CRITICAL INTRODUCTION.


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.