Gold-Bearing Lodes in California, — Hershey. yy 
From the crags and pinnacles of the peaks, long rocky 
slopes descend steeply to lower mountains forming "shoulders" 
to the main masses, and from these again, very steep slopes 
descend to the bottoms of narrow^ boulder-strewn gulches, 
whose altitude varies between 2,500 and 5,500 feet A. T. Un- 
like most of the gulches, the glaciated heads of the main val- 
leys are broad and open, with boulder-strewn "meadows" and 
liny tarns. The higher altitudes are cold and barren, the 
slopes are partly timbered and partly covered with a chaparral 
of manzanita and ceanothus, and the gulches are dark and dis- 
mal from a heavy growth of fir and spruce timber. 
Stratigraphy, 
Aside from the intrusive rocks, four great formations are 
represented in the Sierra Costa mountains. 
The Basement Crystalline. — The oldest rock exposed in 
northwestern California is a coarse aggregate of well- 
formed crystals of dark green and black hornblende, 
embedded in a mass of crystalline white feldspar, 
with occasionally some white quartz. It is local- 
ly known as "picrolyte," but seems most closely related to 
the syenytes. It is remarkable for its coarse texture. Great 
bodies of it are crystallized on a scale of one-half inch, while 
distinct individuals of hornblende six inches in length are not 
tmcommon. It grades thence 'down into fine-grained rocks, 
some of which resemble dioryte, while others are a true syenyte 
with pink orthoclase, black hornblende and white quartz. 
This basement crystalline is a highly metamorphic igneous 
formation of very ancient age. It is massive in structure and 
seems to form the foundation rock of the whole range of moun- 
tains. Its normal position is always under the serpentine, 
from which I infer that it is of greater age, although I have ob- 
served indistinct traces of syenyte dikes passing upward into 
the serpentine. As it forms great mountain masses, its thick- 
ness must be thousands of feet. 
The Serpentine Formatio/i.-Thc great bod)' of this member 
of the stratigraphic series is a very fine-grained or macrosco- 
pically amorphous and structureless, dark green and black ser- 
pentine. Certain belts of it have been converted, by a powerful 
shearing stress, into a lighter green, schistose serpentine, the 
