The lithosphere and its envelopes—The evolution of ideas concerning the earth’s figure—The oblateness of the earth—The arrangement of oceans and continents—The figure toward which the earth is tending—Astronomical _versus_ geodetic observations—Changes of figure during contraction of a spherical body—The earlier figures of the earth—The continents and oceans at the close of the Paleozoic era—The flooded portions of the present continents—The floors of the hydrosphere and atmosphere—Reading references 8
THE NATURE OF THE MATERIALS IN THE LITHOSPHERE
The rigid quality of our planet—Probable composition of the earth’s core—The earth a magnet—The chemical constitution of the earth’s surface shell—The essential nature of crystals—The lithosphere a complex of interlocking crystals—Some properties of natural crystals, minerals—The alterations of minerals—Reading references 20
The processes by which rocks are formed—The marks of origin—The metamorphic rocks—Characteristic textures of the igneous rocks—The classification of rocks—Subdivisions of the sedimentary rocks—The different deposits of ocean, lake, and river—Special marks of littoral deposits—The order of deposition during a transgression of the sea—The basins of deposition of earlier ages—The deposits of the deep sea—Reading references 30
CONTORTIONS OF THE STRATA WITHIN THE ZONE OF FLOW
The zones of fracture and flow—Experiments which illustrate the fracture and flow of solid bodies—The arches and troughs of the folded strata—The elements of folds—The shapes of rock folds—The overthrust fold—Restoration of mutilated folds—The geological map and section—Measurement of the thickness of formations—The detection of plunging folds—The meaning of an unconformity—Reading references 40
THE ARCHITECTURE OF THE FRACTURED SUPERSTRUCTURE
The system of the fractures—The space intervals of joints—The displacements upon joints: faults—Methods of detecting faults—The base of the geological map—The field map and the areal geological map—Laboratory models for study of geological maps—The method of preparing the map—Fold _vs._ fault topography—Reading references 55
THE INTERRUPTED CHARACTER OF EARTH MOVEMENTS: EARTHQUAKES AND SEAQUAKES
Nature of earthquake shocks—Seaquakes and seismic sea waves—The grander and the lesser earth movements—Changes in the earth’s surface during earthquakes: faults and fissures—The measure of displacement—Contraction of the earth’s surface during earthquakes—The plan of an earthquake fault—The block movements of the disturbed district—The earth blocks adjusted during the Alaskan earthquake of 1899 67