Kansas Geological Survey, Bulletin 223, part 1, originally published in 1981
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| Summary of the Copper Project Drilling Operation | ||||
|---|---|---|---|---|
| Drill Location |
Total Depth of Drilling (in feet) |
Cored Interval (in feet) |
Core Extract (in feet) |
Total Amount of Core Extracted (in feet) |
| 1 | 75.0 | 28.00-35.90 | 7.90 | |
| 51.00-65.10 | 14.10 | 22.00 | ||
| 2 | 151.0 | 39.00-47.42 | 8.42 | |
| 74.00-77.50 | 3.50 | |||
| 77.55-86.50 | 8.95 | |||
| 114.00-119.50 | 5.50 | 26.37 | ||
| 3 | 91.0 | 50.00-58.33 | 8.33 | |
| 59.33-68.33 | 9.00 | 17.33 | ||
| 4 | 151.0 | 119-00-132.70 | 13.70 | 13.70 |
| 5 | 136.5 | 18.00-33.00 | 15.00 | 15.00 |
| 6 | 120.0 | uncored | ||
| 7 | 92.0 | 16.67-24.14 | 7.47 | |
| 51.58-56.70 | 5.12 | |||
| 84.00-91.70 | 7.70 | 20.29 | ||
| 8 | 150.0 | uncored | ||
| 9 | 150.5 | uncored | ||
| 10 | 162.5 | 90.00-98.00 | 8.00 | |
| 105.50-114.00 | 8.50 | |||
| 140.00-154.50 | 14.50 | 31.00 | ||
| 11 | 106.0 | 32.00-47.40 | 15.40 | |
| 59-00-67.50 | 8.50 | |||
| 83.00-91.70 | 8.70 | |||
| 102.00-106.00 | 4.00 | 36.60 | ||
| 12 | 65.0 | 31.50-38.46 | 6.96 | |
| 39.50-45.00 | 5.50 | |||
| 56.00-62.50 | 6.50 | 18.96 | ||
| 13 | 105.0 | 46.50-53.00 | 6.50 | |
| 85.00-98.00 | 13-00 | 19.50 | ||
| 14 | 75.5 | 16.00-32.00 | 16.00 | |
| 35.00-38.33 | 3.33 | |||
| 40.00-49.70 | 9.70 | 29.03 | ||
| 15 | 160.0 | 102.00-112.50 | 10.50 | |
| 116.00-131.33 | 15.33 | |||
| 132.50-136.00 | 3.50 | 29.33 | ||
| 16 | 148.5 | 34.50-38.30 | 3.80 | |
| 44.30-50.00 | 5.70 | 9.50 | ||
| Totals | 1939.5 | 288.61 | ||
| Summary of the Copper Project Drilling Operation | ||||
|---|---|---|---|---|
| Drill Location |
Total Depth of Drilling (in meters) |
Cored Interval (in meters) |
Core Extract (in meters) |
Total Amount of Core Extracted (in meters) |
| 1 | 22.9 | 8.53-10.94 | 2.41 | |
| 15.54-19.84 | 4.30 | 6.71 | ||
| 2 | 46.0 | 11-89-14.45 | 2.56 | |
| 22.56-23.62 | 1.06 | |||
| 23.64-26.36 | 2.72 | |||
| 34.75-36.42 | 1.67 | 8.01 | ||
| 3 | 27.7 | 15.24-17.78 | 2.54 | |
| 18.08-20.83 | 2.75 | 5.29 | ||
| 4 | 46.0 | 36.27-40.45 | 4.18 | 4.18 |
| 5 | 41.6 | 5.49-10.06 | 4.57 | 4.57 |
| 6 | 36.6 | uncored | ||
| 7 | 28.0 | 5.08-7.36 | 2.28 | |
| 15-72-17.28 | 1.56 | |||
| 25.60-27.95 | 2.35 | 6.19 | ||
| 8 | 45.7 | uncored | ||
| 9 | 45.9 | uncored | ||
| 10 | 49.5 | 27.43-29.87 | 2.44 | |
| 32.16-34.74 | 2.58 | |||
| 42.67-47.09 | 4.42 | 9.44 | ||
| 11 | 32.3 | 9.75-14.45 | 4.70 | |
| 17.98-20.57 | 2.59 | |||
| 25.30-27.95 | 2.65 | |||
| 31.09-32.31 | 1.22 | 11-16 | ||
| 12 | 19.8 | 9.60-11.72 | 2.12 | |
| 12.04-13.72 | 1.68 | |||
| 17.07-19.05 | 1.98 | 5.78 | ||
| 13 | 32.0 | 14.17-16.15 | 1.98 | |
| 25.91-29.87 | 3.96 | 5.94 | ||
| 14 | 23.0 | 4.88-9.75 | 4.87 | |
| 10.67-11.68 | 1.01 | |||
| 12.19-15.15 | 2.96 | 8.84 | ||
| 15 | 48.8 | 31.09-34.29 | 3.20 | |
| 35.36-40.03 | 4.67 | |||
| 40.39-41.45 | 1.06 | 8.93 | ||
| 16 | 45.3 | 10.52-11.6-1 | 1.15 | |
| 13.50-15.24 | 1.74 | 2.89 | ||
| Totals | 591.1 | 87.93 | ||
| Location NW NW Sec. 33, T. 28 S., R. 3 W. | |
|---|---|
| Cored Interval meters (feet) |
Core Description |
| 8.53-8-75 (28.00-28.70) |
Thinly bedded, medium-gray, limey shale with lighter colored, more silty laminae. Interval is highly fractured. A minor zone of secondary calcite parallel to the bedding occurs at 8.61 m. Below this interval the shale is massive, possibly the result of reworking. |
| 8.75-9.22 (28.70-30.25) |
Bedded, dense dolomite with thin, limey, medium-gray shale interbeds that are more abundant both near the top and bottom of the interval. At the 8.94 in level, a small amount of malachite mineralization occurs associated with the shale. Lower contact is gradational. |
| 9.22-9.34 (30.25-30.65) |
Medium-gray shale with some interbedded dolomite decreasing toward the bottom. Bedding is faint, but regular. At 9.27 m a 1 cm porous zone occurs, probably the result of salt having been leached out. |
| 9.34-9.52 (30.65-31.25) |
Poorly bedded, medium-gray shale. |
| 9.52-9.60 (31.25-31.50) |
Thin-bedded, light-gray dolomite with minor medium-gray shale. |
| 9.60-9.75 (31.50-32.00) |
Light reddish-brown shale with minor medium-gray shale. The shale is partially mottled, and massive. |
| 9.75-10.18 (32.00-33.40 |
Reddish-brown shale and siltstone interbedded with minor gray and red shale. Bedding is for the most part regular. At 10.06 m some interbedded thin black shales. |
| 10.18-10.23 (33.40-33.55) |
Thin unit marked by a 1-2 cm zone of broken-up and recemented medium-gray shale. Vugs are filled with calcite. Lower part consists of medium-gray shale with some dolomite laminae. |
| 10.23-10.45 (33.55-34.30) |
Thinly bedded reddish-brown shale. Silty beds alternate with more shaly beds; bedding planes are wavy and irregular (possibly due to a higher energy environment). Bottom of the interval is marked by a 1 cm-thick, dark-gray shale. |
| 10.45-10.62 (34.30-34.83) |
Massive maroon silty shale having an abrupt but irregular lower contact. |
| 10.62-10.67 (34.83-35.00) |
Limey maroon shale interbedded with gray shale, and thin, indistinct, small limey laminae. Lower contact is abrupt and regular. |
| 10.67-10.74 (35.00-35.25) |
Massive reddish-brown shale. Some mottling with gray shale. Gray shale becomes more prominent toward the bottom. |
| 10.74-10.82 (35.25-35.50) |
Medium-gray shale with interbedded thin dolomite laminae. Laminae are discontinuous and wavy in appearance. |
| 10.82-10.94 (35.50-35.90) |
Medium-gray, massive shale with minor maroon shale. Some quartz crystals in a fracture. |
| * * * * * | |
| 15.54-15.70 (51.00-51.50) |
Dark-gray shale with thin lighter colored siltstone laminae. The bedding planes are wavy; some burrowing, and evidence of erosion. |
| 15.70-15.93 (51.50-52.25) |
Medium-gray shale with some lighter colored silty laminae and dolomite stringers. Burrowing is evident. |
| 15.93-16.69 (52.25-54.75) |
Dark-gray shale containing minor lighter colored siltstone and dolomite laminae. Laminae are wavy and discontinuous. |
| 16.69-16.92 (54.75-55.50) |
Medium-gray shale with thin (about 1 mm) siltstone laminae that are quite regular. |
| 16-92-17.02 (55-50-55.85) |
Irregularly interbedded gray limestone and medium-gray, limey shale. Between 16.92 and 16.95 m interclasts of limestone, which vary widely in size and shape, are present. Fewer and smaller interclasts of gray shale also occur. The gray shale occurs as wavy beds that are partially disrupted. |
| 17.02-17.14 (55.85-56.25) |
Light-gray limey shale containing lighter colored silty laminae. Small-scale deformational features (load casts) are present. |
| 17.14-17.43 (56.25-57.20) |
Massive medium-gray shale. |
| 17.43-17.47 (57.20-57.30) |
Very fine grained light-gray dolomite. |
| 17.47-17.50 (57.30-57.42) |
Light- to medium-gray, limey shale containing thin (1 mm), wavy and discontinuous, limey, lighter colored siltstone laminae. |
| 17.50-17.57 (57.42-57.65) |
Medium- to dark-gray, reworked, silty shale. Some patches of gypsum near the bottom of the interval. |
| 17.57-17.83 (57.65-58.50) |
Interbedded gypsum and dark-gray shale. A 0.5 cm-thick seam of satin spar occurs at the top of the interval. The lower half consists of 60 percent gypsum beds that are discontinuous and change drastically in thickness. |
| 17.83-18.14 (58.50-59.50) |
Interbedded medium-gray shale and thin, light-gray, discontinuous, silty laminae. Three layers of satin spar from 0.5-2 cm thick occur in the interval. |
| 18.14-18.29 (59.50-60.00) |
Interbedded dark-gray shale and thin laminae of light- to medium-gray siltstone. Microscopic cross-bedding is common in the siltstone. An erosional surface at the top of the section is marked by the cutting out of deformed beds. |
| 18.29-18.43 (60.00-60.45) |
Interbedded gypsum and dark-gray shale in the top half of the interval. Dark-gray shale with minor light- gray interbedded siltstone laminae toward the bottom. |
| 18-43-19.19 (60.45-62.95) |
The interval can be divided into six or seven cycles, each consisting of two units that appear to have both top and bottom erosional contacts. The cycle starts out with a top unit of reworked medium-dark-gray shale, containing broken siltstone chips and pieces of bedding. The lower unit in the cycle consists of dark-gray shale containing discontinuous lighter colored siltstone laminae. The laminae often show cross-bedding and small-scale deformational features. In the bedded part of the fifth cycle from the top, two 1 cm-thick gypsum (satin spar) beds are present. The units making up a cycle thicken toward the top. |
| 19.19-19.51 (62.95-64.00) |
Intermixed dolomite, dolomitic medium-gray shale, and gray shale. The dolomite occurs mainly as interclasts in the cray shale. In places (19.22-19.42 m) the interclasts are so closely packed as to form a more or less continuous layer. |
| 19.51-19.63 (64.00-64.40) |
Near the top of the interval, light- gray dolomitic limestone occurs as interclasts in a medium-gray shale. They increase downward in number and coalesce to form a dense dolomitic limestone. In the lower half several distinct beds up to 1 cm thick, of slightly varying color, occur. The beds are commonly separated by fractures filled with gypsum. |
| 19.63-19.84 (64.40-65.10) |
The top 5.1 cm consist of extensively reworked medium-gray shale followed by 10.3 cm of thinly laminated medium-gray shale and lighter colored siltstone. The lower 6.4 cm consist of dark-gray shale containing medium-gray discontinuous siltstone laminae and one (1 cm) dolomite layer at the bottom. Burrowing is common in this interval. |
| Location SE SW Sec. 35, T. 28 S., R. 4 W. | |
|---|---|
| Cored Interval meters (feet) |
Core Description |
| 11.89-11.99 (39.00-39.33) |
Mottled gray shale containing randomly oriented red shale masses. Unit contains very thin (less than 1 mm), more silty laminae. |
| 11.99-12.22 (39.33-40.08) |
Slightly dolomitic medium-gray shale, laminated with light-gray discontinuous siltstone. Bedding is well developed with only minor disturbances and some cross-beds. |
| 12.22-12.34 (40.08-40.50) |
Medium-greenish-gray shale containing up to 50 percent dolomitic and/or silty dolomitic clasts. Clasts seem to be broken-up dolomitic material. The amount of dolomitic material increases and the clasts become larger toward the bottom of the interval. One large clast (1-2 cm diameter) may have been a filled-in burrow at the top of the sequence. |
| 12.34-12.50 (40.50-41.00) |
Limestone with some light-gray shale mixed in. Bedding is generally regular with some minor waviness. Between 12.29 and 12.48 in, a 1.3 cm zone of lithographic limestone occurs. |
| 12.50-12.60 (41.00-41.33) |
Silty gray-green shale with thin (less than 1 mm) discontinuous light-gray siltstone laminae. In places the shale is oxidized to a reddish-brown color, partially related to mud cracks. Regular gradational lower contact. |
| 12.60-12.80 (41.33-42.00) |
Massive dark-reddish-brown siltstone. Extensively reworked. Sharp regular lower contact. |
| 12.80-12.90 (42.00-42.33) |
Slightly dolomitic, reworked, gray siltstone. |
| 12.90-13.21 (42.33-43.33) |
Mainly a reddish-brown shale with minor siltstone. Between 12.90 and 13.05 in the shale is reworked. Between 13.05 and 13.21 in pieces of broken-up bedding are visible. Between 13.OD' and 13.08 in small interclasts and blebs of gray shale occur. |
| 13.21-13.31 (43.33-43.67) |
Transition zone: reddish-brown and gray shales are interbedded. Bedding is generally not distinct and is frequently reduced to blebs without boundaries. The gray shale content increases toward the bottom of the interval. |
| 13.31-13.41 (43.67-44.00) |
Interbedded, thin, light-gray-green, dolomitic siltstone and shale. Bedding is only moderately well developed. Some small irregular red-shale masses found in this interval. Sharp lower erosional contact. |
| 13.41-13.46 (44.00-44.17) |
Massive purplish-brown shale containing some gray shale blebs in the upper part of the interval. |
| 13.46-13.73 (44.17-45.04) |
