CHAPTER XVIII. 
NOTES IN THE GOLD REGION. 
SAN FRANCISCO TO STOCKTON —GREAT INLAND CURRENT OF AIR THROUGH THE GOLDEN GATE.—ALLUVIAL FORMATION AT STOCKTON.—SLOPE 
AND HORIZONTAL STRATA —KNIGHT'S FERRY.—BASALT.—MICA AND He M; NM VR SLATE.'—PLATEAUX OF BASALT.— 
SONORA. GoLp.—IRREGULAR IMESTONE. FE Cave.—Murpay’s.-T. 
MASTODON.—MAMMOTH TREES.—SEQUOIA GIGANTEA.—CAVE CITY. e ی‎ AND CAVE.—TALCOSE SLATES AND GOLD.—MOKELUMNE 
HILL.—COSUMNES RIVER —SACRAMENTO.—ALLUVIUM.—GRANITE.—CLAY SLATE.—BASAUT.— AUBURN.—Y ANKEE JIM’s.—AURIFE 
ALLUVIA —FOREST HILL.—PLACER MINE.—CRYSTALLINE GOLD.—DRIFT AT SARAHYILLE.—F OSSIL W00D.—MICHIGAN CITY.— A 8 
CASON OF THE NORTH FORK.—NEVADA AND GRASS VALLEY.—QUARTZ VEINS AND MINES,—GRASS VALLEY TO COLOMA.—GRANITE AND 
SLATES.—SUTTER'S MILL.—SLATES AND TRAP DIKES AT IRISH CREEK.— CRYSTALS OF GOLD. — GEORGETOWN. —MAMALUKE HILL.—SLATES 
AND AURIFEROUS DRIFT.—METHOD OF MINING.—W ASHINGTON TUNNEL COMPANY.—RICH VEIN OF AURIFEROUS QUARTZ.— ITS AT 
CEMENT HILL.—BED OF AN ANCIENT ee THE GOLD — A SLUICE.—MINERALS.—T ELLURET OF SILVER, —SERPENTI 
VorcANoviLLE —R GRANITE.— CONCLUDING THE GEOLOGY OF THE GOLD REGION. — 
TALCOSE AND CLAY SLATES. RC vafis, ROCKS.—BELT OF GRANITE. Bar OF METAMORPHOSED LIMESTONE, POSSIBLY CARBONIFEROUS.— 
HORIZONTAL STRATA, TERTIARY.—OVERFLOWS OF BASALTIC LAYA.— TABLE MOUNTAINS.—AURIFEROUS DRIFT.—COARSE DRIFT.—RIVER 
DRIFT.—-ALLUVIAL DEPOSITS.— LACUSTRINE DEPOSITS. 
SAN FRANCISCO TO SONORA.! 
August 4, 1854.— Left San Francisco in the high pressure steamboat ** American Eagle" for 
Stockton at 4 o’clock in the afternoon. In passing up the bay we experienced the full force of 
the great air-current that sweeps in from the ocean to the interior. The Golden Gate is like a 
great draught-channel through which the cold winds reach the heated plains on the other side 
of the Coast Mountains. The wind pours in with such violence that a heavy swell is constantly 
rolling in the channel, and small steamers roll and pitch as if there was a severe storm. The 
wind prevails from April to November. 
The small island beyond Angel Island, rising like a pinnacle in the bay, is formed of red rock 
similar to that of Lime Point, and it is probably the same metamorphosed formation. The wild- 
oat covers the hills so thickly that they seem like vast, unreaped fields of grain. The fires have 
not traversed as much of the surface as last year, when nearly all the hills in the vicinity of 
Benicia were burned off, leaving only a blackened surface, and the bare and sun-baked soil. 
A very perceptible change in the climate is felt soon after leaving San Francisco. The high 
ranges between the bay of San Pablo and the Pacific prevent the rush of air which passes so 
freely in at the Golden Gate, and appear to act the part of barriers, or a wall, to break the 
force of the wind. There i is, apparently, less moisture in the air, and its temperature is higher, 
August 5.—Arrived at Stockton early in the morning, and soon left by stage for Sonora. 
Stockton is built on the margin of a slough of the river, and is upon the alluvial clay of the 
delta. We soon pass from this clay to the firmer and more gravelly materials of the long slope 
of the valley, which reaches up to the foot-hills of the mountains, precisely as we find it further 
south PE the Tuslgmne or other streams. This Bars has a very gentle are inclination 
and sections = the drift deposits, was stolen, with other articles, on the Isthm 
BER to present all the observations which were made, or to er pori a map, those now given. 
