SECTION OF CANON OF CASCADE RIVER. 63 
At Camp 74 we found a bed of red shale covering No. 1, which I have supposed to be a 
portion of the series of red sandstones and shales overlying the yellow limestone at the crossing 
of the Little Colorado. 
No. 1 contains no fossils, as far as my observation extended. It is beautifully mottled; the 
color being blood-red and yellow, and very bright, rendering it one of the handsomest marbles 
found on our route. This is doubtless the equivalent of the extreme upper part of the lime- 
stone which occupies so much of the surface between the San Francisco mountain and the 
Little Colorado, called Permian by Mr. Marcou. While it is true that, if the Permian magne- 
sian limestones of Kansas reappear west of the Rocky mountains, this rock is their representa- 
tive, it must also be said that the evidence of their identity is as yet all to be discovered. 
Here the limestone beneath the red shales is separated from that containing Carboniferous 
fossils by a thin band of sandstone; but as will be hereafter seen, where our party crossed the 
surface of the limestone west of the Little Colorado, it seemed homogeneous throughout. At 
Camp 73 this limestone is very different, lithologically, from the Permian limestones of Kan- 
sans. It is silicious rather than magnesian, and contains no fossils whatever. 
The sandstone (No. 2) beneath the last is a coarse and soft rock, quite unlike any of the 
sandstones exposed near the crossing of the Little Colorado, which hold a higher place in 
the series. It is strikingly like the sandstones of the Coal measures in the Mississippi valley, 
and probably should be regarded as of the same age with them. As has already been stated, 
the true Coal measures are said to exist north of the Colorado, at no great distance from this 
locality, and I have regarded this sandstone as an indication that we had here approached near 
to the shores of the Carboniferous continent, near enough to reach one of the strata formed by 
the direct erosion of the land. Further north, could we have proceeded in that direction, we 
should doubtless have found the number and thickness of such beds, intercalated between the 
strata of the limestone, constantly increasing until we reached seams of coal. 
As we went south from this point, we turned our backs upon the ancient land—of which we 
soon lost all traces—and about the San Francisco mountain had beneath our feet the homo- 
geneous calcareous sediment of the open ocean. 
Nos. 3, 4, 5, 6, and 7, of the section, are but subdivisions of what is constantly referred to 
in my notes on the geology of this region as the ‘‘ Cherty limestone.’’ With some new species, 
it contains large numbers of fossils highly characteristic of the coal measures of Kansas, Mis- 
souri, Ohio, Pennsylvania, &c. Such as Productus semireticulatus, P. castatus, Spirifer lineatus, 
Depicer. subtilita, Orthisina umbraculum, Rhynconella uta, etc., ete 
I have supposed the three calcareous beds (Nos. 1, 3 to 1, 9 sad 10) of this section were 
but portions of one great furmation, here by the intercalation of strata of sandstone and gyp- 
siferous shales rendered locally distinct. 
The shales with gypsum (No. 8) have been noticed as observed in detached hillocks, on the 
high mesa near Camp 70. They are here fully exposed, in cliffs which would be perpendicular, 
but that their softness has permitted a portion of the cherty limestone to be undermined and 
removed, and a broad shoulder formed. The prevailing color of this series is green, but por- 
tions of it are gray, white, and red. Like the lower gypsiferous strata these contain no fossils. 
Nos. 9 and 10 compose the crinoidal limestone so fully described at Camp 70. It is here, as 
there, rich in fossils, usually of the same species; but spines of Archcocidaris are much less 
abundant. The upper division is rather darker and harder than at Camp 70, while the lower 
part is much lighter in color, and softer. It is scarcely distinguishable from the yellow Per- 
mian limestone of 
The cross-stratified iteahenien (No. 11) here present nearly the same appearance as at Camp 
10, but, perhaps because better protected by the overlying rocks, are much more massive, 
forming nearly smooth faces in the perpendicular cliff. 
The red calcareous sandstones and shales (No. 12,) first noticed on the other side of the high 
