STRATIGRAPHY. 15 
lower mountain slopes rising out of the red-shale valley. East of 
Laramie this sandstone is overlain by a 6-foot bed of limestone which 
is extensively quarried. It extends some distance to the south. 
South of Gilmore Canyon the purple tint of the limestones is stronger, 
their sandy character is more pronounced, and the beds are thinner. 
This change is such that although about Laramie and northward 
limestones predominate, to the south, in the vicinity and west of Tie 
Siding, red shale and arkosic sandstone are the prevailing rocks. The 
limestones do not disappear, however, but most of them persist as thin 
beds to the Boulder Ridge fault. About 250 feet from the top of the 
formation there is a sandstone member about 200 feet thick divided 
into three ledges by thin limestone beds. This sandstone is fine 
grained, massive, cross-bedded, light red to salmon colored, and 
weathers into fantastic forms or monuments. About Red Buttes, at 
the end of Boulder Ridge, and in the " mushroom gardens" along 
Sand Creek, these monuments are especially numerous, occurring in 
extensive groups, some features of which are shown in Plates II, B, 
and V. 
The formation thins to the southwest, the Pulpit Rock section 
showing only about 500 feet of the formation, or 500 feet less than in 
Gilmore Canyon, and with this decrease in thickness the limestone 
members diminish in number and thickness. The following sections 
show the principal features: 
Partial section of red beds near Pulpit Rock, on Sand Creek, at' Colorado state line. 
Feet. 
Wavy gypsiferous limestone) p , J 2 
Red shales with aragonite J g ] 100 
Wavy gypsiferous limestone (Forelle?) 4 
Light-buff sandstones and shales 100 
Flaggy to massive light-colored sandstones 30 
Limestone (thins out) I 
Massive fine-grained red monumental sandstone 40 
Shale, arkosic sandstone, and conglomerate , 10 
Heavy blocky limestone; forms slope in this vicinity 5 
Sandstone, arkose, and conglomerates 1 70 
Sandstone 5 
Arkosic sandstones and conglomerates 80 
Limestone 2 
Arkosic sandstones and conglomerates. 
(i(Jl 
Section of red beds at Red Mountain . " 
Chug water: Feet. 
Red sandstone and shale 675 
Gray wavy quartzite (gypsiferous limestone?) 5 
Red shale and sandstone LOO 
Red clay and gypsum with aragonite crystals 20 
Sol id gypsum 50 
« Condensed from Knight's section, op. cit., pp. 41&-419. 
