210 G. F. Becker—Mineral Belts of the Pacific Slope. 
and the chain of deposits which extend diagonally across, 
Arizona. 
In the Coast Ranges of California, quicksilver and chromic 
iron occur at a great number of localities. The most southerly 
uicksilver mine known to me is Las Prietas, four miles from 
few and are separated by long intervals. On the whole, how- 
ever, it is strikingly apparent that conditions favoring the 
deposition of quicksilver ores have prevailed at numerous 
ints within a belt in most places of small width and which is 
of great length. Messrs. Whitney and Gabb, as is well known, 
ascribe the elevation of the Coast Ranges of California to a 
post-Miocene uplift. The western edge of the area raised, or 
the present coast of California, is. nearly parallel with, and for 
the most part very close to, the quicksilver belt. 
The gold belt of California is extremely well defined from 
the southern boundary of Mariposa county to the neighborhoo 
of Nevada City, a distance of about 150 miles, and near it is a 
series of copper deposits scarcely distant enough to be regarde 
as a separate system from a general pointof view. Gold deposits 
are found in great abundance but more scattered to the north- 
west of Nevada county, and there is also a little gold to the 
south at a number of points along the foothills of the Sierra 
to its termination at Fort Téjon; in fact though the gold belt 
proper is comparatively short, there can be no doubt thata 
Mera zone of country lies along the western foot of the 
ierra for several hundred miles. This zone also coincides 
with the western edge of the great area of Mesozoic rocks 
which, as was established by the investigations of the California — 
State Survey and the Exploration of the Fortieth Parallel, was 
uplifted after the close of the Jurassic. 
The Utah ore belt lies at the western base of the Wahsatch 
range and its southwesterly continuation. With the exception 
of the Leeds (Silver Reef) district, all the important deposits 0 
the territory are included in this belt, which bears a very def- 
nite relation to the main line of crests. The Wahsatch also 
‘forms the western edge of the Rocky Mountain area, which 
was uplifted at the close of the Cretaceous; the famous Wah- 
satch fault-line passing through or close to many of the mining 
districts. 
