14 LAKAM1E BASIN, WYOMING. 
Local features. — The principal features of the Casper and associated 
formations in the vicinity of Laramie are illustrated in the following 
well-exposed section in Gilmore Canyon: 
Section of Carboniferous formations in Gilmore < 'anyon, Wyoming. 
Feet. 
1. Forelle limestone '20 
2. Satanka red shale; some red sandstone 232 
3. Sandstone (top of Casper formation) 2 
4. Red shale with a few thin beds of white and red sandstone 120 
5. Red to buff sandstone 65 
6. Limestone, fossiliferous 8 
7. Upper monumental sandstone 45 
8. Hard limestone, buff 2\ 
9 . Lower monumental sandstone, red 78 
10. Massive lumpy limestone (in middle of hill 1 mile northwest 
of Colores) ' 20 
11. Reddish soil (rocks concealed) 33 
12. Red sandstone 92 
13. Heavy-bedded limestone, carrying Spirifer cameratus 24 
14. Salmon-red sands and fine-grained sandstone 120 
15. Purple limestone 4 
16. Concealed (shale?) 110 
17. Limestone, with crinoid stems 5 
18. Concealed (shale?) 45 
19 . Purplish sandy limestone 15 
20. Shale? 50 
21. Purple thin slabby sandy limestone 3 
22. Shale? 15 
23. Purplish slabby sandy limestone 15 
24. Massive shelly cross-bedded purple sandy limestone 25 
25. Concealed ; probably red shales and sandstones 90 
26. Purple sandy oolitic limestone 1 
27. Massive red arkose and conglomerate, with |-inch pebbles 
(bottom of Casper formation) 20 
Granite. 
1, 259 \ 
This section exhibits twelve beds of limestone, from 1 to 25 feet in 
thickness and separated by beds of shale and sandstone. The sand- 
stone beds of the lower portion of the section are prevailingly arkosic 
and locally conglomeratic. The limestones are usually crystalline, 
in many places sandy, and range from purple to white in color. The 
purple limestone members near the base of the formation are a 
noticeable feature for many miles along the Laramie Mountains, and 
usually they yield the lowest fossils. The heavy bed of limestone in 
the lower middle portion is especially conspicuous in Cheyenne 
Canyon, where it lies on bright-red sandstone in turn underlain by 
gray sandstones more than 100 feet thick. North of Laramie and to 
some extent in other places the top member of the formation is a 
coarse gray sandstone, 30 to 50 feet thick, which constitutes the 
