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DAVIS: THE PLATEAU PROVINCE OF UTAH AND ARIZONA. 45 
tions in distances of four or five feet. Well-defined outcrops of these 
sandstones, five or ten feet thick, weakened and disappeared when fol-: 
lowed for a few hundred feet along a hillside. This was especially well 
seen on a slope just north of the Sevier-Virgin divide, where it could be 
explained only by the thinning out of the sandstone itself. On the 
divide and over some of the hills near it, we found the residual pebbles 
of a conglomerate that might probably have been discovered in place in 
localities where somewhat higher strata still remained intact. 
Whatever share may have been taken by lakes in providing a site for 
these various deposits, it seems evident that the persistent existence of 
a single, large, continuous water body does not supply the conditions 
necessary for the accumulation of strata in which variations of compo- 
sition, texture, and structure are so common. 
Tue GREEN River Basin, Wyominc. — The following notes on this 
interesting district are based on two half-day walks over the hills north 
and east of Green River station, Wyoming, supplemented by observa- 
tions on natural outcrops and railroad cuts from passing trains. 
The “paper shales” at Green river have often been instanced as proy- 
ing the lacustrine origin of the formation of which they constitute so 
large a part, and it was with the special object of examining them closely 
that I made a short stop at this point on the Union Pacific railroad. 
The cut where most of the fossil fish have been found is now, I was told, 
filled in the new grading of the railroad, but many excellent sections of 
the formation are exposed in the dry ravines that dissect the barren slopes 
of the uplands through which Green river has here opened its valley. 
The outcrops are especially clear on the slopes towards which the river 
has lately swung, thus causing an entrenchment of the lateral water- 
courses and a stripping of the loose waste that tends to accumulate on 
those slopes from which the river has moved away. The best example 
of this kind that I visited was from a quarter to a half mile southeast 
of the point where the railroad leaves the river to turn eastward up the 
valley of Bitter creek, a mile or more east of the station. The lowest 
beds here seen are whitish shales with some partings of fine sandstones, 
about one hundred feet in total thickness. These are capped by a 
stronger sandstone, dull greenish brown in color, commonly showing 
eross-bedding, and varying in thickness up to about fifteen feet. The 
outcrops of this sandstone on both sides of Bitter creek valley determine 
amore or less continuous bench. As the strata here dip gently west- 
ward, the sandstone disappears underground a little west of the mouth 
of Bitter creek, so that it outcrops only near the base of the bluff north- 
