|
Unit No. |
Description |
Thickness |
|
Ogallala
|
|
30
|
Chalk - yellow
|
6 ft.
|
29
|
Bentonite
|
0.05 ft.
|
28
|
Chalk - yellow
|
5.4 ft.
|
27
|
Bentonite
|
0.05 ft.
|
26
|
Chalk - yellow, platy near top
|
16.1 ft.
|
25
|
Limonite
|
0.1 ft.
|
24
|
Chalk - yellow, (chalk becomes punky and more yellow, less silty)
|
12.4 ft.
|
23
|
Chalk - yellow
|
6.8 ft.
|
22
|
Bentonite
|
0.05 ft.
|
21
|
Chalk - yellow
|
2.3 ft.
|
20
|
Bentonite
|
0.05 ft.
|
19
|
Chalk - yellow
|
0.65 ft.
|
18
|
Bentonite
|
0.05 ft.
|
17
|
Chalk - yellow, harder
|
1.15 ft.
|
16
|
Bentonite
|
0.05 ft.
|
15
|
Chalk - yellow
|
2.5 ft.
|
14
|
Chalk - yellow to grayish
|
1.4 ft.
|
13
|
Limonite and bentonite
|
0.2 ft.
|
12
|
Chalk - gray
|
2.5 ft.
|
11
|
Gypsum and limonite
|
0.1 ft.
|
10
|
Chalk - gray
|
3.4 ft.
|
9
|
Gypsum
|
0.1 ft.
|
8
|
Chalk - gray
|
1.2 ft.
|
7
|
Gypsum
|
0.1 ft.
|
6
|
Chalk - gray
|
2 ft.
|
5
|
Resistant ledge - shale?
|
0.2 ft.
|
4
|
Chalk - gray
|
3.3 ft.
|
3
|
Bentonite and gypsum
|
0.1 ft.
|
2
|
Chalk - gray
|
5.7 ft.
|
1
|
Bentonite and limonite
|
0.1 ft.
|
|
Base of Castle Rock Section
|
|
|