Massive, dense, purplish-brown shale. |
| 13.73-13.74 (45.04-45.08) |
Satin spar gypsum bed. |
| 13.74-13.83 (45.08-45.37) |
Dolomite. The top 2.54 cm consists of broken-up clasts of dolomite in a medium-gray shale. In the center, dolomite is predominant. Toward the bottom, dolomite occurs again as clasts in a shale matrix. The amount of shale increases toward the bottom of the interval. Some disturbed bedding is observed. |
| 13.83-14.07 (45.37-46.17) |
Reddish-brown shale mottled with gray shale. The gray, structureless, non-oriented blebs vary in size and shape, but generally are roughly aligned along bedding. Bedding features are absent. Unit is slightly dolomitic. |
| 14.07-14.15 (46.17-46.42) |
Gray shale containing small chips of dolomite. Bedding features are indistinct. The lower contact is abrupt and irregular. |
| 14.15-14.45 (46.42-47.42) |
Massive reddish-brown shale. |
| 22.56-22.58 (74.00-74.08 |
Irregular, structureless, intermixed reddish-brown and gray shale. |
| 22.58-22.64 (74.08-74.29) |
Massive medium-gray shale. Toward the lower contact the dolomite content of the rock increases. The dolomite occurs as small discontinuous masses. |
| 22.64-22.73 (74.29-74.581) |
Alternating medium-dark-gray shale and dolomite. Bedding is fairly regular. Some soft sediment deformation. Between 22.68 and 22.73 in sulfide mineralization occurs, probably consisting of chalcopyrite and bornite. |
| 22.73-22.99 (74.58-75.42) |
Dolomite with thin laminae of medium-dark-gray shale. Bedding is regular. Sulfide mineralization is observed throughout this interval. The lower 5.1 cm consist of beds of broken dolomite in gray shale. Some burrowing is evident. Mud cracks containing sulfides are encountered. Thin sections show alternating shale and carbonate layers. A few veinlets (mud cracks?) filled with coarse-grained carbonate are in contact with coarse irregular opaques. Polished sections examined with reflected light microscopy show the following: 22.77 m: chalcopyrite-bornite 22.80 m: chalcopyrite-bornite minor digenite 22.81 m: chalcopyrite-bornite 22.86 m: chalcopyrite |
| 22.99-23.25 (75.42-76.29) |
Gray-green shale interbedded with thin, discontinuous, lighter colored silty laminae. Bedding varies from wavy to quite disturbed. Some of these disturbances seem to result from burrowing. Near the lower contact, some red shale is mixed with the gray shale. |
| 23-25-23.26 (76.29-76.33) |
Thin layer (1.3 cm) of satin spar (gypsum). |
| 23.26-23.57 (76.33-77.33) |
Gypsum mush with red and gray shale that becomes more gray toward the bottom. |
| 23.57-23.60 (77-33-77.42) |
Dark-gray shale having gypsum-filled fractures. Some lighter, wavy, discontinuous siltstone laminae. |
| 23.60-23.62 (77.42-77.501) |
Reddish-brown shale with thin laminae of lighter red siltstone. |
| * * * * * | |
| 23.64-23.66 (77.55-77.62) |
Gypsum mush mixed with red and gray shale. |
| 23.66-23.72 (77.62-77.83) |
Dark-gray shale with thin wavy laminae of light-gray siltstone. A few red-shale blebs are present. |
| 23.72-24.15 (77.83-79.25) |
Purplish-red shale containing thin, wavy, siltier laminae. Bedding is generally regular, although on a fine scale all laminae are wavy and discontinuous. Cross-bedding can be seen. Rapid thickening and thinning of laminae is common. At 23.93 m and 24.12 m, a thin 1.3 cm layer of satin spar gypsum occurs. Above the satin spar the laminae are broken and disturbed. |
| 24.15-24.22 (79.25-79.46) |
Interbedded and mixed purplish-red shale, lighter colored siltier material and dark-gray shale and siltstone. The top half of the section is disturbed. The lower half of the section consists of discontinuous wavy siltstone laminae alternating with shale. Some burrowing is observed. |
| 24.22-24.30 (79.46-79.71) |
Extensively reworked gray shale. A 1.3 cm bed of broken gray dolomitic siltstone occurs at 24.26 m. |
| 24.30-24.41 (79.71-80.08) |
Interbedded medium-gray and light- reddish-brown shale and siltstone. Bedding is irregular and in places quite disturbed. Burrowing is common. |
| 24.41-24.48 (80.08-80.33) |
Gypsum mush intermixed with gray shale. |
| 24.48-24.65 (80.33-80.87) |
Reddish-brown shale interbedded with thin discontinuous laminae of lighter red siltstone and some gray shale. Bedding is quite regular. |
| 24.65-24.74 (80.87-81.17) |
Mainly reworked dark maroon shale and siltstone. In the middle of the interval is a 2 cm medium-gray shale with minor light-gray siltstone laminae. |
| 24.74-24.88 (81.17-81.62) |
Interbedded medium- and dark-reddish-brown shale and siltstone. The lower 6.4 em consists mainly of disturbed and broken-up dark-gray shale alternating with lighter siltstone laminae. |
| 24.88-25.02 (81.62-82.08) |
The top 3 cm consist mainly of medium-gray massive shale with increasing light-gray siltstone laminae toward the top. This is followed by 10 cm of massive reddish-brown shale showing minor gray mottling mainly toward the top. The lower 3 cm consist of massive medium-gray shale showing some reddish mottling. |
| 25.02-25.12 (82.08-82.42) |
Slightly dolomitic gray shale, finely laminated with lighter gray siltstone and dolomitic siltstone. In detail, the bedding is slightly wavy and discontinuous. |
| 25.12-25.76 (82.42-84.50) |
Medium-gray shale. In places massive, but mostly extensively reworked as evidenced by small differences in coloration. At 25.20 m, a 2 cm zone with a couple of dolomite and/or dolomitic siltstone laminae. From 25.39 to 25.45 m mineralization is observed, which in polished section is shown to be pyrite. |
| 25.76-26.01 (84.50-85.33) |
Dolomite, irregularly bedded with minor discontinuous shale laminae that increase in number toward the top and the bottom. Possibly some desiccation features. From 25.81 m down, some sulfide mineralization. |
| 26.01-26.11 (85.33-85.67) |
Poorly bedded, dark-gray silty shale. Interclasts of lighter gray silty shale are floating in the dark silty shale. |
| 26.11-26.33 (85.67-86.37) |
Gypsum mush and satin spar gypsum interbedded with medium-dark-gray shale. The gray shale appears to be floating in a gypsum matrix. |
| 26.33-26.36 (86.37-86.50) |
Very thinly laminated medium-gray shale. |
| * * * * * | |
| 34.75-34.85 (114.00-114.33) |
Very thinly laminated medium-gray shale and lighter gray siltstone. The siltstone occurs as discontinuous wavy laminae. Rock is slightly salty to the taste. |
| 34.85-35.05 (114.33-115.00) |
Light-gray salty shale. Several salty-tasting beds occur near the base of this generally massive unit. |
| 35.05-35.13 (115.00-115.25) |
Salty gray dolomitic shale becoming mainly dolomite near the center. Bedding is partially disturbed, perhaps the result of soft sediment de- formation or salt leaching. Between 35.10 and 35.13 m, a 2.5 cm salty bed is present with laminae of darker gray shale. |
| 35.13-35.24 (115.25-115.62) |
Gray-green salty shale, thinly laminated with lighter gray siltstone. |
| 35.24-35.36 (115.62-116.00) |
Massive, salty-tasting, gray-green shale. |
| 35.36-35.55 (116.00-116.62) |
Extensively reworked, medium-dark- gray shale. Between 35.38 and 35.43 m the shale has a reddish tint. Scattered throughout the interval are lighter and darker pieces of broken laminae. Salt gives a distinctive brownish speckled appearance. |
| 35.55-35.66 (116.62-117.00) |
Salty, massive, light-gray shale. |
| 35.66-35.77 (117.00-117.37) |
Dark-gray salty shale with distinct broken beds of light-gray, dolomitic, salty siltstone. |
| 35.77-36.00 (117.37-118.12) |
Thinly laminated, silty and salty, light- and dark-colored shale and dolomite. The dolomite is frequently broken up and surrounded by thin shale laminae. Evidence of mud cracks throughout interval. At 35.95 m some vugs are filled with gypsum and barite(?). |
| 36.00-36.15 (118.12-118.62) |
Dark-gray salty shale, interbedded with light-gray siltstone and some salt blebs. |
| 36.15-36.42 (118.62-119.50) |
Gypsum mush and satin spar intermixed with medium-gray shale and salt. Becomes black in color toward the bottom. |
| Location SW NW Sec. 11, T. 28 S., R. 4 W. | |
|---|---|
| Cored Interval meters (feet) |
Core Description |
| 15.24-15.26 (50.00-50.08) |
Intermixed medium- to dark-gray and reddish-brown reworked shale, grading into the unit described below. |
| 15.26-15.37 (50.08-50.42) |
Medium- to dark-gray shale containing discontinuous wavy laminae of light- to medium-gray siltstone in the upper part. Lower part changes to a reddish-brown color and becomes totally reworked. |
| 15.37-15.43 (50.42-50.62) |
Massive grayish to light-reddish-brown shale grading into the unit below. |
| 15.43-15.47 (50.62-50.75) |
Massive medium-gray shale containing an increasing number of reddish-brown spots and grading into the unit described below. |
| 15.47-15.64 (50-75-51.30) |
Massive reddish-brown shale. |
| 15.64-15.70 (51.30-51.50) |
Light reddish-brown and medium-gray shale with wavy, discontinuous, lighter colored siltstone laminae. It seems that the gray shale was oxidized secondarily along bedding planes. Some sulfide in both the red and gray fractions. In the red fraction the sulfide is surrounded by a gray halo. The sulfide is probably the same as that described below. |
| 15.70-15.82 (51.50-51.90) |
Light-medium-gray shale and siltstone. The upper 7.6 cm contain wavy discontinuous siltstone laminae. In the lower half the laminae are disturbed and broken up. The unit grades into dolomite at the bottom. A polished section at 15.78 m contains chalcopyrite-bornite-minor digenite. |
| 15.82-16.07 (51.90-52.71) |
Dolomite interbedded with light- to medium-gray shale and/or dolomitic shale that constitutes about 20 percent of the rock. Shale laminae are continuous and wavy. Dolomite near center of the interval is vuggy. Whole interval is mineralized. A polished section from 15.82 m contains chalcopyrite-bornite-digenite. A thin section from the same depth shows a very fine grained dolomite containing a few opaques. |
| 16.07-16.23 (52.71-53.25) |
Dark-gray dolomitic shale interbedded with wavy dolomite and/or dolomitic siltstone laminae. Bedding seems to have experienced some disturbance. Minor sulfide mineralization is observed in a 1.3 cm zone between 16.07 and 16.08 m. Medium-greenish-gray shale occurs between 16.18 and 16.23 m. |
| 16.23-16.56 (53.25-54.33) |
Slightly dolomitic reddish-brown shale. It is massive with indistinct gray shale beds and gypsum mush toward the bottom. At 16.41 m, 16.46 m, and 16.55 m, 1.3 cm thick satin spar beds occur. |
| 16.56-16.66 (54.33-54.67) |
Dark-gray dolomitic shale, interbedded with wavy discontinuous siltstone laminae. Bottom part of interval is reworked. |
| 16.66-16.70 (54.67-54.79) |
Red gypsum mush mixed with minor amounts of gray shale. A 1 cm satin spar zone is observed at the top of the interval. |
| 16.70-17.04 (54.79-55.90) |
Medium-dark-gray shale, interbedded with lighter colored siltstone laminae that make up about 40 percent of the section. Bedding is wavy and discontinuous, and individual laminae thicken and thin rapidly. |
| 17.04-17.08 (55.90-56.05) |
The above grades into a zone that contains reworked material and is diffusely light-reddish-brown in the center. |
| 17.08-17.27 (56.05-56.67) |
Dark-gray shale interbedded with siltstone laminae that make up about 40 percent of the section. Bedding is discontinuous and wavy; and the laminae thicken and thin. The laminae are generally thicker than in the other parts of the section. A 3 cm dark-black shale unit occurs in the middle and contains very few siltstone laminae. A polished section from 17.19 m contains round chalcopyrite grains and one irregular grain composed of chalcopyrite surrounding pyrite. Sulfides occur throughout the interval. |
| 17.27-17.33 (56.67-56.85) |
Gray gypsum mush with an irregular lower contact. |
| 17.33-17.78 (56.85-58.33) |
Medium-gray shale and light-gray siltstone laminae that make up about 60 percent of the section. Bedding is wavy and discontinuous; and the laminae thicken and thin. Small sulfide grains, probably chalcopyrite, are scattered throughout the interval, but are more concentrated above 17.56 m. |
