E-Book Overview
The book has no illustrations or index. Purchasers are entitled to a free trial membership in the General Books Club where they can select from more than a million books without charge. Subjects: Juvenile Nonfiction / Science
E-Book Content
Coral Reefs: Title
Page 1 of 230
GEOLOGICAL OBSERVATIONS ON SOUTH AMERICA by
CHARLES DARWIN
CONTENTS CRITICAL INTRODUCTION Page 269 Chapter I ON THE ELEVATION OF THE EASTERN COAST OF SOUTH AMERICA. Upraised shells of La Plata.—Bahia Blanca, Sand-dunes and Pumice-pebbles.—Step-formed plains of Patagonia, with upraised shells.—Terrace-bounded valley of Santa Cruz, formerly a sea-strait.—Upraised shells of Tierra del Fuego.—Length and breadth of the elevated area.—Equability of the movements, as shown by the similar heights of the plains.—Slowness of the elevatory process.—Mode of formation of the step-formed plains.—Summary.—Great shingle formation of Patagonia; its extent, origin, and distribution.— Formation of sea-cliffs. Page 277
Chapter II ON THE ELEVATION OF THE WESTERN COAST OF SOUTH AMERICA. Chonos Archipelago.—Chiloe, recent and gradual elevation of, traditions of the inhabitants on this subject.— Concepcion, earthquake and elevation of.—VALPARAISO, great elevation of, upraised shells, earth or marine origin, gradual rise of the land within the historical period.—COQUIMBO, elevation of, in recent times; terraces of marine origin, their inclination, their escarpments not horizontal.—Guasco, gravel terraces of.— Copiapo.—PERU.—Upraised shells of Cobija, Iquique, and Arica.—Lima, shell-beds and sea-beach on San Lorenzo.—Human remains, fossil earthenware, earthquake debacle, recent subsidence.—On the decay of upraised shells.—General summary. Page 303
Chapter III ON THE PLAINS AND VALLEYS OF CHILE:—SALIFEROUS SUPERFICIAL DEPOSITS. Basin-like plains of Chile; their drainage, their marine origin.—Marks of sea-action on the eastern flanks of the Cordillera.—Sloping terrace-like fringes of stratified shingle within the valleys of the Cordillera; their marine origin.—Boulders in the valley of Cachapual.—Horizontal elevation of the Cordillera.—Formation of valleys.—Boulders moved by earthquake-waves.—Saline superficial deposits.—Bed of nitrate of soda at Iquique.—Saline incrustations.—Salt-lakes of La Plata and Patagonia; purity of the salt; its origin. Page 333
file://C:\Documents and Settings\moawad\Desktop\crvsg10h\southam.html
1/27/2008
Coral Reefs: Title
Page 2 of 230
Chapter IV ON THE FORMATIONS OF THE PAMPAS. Mineralogical constitution.—Microscopical structure.—Buenos Ayres, shells embedded in tosca-rock.— Buenos Ayres to the Colorado.—S. Ventana.—Bahia Blanca; M. Hermoso, bones and infusoria of; P. Alta, shells, bones, and infusoria of; co-existence of the recent shells and extinct mammifers.—Buenos Ayres to St. Fe.—Skeletons of Mastodon.—Infusoria.—Inferior marine tertiary strata, their age.—Horse's tooth. BANDA ORIENTAL.—Superficial Pampean formation.—Inferior tertiary strata, variation of, connected with volcanic action; Macrauchenia Patachonica at S. Julian in Patagonia, age of, subsequent to living mollusca and to the erratic block period. SUMMARY.—Area of Pampean formation.—Theories of origin.—Source of sediment.—Estuary origin.—Contemporaneous with existing mollusca.—Relations to underlying tertiary strata. Ancient deposit of estuary origin.—Elevation and successive deposition of the Pampean formation.— Number and state of the remains of mammifers; their habitation, food, extinction, and range.— Conclusion.—Supplement on the thickness of the Pampean formation.—Localities in Pampas at which mammiferous remains have been found. Page 350
Chapter V ON THE OLDER TERTIARY FORMATIONS OF PATAGONIA AND CHILE. Rio Negro.—S. Josef.—Port Desire, white pumiceous mudstone with infusoria.—Po