GEOLOGY. 47 
OHAPTER III. 
GEOLOGY. 
§ 34. General Geological Character—California, geologi- 
cally considered, belongs chiefly to the paleozoic and tertiary 
epochs. The carboniferous rocks are wanting, or their exist- 
ence in the state is confined to a very small district, and has 
not been demonstrated even there. A tertiary sandstone, some 
of which is metamorphic, having lost its original stratification 
under the influence of intense heat, underlies the valleys of the 
Sacramento, the San Joaquin, and the coast, and is seen in the 
Coast Mountains, the Great Basin, and the Colorado Desert. 
Granite occupies the higher portions of all the mountainous 
districts, and considerable portions of the Great Basin and the 
borders of the Colorado Desert. The scarcity of stratified 
rocks is plainly discoverable by the traveller in the number 
and ruggedness of the mountains; only primary, eruptive, and 
metamorphic rocks make such steep hill-sides. The thinly- 
stratified rocks, with intervening layers of clay, are soon worn 
down by the water into gentle slopes, and covered with fertile 
soil, every foot of which may be turned over by the plough, 
and with profit. Such is not the character of California, nearly 
all of which is primary or metamorphic. 
Many rocks besides granite and tertiary sandstone appear 
in irregularly-distributed patches. About Mounts Shasta and 
Lassen, Castle Peak, the Marysville Buttes, in the plateau of 
the Sierra Nevada, the Great Basin, and the Colorado Desert, 
there are considerable tracts of basalt, lava, trap, and trachyte ; 
and in other places there are small tracts. Some very remark- 
able hills of basalt, called “Table Mountains,” are found in the 