| * * * * * | |
| 18.08-18.42 (59.33-60.42) |
Gray shale. Between 18.08 and 18.16 m light-gray shale occurs as interclasts (broken-up bedding) in a matrix of darker gray shale. Most of the material seems to be reworked or broken up. Scattered pockets of very fine sulfide grains, which, in a polished section from 18.41 m, are shown to be irregular pyrite grains, occur throughout the interval. |
| 18.42-18.48 (60.42-60.62) |
Light-gray dolomite bed. Bed is composed of irregular individual units that are wavy, partially broken up, and thicken and thin. Very thin shaly laminae separate the dolomite units. The upper and lower contacts are abrupt and irregular. Some sulfide mineralization is observed. |
| 18.48-18.52 (60.62-60.75) |
Dark-gray shale with intensely disturbed bedding. Clasts and stringers of dolomite are present in the section. A polished section from 18.48 m contains spores replaced by pyrite. Pyrite grains also are replaced by chalcopyrite, leaving the center of the grains unaltered. |
| 18.52-18.57 (60.75-60.92) |
Dolomite bed consisting of a number of thin, wavy, partially discontinuous units separated by shaly laminae. Some burrowing and sulfide mineralization are present. |
| 18.57-18.67 (60.92-61.25) |
Interbedded gray and black shales. Small interclasts of dolomite are present in a 2 cm zone at the top of interval. The rest of the interval is extensively reworked and disturbed. Sulfide mineralization occurs throughout as individual grains and as grain aggregates. |
| 18-67-18.77 (61.25-61.58) |
Intermixed dark-gray shale and gypsum mush. |
| 18-77-18.80 (61.58-61.67) |
A 2.5 cm gypsum (satin spar) unit. |
| 18.80-18.81 (61.67-61.71) |
A 1.3 cm gray shale zone. |
| 18.81-18.90 (61.71-62.00) |
Gypsum mush unit with an abrupt lower contact. |
| 18.90-19.15 (62.00-62.83) |
Dark-gray dolomitic shale. Bedding is indistinct but regular with lighter and darker gray shale interbeds in the upper half, while the lower half is more massive. Some sulfide mineralization throughout, which is probably pyrite as in the interval described below. The lower contact is gradational, consisting of gray shale interclasts in an increasingly dolomitic matrix. |
| 19.15-19.20 (62.83-63.00) |
Shaly dolomite. No apparent bedding. A polished section from 19.17 m shows pyrite replacing spores. |
| 19.20-19.23 (63.00-63.08) |
Massive dolomitic gray shale. The lower contact is gradational. |
| 19.23-19.25 (63.08-63.17) |
Dolomite and dolomitic medium-gray shale. Dolomite is partially bedded. In detail, the dolomite beds consist of dolomite in a more shaly matrix. |
| 19.25-19.51 (63.17-64.00) |
Dolomitic dark-gray shale. No apparent bedding, but broken pieces of silty laminae are distributed throughout the interval. At 19.32 m and 19.41 m the amount of dolomite or silty dolomite in the shale increases, giving it a lighter color. Some of the lighter colored silty dolomite occurs as broken pieces in a darker shale matrix. At 19.25 m, a 1.3 cm bed of dolomite with minor sulfide mineralization occurs. Sulfide mineralization, probably pyrite, is in the form of very fine grains, mainly associated with dolomitic zones. The lower contact is gradational. |
| 19.51-19.56 (64.00-64.17) |
Clasts of dolomitic siltstone in a matrix of medium-gray shale. Very fine grains of sulfide are scattered throughout the interval. |
| 19.56-19.66 (64.17-64.50) |
Extensively reworked dolomitic gray shale. |
| 19.66-19.81 (64.50-65.00) |
Dark-gray shale; thinly interbedded with lighter colored siltstone. Siltstone laminae are wavy, and thicken and thin rapidly. The laminae make up about 40 percent of the rock. |
| 19.81-19.94 (65.00-65.42) |
A more massive gray shale with only minor lighter colored siltstone laminae. |
| 19.94-19.98 (65.42-65.54) |
Dark-gray shale intermixed with gypsum mush. |
| 19.98-19.99 (65.54-65.58) |
A 1.3 cm gypsum bed (satin spar). |
| 19.99-20.10 (65.58-65.96) |
Extensively reworked dark-gray shale. Some sulfide (probably pyrite) mineralization is observed. |
| 20.10-20.12 (65.96-66.00) |
A 1.3 cm gypsum unit containing both satin spar and gypsum mush. |
| 20.12-20.14 (66.00-66.08) |
Reworked gray shale containing up to 1 percent sulfides. Sulfide is probably pyrite as identified in the interval 20.42 to 20.50 m. |
| 20.14-20.15 (66.08-66.12) |
A 1.3 cm bed of satin spar gypsum. |
| 20-15-20.18 (66.12-66.20) |
Extensively reworked dark-gray shale. Parts of broken siltstone and shale laminae are visible. |
| 20.18-20.24 (66.20-66.42) |
Medium-gray dolomitic siltstone intermixed with dark-gray shale. |
| 20.24-20.42 (66.42-67.00) |
Dark-gray dolomitic shale, partially interbedded with discontinuous light-gray siltstone laminae. Other parts of the interval are extensively reworked. The lower contact is abrupt. |
| 20-42-20.50 (67.00-67.25) |
Intermixed gypsum mush and gray shale. A polished section from 20.43 m shows round and irregular pyrite grains. |
| 20-50-20.73 (67.25-68.00) |
Medium-gray shale, interbedded with discontinuous wavy siltstone laminae. This interval is partially reworked. Between 20.50 and 20.51 m, a 1.3 cm bed of dark-gray massive shale occurs. The entire section contains sulfide mineralization, probably pyrite, as in the interval described above. At 20.60 m, a 0.6 cm gypsum bed (satin spar) occurs. |
| 20-73-20.79 (68.00-68.21) |
Gypsum mush and satin spar, interbedded with gray shale. |
| 20.79-20.83 (68.21-68.33) |
Dark-gray shale, interbedded with lighter gray siltstone laminae. A polished section from 20.79 m shows spores replaced by pyrite. |
| Location NW NW Sec. 9, T. 31 S., R. 3 W. | |
|---|---|
| Cored Interval meters (feet) |
Core Description |
| 36.27-36.59 (119.00-120.05) |
Massive maroon shale with some gray, generally round (less than 3 mm) patches at the 36.35 m level. These patches look like reaction halos. At this level slickenside is also common. Between 36.50 and 36.55 m discontinuous thin light-colored silty laminae appear. The lower contact is abrupt and regular. |
| 36.59-36.78 (120.05-120.67) |
Light- and medium-gray shale, chaotically intermixed. The lighter shale appears as interclasts floating in the medium-gray shale. Toward the lower contact the unit becomes evenly bedded. The lower contact is abrupt and generally regular. |
| 36.78-37.01 (120.67-121.42) |
Silty limestone interbedded with limey gray shale. Between 36.93 and 37.01 m sulfide mineralization occurs. Sulfide grains appear as growths in vugs and along fractures. Some secondary calcite appears in some of the vugs. The thin gray shale laminae, interbedded with the limestone, form irregular discontinuous wavy beds. The lower contact is abrupt and regular. |
| 37.01-37.16 (121.42-121.92) |
Medium-gray limey shale, thinly interbedded with light-gray silty laminae near both upper and lower contacts. The middle interval of this unit is massive. The lower contact is abrupt and regular. |
| 37.16-37.34 (121.92-122.50) |
Massive light-reddish- gray shale. Up- per third is light-reddish-gray shale, followed by a middle third of light-gray shale and by a lower third of light-reddish- gray shale. Irregular patches of light gray occur in the reddish shale. |
| 37.34-37.55 (122.50-123.21) |
Gypsum mush mixed with minor red and gray shales. Thin satin spar gypsum veinlets cut at all angles through the rock. At the 37.49 m level a 1.3 cm bed of red shale cuts across this section. just above this level gray shale masses occur. The lower contact is abrupt and somewhat irregular. |
| 37.55-37.85 (123.21-124.17) |
Intermixed gray and reddish-brown shale. In the upper half, bedding is indistinct and the units are reworked. In the lower half, bedding becomes quite regular and even. However, coloration does not follow bedding. Bedding is accentuated by lighter colored silty laminae. |
| 37.85-37.92 (124.17-124.42) |
Massive reddish-brown shale. The lower contact is gradational. |
| 37.92-38.01 (124.42-124.71) |
Massive gray shale. The lower contact is abrupt and irregular. |
| 38.01-38.08 (124.71-124.95) |
Dolomitic limestone, irregularly fractured and filled with minor shale. Toward the bottom, larger pieces of shale are imbedded in the limestone. The shale still shows some bedding in these pieces. Barite, in the lower part, fills what may be vugs or pores. |
| 38.08-38.18 (124.95-125.25) |
Well-bedded medium-gray shale with thin (0.5 cm) discontinuous light-gray siltstone units. Small rounded aggregates of gypsum occur in the lower half of the interval within the siltstone units. Cross-bedding and ripple marks are common in this section. |
| 38.18-38.25 (125.2~5-125.50) |
Mainly silty dolomitic gray limestone with some thin (up to 0.5 cm) medium-gray shale intervals. In the center, rounded aggregates and grains of intermixed gypsum occur. Toward the bottom, barite occurs. |
| 38.25-38.35 (125.50-125.83) |
Massive medium-gray shale. The lower contact is quite abrupt and regular. |
| 38.35-39.32 (125.83-129.00) |
Massive reworked reddish-brown shale. Minor gray shale blebs present between 38.50 and 38.56 m. |
| 39.32-40.10 (129.00-131.55) |
Reddish-brown shale and siltstone. The interval can be divided into three cycles. At the top is a shale unit containing broken and disturbed lighter colored siltstone laminae as well as bedded shale. This is followed by a unit that is completely reworked and has a massive appearance. The rock is slightly limey or dolomitic. Cycle I--Disturbed from 39.32 to 39.41 m. Reworked from 39.41 to 39.61 m Cycle II--Disturbed from 39.61 to 39.75 m. Reworked from 39.75 to 39.85 m Cycle III--Disturbed from 39.85 to 39.90 m. Reworked from 39.90 to 40.10 m The lower contact is gradational and irregular. Evidence of post-depositional oxidation. |
| 40.10-40.45 (131.55-132.70) |
Thinly interbedded light- to medium-gray and reddish-brown shales and lighter colored siltstone laminae. In some places bedding is disturbed. The interval becomes more gray and regularly bedded toward the bottom. Thin discontinuous silty laminae become prominent toward the bottom. Filled-in mud cracks occur in the interval. is abrupt and uneven. |
| Location SW SE Sec. 20, T. 31 S., R. 2 W. | |
|---|---|
| Cored Interval meters (feet) |
Core Description |
| 5.49-5.61 (18.00-18.42) |
Reddish-brown shale containing thinly and evenly interbedded lighter colored silty units. |
| 5.61-5.74 (18.42-18.83) |
Interbedded medium-gray and reddish-brown shale containing minor lighter colored silty laminae. Oxidation roughly parallels bedding. |
| 5.74-6.02 (18.83-19.75) |
Reddish-brown shale with minor gray shale blebs. The lower contact is irregular but abrupt. |
| 6.02-6.22 (19.75-20.42) |
Medium-gray shale with thin, discontinuous, light-gray silty stringers. Bedding is quite even. Probable root canals are present. |
| 6.22-6.40 (20.42-21.00) |
Intermixed medium-gray and reddish-brown shale with undulating bedding. Lighter colored silty laminae are common. Oxidation roughly parallels bedding. Mud cracks are common. The cracks themselves are sometimes filled with reddish-brown shale while the rest is gray. |
| 6.40-6.58 (21.00-21.58) |
Reddish-brown shale containing some gray shale blebs scattered throughout. Gray shale is concentrated at the 6.53 m level. The gray shale blebs may be remnants of nonoxidized original material. This interval is heavily bioturbated. |
| 6.58-6.65 (21.58-21.83) |
Light- to medium-gray shale with thin, discontinuous, interbedded silty laminae. |
| 6.65-6.69 (21.83-21.95) |
Mixed medium-gray and reddish-brown shale having even bedding. Oxidation generally follows bedding. Vertical cracks (mud cracks) filled with gray shale are common. |
| 6.69-6.93 (21.95-22.75) |
Interbedded reddish-brown and medium-gray shale. Oxidation patterns are uneven. Bedding is moderately disturbed. This part of the core is poorly preserved. The lower contact appears gradational. |
| 6.93-7.26 (22.75-23.83) |
Slightly limey, medium- to dark-gray shale, with a 5.1 cm black shale bed between 7.01 and 7.06 m. Bedding is even and regular. Minor lighter colored silty laminae. The lower contact |
