T. B. Comstock— Geology of Western Wyoming. 429 
theCretaceous. It is sufficient, however, for our present purpose, 
to state that the Triassic beds are represented by thick deposits 
of bright red sandstones, which are overlaid by lighter, or buff- 
colored sandstones of Jurassic age, and these again by sand- 
stones and shales, with interstratified brown lignite beds, and oe- 
casional seams of coal, which, I cannot doubt, are of Cretaceous 
An interesting and peculiar fold in the sedimentary strata, 
nga a parallel ridge to the mountains, causes a kind 
Gryphoa is remarkably abundant in the Jurassic limestones, 
which are here nearly vertical. 
The fresh water Tertiary beds jut against the older deposits 
almost exactly as those of the Green River basin overlie the 
ted sandstones of the Uintah Mountains, and like them 
currence of shore deposits of soft sandstones and conglomer- 
any ft eds of considerable thickness, which contain scarcely 
ee t Hocene. e 
lami de a considerable thickness of interstratified marls and 
app 
*Dr ” 
187], sn 27 Gen, “ Geol. Surv. of Wyoming,” 1870; “Geol. Surv. of Montana, 
i ga coal beds of the same navies to the" Lower Tertiary or Upper Cre- 
