en ee 
ay ee ee 
RECONNAISSANCE IN COLORADO AND UTAH 655 
illustrates this unconformity, which may be traced for about half a 
mile, and it was estimated that at least 600 or 800 feet of beds are 
visibly truncated by the conglomerate in one continuous exposure. 
The occurrence of an extensive section of gypsiferous sandstones and 
shales beneath the Dolores conglomerate in Fisher Valley on the 
northwest side of the La Sal Mountain adds so much to the beds 
trangressed; and a still higher series of sandstones and conglomerates 
is known, so that, altogether, it is estimated that not less than 1,500 
Fic. 6.—The lowest strata of the La Plata sandstone, north side of Cafion Colorado 
near its head. Shows the characteristic cross-bedding and cavernous weathering. 
Nodular masses on level floor of foreground belong to upper beds of Vermilion Cliff 
(Dolores) sandstone (p. 646). 
and possibly 2,000 feet of Permian (?) or upper unfossiliferous 
Pennsylvanian beds have been eroded in the locality of the section 
first mentioned, opposite Moab. : 
On West Creek, the western stream from Unaweep Canyon, 
the “saurian conglomerate” is seen overlapping from the heavy con- 
glomerates of the Permian (?) to the granite-gneiss-schist complex of 
Uncompahgre Plateau. This is the overlap represented on the 
Hayden Map of western Colorado, and interpreted by Peale as a part 
of the overlap of all formations from the upper Carboniferous’to the 