| 7.26-7.70 (23.83-25.25) |
Massive reddish-brown shale. |
| 7.70-8.23 (25.25-27.00) |
Massive reddish-brown shale. Bedding partially preserved, but most is extensively reworked. |
| 8.23-8.46 (27.00-27.75) |
Extensively reworked, interbedded, gray and reddish-brown shale. Oxidation generally parallels bedding. |
| 8.46-8.58 (27.75-28.15) |
Medium-dark-gray shale containing thin (less than 1 mm) lighter colored silty laminae. |
| 8.58-8.94 (28.15-29.33) |
Reddish-brown shale containing lighter colored, more silty laminae. Bedding is disturbed and part of the section is reworked. The lower contact is gradational. |
| 8.94-9.14 (29.33-30.00) |
Reddish-brown shale containing lighter grayish-red shale that becomes predominant toward the bottom. Oxidation generally follows bedding. Lighter colored silty laminae are common. |
| 9.14-9.22 (30.00-30.25) |
Dolomitic limestone containing red- dish-brown shale giving most of the rock a reddish appearance. At 9.20 in the limestone grades into a medium-gray shale. |
| 9.22-9.40 (30.95-30.83) |
Massive reddish-brown shale. |
| 9.40-9.63 (30.83-31.60) |
Dolomite, becoming a dolomitic limestone toward the bottom. Except for the center 2.5 cm, which is a dense lithographic dolomite, up to 0.6 cm dolomitic beds are separated by thin (about 1 mm) gray shale units. Bedding is regular and seems to be continuous. |
| 9.63-9.75 (31.60-32.00) |
Medium-gray shale and interbedded dolomitic limestone near the top. Mud cracks in the lower part, filled with medium-gray shale, are common. Discontinuous patches of red- dish-brown shale increase toward the bottom where the shale also becomes increasingly oxidized. |
| 9.75-10.06 (32.00-33.00) |
Reddish-brown shale. |
| Location SW NW Sec. 34, T. 31 S., R. 3 W. | |
|---|---|
| Cored Interval meters (feet) |
Core Description |
| 5.08-5.37 (16.67-17.62) |
Massive reddish-brown shale. |
| 5.37-5.59 (17.62-18.33) |
Reddish-brown shale, interbedded with minor thin (up to 2 mm), discontinuous gray shale laminae. The laminae thicken and thin rapidly. Extremely fine laminations of lighter siltstone are also present. The lower contact is abrupt. At 5.56 m, a 0.6 cm gray shale bed occurs. |
| 5.59-5.74 (18.33-18.83) |
Reddish-brown shale. Material is re- worked. Parts of what may have been original bedding are present. Bedding becomes regular toward the bottom. The lower contact is gradational and irregular. |
| 5.74-5.92 (18.83-19.42) |
Reworked medium-gray shale. Con- tact with the upper reddish-brown shale is gradational. The lower contact is abrupt and regular. |
| 5.92-6.01 (19.42-19.71) |
Limestone. A polished section and microprobe analyses of sulfides occurring in a vuggy zone at 6.00 m show covellite replacing anilite and azurite replacing both covellite and anilite. Malachite, in turn, replaces azurite. |
| 6.01-6.08 (19.71-19.96) |
Limestone interbedded with limey- gray shale. Bedding is regular, continuous, and wavy. |
| 6.08-6.28 (19.96-20.62) |
Massive, reworked, medium-gray shale. The upper contact with the limestone is abrupt and regular, while the lower contact with the reddish-brown shale is gradational. |
| 6.28-6.55 (20.62-21.50) |
Limey, light-reddish-brown, reworked shale becoming more silty toward the bottom. The lower contact is abrupt and even. |
| 6.55-6.64 (21.50-21-80) |
Massive medium- gray-green shale. |
| 6.64-6.80 (21.80-22.30) |
Friable, finely intermixed medium- gray and reddish-brown shale. Bedding is poorly developed, with oxidation roughly paralleling bedding. |
| 6.80-7.10 (22.30-23.30) |
Reddish-brown shale with lighter colored discontinuous silty laminae. Irregular patches of grayish-red shale distributed throughout the upper part of the interval. Material is massive and reworked in the lower half of the interval. The lower contact is diffuse but regular. |
| 7.10-7.15 (23.30-23.47) |
Medium-gray shale containing small (up to 1 mm) limestone clasts that are generally aligned along what may be bedding. The upper contact is gradational and even. The lower contact with the limestone is regular and is marked by a 3 cm zone of reworked limestone clasts up to 1 cm in diameter in a gray shale matrix. |
| 7.15-7.17 (23.47-23.54) |
Massive light-gray limestone. The lower contact is abrupt and somewhat irregular. |
| 7.17-7.24 (23.54-23.75) |
Massive, slightly limey, greenish-gray shale. |
| 7.24-7.36 (23.75-24.14) |
Massive reddish-brown shale. |
| 15.72-15.93 (51.58-52.25) |
Massive maroon-colored shale, interbedded with a few partially discontinuous thin gray shale units. Bedding is generally poorly developed due to reworking of the material. |
| 15.93-16.14 (52-25-52.96) |
Dark-gray shale, irregularly interbedded with reddish-brown shale along with a few minor laminae of siltstone toward the bottom. Bedding is more regular toward the bottom. Oxidation of the shale is restricted to the upper half of the unit and is irregular. The lower contact is abrupt and regular. |
| 16-14-16.18 (52.96-53.08) |
Massive, slightly limey, reddish-brown shale. The lower contact is abrupt and regular. |
| 16.18-16.29 (53.08-53.45) |
Interbedded medium-gray shale and silty dolomite. The top half is extensively reworked, becoming more regularly bedded in the lower half. A burrow is visible through the entire interval. |
| 16.29-16.46 (53.45-54.00) |
Mainly light-gray dolomitic limestone. Medium-gray shale beds up to 1.3 cm thick occur at 16.31 m and 16.38 m. Sulfide mineralization occurs at 16.35 m. A thin section from 16.34 m shows extensively reworked gray shale with quartz of two generations between the reworked clasts. Euhedral quartz rims the edges of the formerly open spaces between the interclasts. Second-generation, finer grained quartz fills the rest of the space and corrodes the edges of the euhedral quartz grains. Some opaques are found in the fine-grained quartz. |
| 16.46-16.53 (54.00-54.25) |
Limey black shale with thin discontinuous dolomite laminae. The lower 2.5 cm consist mainly of silty dolomitic light-gray limestone. |
| 16.53-16.95 (54.25-55.62) |
Massive dark-reddish-brown shale. |
| 16.95-16.97 (55.62-55.67) |
A gray-green shale bed. This thin unit is riddled with sulfide grains. Near the lower contact, which is abrupt and regular, the shale becomes predominantly dolomitic. A polished section from 16.95 m shows bornite replacing chalcopyrite. |
| 16.97-17.14 (55.67-56.25) |
The top half is light-gray, poorly bedded, and broken-up dolomitic limestone with interbedded medium-gray shale laminae. Burrowing is evident and mineralization is associated with the burrows. Lower half consists of vuggy silty dolomite and minor shale, with some mineralization. |
| 17.14-17.21 (56.25-56.45) |
Light-gray dolomitic limestone with minor wavy gray shale laminae throughout. Several thin zones have small (1 mm) clasts concentrated within them. |
| 17.21-17.28 (56.45-56.70) |
Massive medium-gray shale showing some color variations related to indistinct bedding. |
| * * * * * | |
| 25.60-26.07 (84.00-85.54) |
Limey, medium to dark, reworked, massive gray shale containing minor wavy silty laminae. In the 25.81 to 25.86 m interval, the number of laminae increases. At 25.98 m, a 1.3 cm gypsum bed occurs; slickensides are present above and below the gypsum bed. |
| 26.07-26.11 (85.54-85.67) |
Massive light-gray shale. The lower contact is gradational. |
| 26.11-26.20 (85.67-85.96) |
Massive light-reddish-brown shale with small (about 2 mm in diameter) gray blebs distributed throughout the interval. The lower contact is gradational. |
| 26.20-26.33 (85.96-86.37) |
Slightly limey, medium-gray shale with minor silty laminae. At 26.33 m, a 1.6 cm gypsum bed (satin spar) occurs. Slickensides are found above and below this unit. |
| 26.33-26.36 (86.37-86.50) |
Massive dark-gray shale. Fractures filled with thin gypsum stringers. |
| 26.36-26.49 (86.50-86.90) |
Dolomitic limestone interbedded and intermixed with medium-gray shale. A couple of shale beds extend across the core. At 26.43 m, a 2.5 cm zone is characterized by iron staining associated with a porous and vuggy unit. |
| 26.49-26.67 (86.90-87.50) |
Medium- to dark-gray shale. Discontinuous dolomite laminae grading into irregular patches lower down occur in the upper 5.1 cm. One 3 mm dolomitic limestone unit occurs at 26.52 m. The rest of the shale is massive and reworked. |
| 26.67-27.10 (87.50-88.92) |
Massive reddish-brown shale with a gradational lower contact. |
| 27.10-27.16 (88.92-89.10) |
Zone consisting of mixed reddish-brown and medium-gray massive shale. |
| 27.16-27.28 (89.10-89.50) |
Massive medium- to dark-gray shale. |
| 27.28-27.65 (89.50-90.72) |
Intermixed medium-gray shale and limey dolomite. The upper contact is quite sharp, whereas the lower contact is more gradational. The interval consists of about half dolomite that occurs as disconnected blebs, generally elongated parallel to the bed- ding. Alternating layers are richer in either carbonate or shale. Some burrowing is observed. Carbonate be- comes dominant in the bottom 5.1 cm. |
| 27.65-27.76 (90.72-91.07) |
Predominantly dolomite with regular thin shale laminae. Some bioturbation is evident. The lower contact is quite abrupt. |
| 27.76-27.86 (91.07-91.42) |
Dark-gray shale with thin (less than 1 mm) dolomitic or silty laminae throughout the interval. |
| 27.86-27.88 (91.42-91.47) |
Gypsum, consisting of satin spar in the lower half. |
| 27.88-27.95 (91.47-91.70) |
Massive medium-gray shale with up to 50 percent disconnected dolomitic limestone blebs in the upper 1.3 cm. |
| Location NE NE Sec. 24, T. 33 S., R. 4 W. | |
|---|---|
| Cored Interval meters (feet) |
Core Description |
| 27.43-27.58 (90.00-90.50) |
Reddish-brown shale with broken-up and disturbed lighter colored silty laminae. |
| 27.58-27.89 (90.50-91.50) |
Reddish-brown shale with alternating minor small gray-green shale units that increase in number toward the bottom. Evidence of mud cracks in the upper part. |
| 27.89-27.94 (91.50-91.67) |
Medium-gray shale. The upper 2.5 cm contain 1 mm discontinuous silty dolomite laminae that make up about 10 percent of the rock. The lower 2.5 cm consist of a mixture of light- gray dolomitic siltstone in a medium- gray shale matrix. The shale matrix is oxidized along an irregular front near the bottom of the interval. |
| 27.94-28.19 (91.67-92.50) |
Reworked reddish-brown shale with worm-like burrows. |
| 28.19-28.27 (92.50-92.75) |
Half medium-gray, half reddish-brown massive shale, irregularly intermixed. |
| 28.27-28.65 (92.75-94.00) |
Massive reddish-brown shale. At 28.57 m the color changes to a darker reddish-brown. Some rounded gray blebs distributed throughout the upper part. Lighter colored silty laminae are present in a few places. |
| 28.65-28.96 (94.00-95.00) |
Interbedded brownish-gray and reddish-brown shale. Discontinuous, wavy, lighter colored silty laminae mark the bedding. Mud cracks and burrows are common. Both upper and lower contacts gradational over a short interval. |
| 28.96-29.87 (95.00-98.00) |
Massive dark-reddish-brown shale with minor gray shale interbeds at 29.41 m. Unit contains small (up to 1 cm) rounded medium-gray reaction halos that frequently have centers with some form of mineralization. At 29.21 m the shale becomes less massive and totally reworked and contains minor amounts of disconnected gray shale chips. At 29.36 m the shale is thinly interbedded with lighter colored silty laminae. Irregular medium-gray blebs and discontinuous gray shale laminae occur between 29.41 and 29.50 m. |
| * * * * * | |
| 32.16-32.26 (105.50-105.83) |
Limey dolomite with small medium-gray shale interbeds mainly near the top of the unit. Sulfide mineralization is clearly visible throughout the interval and is primarily concentrated in vugs, but also occurs as scattered grains in the dolomite and limey gray shales. Secondary quartz is also present in vugs. A thin section from 32.19 m shows interclasts of shale within fine-grained dolomite. |
