8 
GEOLOGY. 
have been cultivated, heavy crops of wheat and barley verify this natural indication of the 
fertility of the soil. Many large fields of grain presented a beautiful appearance, and were 
being harvested by the aid of the patent reaping-machines. 
The valleys through which we passed are mostly well watered, and are timbered with ma¬ 
jestic oak trees, forming open groves free from any undergrowth. 
The hills are usually free from timber of any kind, but an occasional ravine or side valley, 
that is sheltered from the high winds or is watered by a spring, sustains a growth of oaks. 
Wherever the trees of that region are exposed to the prevailing wind from the coast they 
become bent over to one side, and show the effect of the wind in a most remarkable manner. 
It is not uncommon to find trees growing almost horizontally along the ground. All the 
degrees of inclination and peculiar forms shown in the annexed wood cut were observed. 
EFFECT OF THE PREVAILING WIND UPON TREES 
Livermore’s Valley .—We reached Livermore’s on the 13th of July, and camped near the 
entrance to the pass called by the same name. This valley is a widely extended plain, looking 
at this season perfectly brown and barren, and yet it is covered in places by droves of cattle appar¬ 
ently well fed. It is several miles in length and breadth, extending between the range on the 
west, which separates it from the valley of San Jose, and the low range on the east, through 
which Livermore’s pass conducts to the broad valley of the San Joaquin. The mountains on the 
west side appear high, and are perfectly brown and nearly treeless. A double line of summits is 
presented to the view, as if there were two lines of elevation. A long line of trees, which appear 
very small in the distance, is visible at the base of the range and on the margin of the plain. 
Near the camp, there is a range of low hills, their elevation, as shown by the aneroid barometer, 
being one hundred and fifty feet. There is no indication of strata ; the surface is covered with 
a thick coating of gravel and pebbles, apparently the deposits of a stream. The soil is loose 
and poor, and does not appear to sustain the usual growth of the wild oat. It is reported that 
“fossil oysters ” occur in this valley, but the locality was not found. 
Livermore’s Pass, July 16.—The entrance to the pass is among low rounded hills, and the 
road follows the circuitous windings of the narrow valleys between them. These hills increase 
in altitude towards the centre of the range, and have very steep slopes. This range of hills 
extends from Mount Diablo southeasterly, and is the last or most eastern of the Coast Moun¬ 
tains, and borders upon the plains of the San Joaquin river. 
The rocks along the route were stratified, being chiefly sandstone and conglomerate. No other 
formations were observed. These sandstones rarely appear above the surface of the hills, being 
covered with a soil that is apparently derived from their decomposition. Natural sections along 
the streams, favorable to the observation of the characters of the strata, were also rare. I was, 
however, able to determine that the strata are inclined in various directions, and at angles 
varying from 30° to 50°. The prevailing trend is northwest and southeast. The sandstone is 
more firmly consolidated than that at Navy Point and at Martinez, and more nearly resembles 
the rock quarried at Benicia for buildings. 
