j 
; 
Geological Survey of the Territories in 1872. 197 
cones were found, standing the river bottoms within 
walls of basalt which bound the immediate valley of the present 
stream, and so evidently of comparatively modern date. The 
evidently came from one of the beds of river ‘gravel under the 
basalt, through which the eruption took place. 
The Sand Hill Mts. were visited, and gave some evidence of 
having been once a volcanic crater, though the bounding walls 
are.now so much broken down as to make their original cont- 
nuity somewhat doubtful 
In approaching the Teton Mts., the basalts, which are, 1n 
some parts, cut up by cafions 700 feet or more in depth, were 
left behind; and more ancient porphyries formed the foot-hills 
of the range. The axis of the range was found to consist of 
granites, gneisses and schists, overlaid unconformably by from 
fifty to seventy-five feet of compact ferruginous quartzite, soe 
posably of Potsdam age, followed by about 300 feet of partly 
compact, partly shaly, glauconitic sandstone, and about 400 
feet of blue, impure, thin-bedded and partly shaly limestones, 
both belonging to the Quebec Group. These limestones 
yielded a few small Trilobites. They are followed by about 
600 feet of a. heavy-bedded, drab to hight buff, vesicular, mag- 
hesian limestone, containing no fossils except small fragments 
of crinoid stems, but referred with little doubt to the Niagara 
p. This is followed immediately by over 2000 feet of 
compact, gray to drab, Carboniferous limestone, often quite 
~aiie 4 mostly rather barren, though a few beds are rich 
1n fossils, 