| 32.26-32.31 (105.83-106.00) |
Dolomitic gray-green shale containing sulfide mineralization. Small elongated pieces of dolomite are scattered throughout the shale. Sulfide grains are much smaller than in the interval above and appear to be diffused throughout. Some of the sulfide grains occur in vertically oriented short stringers, possibly the result of structural control (i.e., burrows). A polished section from 32.31 m contains "chalcocite-like" (probably djurleite or anilite) stringers. A thin section from the same depth contains some unreplaced spores. |
| 32.31-32.38 (106.00-106.25) |
Massive (gray-green shale. The lower contact is uneven but sharp. Sulfides are scattered throughout parts of the unit. |
| 32.38-32.46 (106.25-106.50) |
Mottled reddish-brown shale. Mottling caused by lighter colored grayish irregular blebs. |
| 32.46-32.79 (106.50-107.58) |
Light- to medium-reddish-brown shale. Bedding partially preserved in places becoming more massive below 32.67 m. Between 32.49 and 32.52 m the rock is partially unoxidized and has a medium-gray color. Some small gray reaction halos are present throughout. |
| 32.79-33.02 (107.58-108.33) |
Dark reddish-brown shale. Material is poorly preserved but appears reworked. Fractures and slickensides are common. |
| 33.02-33.53 (108.33-110.00) |
Massive or reworked, dark-reddish-brown shale. At 33.07 m, a 0.6 cm gypsum bed occurs. Slickensides are common. |
| 33.53-33.56 (110.00-110.10) |
Intermixed dark-reddish-brown and gray shale. The gray shale, making up 50 percent of the rock, occurs as broken-up patches in the dark shale and becomes more continuous toward the bottom. |
| 33-56-33.68 (110.10-110.50) |
Interbedded reddish-brown and gray shale showing regular bedding. |
| 33.68-33.86 (110.50-111.10) |
Medium-gray shale and gypsum. Satin spar beds up to 5 mm occur near the top of the unit. Gypsum content increases to 90 percent toward the center and occurs as a mush, then again decreases and forms satin spar beds toward the bottom. At 33.86 m, a 1.9 cm satin spar bed occurs. |
| 33.86-33.88 (111.10-111.17) |
Thinly laminated, medium-gray shale. The lower contact with the red shale is knife-edge sharp. |
| 33.88-33.98 (111.17-111.50) |
Reworked, light-reddish-brown shale mixed with small gray shale blebs, giving, the rock a grayish mottled appearance. Lower contact is gradational. |
| 33.98-34.11 (111.50-111.91) |
Medium-gray dolomitic shale. Broken-up pieces of silty dolomite as well as other reworked fragments occur in the interval. |
| 34.11-34.21 (111.91-112.25) |
Medium-gray shale, interbedded with dolomite. Between 34.11 and 34.14 m the dolomite occurs as broken-up clasts making up about 50 percent of the rock. Between 34.14 and 34.21 m gray shale is interbedded with dolomite beds up to 1.3 cm thick. Sulfide mineralization is observed and is related to a more porous part of the dolomite. The sulfide is probably a "chalcocite-like" phase (djurleite or anilite). |
| 34.21-34.34 (112.25-112.67) |
The upper 3 cm consist of massive medium-greenish-gray shale changing to a mottled greenish-gray and reddish-brown shale. The amount of oxidation increases toward the bottom. |
| 34.34-34.74 (112.67-114.00) |
Massive dark-reddish-brown shale showing small round (up to 0.5 cm) gray reaction halos. |
| * * * * * | |
| 42.67-42.98 (140.00-141.00) |
Six cyclic sequences of purplish-red shale. Each sequence starts at the top with a thinly bedded unit made up of interbedded shale and lighter colored silty laminae, followed by a unit in which the beds are broken up and disturbed. |
| 42-98-43.16 (141.00-141.60) |
Massive dark-purplish-red shale with indistinct fine minor gray mottling. |
| 43.16-43.33 (141.60-142.17) |
The upper 2.5 cm consist of medium-gray shale, containing some lighter colored laminae. Some irregular oxidation has taken place. This is followed downwards by a 6 cm unit of dark-purplish-red shale with minor gray mottling. The lower 5 cm are similar to the upper interval. |
| 43.33-43.49 (142.17-142.67) |
Massive, reworked, dark-reddish-brown shale with minor gray interbedded shale at 43.49 m. Minor gray shale blebs occur throughout. |
| 43.49-43.59 (142.67-143.00) |
Massive dark-reddish-brown shale with minor indistinct gray shale particles. |
| 43.59-43.99 (143.00-144.33) |
Poorly consolidated, massive, dark-reddish-brown shale. Thin fractures filled with gray shale and/or gypsum. |
| 43.99-44.07 (144.33-144.60) |
Medium-gray massive shale containing sulfide mineralization that occurs as scattered grains throughout. Lower contact gradational. |
| 44.07-44.29 (144.60-145.30) |
Light-gray dolomite containing a few greenish-gray shale units and wavy discontinuous shaly laminae throughout. Sulfide mineralization is limited to the interval above 44.23 m and is especially concentrated at the 44.12 m level, where it occurs in vertically aligned cracks up to 3 mm wide (desiccation cracks) in the dolomite. |
| 44.29-44.35 (145.30-145.50) |
Interbedded light-gray dolomite and greenish-gray shale, turning into greenish-gray shale toward the bottom. Sulfide mineralization is essentially limited to the shale. The sulfide is a "chalcocite-like" mineral (probably djurleite-anilite) that is being replaced by covellite. |
| 44.35-44.42 (145.50-145.75) |
Massive dark-reddish-brown siltstone. |
| 44.42-44.60 (145.75-146.33) |
Intermixed medium-gray and red- dish-brown shale, becoming gray toward the bottom. Reddish-brown shale penetrates the gray shale along what were probably mud cracks. Silty discontinuous laminae occur in the gray shale. |
| 44.60-44.70 (146.33-146.67) |
Mainly medium-gray silty shale with lighter colored silty laminae. Bedding is wavy to somewhat irregular. At 44.64 m, a 3 mm gypsum bed occurs. |
| 44.70-44.83 (146.67-147.08) |
Light-reddish-brown shale, irregularly intermixed with medium-gray shale that makes up 10 to 20 percent of the interval. Gray shale occurs as randomly mixed irregular blebs and patches, although in places infilling along mud cracks is suggested. Bedding is indistinct and discontinuous. |
| 44.83-44.86 (147.08-147.17) |
Medium-gray shale with reddish- brown shale filling in mud cracks. |
| 44.86-44.93 (147.17-147.42) |
Mainly a reddish-brown shale with small irregular gray shale blebs. |
| 44.93-44.98 (147.42-147.58) |
Medium-gray shale with reddish-brown shale filling in what are believed to be mud cracks. |
| 44.98-45.06 (147.58-147.83) |
Gypsum mush, containing reddish-brown shale and some satin spar layers. |
| 45.06-45.26 (147.83-148.50) |
Reddish-brown shale interbedded with lighter colored, more silty layers. Bedding is regular. Burrows with reworked material are common. Toward the bottom, some medium-gray shale appears in the section. At 45.09 m, a 0.6 cm satin spar (gypsum) unit. |
| 45.26-45.41 (148.50-149.00) |
Dark-gray and reddish-brown shale interbedded with light-reddish-brown silty laminae whose color changes to light-gray toward the bottom. Bedding is regular. Progressive oxidation starting with the coarser units and also affecting the shale increases toward the top. |
| 45.41-45.54 (149.00-149.42) |
Dark-gray shale with thin light-gray silty laminae. |
| 45.54-45.57 (149.42-149.50) |
One thin (1 cm) reddish-brown layer. Gypsum mush. |
| 45.57-45.82 (149.50-150.33) |
Well-bedded dark-gray shale with thin (1-2 mm) reddish-brown silty laminae as well as some light-gray silty laminae. Load marks and micro-cross-bedding are present. Most of the reddish-brown laminae occur in the 45.66 to 45.75 m interval. |
| 45.82-46.02 (150.33-151.00) |
Massive, limey, reddish-brown shale and light-reddish limestone, giving the unit a mottled appearance. |
| 46.02-46.18 (151.00-151.50) |
Massive limey, gray shale. |
| 46.18-46.33 (151.50-152.00) |
Dolomite, with thin, discontinuous, wavy stringers of greenish-gray shale. Between 46.20 and 46.25 m barite and minor copper sulfide occurs. Barite grains fill vugs and concentrate along bedding planes. Some secondary quartz is associated with barite. |
| 46.33-46.41 (152.00-152.25) |
Upper half is limestone mixed with greenish-gray shale, the amount of which increases toward the bottom. The unit is disturbed and not well bedded. The lower part consists of greenish-gray shale with thin (up to 1 mm) dolomite stringers. Between 46.33 and 46.35 m barite and copper sulfide occurs. |
| 46.41-46.50 (152.25-152.55) |
Medium- to dark-gray dolomitic shale and shaly dolomite intermixed. The upper 2.5 cm is mainly a dark dolomitic shale followed by 1.3 cm of lighter colored shaly dolomite with minor shale stringers. The bottom 2.5 cm is dark-gray dolomitic shale with discontinuous wavy shaly stringers. |
| 46.50-46.53 (152.55-152.67) |
Massive medium-gray shale; the lower contact is gradational. |
| 46.53-46.66 (152.67-153.08) |
Reddish-brown shale with thin lighter colored silty laminae. |
| 46.66-46.69 (153.08-153.17) |
Gypsum, satin spar. |
| 46.69-46.79 (153.17-153.50) |
Massive, mottled, reddish-brown and light-gray shale. The gray shale makes up about 30 percent. Overall color appearance of the unit is reddish-brown. |
| 46.79-46.94 (153.50-154.00) |
Reddish-brown shale with some irregularly distributed, medium-gray shale that is usually associated with gypsum mush. At 46.94 m there is a 0.6 cm gypsum layer. |
| 46.94-46.96 (154.00-154.08) |
Gypsum, mixed with reddish-brown and gray shale. |
| 46.96-47.09 (154.08-154.50) |
Reworked purplish shale and dolomite, irregularly interbedded. Dolomite is mainly concentrated in the center of the unit. |
| Location SW SW Sec. 10, T. 34 S., R. 3 W. | |
|---|---|
| Cored Interval meters (feet) |
Core Description |
| 9.75-9.80 (32.00-32.15) |
Massive, reworked, dark-reddish-brown shale. One medium-gray shale bleb 1.9 cm in diameter included in the reddish-brown shale. |
| 9.80-10.21 (32.15-33.50) |
Extensively reworked reddish-brown shale containing minor gray shale blebs. |
| 10.21-10.53 (33.50-34.55) |
Light reddish-brown shale, extensively reworked. Lighter colored to- ward the bottom. Irregularly distributed light-gray patches up to 2.5 cm make up 10 percent of the rock. |
| 10.53-10.82 (34.55-35.50) |
The upper 6 cm consist of greenish-gray shale intermixed with light-gray dolomite. Below that, the shale occurs as wavy laminae in the dolomite. The amount of shale decreases downward. |
| 10.82-11.12 (35.50-36.50) |
Light-cream to light-reddish dolomite containing irregular thin (up to 1 mm) shale stringers in various orientations. At 10.87 m, a 1.3 cm red- dish-brown limey shale unit. At 10.90 m fossils (brine shrimp). |
| 11.12-11.23 (36.50-36.85) |
Silty light-reddish-brown dolomite containing irregular oxidized reddish-brown patches giving the rock a mottled appearance. Oxidation is roughly aligned along bedding. Thin shale laminae occur throughout. Mud cracks filled with silty dolomite are observed. |
| 11.23-11.55 (36.85-37.90) |
Mainly a light-cream to light-reddish-gray silty dolomite. Minor reddish-brown and gray shaly units and brine shrimp occur throughout the interval. |
| 11.55-11.67 (37.90-38.30) |
Mixed light-gray and reddish-brown shale, giving it a mottled appearance. Some fossils on indistinct bedding planes. |
| 11.67-12.19 (38.30-40.00) |
Friable, massive, dark-reddish-brown shale. A few small gray reaction halos. |
| 12.19-12.28 (40.00-40.30) |
Massive dark-reddish-brown shale. |
| 12.28-12.59 (40.30-41.30) |
Limey light-reddish-brown shale. Between 12.28 and 12.34 m the shale contains thin silty laminae. Gray mottling occurs in this interval. Between 12.34 and 12.59 m the limey light-reddish-brown shale has a mottled appearance due to the amount of intermixed gray shale. Thin-bedded reddish-brown shale with lighter colored, more silty layers characterizes the top 2 cm of the interval. Below that is a zone 6.35 cm thick in which the bedding is wavy and disturbed. The lower part of the interval consists of reworked material. A 2 cm-wide light-gray limey shale marks the bottom of the section. |
| 12.59-12.65 (41.30-41.50) |
Dark, reddish-brown, disturbed, broken-up, friable shale. |
