STRATIGRAPHY. 21 
The limestone is hidden by alluvium in the flat extending from 
Sportsman Lake to and up Lone Tree Valley, but an outcrop on 
Antelope Creek near the center of sec. 16, T. 13 N., R. 74 W., is 
believed to be the same bed. It contains the same fossil (Myalina 
perattenuata) that occurs north of Laramie. This bed outcrops along 
the west side of Sand Creek, where the lower red shales are absent and 
the limestone lies directly upon sandstones. Apparently it is the 
Forelle limestone that immediately underlies the 67-foot gypsum 
bed in Red Mountain and yields the numerous fossils discovered by 
W. C. Knight." On the slopes 2 miles south of Ring Mountain the 
limestone under the gypsum is thin, but yields distinctive fossils. 
At Boswell Spring the Forelle limestone rises in a short, low ridge. 
It is 3 feet thick, impure, pink in color, and lies upon red shabby sand- 
stone merging downward into red shales which underlie a valley 
extending eastward to slopes of gray sandstone. On Sybille Creek 
it is 4 feet thick and lies on about 125 feet of red shale. 
In the Laramie-Red Buttes area the Forelle limestone contains 
Myalina perattenuata and fragments of other species. 
The supposed Forelle limestone just below the gypsum 2 miles 
south of Ring Mountain afforded great numbers of Avieulipecten 
occidentalis, Myalina perattenuata, Allerisma terminale, and Schizodus 
compressus. 
The limestone believed to represent this bed in the Red Mountain 
section consists mostly of casts and impressions of fossils which were 
discovered by Knight in 1902. a According to Doctor Girty they 
comprise the following: 
Solenomya n. sp. 
Deltopecten manzanicus. 
Deltopecten coreyanus? 
Schizodus meekanus. 
Myalina perattenuata. 
Pleurophorus aft". P. taffi. 
Dentalium canna. 
Orthonema? sp. 
This fauna is regarded as late Pennsylvanian or possibly equiva- 
lent to the lowest limestones of the so-called Permian of Kansas. 
If it were not for this evidence the beds might be regarded as a por- 
tion of the Chugwater formation, for near Laramie and Red Buttes 
the stratigraphic succession is suggestive of Minnekahta limestone 
lying upon red shale of the Opeche formation. The Minnekahta 
limestone occurs on the east side of the Laramie Mountains and in 
the Black Hills and contains Permian fossils. 
The Forelle limestone may represent the Embar formation of the 
Owl Creek b and Bridger Mountain ranges. 
«The Laramie Plains Red Beds and their age: .lour. Geology, vol. 10, 1902, p. 419. 
'' Darton, N. H., Geology of the Owl Creek Mountains: Senate Doe. 219, 59th Cong., 1st sess., 1906, 
p. 17. 
