 0.23 foot below top, is granular; contains numerous very thin, discontinuous beds and small lenses of chalk limestone, thinly laminated, brittle, speckley; also contains lenses of brittle, thinly laminated to gently cross laminated skeletal limestone having petroliferous odor; chalky limestone, 0.2 foot thick, with undulating base, lies 0.55 foot below top and lies on 0.2-foot-thick bed of locally deformed, very thin bedded chalky limestone or skeletal limestone; bentonite, 0.02 foot thick, grayish orange, punky with thin layer of selenite at top, lies at top of unit. FOSSILS: Inoceramus fragments, fish scale, Acanthoceras wyomingense | 2.55 |
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4. | Shaly chalk, olive black, mostly weathers medium yellowish brown (10YR5/2), dark part not much speckled, less calcareous than weathered part; bentonite, 0.02 foot thick, grayish orange, lies 0.65 foot below top, underlain by 0.02 foot thick gypsum seam; unit contains very thin beds of brittle, thinly laminated chalky limestone scattered throughout the unit. FOSSILS: Inoceramus prefragilis, whole and fragments, cirriped plate, Ostrea beloiti valve, Camptonectes sp., Borissjakoceras? sp. (mold), Desmoceras sp., Pseudocalycoceras? sp. (mold), fish scales and bones, coprolite, chunk of charcoal | 3.05 |
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3. | Bentonite, nearly white to dark yellowish orange with 0.04-foot-thick seam of selenite and jarosite 0.05 foot below top | 0.21 |
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2. | Chalky shale, olive black, mostly weathered medium yellowish brown (10YR6/4), specks less abundant than in typical shaly chalk; contains gritty, thinly laminated chalky limestone bed, 0.04 foot thick, 0.21 foot below top; also contains very thin lenses of laminated, gritty chalky limestone. FOSSILS: Inoceramus fragments, baculitid mold, Inoceramus sp. (juvenile), Desmoceras sp., ammonite fragment (mold), fish scales and bones, chunk of charcoal | 1.6 |
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1. | Chalky limestone, weathered grayish orange, lensing bed, thinly laminated, much speckled, very gritty, passes laterally into chalky skeletal limestone bed. FOSSILS: scraps of vertebrate bones. Bed forms arbitrary base of Greenhorn. Rests on dark olive gray to olive black very impure chalky shale and calcareous shale that is only sparsely speckled and assigned to Graneros Shale | 0.08 |
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Total thickness of Lincoln Member | 16.2 | ||
| Total thickness of Greenhorn Limestone | 135.9 | |||
| Rests conformably and gradationally on Graneros Shale | ||||
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Kansas Geological Survey, Geology
Placed on web June 5, 2010; originally published May 1975.
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