| 12.65-13.00 (41.50-42.65) |
Massive dark-reddish-brown shale. A few small (up to 1 cm) reaction halos in the top and bottom portion. In the center, a distinct disturbed zone, 5.1 cm thick, which is more friable. Bedding is indistinct to non-existent. |
| 13.00-13.17 (42.65-43.20) |
Friable dark-reddish-brown shale, changing to light-reddish-brown near the bottom. Rock is disturbed and mud cracks are common. A couple of 1 mm-thick gypsum stringers occur in the interval. |
| 13.17-13.50 (43.20-44.30) |
Dolomitic limestone, interbedded with light-greenish-gray shale. Between 13.21 and 13.28 m the unit is disturbed, with no observable bedding. About 50 percent limestone. Between 13.28 and 13.33 m limestone interbedded with limey greenish-gray shale. Bedding is broken up and wavy due to soft-sediment deformation. Between 13.33 and 13.38 m mainly dolomitic limestone. Between 13.38 and 13.45 m dolomitic limestone and wavy greenish-gray shale are interbedded. Between 13.45 and 13.50 m massive, limey, greenish-gray shale with small interclasts of limestone; the lower contact is abrupt but irregular. |
| 13.50-13.81 (44.30-45.30) |
Massive, reworked, reddish-brown shale. Some gray reaction halos. Section is highly disturbed, containing angular fragments that are usually somewhat lighter colored. |
| 13.81-13.85 (45.30-45.45) |
Massive light-gray shale. Upper and lower contacts are irregular. Some material that looks like barite is scattered throughout. |
| 13.85-14.05 (45.45-46.10) |
Extensively reworked and disturbed light- and dark-reddish-brown shale containing some gray reaction halos. Bedding, wherever present, is disturbed. |
| 14.05-14.16 (46.10-46.45) |
Light-gray shale containing some lighter colored, discontinuous, silty laminae. At 14.06 m, a 1.3 cm red siltstone bed occurs. Possibly some barite in the section. |
| 14.16-14.45 (46.45-47.40) |
Massive, reworked, reddish-brown shale with gray reaction halos up to 1.3 cm in diameter. |
| * * * * * | |
| 17.98-18.38 (59.00-60.30) |
Massive dark-reddish-brown shale containing some small (up to 2 mm) gray reaction halos. |
| 18.38-18.49 (60.30-60.65) |
Interbedded dark-reddish-brown shale and lighter siltier units. Minor gray mottling. Bedding is wavy and broken up, probably due to burrowing. |
| 18.49-18.79 (60.65-61.65) |
Reworked purplish-red shale. Over most of the interval, lighter colored angular chips (up to 0.5 cm) are surrounded by a darker matrix, probably the result of filling in between and breaking up of mud cracks. |
| 18.79-19.16 (61.65-62.85) |
Interbedded, creamy to light-gray, limey, silty dolomite and greenish-gray to reddish-brown shale. The unit becomes more of a dolomitic limestone toward the bottom of the interval. Oxidation increases toward the top. Between 18.79 and 18.92 m dark-reddish-brown shale having a wavy appearance is interbedded with lesser amounts (40 percent) of creamy-colored, silty, limey dolomite. The top of the section consists of a 2 cm recemented limey zone, probably denoting an erosion surface. Vugs up to 4 cm lined with calcite crystals or partially filled with a limey debris are numerous toward the top, then diminish in size and frequency toward the bottom. The vugs could be the result of evaporates that were leached out of the rock. Between 18.93 and 19.03 m creamy dolomite with greenish-gray discontinuous and wavy shale laminae. The amount of reddish-brown shale is subordinate. Vugs are also less in this interval. Between 19.03 and 19.13 m mainly creamy to light-gray, silty, limey dolomite with greenish-gray shale laminae. Minor amount of reddish-brown shale. Between 19.13 and 19.16 m the amount of oxidized shale and unoxidized shale are about equal; otherwise, the interval is as above. Small vugs still persist. |
| 19.16-19.32 (62.85-63.40) |
Light-gray dolomitic limestone and minor greenish-gray shale, much like the unit above. The shale laminae are discontinuous and broken up. Evidence of some burrowing. |
| 19.32-19.35 (63.40-63.50) |
Silty dolomitic limestone containing subrounded chips of cleaner limestone up to 1 cm in diameter. Unit is very disturbed with no continuous bedding. Toward the bottom, the unit is irregularly oxidized. |
| 19.35-19.43 (63.50-63.75) |
Half light-gray and half reddish- brown, irregularly intermixed shale. Also contains minor (2 mm) gypsum ribbons. |
| 19.43-19.81 (63.75-65.00) |
Friable dark-reddish-brown shale and siltstone. Massive appearance, but may have been extensively reworked. Minor amounts of intermixed gray shale toward the bottom. Also some gypsum stringers. |
| 19.81-20.45 (65.00-67.10) |
Poorly consolidated massive, inter- mixed, medium-gray and dark-reddish-brown shale. Material possibly extensively reworked. Some of the gray shale seems to be filling mud cracks or other fractures. |
| 20.45-20.57 (67.10-67.50) |
Dark-reddish-brown shale containing thin, regular, lighter colored Silty laminae. Some medium-gray shale unevenly distributed throughout, partly related to filling in of mud cracks or fractures. |
| * * * * * | |
| 25.30-25.76 (83.00-84.50) |
Massive dark-reddish-brown shale with a few (less than 0.5 percent) small (1 mm in diameter) gray reaction halos. Abrupt lower contact. |
| 25.76-25.98 (84.50-85.25) |
Silty dolomite and greenish-gray shale intermixed. The gray shale is more prominent in the top half, comprising up to 50 percent of the rock; in the lower half it comprises up to 25 percent. The shale shows a certain degree of bedding, but the laminae are wavy and broken. Some gypsum mixed with the dolomite. |
| 25.98-26.26 (85.25-86.15) |
Interbedded, creamy to light-reddish-gray silty dolomite and reddish-brown shale. The shale generally is well bedded in the top half and becomes disturbed and wavy in the bottom half. Beds are generally about 2 to 3 mm thick, although one 1.3 cm-thick bed is present. Shale makes up about 40 percent of the interval. Some burrowing is apparent. |
| 26.26-26.36 (86.15-86.50) |
Completely disturbed section marked by angular pieces of dark-reddish-brown shale in a light-reddish-brown silty dolomitic matrix. |
| 26.36-26.67 (86.50-87.50) |
Intermixed dark-reddish-brown and greenish-gray shale that makes up about 30 percent of the section. Unit is poorly consolidated and shows no apparent bedding. The gray shale appears in places to be filling in mud cracks. |
| 26.67-26.82 (87.50-88.00) |
Mainly intermixed greenish-gray shale and thin, discontinuous, wavy, lighter dolomitic silty laminae. About 20 percent of the section is oxidized to a reddish-brown color along definite horizons. Some burrows are present. This interval and the one below are similar to the lower half of the 25.98 to 26.26 m and the 26.26 to 26.36 m intervals. Fossil brine shrimp in gray shale at 26.70 m. |
| 26.82-26.93 (88.00-88.35) |
Broken-up, completely disturbed section, marked by dark-reddish-brown angular pieces and parts of broken beds of shale in a lighter colored shale matrix. |
| 26.93-27.31 (88.35-89.60) |
Dark-reddish-brown massive shale. At 27.05 m a 1.3 cm gray shale band having sharp but wavy contacts. Thin stringers of what may be gyp- sum occur in the gray shale. Minor gray irregular patches occur in the interval above 27.05 m. At 27.13 m darker colored angular pieces of shale are enclosed in a lighter matrix. |
| 27.31-27.39 (89.60-89.85) |
Unit characterized by medium-gray shale that contains mud cracks and is broken. The mud cracks and broken pieces are filled in by reddish-brown shale that makes up about 30 percent of the rock. |
| 27.39-27.95 (89.85-91.70) |
Massive dark-reddish-brown shale that is a little more grayish-red at about 27.58 m. Minor amount of small (up to 2 mm) gray reaction halos. Also, one small irregular gray shale unit at 27.68 m. |
| * * * * * | |
| 31.09-31.10 (102.00-102.05) |
Interbedded light-gray shale and dolomite. |
| 31.10-31.73 (102.05-104.10) |
Massive dark-reddish-brown shale changing to gray siltstone at the bottom. The contact is gradational. |
| 31.73-31.77 (104.10-104.25) |
Light-greenish-gray shale with minor dolomite that occurs as irregular patches. |
| 31.77-31.96 (104.25-104.85) |
Mainly dolomite. Throughout the interval, sulfide mineralization occurs in horizontal and vertical fractures as well as in pore spaces. A polished section from 31.93 m shows a veinlet containing a "chalcocite-like" phase (probably djurleite-anilite). Minor thin discontinuous beds of greenish- gray shale. Some secondary mineral, which may be gypsum, occurs with the mineralization. |
| 31.96-32.03 (104.85-105.05) |
Greenish-gray shale. Sulfide mineralization as fairly evenly distributed small grains occurs down to 32.00 m. A polished section from 32.00 m shows pyrite being replaced by a "chalcocite-like" phase (probably djurleite-anilite). |
| 32.03-32.31 (105.05-106.00) |
Massive dark-reddish-brown shale. |
| Location NE NE Sec. 10, T. 34 S., R. 3 W. | |
|---|---|
| Cored Interval meters (feet) |
Core Description |
| 9.60-9.98 (31.50-32.75) |
Massive reddish-brown shale with minor gray reaction halos. At 9.75 m a couple of thin fractures filled with calcite. |
| 9.98-10.29 (32.75-33.75) |
Friable reddish-brown shale crisscrossed with uneven (usually vertical) burrows or mud cracks filled with a lighter reddish-brown shale. Some very thin calcite-filled fractures. |
| 10.29-10.46 (33.75-34.33) |
Reddish-brown shale with thin (up to 2 mm) discontinuous, lighter colored silty laminae that make up 5 percent of the rock. |
| 10.46-10.54 (34-33-34.58) |
Crumbly dark-reddish-brown shale. |
| 10.54-10.60 (34.58-34.79) |
Intermixed light-greenish-gray and light-reddish-brown shale. Bedding is irregular and faint. |
| 10.60-10.66 (34.79-34.96) |
Massive reddish-brown shale. |
| 10.66-10.70 (34.96-35.12) |
Dolomitic light-gray shale. Upper contact is irregular. |
| 10.70-10.77 (35.12-35.33) |
Dolomitic limestone mixed with minor amounts of greenish-gray shale. Unit is porous and contains vugs with secondary calcite. Near the lower contact, greenish-gray shale becomes predominant. Some malachite mineralization associated with vugs and pores. |
| 10.77-11.05 (35.33-36.25) |
Massive reddish-brown shale. |
| 11.05-11.10 (36.25-36.42) |
Dark-reddish-brown shale containing irregular gray shale patches that make up 35 percent of the rock. |
| 11-10-11.18 (36.42-36.67) |
Massive dark-reddish-brown shale. |
| 11.18-11.25 (36.67-36.92) |
Massive light-reddish-brown shale turning into light-gray shale. |
| 11.25-11.30 (36.92-37.08) |
Massive light-gray shale. |
| 11.30-11.38 (37.08-37.33) |
Argillaceous dolomitic limestone with malachite staining along bedding planes and some fine copper sulfide grains scattered throughout. Rock is vuggy and porous with mineralization concentrated in those areas. |
| 11.38-11.47 (37.33-37.63) |
Friable, massive, limey, light-greenish-gray shale. Mineralization, possibly a "chalcocite-like" phase, is found throughout. |
| 11-47-11.72 (37.63-38.46) |
Massive reddish-brown shale. The upper contact is gradational. Slickenside surfaces present. |
| * * * * * | |
| 12.04-12.12 (39.50-39.75) |
Thinly laminated, limey, light-gray shale. The top 2 mm are more silty and massive. |
| 12.12-12.31 (39.75-40.40) |
Medium-gray limey shale with lighter colored silty laminae. Between 12.20 and 22.22 m some reddish shale occurs. Below 12.24 m shale has good parting resulting from 1 mm-thick calcite layers that make up 50 percent of the rock. |
| 12-31-12.34 (40.40-40.50) |
Massive light-purplish-brown shale. |
| 12-34-12.52 (40.50-41.08) |
Massive reddish-brown shale. Minute gray reaction halos scattered throughout. |
| 12-52-12.72 (41.08-41.75) |
Friable reddish-brown shale with small gray reaction halos scattered throughout the interval. Unit becomes massive toward the bottom. |
| 12-72-13.26 (41.75-43.50) |
Massive reddish-brown shale with gray reaction halos up to 0.5 cm in diameter that are most prominent between 1.3.04 and 13.15 m. |
| 13.26-13.28 (43.50-43.58) |
Massive reddish-brown dolomitic shale. |
| 13.28-13.44 (43.58-44.08) |
