Gold-Bearing Lodes in California. — HersJiey. 8 1 
Faidts. — There are many minor faults, but onl\- three of 
sufificient importance to deserve mention here. The Trinity 
Centre Fault \s that which bounds the range along its entire 
southeastern side. On the southeast are the Jurassic diabase 
and black slates lying at levels between 2,000 and 4.000 feet 
above the sea. On the northwest, the serpentine and 
"picrolyte," rise abruptly to altitudes of 7,000 and 8,000 feet A. 
T. The change from the lower to the higher mountain country 
is so sharp that it cannot be charged wholly to folding. Un- 
doubtedly there has been faulting to the extent of at least sev- 
eral thousand feet. Over 5,000 feet of schists and slates are 
due between the serpentine and Jurassic diabase, but I charge 
the hiatus upon pre- Jurassic erosion rather than upon, faulting, 
as I have noticed evidence in other districts that the diabase 
is, in some places, normally present immediately over the ser- 
pentine. Yet there remains sufficient evidence to demonstrate 
that a profound fault actually exists along this line. The con- 
tact is rarely well exposed, but I have seen it in several places 
where the strata are crushed, and schistose bands produced, as 
in other faults of northwestern California. 
The Upper Coffee creek district possesses two prominent 
faults, whicTi are of great importance because the rich gold- 
bearing belt of that region lies mainly between and including 
them, and seems, in some way, dependent on these great 
breaks in the strata. Hence, I will describe them in some de- 
tail. 
Immediately northwest of the line of "picrolyte" peaks, 
which marks the axis of the second anticline, there is one of 
the so-called "dikes" of serpentine. This stands nearly ver- 
tical, with a slight inclination to the westward. On its west- 
ern side is a narrow belt of dark green hornblende schists dip- 
ping steeply to the east and hence toward the serpentine. 
Along the contact, both serpentine and schist have been crush- 
ed and the former in places converted into a schist, which, by 
metasomatic action, has been altered to a talcose schist. Con- 
tract-metamorphism is very distinct along this line and leaves 
no doubt that faulting has occurred. This is corroborated 1)\- 
the dip of the schists toward the serpentine instead of awa\ 
from it as they do when in normal position ; the plane of the 
fault cuts them at a high angle. Furthermore, in following 
