CONTENTS. 
CHAPTER I. 
Geology of the coast of Southern California. 
‘ Comparison of structure of Coast Mountains north and south of San Francisco.—Evidences of identity.—Infusorial beds and 
bitumen of Monterey, Santa Barbara, San Luis Obispo, &c.—Origin of bituminous exudations. —Relative age of the 
Coast Mountains. —Miocene strata of Coast Mountaius wanting in Sierra Nevada —Sierra Nevada oldest.—Mr. Marcou’s 
description of the ‘‘ Coast Range System.’’—Raised sea bottoms and shell teds at San Luis Obispo, San Pedro, and Sin 
F Diego, 
CHAPTER II. 
Geology of route from San Diego to Fort Yuma. 
General features. —The Peninsular Mountains.—Their relations to the Sierra Nevada.—Prevalence of granitic and gneissoid 
‘ . tocks.—Character of the granites.—Modern deposits skirting their bases proof of recent elevation.—Principal upheaval 
after Eocene and before Miocene period.—Local geology.—Vicinity of San Diego.—Miocene strata and fossils.— 
eee Modern trap eruption east of the Mission —San Diego to the Desert.—Trap near Penasquitas.—Granites with felspathic 
7 veins of San Pasqual and Laguna.—Santa Isabel.—Warner’s.—The Oaks.—San Felipe.—Tertiaries of Carisso Creek.— 
Ostreas, Anomias, Gnathodons, contained in them.—The Colorado Desert.—Arroyos or ‘‘ Washes.”’— rted 
ical blocks. —Eroded and polished pebbles—Structure and origin of the Desert.—Ancient fresh-water lakes.—New River, 
Alamo Mocho, Cooke’s Well.—Desert gravel transported from Upper Colorado. 
CHAPTER III. 
Geology of country bordering Lower Colorado. 
General features of Colorado Basin —Desert Plains and network of Mountains.—Volcanic character of the district.—Local 
geology.—Mouth of the Colorado to Fort Yuma.—Transport and deposition of sediment by the river.—Fort Yuma.— 
Purple Hills.—Highly colored porphyries, trachytes, and tufas.—Explorer’s Pass.—Granite.—Gold, copper, iron, and 
lead of Purple Hills.—Chimney Peak.—Turreted summits of volcanic mountains in this region.—Theory of their forma- 
tion.—Barrier Islands —Quaternary and Tertiary conglomerates.—Spire Range.—Light-house Rock.—Metamorphosed 
red sandstones.—Gneissoid rocks of Chocolate Mountains.—Gravel beds bordering river.—Great Colorado Valley.— 
Stratification of sediments. —Origin of cross and curved stratification.—Alternations of layers of sand and clay.—Sun+ 
cracked clay seams.—Half way and Riverside Mountains.—Metamorphic limestone.—Talcose slate.—Metalliferous 
rocks.—Monument Mountain and Caiion.—Tertiary conglomerates.—Granite with metalliferous veins.—Metamorphic 
limestone.—Silver, copper, lead, iron.—Geological scenery. 
CHAPTER IV. 
Geology of region between Bill Williams's Fork and Rio Virgen. 
Tnfusorial strata of White Rock. ehuevis Valley. Mountai Mojave Cafion.—Met phosed Tertiary rock 
Chem 
Porphyries and trachytes,—Mojave Valley. —Black iscuink —Prevalence of erupted rocks.—Dead Mountai Pyramid 
Cafion.—Cottonwood Valley.—Tertiary and modern gravels.—General structure of valleys traversed by Colorado,— 
Mount Davis.—Tertiary conglomerate.—Quaternary deposits.—Elepbant Hill.—Trough of the Colorado at entrance of 
Black Cafion.—Black Cafion.—Great variety of erupted rocks.—Amygdaloids containing chalcedony and cee 
quartz,—Plutonic character and scenery of the Black Mountains.—Rock salt and gypsum from Rio Virgen. 
