Mountain Upthrusts. 401 
The irregular line, SS, represents the land-surface, and the straight 
line, AA, the sea-level. The dotted line at either side of B represents 
the depth to which Green River has cut its cafion in traversing the 
Uinta Range. ‘The dotted lines above the surface-line represent the 
portions of the formations which have been eroded, and the extent 
to which they would have been elevated in the fold if they had 
suffered no erosion. 
The dotted line, ccc, is continuous with the top of the Laramie 
group. This indicates that all the formations below that line were 
fully involved in the fold; while the other dotted lines which lap 
upon either side represent the eroded portions of the four fresh-water 
Tertiary formations, which were successively less and less involved — 
in the fold as the elevation progress 
The initial U. indicates the Uinta a: Cb. indicates the 
Carboniferous; J. T., the Jura-Trias ; D., the Dakota Group ; Co., 
the Colorado Group ; ; F. H., the Fox Hills Group; L., the Lara- 
mie Group; W., the Watch Group ; G. R., the Green Hve Group; 
B., the Bridger Group, and B: P., the Brown’s Park Group. 
The following table gives the names and the ascertained thickness 
of the formations which are more or less involved in the fold, or 
which occur in its immediate vicinity :— 
Brown’s Park Group...... 1200- 1800 feet. 
: Bridger Group 100- 2000 ‘ 
Cenozoic ...... .....,. Tertiary. | Green River Group......... 1400- 2000 *“ 
Wasatch Group...........000 2000- 2500 * 
Laramie Group !?.........+++. 2000- 7 
Fox Hills Group 1800 j 
Cretaceous. Chldredo Gidin 2000 t 
Mesozoic....... Dakota Group. 500 
Jura-Trias 2500- 5000 “' 
= ee 3000 fe 
Paleozoic scossi { aah EEE AS REE i Sane is sc 
Archmwan 
The facts upon which the construction of the foregoing general- 
ized section is based indicates that all the formations, from the Uinta 
Sandstone to the Laramie Group (inclusive), were fully involved in 
the great fold, and that the four fresh-water Tertiary formations are 
only partially involved in it. The latter formations were respectively 
deposited in large fresh-water lakes, the existence, height and limits 
‘There provisionally place the whole of the Laramie Group with the 
Cretaceous formations, 
