Tlw Pre-Cretaveous of ('(illfornla. — Falvbanhx. 75 
from the Coast system in Shasta eonnt3^ also extends parallel to 
the coast but at a distance of two hundred miles from it. In the 
course of six hundred miles this range gradually approaches the 
Coast system in the form of an immense arc, and finally unites 
with it in northern A'entura county. This union is so intimate at 
both ends that no one can say where the one terminates and the 
other begins. From northern California to the point where the 
ranges approach each other on the south, the compression, pro- 
ducing the folding and crushing and which gave rise to the moun- 
tain axes, acted in (juite a uniform direction, northeast and south- 
west, forming the two approximatel}' parallel systems. South of 
a line running east and west through the southern end of the San 
Joaquin valley, the compression has been from a different direc- 
tion, that is from the north and south; producing an east and 
west system, of which the mountains in southern Santa Barbara, 
Ventura and liOs Angeles counties, and the islands south of the 
Santa Barbara channel are examples. As another result of this 
north and south compression, the Sierra system was turned out 
of its normal course into one taking the form of the resultant of 
the two forces; consequently the nearer it approached the Coast 
system, the more it was deflected, assuming successively a south, 
southwest, west, and finall}' a northwest course; the actual exposed 
portion of the crystalline rocks terminating in the high peaks at 
the western end of the San Emedio range. The main mountain 
system extending from Frazer mountain south of the Mojave 
desert, including the Sierra Libre, the Sierra Madre or San 
Gabriel, and San Bernadino ranges, shows a union of the two 
forces, producing a fold having a direction a little south of east 
and north of west. Through San Diego county the normal south- 
east direction is shown in the regularity of the Peninsula range. 
The two forces acting simultaneously gave to southern California 
the irregular system of mountains which has been included by 
some in the Sierras and by others in the Coast system. The posi- 
tion assumed by the mountains formed by the union of the 
southern Sierras and the northwest prohmgation of the Sierra 
Madre is very suggestive. They are inseparably connected with 
the Sierras, and yet seem an integral i){irt of the Coast system. 
Thus we may conceive as having been formed at the same time 
with the final great upheaval of the Sierra system, and its accom- 
panying granitic rocks and intense metamorphisui. the Coast range 
