656 WHITMAN CROSS 
Dakota about an island of ancient rocks which he believed to have 
never been completely submerged until the Dakota epoch (29). This 
view is manifestly not wholly correct, in that it does not recognize the 
extent of the denudation of the intervals preceding and following the 
Dolores epoch. Only the latter of these was known to Peale. As 
for the uppermost Paleozoic beds of West Creek there is evidence 
(presented on p. 662) that they do there abut against the granite 
of a continental mass, as noted by Peale. The point of interest 
here is that the Dolores conglomerate has no such boundary and 
was probably deposited on the granites, gneisses, etc., over the 
whole area of the Uncompahgre Plateau, its absence in any given 
locality being satisfactorily explained by the pre-La Plata erosion. 
From the facts presented, it would seem established that the 
Dolores formation is represented in the Grand River Valley by the 
Vermilion Cliff sandstone, together with about too feet of thin-bedded 
sandstones, shales, and limestone conglomerate below it. 
Relation of the Dolores conglomerate to the Shinarump conglome- 
vate-—The discovery of the “‘saurian conglomerate” and the uncon- 
formity below it makes it necessary to trace that horizon with care 
through the Plateau province. There seems to be no suggestion of 
such a conglomerate in the statements of any writer on the geology of 
the region, except Newberry. In his “General Section of the Valley 
of the Colorado” (28, p. 99) there is a member, 92 feet in thickness, 
described as, ‘“‘Greenish gray micaceous conglomerate and gray 
sandstone, separated by red and purple shales.’”? ‘This occurs below 
350 feet of red sandstone which I correlate with the Vermilion Cliff 
sandstone, and there is evidently a general correspondence to the 
104 feet of strata below the Vermilion Cliff west of Moab. As 
Newberry measured this member of his section only a few miles 
below Moab it seems almost necessary to assume that the 92 feet of 
strata here referred to belong to the lower part of the Dolores, and 
include the fossiliferous conglomerate. Between this conglomerate 
and fossiliferous Pennsylvanian limestone Newberry found 514 feet 
of sandstone described as liver-colored, brick red, or white, with 
shale partings. Clearly the gypsiferous series of Fisher Creek, the 
overlying conglomerates and sandstones, and a considerable part of 
the underlying Permian ( ?) beds are absent on the line of Newberry’s 
