CONTENTS 
No. 1. 
GENERAL REPORT UPON THE GEOLOGICAL COLLECTIONS. 
BY WILLIAM P. BLAKE, 
GEOLOGIST OF THE OFFICE OF THE UNITED STATES PACIFIC RAILROAD EXPLORATION AND SURVEYS. 
INTRODUCTORY LETTER. 
CHAPTER I. 
OBSERVATIONS UPON THE MOUNTAIN RANGES AND GENERAL RELIEF OF THE SURFACE ALONG THE ROUTE. 
Direction and length of the line.—Barometric profile.—Six principal chains crossed by the survey.—Sandia and Santa Fd 
ranges.—Sierra Madre—Aztec and Aquarius ranges. —Cerbat ranges.—Ranges along the Colorado.—Pai Ute ranges. 
Bernardino Sierra.—Mogoyon Sierra.—Elevation produced by the volcano of San Francisco.—Table-lands, plains, moun¬ 
tain slopes, and valleys.—Character of the eastern slope of the Anahuachian chain, near the line of survey.—Bluff borders 
of the Llano : its extent and mean elevation.—Plain between the Santa Fe and Albuquerque mountains and the Sierra 
Madre—Its character and average elevation.—Table-lands and slopes west of the Sierra Madre—Extent west and north—The 
slope on the west more gradual than on the east—Stair-like descents—General elevation.—Val del China.—Valley of 
Hawilhamook—Its deep narrow character.—Plain or valley between the Cerbat range and the Colorado river.—Valley of 
the Colorado.—Great Basin—Its general character formed by a combination of short ridges and slopes—Inclination of 
the slopes, and their origin.—Plain and valleys bordering the Pacific. 
CHAPTER II. 
OBSERVATIONS ON THE GEOLOGY OF THE ROUTE. 
From the Mississippi river to the base of the Santa Fe and Albuquerque mountains. 
Alluvial formation of the Mississppi and Arkansas.—Bluffs.—Metamorphic rocks at Rittle Rock.—Tertiary fossils.—Carbon¬ 
iferous strata.—Petit Jean mountain.—Dardanelle rock—Trap dikes.—Bituminous coal.—Fort Smith.—Poteau mountains 
and Sugar Loaf.—Coal.—Carboniferous around Fort Smith —Coal in Arkansas.-—View near Fort Coffee.—Disturbances of the 
carboniferous straia.—San Bois range.—Coal at Ring’s plantation.—Fossil coal plants.—Delaware mountain.—Carbonif¬ 
erous limestone in ridges.—Proximity of outcrops of granite.—Delaware mountain to Antelope hills.—Gypsum forma¬ 
tion.—Lithological characters.—Denudation mountain.—Rock Mary, and other mounds—Their origin explained.—Gyp¬ 
sum in thick beds.—Dolomite.—Disturbed strata.—Cretaceous formations and fossils.—Accumulations of pebbles : allu¬ 
vium.- -Antelope hills.—White sandstone in bluffs along the route.—Table hill.—Upraised sandstone near the line. 
Bluff formation or loess.—Llano Estacado—its vertical cliffs.—Encampment creek—sections —Tucumcari hill.—Pyramid 
mound.—Colored section.—Fossils.—Plaza Larga.—Degradation of the strata.—Cretaceous fossils. -Anton Chico.—Canon 
Blanco and Cuesta.—Galisteo.—Trap dyke and volcanoes.—Granite. 
CHAPTER III. 
OBSERVATIONS ON THE GEOLOGY OF THE ROUTE—Continued. 
Santa Fe, Albuquerque, and the Valley of the Rio Grande del Norte. 
General remarks.—Sandia and Santa Fe mountains.—View of Albuquerque and the Sandia mountains.—Carboniferous lime¬ 
stone.—Granite.—Fossils.—Relative positions of the strata.—Coal measures.—Absence of outcrops on the west side of 
the mountains.—Metamorphic rocks.—Granite.—Trap dikes, at Galisteo and the headwaters of theTuerto.—Resemblance 
to ruins and walls.—Quartz veins.—Volcanoes and lava, Cerritos.—Plains of lava or basalt.—Bluff at San Felipe.—Sedi¬ 
mentary deposits of the valley of the Rio Grande.—Bluffs and horizontal beds -—Resemblance of the strata to those on 
the Canadian.—Cretaceous fossils at Pablazon.—Sandstone and selenite.—Probable cretaceous age of the strata in the 
valley of the Rio Grande.—Alluvial deposits.—Soil of the valley of the RioGranie.—-Sand-dunes.—Valley of the Puerco. 
