Review of Recent Geological Literature. 339 
Dr. A. C. Peale in central Montana, has examined a type section of 
the entire Paleozoic system from the Carboniferous to the Algonkian, 
inclusive, finding every principal division distinctively developed. 
The field work in the Yellowstone National Park, under the direction 
of Mr. Arnold Hague, comprised the continuation of observations of the 
geysers, and especially the careful study of the Excelsior geyser, which, 
after lying dormant for nearly six years has burst into renewed activity, 
concurrently with the disappearance of several hot springs and small 
streams. The topographic maps of the Park, and the delineation of the 
areal geology, are completed. 
Mr. 8. F. Emmons has nearly finished the preparation of monographs on 
the Ten Mile and Silver Creek mining districts in Colorado, and on the 
Denver coal basin. A most interesting formation, underlying the city of 
Denver from which it is named, was discovered during the year covered 
by this report and has been described by Mr. Whitman Cross. It is prob- 
ably of Eocene age, and consists of sediments-eroded from andesitic lavas , 
but the situation of the area thus denuded has not been determined. 
In California Mr. G. F. Becker, spent the greater part of the year in 
surveys of the Gold Belt, tentatively mapping the geologic formations 
of about half of the auriferous region. Well-preserved glacial strice 
have been found on portions of the walls of the Yosemite Valley, and 
on the head-waters of the Kaweah river, farther south than any locality 
previously known. ‘Here, as elsewhere in the Sierras, the ice marking 
is wonderfully fresh. Although the streams are roaring torrents of 
high declivity they have corraded but a few feet of rock since the 
glaciers disappeared.” 
Mr. J. $8. Diller, in charge of the Cascade division, was occupied 
during most of the season of field work in the collection of speci- 
mens of voleanic rocks from various points of the Cordilleran mountain 
belt, to form part of a series for distribution to the educational institu- 
tions of the country. The number of specimens collected to represent 
each variety of rock in the series, is 250. 
The chief work of Mr. W. J. McGee during the year was the com- 
pietion of his researches on the Pleistocene formations of northeastern 
Iowa. Dr. G. H. Williams was engaged in study of the crystalline 
rocks of the Piedmont region in Maryland; and Mr. L. C. Johnson in- 
vestigated the Tertiary beds of the coastal plain in the southern states. 
This report also reviews the palieontologic work done for this survey 
by Prof. Marsh, Dr. Newberry, Prof. L. 3°. Ward, Mr. F. H. Knowlton, 
Prof. W. M. Fontaine, Mr. C. D. Walcott, Prof. H. 8S. Williams, Dr. C. A. 
White, Dr. W. H. Dall, and Mr. 8. H. Scudder ;: the work in the chemical 
and physical laboratories by Prof. F. W. Clarke, Dr. Carl Barus, and 
their assistants; the work of the petrographic laboratory by Messrs 
Diller, Hague, Iddings, Bayley, and others; and the work in mining 
statistics, and technology by Dr. David T. Day. 
The total value of the metallic products of the United States, during 
1888 was $256,245,000, of which iron was $107,000,000 ; silver $59,000,000 ; 
and gold and copper, each $33,000,000, Among the non-metallic mineral 
