54 The American Geologist. J"^^'- i^^*- 
REVIEW OF RECENT GEOLOGICAL 
LITERATURE. 
Contributions to the Geology of IVasliington: Geology and Physiog- 
raphy of Central JVashington. By George Otis Smith. Physiog- 
raphy and Deformation of the Wcnatchee-Chelan District, Cascade 
Range. By Bailey Willis. U. S. Geo!. Survey, Professional Pa- 
per, No. ig. Pages loi, with 20 plates and 3 figures in the text. 
1903. 
The first part of this work comprises 39 pages, with seven plates, 
in which Dr. Sn^iih .^hows that the region of the Cascade range in 
Washington, after the eruption of its great lava flows of Miocene age. 
was reduced by general erosion in the Pliocene period to a low pene- 
plain, which, toward the end of that period and later, was uplifted to 
form the Cascade range, with great erosion during the uplift and to 
the present time. These studies supplement the former work of Rus- 
sell, and confirm his estimate that the maximum vertical extent of the 
late Pliocene and Pleistocene uplift was about 7.500 feet along parts of 
the axis of the range. 
The uplift appears to have been a broad upward flexure or arch- 
ing of the earth's crust upon an area averaging about a hundred miles 
in width and extending from south to north across the state of Wash- 
ington. On the eastern slope of the range, extensive warping produced 
broad buttresses, one of which is represented by the Wenatchee moun- 
tains, culminating in Mt. Stuart, 9,470 feet high, fifteen miles east of 
the main crest of the Cascade range. 
South of the Wenatchee mountains, minor ridges, from 2 or 3 mile.s 
to 10 miles or more in width, running easterly from the Cascade range, 
were gently arched to bights of i.coo to 3,000 feet above the valleys; 
and the Yakima river intersects several of these ridges in its canyons 
below Ellensburg. This river, like the Columbia in its cutting through 
the high Cascade range, remains in the same course which it had before 
the complex uplifts and warping of the Miocene and older eruptive and 
sedimentary rock formations. The rivers are older than the mountains. 
Willis, in the second part of this work, discusses the evidences of 
these great events in the history of the Cascade region as observed by 
him in the district of the Wenatchee, Entiat, Chelan, and Methow 
mountains, eastern buttresses of the great main range, with the valley 
gorges or canyons of lake Chelan and the Columbia river. He esti- 
mates the ajea of the Cascade uplift in Washington to be about 20,000 
square miles. Its time of broad erosion, producing a low peneplain with 
nionadnocks. is named by Willis the Methow stage, and is considered 
as a part of the Pliocene period. Two stages of uplift, named the 
Entiat and Twisp stages, are recognized, and are referred to the end 
of the Pliocene period, with probability that they extend i;ito the Pleis- 
tocene period so far as to include the time of accumulation of the 
continental ice-sheet. 
