|
| Unit No. |
Description |
Thickness |
|
9
|
Limestone, algae, mostly Osagia but a few layer-like Cryptozoan near the center. Made up mostly of Osagia with locally crinoid stems and a few corals and brachiopod and pelecypod fragments. Weathered surface has many small olive gray (5Y4/1) bodies throughout, but the general color is yellowish gray (5Y8/1). Fresh surface is very pale brown (5Y6/2) to light brownish gray (5YR6/1). This bed caps the hill at this exposure, but is about 1.5 ft. below the Capt. Creek limestone to the east, separated by shale, apparently
|
1.25 ft.
|
|
8
|
Shale, light olive gray (5Y5/2)
|
25 ft.
|
|
7
|
Covered interval
|
15 ft.
|
|
6
|
Siltstone, micaceous, between yelloiwsh gray (5Y7/2) and grayish yellow (5Y8/4) in color. Cross bedded, ripple marked, and locally contains molds of pelecypods(?). Forms a distinct topographic bench
|
2 ft.
|
|
5
|
Covered interval. Apparently a claystone, but becomes more silty upward
|
13 ft.
|
|
4
|
Claystone, slightly silty, light olive gray (5Y5/2)
|
11 ft.
|
|
3
|
Shale, fissile, slightly silty, light olive gray (5Y5/2) to yellowish gray (5Y7/2) with ironstone concretions at the base and near the top. Grades upward into
|
+ 6 ft.
|
|
2
|
Shale, fissile, slightly silty, medium bray (N5) with a bluish cast. Contains three lenticular beds of yellowish orange (10YR7/6) to dark yellowish brown (10YR4/2) ironstone concretions, one neart the base, one about 3 ft. above the base, and one about 5 ft. above the base. This shale grades upward into a
|
+ 10 ft.
|
|
1
|
Limestone, medium gray, pale yellowish brown (10YR6/2) to dark brownish gray (5YR3/1) on weathered surface. Breaks to irregular, grainy brownish gray (5YR3/1) and dark gray (N3) fresh surface. At this exposure it is even-bedded and has eroded to a 40 x 300 ft. surface which is largely on the upper layer of the formation. This surface is smooth from a distance but at close range appears very irregular and lumpy on a small scale. The bedding planes are wavy bedded but on a much smaller scale than is exhibited in the Plattsmouth limestone member of the Oread formation. A very well developed joint system is evident at this exposure. The trends are N4OW, N85E, and N55E. This limestone is very fossiliferous. The uppermost 8 in. layer consists largely of small crinoid fragments, small brachiopods and large fenestellate bryozoans. The fossil content of the rest of the bed, exposed here, consists of large pelecypods, large brachiopods, crinoid remains and fenestellate bryozoans. The uppermost 2 in. of the formation has a reddish cast and contains Myalina valves.
|
+ 3 ft.
|
|
