210 SCIENCE. 
The desert region of Nevada south of the 
40th Parallel Surveys is geologically almost 
unknown, and the blank in the geologic 
map of the United States is correspondingly 
extensive. Surveys are begun with the pres- 
ent field season to accomplish a reconnais- 
sance of this area, extending south into 
southern California. If appropriations per- 
mit, it is hoped that reconnaissance surveys 
may, in the course of a few years, be ex- 
tended over all of the little known districts 
of the United States, so that a complete 
geologic map may be published on the scale 
of what is known as the nine-sheet base, 
namely 40 miles to the inch. 
The geological survey of the Sierra Ne- 
vada has been completed over an area com- 
prising about 21,000 square miles between 
the 37th and 40th parallels of latitude. 
Twenty geologic folios have been or are to 
be published illustrative of the results. 
The work at the present time is proceeding 
in the Yosemite quadrangle and further 
south on the eastern slope of the Sierra Ne- 
vada in the Silver Peak quadrangle, which 
includes the Silver Peak mining district. 
Following the general study of the moun- 
tain range and its geologic structure, special 
work has been done upon some of the prin- 
cipal mining districts—for instance, that of 
Nevada City, and more recently upon the 
Mother Lode. For the last-named work a 
large-scale topographic map was prepared 
with great care, and Mr. Becker entered 
upon the studies of physics of ore deposi- 
tion along the lode. In July, 1898, he was, 
however, diverted therefrom by an assign- 
ment to ascertain the mineral resources of 
the Philippines. The performance of this 
duty required the acceptance of a military 
commission, and he was attached to the 
Bureau of Information at Manila. Geologic 
investigations being precluded by the ac- 
tivity of the insurgents, Mr. Becker accepted 
his military duties with sang froid, and 
with the troops under fire rendered service 
{[N.S. Von. X. No. 242. 
which has been the subject of highly com- 
plimentary reports from his superior officers 
in the field. The information which he 
was able to obtain in the old Spanish bu- 
reau of mines in Manila and presumably 
from other reliable sources is contained in 
Part VI., of the 19th Annual Report. 
In the Cascade Range of Washington 
studies conducted for the past two years 
with reference to the geology of the Mount 
Stuart quadrangle reveal a series of phe- 
nomena closely resembling those of the 
Sierra Nevada. The volcanic flows of 
which the range is composed throughout 
Oregon and into southern Washington give 
place about latitude 46° 30’ to schists and 
granites of pre-Tertiary age, which are un- 
conformably overlain by sandstones of the 
Eocene and Miocene periods. The struc- 
ture of the range cannot be said to be un- 
derstood at the present time, but work is 
energetically proceeding with the purpose 
of developing the facts in such detail and 
so accurately as to secure conclusive in- 
formation. A reconnaissance of the north- 
ern portion of the range carried out during 
the past summer has resulted in an article 
in the 20th Annual—Geology of the Cas- 
cade Mountains of Northern Washington, 
by I. C. Russell. 
In the Coast Ranges of California and 
Oregon, a geologist who has acquired 
ideas of mountain growth from the Paleo- 
zoic rocks of the Appalachian province must 
completely revise his conception of that 
process. Where the early Cretaceous or 
late Jurassic rocks appear as a schistose 
basement complex, and the Cretaceous and 
Tertiary formations are separated by as 
many unconformities as there are distinct 
episodes of history, the activity of the 
earth’s crust seems an imminent phenom- 
enon. The contributions to the stratigraphy 
and structure of these youngest ranges pro- 
ceed from studies in Oregon (Coos Bay 
Coal Field, Oregon, J. 5S. Diller, 19th An- 
ical Ss ) Sanaa 
