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.
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.
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.
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.
CHAPTER V.
ON THE OLDER TERTIARY FORMATIONS OF PATAGONIA AND CHILE.
Rio Negro.—S. Josef.—Port Desire, white pumiceous mudstone with
infusoria.—Port S. Julian.—Santa Cruz, basaltic lava of.—P.
Gallegos.— Eastern Tierra del Fuego; leaves of extinct
beech-trees.—Summary on the Patagonian tertiary
formations.—Tertiary formations of the Western Coast.—Chonos and Chiloe
groups, volcanic rocks of.—Concepcion.—Navidad.—
Coquimbo.—Summary.—Age of the tertiary formations.—Lines of
elevation.— Silicified wood.—Comparative ranges of the extinct and
living mollusca on the West Coast of S. America.—Climate of the tertiary
period.—On the causes of the absence of recent conchiferous deposits on
the coasts of South America.—On the contemporaneous deposition and
preservation of sedimentary formations.
CHAPTER VI.
PLUTONIC AND METAMORPHIC ROCKS:—CLEAVAGE AND FOLIATION.
Brazil, Bahia, gneiss with disjointed metamorphosed dikes.—Strike of
foliation.—Rio de Janeiro, gneiss-granite, embedded fragment in,
decomposition of.—La Plata, metamorphic and old volcanic rocks
of.—S. Ventana.—Claystone porphyry formation of Patagonia; singular
metamorphic rocks; pseudo-dikes.—Falkland Islands, palaeozoic fossils
of.—Tierra del Fuego, clay-slate formation, cretaceous fossils of;
cleavage and foliation; form of land.—Chonos Archipelago, mica-schists,
foliation disturbed by granitic axis; dikes.—Chiloe.—Concepcion,
dikes, successive formation of.—Central and Northern
Chile.—Concluding remarks on cleavage and foliation.—Their close
analogy and similar origin.—Stratification of metamorphic
schists.—Foliation of intrusive rocks.—Relation of cleavage and
foliation to the lines of tension during metamorphosis.
CHAPTER VII.
CENTRAL CHILE:—STRUCTURE OF THE CORDILLERA.
Central Chile.—Basal formations of the Cordillera.—Origin of the
porphyritic clay-stone conglomerate.—Andesite.—Volcanic
rocks.—Section of the Cordillera by the Peuquenes or Portillo
Pass.—Great gypseous formation.—Peuquenes line; thickness of
strata, fossils of.—Portillo line.—Conglomerate, orthitic granite,
mica-schist, volcanic rocks of.— Concluding remarks on the denudation and
elevation of the Portillo line.— Section by the Cumbre, or Uspallata
Pass.—Porphyries.—Gypseous strata.— Section near the Puente
del Inca; fossils of.—Great subsidence.—Intrusive
porphyries.—Plain of Uspallata.—Section of the Uspallata
chain.— Structure and nature of the strata.—Silicified vertical
trees.—Great subsidence.—Granitic rocks of axis.—Concluding
remarks on the Uspallata range; origin subsequent to that of the main
Cordillera; two periods of subsidence; comparison with the Portillo chain.
CHAPTER VIII.
NORTHERN CHILE.—CONCLUSION.
A Section from Illapel to Combarbala; gypseous formation with silicified
wood.—Panuncillo.—Coquimbo; mines of Arqueros; section up valley;
fossils.—Guasco, fossils of.—Copiapo, section up valley; Las
Amolanas, silicified wood.—Conglomerates, nature of former land, fossils,
thickness of strata, great subsidence.—Valley of Despoblado, fossils,
tufaceous deposit, complicated dislocations of.—Relations between ancient
orifices of eruption and subsequent axes of injection.—Iquique, Peru,
fossils of, salt-deposits.—Metalliferous veins.—Summary on the
porphyritic conglomerate and gypseous formations.—Great subsidence with
partial elevations during the cretaceo-oolitic period.—On the elevation
and structure of the Cordillera.—Recapitulation on the tertiary
series.— Relation between movements of subsidence and volcanic
action.—Pampean formation.—Recent elevatory
movements.—Long-continued volcanic action in the
Cordillera.—Conclusion.