Massive reddish-brown silty shale, irregularly mixed with gray shale and a 2 mm layer of predominantly gray shale. |
| 13.44-13.49 (44.08-44.25) |
Friable reddish-brown shale with a few gray reaction halos. Toward the lower contact the shale is broken up and gray shale is intermixed. |
| 13.49-13.72 (44.25-45.00) |
Alternating light- and dark-gray shale, somewhat reddish in a few places. Ripple marks observed. Minor lighter colored silty laminae. |
| * * * * * | |
| 17.07-17.75 (56.00-58.25) |
Reddish-brown shale. Between 17.07 and 17.35 m bedding is irregular and appears to be disturbed (root casts and possibly stromatolites). Between 17.35 and 17.44 m the shale is interbedded with lighter colored, more silty laminae. Bedding is disturbed by root casts. Between 17.44 and 17.70 m the shale is massive. Between 17.70 and 17.71 m a satin spar (gypsum) bed. Between 17.71 and 17.75 m the shale is massive, with gypsum along fracture planes. |
| 17.75-17.81 (58.25-58.42) |
Intermixed reddish-brown and gray silty shale. |
| 17.81-17.89 (58.42-58.71) |
Massive light-gray shale with minor lighter colored silty laminae. |
| 17.89-17.96 (58.71-58.92) |
Dolomite, massive, with minor gray shale. |
| 17.96-18.03 (58.92-59.17) |
Medium-gray shale, interbedded with lighter colored, more silty laminae. |
| 18.03-18.19 (59.17-59.67) |
Intermixed medium-gray and red- dish-brown shale. Bedding is quite disturbed but becomes more regular toward the bottom. |
| 18.19-18.67 (59.67-61.25) |
Reddish-brown shale containing lighter colored, more silty laminae and several thicker beds (up to 1.3 cm thick) consisting of silt or very fine grained sand. |
| 18.67-19.05 (61.25-62.50) |
Massive reddish-brown shale. |
| Location NE NE Sec. 6, T. 33 S., R. 3 W. | |
|---|---|
| Cored Interval meters (feet) |
Core Description |
| 14.17-14.83 (46.50-48.67) |
Reddish-brown shale containing gray reaction halos between 14.17 and 14.63 m. Between 14.17 and 14.48 m the unit is massive and contains numerous gray reaction halos up to 1 cm in diameter. Between 14.48 and 14.83 m the unit is more friable. |
| 14.83-14.86 (48.67-48.75) |
Interbedded reddish-brown and gray shale forming a gradational contact with the unit below; this interval of core is poorly preserved and bedding appears to be irregular. |
| 14.86-14.99 (48.75-49.17) |
Massive medium-gray shale with a few thin limey stringers. |
| 14.99-15.06 (49.17-49.42) |
Limestone, containing up to 1 percent malachite grains and stains concentrated along fractures and in vugs. Unit is porous and vuggy. |
| 15.06-15.19 (49.42-49.83) |
Friable, limey, greenish-gray shale with thin limestone interbeds. |
| 15.19-15.29 (49.83-50.17) |
Massive reddish-brown shale with sharp upper and lower contacts. |
| 15.29-15.54 (50.17-51.00) |
Massive light-reddish-brown shale. Contains burrows of some kind. |
| 15.54-15.67 (51.00-51.42) |
Friable, mixed, limey, light-reddish- brown and gray shale. |
| 15.67-15.77 (51.42-51.75) |
Dolomitic limestone, unevenly bedded with thin laminae of gray shale. Small limestone interclasts are scattered throughout the interval. Considerable calcite crystal growth in vugs. |
| 15.77-15.85 (51.75-52.00) |
Friable, limey, light-gray shale. Some reddish-brown shaly laminae. Evidence of mud cracks filled with reddish-brown shale. |
| 15.85-16.15 (52.00-53.00) |
Reddish-brown shale with minor limey gray shale intermixed. Unit has a mottled appearance. Lighter colored silty laminae increase toward the bottom. The amount of gray increases to 30 percent toward the bottom. |
| * * * * * | |
| 25.91-25.98 (85.00-85.25) |
Massive dark-reddish-brown shale. The lower contact with a gypsum bed is abrupt. |
| 25.98-26.00 (85.25-85.29) |
A 1.3 cm gypsum bed (satin spar) plastically deformed after deposition. |
| 26.00-26.11 (85.29-85.67) |
Massive light-gray shale. Sulfide mineralization dispersed throughout and occurring as short stringers perpendicular to the bedding. The lower contact is gradational. A polished section from 26.03 m shows a "chalcocite-like" phase. |
| 26.11-26.39 (85.67-86.58) |
Dolomite. Between 26.29 and 26.31 m a thin band of gray interbedded shale is present. Sulfide mineralization is found throughout this dolomite unit, tending to concentrate at two levels: (1) a 1.3 cm thick unit at 26.14 m; (2) a 0.6 cm thick unit at 26.28 m. Some sulfide grains are found in vugs. The lower contact is abrupt. |
| 26.39-26.42 (86.58-86.67) |
Massive light-purplish-brown shale. The lower contact is gradational. |
| 26.42-26.49 (86.67-86.92) |
Mainly massive medium-gray shale with some lighter colored, more silty laminae. |
| 26.49-26.64 (86.92-87.42) |
Interbedded medium-gray limey shale and limestone. Between 26.54 and 26.64 m "chalcocite" mineralization occurs mainly as short stringers and undefined patches. Often the stringers are perpendicular to bedding. Between 26.59 and 26.64 m the unit is well bedded. The lower contact is abrupt. |
| 26.64-27.43 (87.42-90.00) |
Mainly dark-reddish-brown shale. Part of the core is poorly preserved. Between 27.13 and 27.43 m some gray chips and gypsum (satin spar) fragments occur. At 27.07 m a 1.3 cm interval containing some dark-gray shale occurs. |
| 27.43-27.74 (90.00-91.00) |
Dark-reddish-brown shale containing lighter colored and some grayish, more silty laminae. |
| 27.74-27.87 (91.00-91.45) |
Dark-gray shale containing lighter colored, more silty laminae. |
| 27.87-27.91 (91.45-91.58) |
Medium-gray shale with light-red- dish-brown, more silty interbeds. The silty units, having a slightly greater porosity, are preferentially oxidized. |
| 27.91-27.94 (91.58-91.67) |
Gypsum mush, intermixed with gray and reddish-brown shale. |
| 27.94-28.17 (91.67-92.42) |
Dark-gray shale containing lighter colored (some reddish-brown), more silty laminae. Lower contact is gradational. |
| 28.17-28.27 (92.42-92.75) |
Intermixed dolomitic limestone and medium-gray shale, becoming reddish-brown toward the bottom. Lower contact is gradational. |
| 28.27-28.65 (92.75-94.00) |
Purplish-brown shale, slightly limey in places. Mainly reworked or massive. Between 28.27 and 28.32 m the shale is reworked and contains a few discontinuous, lighter colored, more silty laminae. At 28.57 m a minor gray shale is interbedded. The lower contact with the gray shale is abrupt. |
| 28.65-28.80 (94.00-94.50) |
Massive limey, medium-gray shale with limestone interclasts dispersed throughout the upper half. |
| 28.80-29.06 (94.50-95.33) |
Limestone with thin interbeds of limey gray shale. Sulfide mineralization and barite occur between 28.91 and 28.99 m. Sulfides and barite are observed filling the same vugs. A few small pyrite and "chalcocite-like" grains are present in a polished section from 28.80 m. A thin section from the same depth shows quartz veinlets containing opaques within the carbonate. The shale laminae are wavy. Limestone is quite argillaceous in the upper part. |
| 29.06-29.13 (95.33-95.58) |
Light- and dark-gray shale chaotically mixed with limestone interclasts. Sulfide mineralization is observed only in the light-gray shale and limestone. In a polished section from 29.08 m an unreplaced spore and a "chalcocite-like" grain are visible. |
| 29.13-29.18 (95.58-95.75) |
Laminated medium-gray shale. |
| 29.18-29.41 (95.75-96.50) |
Reddish-brown shale with minor gypsum beds and thin, discontinuous, gray shale laminae. Between 29.26 and 29.28 m, a 2.5 cm gypsum bed (satin spar). Between 29.39 and 29.41 m the shale contains irregular gray shale blebs that are more prominent in the lower half. |
| 29.41-29.46 (96.50-96.67) |
Intermixed gypsum mush and gray shale, which becomes more reddish-brown toward the bottom. Fractures are filled with satin spar gypsum. |
| 29.46-29.54 (96.67-96.92) |
Massive dark-reddish-brown shale. |
| 29.54-29.64 (96.92-97.25) |
Intermixed, light-reddish-brown shale and argillaceous dolomite. Material completely reworked. Lower contact is gradational. |
| 29.64-29.77 (97.25-97.67) |
Intermixed medium-gray shale and argillaceous dolomite. Material completely reworked. |
| 29.77-29.87 (97.67-98.00) |
Massive, reworked, dark-reddish-brown shale. |
| Location NE SE Sec. 13, T. 31 S., R. 6 W. | |
|---|---|
| Cored Interval meters (feet) |
Core Description |
| 4.88-4.93 (16.00-16.17) |
Poorly consolidated gray shale having a gradational lower contact. |
| 4.93-4.96 (16.17-16.29) |
Massive, reddish-brown, silty shale. Gradational lower contact. |
| 4.96-5.05 (16.29-16.58) |
Intermixed, poorly consolidated, massive, reddish-brown and gray silty shale. |
| 5.05-5.67 (16.58-18.62) |
Massive, reddish-brown, silty shale. Sharp lower contact. |
| 5.67-5.81 (18.62-19.08) |
Calcareous, light-gray, silty shale; evenly and thinly bedded. |
| 5.81-6.10 (19.08-20.00) |
Mixed light-reddish-brown and gray silty shale. Lighter colored siltstone laminae are present in places. Gradational upper and lower contact. |
| 6.10-6.96 (20.00-22.83) |
Massive, reddish-brown, silty shale. |
| 6.96-7.01 (22.83-23.00) |
Poorly consolidated, greenish-gray, silty shale. |
| 7.01-7.31 (23.00-24.00) |
Intermixed reddish-brown and gray silty shale. |
| 7.31-7.72 (24.00-25.33) |
Massive, dark-reddish-brown, silty shale. |
| 7.72-7.92 (25.33-26.00) |
Mainly reddish-brown silty shale with minor gray shale intermixed, some of which may be related to mud crack infillings. |
| 7.92-8.09 (26.00-26.54) |
Massive, light-reddish-brown, silty shale. |
| 8.09-8.63 (26.54-28.33) |
Interbedded medium-gray shale and lighter colored gray dolomitic and/or silty laminae. Sharp upper and lower contact. |
| 8.63-8.79 (28.33-28.83) |
Poorly consolidated, light-reddish- brown silty shale. Minor gray shale is present as diffuse small patches or stringers. Lower contact is gradational. |
| 8.79-8.85 (28.83-29.04) |
Massive, reworked, light-gray shale that is in the middle of the interval partially oxidized to a reddish-brown color. |
| 8.85-9.30 (29.04-30.50) |
Irregularly intermixed, reddish- brown and gray silty shale and siltstone. Solution cavities are common. |
| 9.30-9.75 (30.50-32.00) |
Massive, dark-reddish-brown, silty shale. |
| 10.67-11.07 (35.00-36.33) |
Poorly consolidated, massive greenish-gray shale. |
| 11.07-11.28 (36.33-37.00) |
Diffuse and irregularly intermixed light-gray and reddish-brown silty shale. |
| 11.28-11.68 (37.00-38.33) |
Light-reddish-brown silty shale, thinly laminated with more silty units, Between 11.48 and 11.63 m the unit is more grayish-red and becomes dark-reddish-brown below that. |
| * * * * * | |
| 12.19-12.40 (40.00-40.67) |
Poorly consolidated light-reddish-brown siltstone with faint gray blebs. |
| 12.40-12.60 (40.67-41.33) |
Poorly consolidated, irregularly intermixed, light-gray and light-reddish-brown siltstone. |
| 12.60-12.75 (41.33-41.83) |
Massive, poorly consolidated, reddish-brown siltstone. |
| 12.75-12.80 (41.83-42.00) |
Mainly medium-gray silty shale with a diffuse upper contact and irregular lower contact. Minor oxidation in places. |
| 12.80-12.90 (42.00-42.33) |
Massive, reddish-brown, silty shale, with minor intermixed gray silty shale. |
| 12.90-12-99 (42.33-42.62) |
Light-gray, calcareous, silty shale. Irregular lower contact. |
| 12.99-13.26 (42-62-43.50) |
Light-reddish-brown and gray silty shale, irregularly intermixed. |
| 13.26-13.47 (43.50-44.20) |
Poorly consolidated, massive, calcareous, light-gray, silty shale. Sharp lower contact. |
| 13.47-13.77 (44.20-45.17) |
Medium-gray shale with minor, more silty, lighter colored laminae in the top half. Lower contact gradational. |
| 13.77-13.97 (45.17-45.83) |
Reddish-brown and gray shale intimately intermixed. Slickensides present. |
| 13-97-14.17 (45,83-46.50) |
Calcareous light-gray shale with thin (less than 1 mm) lighter colored silty laminae. Some secondary calcite in fractures and vugs. |
| 14.17-14.38 (46.50-47.17) |
Irregularly intermixed, reddish-brown and gray, calcareous siltstone. Upper contact gradational. Lower contact abrupt. |
| 14.38-14.65 (47.17-48.08) |
Calcareous, light-gray, silty shale. |
