| CHAPTER I |
| The Compilation of Earth History |
| | PAGE |
| The sources of the history—Subdivisions of geology—The study of earthfeatures and their significance—Tabular recapitulation—Geologicalprocesses not universal—Change, and not stability, the order of nature—Observationalgeology versus speculative philosophy—The scientificattitude and temper—The value of the hypothesis—Heading references | [1] |
| CHAPTER II |
| The Figure of the Earth |
| The lithosphere and its envelopes—The evolution of ideas concerning theearth’s figure—The oblateness of the earth—The arrangement ofoceans and continents—The figure toward which the earth is tending—Astronomicalversus geodetic observations—Changes of figure duringcontraction of a spherical body—The earlier figures of the earth—Thecontinents and oceans at the close of the Paleozoic era—Theflooded portions of the present continents—The floors of the hydrosphereand atmosphere—Reading references | [8] |
| CHAPTER III |
| The Nature of the Materials in the Lithosphere |
| The rigid quality of our planet—Probable composition of the earth’s core—Theearth a magnet—The chemical constitution of the earth’s surfaceshell—The essential nature of crystals—The lithosphere a complexof interlocking crystals—Some properties of natural crystals,minerals—The alterations of minerals—Reading references | [20] |
| CHAPTER IV |
| The Rocks of the Earth’s Surface Shell |
| The processes by which rocks are formed—The marks of origin—Themetamorphic rocks—Characteristic textures of the igneous rocks—Theclassification of rocks—Subdivisions of the sedimentary rocks—Thedifferent deposits of ocean, lake, and river—Special marks oflittoral deposits—The order of deposition during a transgression ofthe sea—The basins of deposition of earlier ages—The deposits of thedeep sea—Reading references | [30] |
| CHAPTER V |
| Contortions of the Strata within the Zone of Flow |
| The zones of fracture and flow—Experiments which illustrate the fractureand flow of solid bodies—The arches and troughs of the foldedstrata—The elements of folds—The shapes of rock folds—The overthrustfold—Restoration of mutilated folds—The geological map andsection—Measurement of the thickness of formations—The detectionof plunging folds—The meaning of an unconformity—Reading references | [40] |
| CHAPTER VI |
| The Architecture of the Fractured Superstructure |
| The system of the fractures—The space intervals of joints—The displacementsupon joints: faults—Methods of detecting faults—Thebase of the geological map—The field map and the areal geologicalmap—Laboratory models for study of geological maps—The methodof preparing the map—Fold vs. fault topography—Reading references | [55] |
| CHAPTER VII |
| The Interrupted Character of Earth Movements: Earthquakesand Seaquakes |
| Nature of earthquake shocks—Seaquakes and seismic sea waves—Thegrander and the lesser earth movements—Changes in the earth’ssurface during earthquakes: faults and fissures—The measure ofdisplacement—Contraction of the earth’s surface during earthquakes—Theplan of an earthquake fault—The block movements of thedisturbed district—The earth blocks adjusted during the Alaskanearthquake of 1899 | [67] |
| CHAPTER VIII |
| The Interrupted Character of Earth Movements: Earthquakesand Seaquakes (concluded) |
| Experimental demonstration of earth movements—Derangement of waterflow by earth movement—Sand or mud cones and craterlets—Theearth’s zones of heavy earthquake—The special lines of heavy shock—Seismotectoniclines—The heavy shocks above loose foundations—Constructionin earthquake regions—Reading references | [81] |
| CHAPTER IX |
| The Rise of Molten Rock to the Earth’s Surface; VolcanicMountains of Exudation |
| Prevalent misconceptions about volcanoes—Early views concerning volcanicmountains—The birth of volcanoes—Active and extinct volcanoes—Theearth’s volcano belts—Arrangement of volcanic ventsalong fissures, and especially at their intersections—The so-calledfissure eruptions—The composition and the properties of lava—Thethree main types of volcanic mountain—The lava dome—The basalticlava domes of Hawaii—Lava movements within the caldron of Kilauea—Thedraining of the lava caldrons—The outflow of the lava floods | [94] |
| CHAPTER X |
| The Rise of Molten Rock to the Earth’s Surface; VolcanicMountains of Ejected Materials |
| The mechanics of crater explosions—Grander volcanic eruptions of cindercones—The eruption of Volcano in 1888—The eruption of Taalvolcano on January 30, 1911—The materials and the structure of cindercones—The profile lines of cinder cones—The composite cone—Thecaldera of composite cones—The eruption of Vesuvius in 1906—Thesequence of events within the chimney—The spine of Pelé—Theaftermath of mud flows—The dissection of volcanoes—Theformation of lava reservoirs—Character profiles—Reading references | [115] |
| CHAPTER XI |
| The Attack of the Weather |
