VI 
CONTENTS. 
CHAPTER IV. 
OBSERVATIONS ON THE GEOLOGY OF THE ROUTE—Continued. 
From the Rio Grande to the Colorado Chiquito. 
Coal along the Puerco.—Las Lunas.—Burning coal-bed at Cabolleta—Red sandstone strata.—Lava.—Volcanoes, San 
Mateo.—Blue clay and fossils.—Covero.—Lava stream.—Coulee.—Small crater.—Granite of the Sierra Madre.—Car¬ 
boniferous.—Gneiss.—Limestone on the east side, at Campbell's Pass.—Summit.—Carboniferous.—Volcano at the south.— 
Table lands west of the Sierra Nevada.—Mounds in peculiar forms.—El Moro, or Inscription Rock.—Perfection of old 
inscriptions show the slow wearing of the sandstone.—Ojo Pescado.—Lava stream in the valley.—Lava covers the stream.— 
Ruins at the springs.—Coal.—Zufii and its vicinity.—Cliffs of white sandstone.—Curious forms resulting from weather¬ 
ing.—Traditions of a deluge.—Fossils.—Jacob’s Well.—Drift of pebbles of jasper and agate.—Puerco of the west.— 
Fossil tree.—Red strata.—General view of the extent of the table-land.—Canon of the Colorado probably in the pla¬ 
teau.—Valley of the Colorado Chiquito.—Red clay and gypsum.—Fossil trees silicified.—Drift.—Basaltic buttes. 
CHAPTER V. 
OBSERVATIONS ON THE GEOLOGY OF THE ROUTE—Continued. 
From the Colorado Chiquito to San Pedro. 
From the Colorado Chiquito to the Great Colorado.—Magnesian limestone.—Canon Diablo in limestone.—Similar limestone 
at other places.—Granite.—Older than the magnesian limestone.—Extinct volcano called San Francisco Mt.—Lava 
streams.—Secondary cones.—Volcanic ashes.—Direction and extent of the lava streams.—Sandstone.—Bill Williams’ 
mountain, volcanic : its lava streams.—Carboniferous limestone.—Picacho, of granite.—Carboniferous limestone and 
fossils.—Aztec mountains.—Horizontal strata forming a clilf.—Lava.—Cygnus mountain.—Aquarius mountains.—Gneiss 
and metamorphic rocks.—Tertiary strata.—Trap dikes.—Valley of the Hawilhamook.—Cerbat mountains.—Volcanic 
rocks.—Colorado river.—Colorado river to San Pedro.—Granitic ranges.—Great Basin.—Soda lake and Mojave river.—- 
Nature of the incrustation.—Sand-dunes.—Metamorphic rocks.—Soil of the slopes.—Cajon Pass.—Sandstone probably 
tertiary.—Granite and metamorphic rocks.—Tertiary strata.—Fossils.—Recent elevation.—Bitumen and tar springs.— 
Trap rock.—Alluvial. 
CHAPTER YI. 
GENERAL DESCRIPTION OF THE GEOLOGICAL FORMATIONS. 
Granite , Metamorphic , Devonian, and Carboniferous. 
General remarks.-—Granitic rocks predominate west of the Aztec mountains —Red or pink granite predominates —Principal 
places at which metamorphic rocks have been identified : their probable age.—Azoic.—Silurian.—Carboniferous.—- 
Relative ages of the granitic chains.—Anterior to and later than the carboniferous.—Tertiary or post-tertiary. —Ranges of 
the same age not coincident in direction.—Devonian, uncertainty of its existence -—Carboniferous.—Of the Sandia and 
Santa Fe mountains.—General extent along the line.—Lithological characters.—Thickness of the strata.—Fossils.—Sand¬ 
stone and coal measures.—Lithological characters.—View near Fort Coffee.—Overhanging strata at Sugarloaf mountain.— 
Ferruginous sandstone.—Thickness of the coal measures.—Diminish towards the west.—Fossils.—Coal.—General obser¬ 
vations on the carboniferous formation.—Disturbances of the formation.—Denudation.—Limestone of Canon Diablo.— 
Metamorphic limestone of Cajon and Tejon, probably carboniferous. 
CHAPTER VII. 
GENERAL DESCRIPTION OF THE GEOLOGICAL FORMATIONS—Continued. 
Gypsum formation, Cretaceous, Tertiary, and Volcanic. 
Gypsum formation supposed to be Trias by Mr. Marcou.—Absence of fossils.—Called gypsum formation by Prof. Hitchcock.— 
Extent and boundaries of the formation.—Lithological characters.—Section at Pyramid mountain.—Gypsum.—Extent 
and locality of the deposits.—Most abundant east of the mountains.—Dolomite, east and west of the mountains.— 
Thickness of the gypsum formation.—Disturbances of the strata.—Uplift near San Antonio due to trap dikes.—Extend 
in nearly unbroken strata from the east to the west side of the mountains.—Probable age of the formation and its 
reported synchronism with the Trias of Europe.—Cretaceous formation.—Points at which it is identified by fossils.— 
Cretaceous age of the Llano Estacado.—Of the plateau west of the Sierra Madre.—Extent of the cretaceous along the 
route.—Mineral characters.—Thickness.—Dislocations.—Mountain ranges older than the cretaceous.—Submerged in 
part by the Cretaceous sea.—Reported Jurassic age of the Llano.—Tertiary.-Post-tertiary.—Alluvial. 