| 14-65-14.69 (48.08-48.20) |
Intermixed, reddish-brown and gray, calcareous, silty shale. Has the appearance of a caliche laver and is poorly consolidated. |
| 14.69-15.01 (48-20-49.25) |
Irregularly and diffusely intermixed medium-gray and purplish-brown massive shale. |
| 15.01-15.15 (49.25-49.70) |
Irregularly intermixed, poorly consolidated, calcareous, reddish-brown and greenish-gray silty shale. |
| Location NE NE Sec. 9, T. 31 S., R. 6 W. | |
|---|---|
| Cored Interval meters (feet) |
Core Description |
| 31.09-31.89 (102.00-104.62) |
Massive reddish-brown shale. Small and minor gray siltstone laminae are also present. There is some gypsum along fracture surfaces with possibly some copper mineralization between 31.55 and 31.70 m. Fractures with gray walls are common. Between 31.70 and 31.89 m some gypsum, mainly along planes cutting bedding features. Between 31.83 and 31.89 m gray shale interclasts and undulating laminae occur in the reddish-brown shale. The lower contact is gradational. |
| 31.89-32.00 (104.62-105.00) |
Medium-gray shale with wavy, discontinuous, more silty laminae. The entire interval is riddled with black specks, but because they are so minute in size their identity is difficult to determine. The lower contact is gradational. |
| 32.00-32.41 (105.00-106.33) |
Reddish-brown shale, massive and extensively reworked. The upper contact is quite irregular. Numerous small interclasts of gray and reddish-brown shale scattered throughout. Some rounded gypsum blebs are also found within this unit. |
| 32.41-32.71 (106.33-107.33) |
Interbedded medium-gray shale and lighter colored silty laminae that make up 50 percent of the unit. Minor laminae of reddish-brown shale are also present. The laminae thicken and thin and are wavy. At 32.60 m a fair amount of a "chalcocite-like" phase occurs in fractures. The occurrence of "chalcocite-like" material in this fashion is common throughout the interval. A polished section from 32.67 m contains pyrite partially replaced by a "chalcocite-like" phase. |
| 32.71-32.80 (107.33-107.62) |
Massive, reworked, reddish-brown shale with a gradational lower contact. |
| 32.80-32.88 (107.62-107.87) |
Massive medium-gray shale. Between 32.85 and 32.88 m the shale becomes darker and is interbedded with lighter gray, more silty laminae. Thin laminae of copper sulfides occur at this level. These sulfide layers are interrupted by small-scale faulting and do not extend across the thickness of the core. Copper sulfide occurs all through the interval, becoming greater in concentration to- ward the bottom. A polished section from 32.83 m contains round grains of a "chalcocite-like" phase. A thin section from the same depth contains opaque grains grown together to form a more or less continuous band. |
| 32.88-32.93 (107.87-108.0,4) |
Massive, reworked, dark-reddish-brown shale, containing thin lighter colored streaks. |
| 32.93-33.12 (108.04-108.67) |
The upper half consists of interlaminated light-gray siltstone with lesser medium-gray shale. Laminae are wavy, discontinuous, and show crosscutting relationships. Two beds consist mainly of light-gray siltstone. The lower half consists of reworked medium- dark-gray shale and minor broken-up silty laminae. Bedding dips at about 10°. Lower contact is gradational. |
| 33.12-34.04 (108.67-111.67) |
Mainly massive dark-reddish-brown shale with masses of gray shale intermixed. This interval is extensively reworked. It appears that gray material is progressively oxidized. Some patches of original laminae and beds are still recognizable. At 33.32 m, a 0.6 cm gypsum bed occurs (satin spar) together with gypsum mush. At 33.66 m is more gypsum mush. Between 33.98 and 34.04 m dark-gray shale and gypsum are intermixed with the dark-reddish-brown shale and make up about 20 percent of the unit. The unit is broken up, possibly due to dissolution processes. The lower contact is sharp and is marked by a thin bed of gypsum. |
| 34.04-34.22 (111.67-112.29) |
Light-gray siltstone interbedded with medium-gray shale. Bedding is disturbed by burrowing and small fractures. Minor sulfide grains occur at the 34.19 m level. The lower 2.5 cm consists of reworked medium-gray shale. |
| 34.22-34.29 (112.29-112.50) |
Massive, reworked, dark-reddish-brown shale. |
| * * * * * | |
| 35.36-35.46 (116.00-116.33) |
Mixed reddish-brown and medium-gray shale with lesser amounts of lighter colored, more silty material. This interval is extensively reworked. Some generally discontinuous patches of laminated material distributed throughout. |
| 35.46-35.88 (116.33-117.71) |
Mixed reddish-brown and medium-dark-gray shale. Gypsum in the form of patches, veinlets, and satin spar beds up to 0.5 cm thick makes up 25 percent of the interval. Soft sediment deformation is prominent. However, in one place disturbed bedding is clearly visible. |
| 35.88-36.04 (117.71-118.25) |
Reddish-brown shale that is quite disturbed, probably the result of soft sediment deformation. Gypsum mush makes up about 15 percent of the interval. |
| 36.04-36.14 (118.25-118.58) |
Intermixed dark-gray and minor reddish-brown shale. A gypsum (satin spar) bed of 1 cm and also gypsum mush in the interval. |
| 36.14-36.42 (118.58-119.50) |
Mainly gypsum mush (70 percent) throughout with a few satin spar beds. Reddish-brown and medium-gray shale surrounds and is caught up in the mush. |
| 36.42-36.86 (119.50-120.92) |
Interbedded shale and lighter colored silty units that make up about 50 percent of the interval. About half of the unit is oxidized to a reddish-brown color. The oxidation generally follows thin beds and laminae. The rest of the shale is light-greenish-gray and the silty units are light-gray. Minor gypsum, filling fractures, occurs near the top of the interval. The silty units occur as thin beds and laminae that are mostly wavy and discontinuous. Crosscutting features are common. Burrowing also observed. Pyrite occurs between 36.42 and 36.50 m. |
| 36.86-37.01 (120.92-121.42) |
The upper 7.6 cm consists of medium-gray shale. This material is extensively reworked. The lower portion is more reddish-brown in color. The lower contact is irregular and is marked by a 0.6 cm satin spar bed. |
| 37.01-37.49 (121.42-123.00) |
Mainly a reddish-brown shale with some blotchy grayish shale interbedded. Gray shale seemingly was progressively oxidized. Broken-up parts of lighter colored, more silty laminae are present. There is a minor amount of gypsum mush present throughout most of the section. Most of the interval is extensively reworked and/or deformed. |
| 37.49-37.62 (123.00-123.42) |
Intermixed medium- to dark-gray and light-reddish-brown shale and gypsum (about 10 percent). The top 1.3 cm consists of a dark-gray shale. The interval is extensively reworked. It seems as if the gray is being progressively oxidized. |
| 37.62-37.72 (123,42-123.75) |
Interbedded medium-gray shale and lighter colored silty laminae. The interbedding is mainly in the form of laminae on the order of 1 to 2 mm. The laminae are discontinuous and crossbedding is common. A 3 mm satin spar bed is observed. Some "chalcocite-like" mineralization is present in the siltstone. |
| 37.72-37.92 (123.75-124.42) |
Medium-gray massive, reworked shale. Pieces of laminated material can be recognized. Some gypsum patches are found throughout the interval. An irregular area of light-reddish oxidized material occurs near the bottom. |
| 37.92-38.25 (124.42-125.50) |
Massive, reworked, light-reddish-gray shale. |
| 38.25-38.40 (125.50-126.00) |
Massive, reworked, medium-gray shale. Broken-up shale and silty laminae increase in number toward the bottom. Lower contact irregular. |
| 38.40-38.91 (126.00-127.671) |
Massive intermixed medium-gray and dark-reddish-brown shale that makes up about 5 percent of the interval. The unit becomes more gray and silty toward the bottom. |
| 38.91-39.07 (127.67-128.20) |
Mixed medium-reddish-brown and gray shale. This interval has been extensively reworked as evidenced by streaks and patches of broken-up laminated beds. |
| 39.07-39.32 (128.20-129.00) |
Massive, reworked, medium-gray shale being diffusely and irregularly oxidized to a reddish-brown color that makes up about 45 percent of the unit. A 2.5 cm thick unit of gypsum, as satin spar and mush, occurs near the center of the unit. |
| 39.32-39.71 (129.00-130.30) |
Massive, reworked, dark-reddish-brown shale containing small (less than 3 mm), often diffuse, gray shale patches. Slickensides are common. |
| 39.71-39.81 (130.30-130.62) |
Reworked medium-gray shale having gradational lower and upper contacts. |
| 39.81-39.93 (130.62-131.00) |
Intermixed greenish-gray shale and gypsum in the form of satin spar and mush. |
| 39.93-40.03 (131-.00-131.33) |
Massive greenish-gray shale with minor fractures filled with gypsum. Also some small (less than 2 mm) dissolution cavities. |
| * * * * * | |
| 40.39-40.54 (132.50-133.00) |
Interbedded medium-gray shale and lighter colored gray siltstone. The siltstone is in the form of thin (up to 3 mm) beds and laminae that are discontinuous and wavy, and show crosscutting relationships. Some very fine grained "chalcocite-like" grains are observed in the siltstone and shale in the lower half of the unit. |
| 40.54-40.77 (133.00-133.75) |
Mainly reworked and massive medium-gray shale and minor lighter colored siltstone laminae. Minor "chalcocite-like" mineralization is observed throughout, but appears to be more concentrated in the lower 2.5 cm. |
| 40.77-41.02 (133.75-134.58) |
Mainly a light-gray reworked shale. Broken-up silty laminae are common. At 40.79 m, a 2 cm zone of interbedded dark-gray shale and lighter colored gray siltstone occurs. This zone is rich in "chalcocite-like" material and possible pyrite. Mineralization is distributed throughout the entire section except for the last 7.6 cm. Lower contact is gradational. |
| 41.02-41.40 (134.58-135.83) |
Massive, dark-reddish-brown, silty shale. Poorly preserved core. Some minor gypsum in fractures, and gray reaction halos in the upper few inches. |
| 41.40-41.45 (135.83-136.00) |
Finely interbedded dark-gray shale and lighter gray siltstone laminae that are discontinuous, wavy, and show crosscutting relationships. Sulfide mineralization is found throughout. |
| Location SW SW Sec. 24, T. 31 S., R. 7 W. | |
|---|---|
| Cored Interval meters (feet) |
Core Description |
| 10.52-10.61 (34.50-34.80) |
Massive fine- to medium-grained sandstone. Rock oxidized to an orange-brown color. |
| 10.61-11.00 (34.80-36.10) |
Varicolored orange-brown, generally poorly sorted and massive, very fine to fine-grained sandstone. |
| 11.00-11.02 (36.10-36.15) |
Fine-grained, varicolored, orange- brown sandstone. |
| 11.02-11.40 (36.15-37.40) |
Poorly sorted, very fine grained, light-brown sandstone and silt. |
| 11.40-11.58 (37.40-38.00) |
Interbedded, massive, gray and reddish-brown siltstone. Color distribution is irregular and about equal. |
| 11.58-11.67 (38.00-38.30) |
Massive dark-reddish-brown and minor gray siltstone. |
| * * * * * | |
| 13.50-13.68 (44.30-44.90) |
Massive reddish-brown siltstone. |
| 13.68-13.81 (44.90-45.30) |
Slightly calcareous reddish-brown and gray siltstone. Color distribution is irregular and about even. Secondary porosity developed throughout the interval. |
| 13.81-13.91 (45.30-45.65) |
Massive reddish-brown siltstone. |
| 13.91-14.25 (45.65-46.75) |
Broken and recemented reddish-brown siltstone. Minor amount of small gray blebs. |
| 14.25-14.54 (46.75-47.70) |
Massive reddish-brown siltstone with about 5 percent intermixed gray siltstone. Toward the lower contact the siltstone becomes darker colored. |
| 14.54-15.24 (47.70-50.00) |
Calcareous, massive, light-gray siltstone. Minor reddish-brown shale, intermixed. |
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Kansas Geological Survey, Stratigraphy of Copper Sulfides, Lower Permian Redbeds, South-Central Kansas
Placed on web May 18, 2010; originally published in Oct. 1981.
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