| The two contrasted processes of weathering—The rôle of the percolatingwater—Mechanical results of decomposition: spheroidal weathering—Exfoliationor scaling—Dome structure in granite masses—Theprying work of frost—Talus—Soil flow in the continued presence ofthaw water—The splitting wedges of roots and trees—The rock mantleand its shield in the mat of vegetation—Reading references | [149] |
| CHAPTER XII |
| The Life Histories of Rivers |
| The intricate pattern of river etchings—The motive power of rivers—Oldland and new land—The earlier aspects of rivers—The meshesof the river network—The upper and lower reaches of a river contrasted—Thebalance between degradation and aggradation—Theaccordance of tributary valleys—The grading of the flood plain—Thecycles of stream meanders—The cut-off of the meander—Meanderscars—River terraces—The delta of the river—The levee—Thesections of delta deposits | [158] |
| CHAPTER XIII |
| Earth Features shaped by Running Water |
| The newly incised upland and its sharp salients—The stage of adolescence—Thematurely dissected upland—The Hogarthian line of beauty—Thefinal product of river sculpture: the peneplain—The river crosssections of successive stages—The entrenchment of meanders withrenewed uplift—The valley of the rejuvenated river—The arrest ofstream erosion by the more resistant rocks—The capture of one river byanother—Water and wind gaps—Character profiles—Reading references | [169] |
| CHAPTER XIV |
| The Travels of the Underground Water |
| The descent within the unsaturated zone—The trunk channels of descendingwater—The caverns of limestones—Swallow holes and limestonesinks—The sinter deposits—The growth of stalactites—Formationof stalagmites—The Karst and its features—A desert from thedestruction of forests—The ponore and the polje—The return of thewater to the surface—Artesian wells—Hot springs and geysers—Thedeposition of siliceous sinter by plant growth—Reading references | [180] |
| CHAPTER XV |
| Sun and Wind in the Lands of Infrequent Rains |
| The law of the desert—The self-registering gauge of past climates—Somecharacteristics of the desert waste—Dry weathering: the red andbrown desert varnish—The mechanical breakdown of the desert rocks—Thenatural sand blast—The dust carried out of the desert | [197] |
| CHAPTER XVI |
| The Features in Desert Landscapes |
| The wandering dunes—The forms of dunes—The cloudburst in thedesert—The zone of the dwindling river—Erosion in and about thedesert—Characteristic features of the arid lands—The war of duneand oasis—The origin of the high plains which front the RockyMountains—Character profiles—Reading references | [209] |
| CHAPTER XVII |
| Repeating Patterns in the Earth Relief |
| The weathering processes under control of the fracture system—Thefracture control of the drainage lines—The repeating pattern in drainagenetworks—The dividing lines of the relief patterns: lineaments—Thecomposite repeating patterns of the higher orders—Readingreferences | [223] |
| CHAPTER XVIII |
| The Forms carved and molded by Waves |
| The motion of a water wave—Free waves and breakers—Effect of thebreaking wave upon a steep, rocky shore: the notched cliff—Coves,sea arches, and stacks—The cut rock terrace—The cut and builtterrace on a steep shore of loose materials—The work of the shorecurrent—The sand beach—The shingle beach—Bar, spit, and barrier—Theland-tied island—A barrier series—Character profiles—Readingreferences | [231] |
| CHAPTER XIX |
| Coast Records of the Rise or Fall of the Land |
| The characters in which the record has been preserved—Even coast linethe mark of uplift—A ragged coast line the mark of subsidence—Slowuplift of the coasts; the coastal plain and cuesta—The sudden upliftsof the coast—The upraised cliff—The uplifted barrier beach—Coastterraces—The sunk or embayed coast—Submerged river channels—Recordsof an oscillation of movement—Simultaneous contrary movementsupon a coast—The contrasted islands of San Clemente andSanta Catalina—The Blue Grotto of Capri—Character profiles—Readingreferences | [245] |
| CHAPTER XX |
| The Glaciers of Mountain and Continent |
| Conditions essential to glaciation—The snow-line—Importance of mountainbarriers in initiating glaciers—Sensitiveness of glaciers to temperaturechanges—The cycle of glaciation—The advancing hemicycle—Continentaland mountain glaciers contrasted—The nourishmentof glaciers—The upper and lower cloud zones of the atmosphere | [261] |
| CHAPTER XXI |
| The Continental Glaciers of Polar Regions |
| The inland ice of Greenland—The mountain rampart and its portals—Themarginal rock islands—Rock fragments which travel with theice—The grinding mill beneath the ice—The lifting of the grindingtools and their incorporation within the ice—Melting upon the glaciermargins in Greenland—The marginal moraines—The outwash plainor apron—The continental glacier of Antarctica—Nourishment ofcontinental glaciers—The glacier broom—Field and pack ice—Thedrift of the pack—The Antarctic shelf ice—Icebergs and snowbergsand the manner of their birth—Reading references | [271] |
| CHAPTER XXII |
| The Continental Glaciers of the “Ice Age” |
| Earlier cycles of glaciation—Contrast of the glaciated and nonglaciatedregions—The “driftless area”—Characteristics of the glaciatedregions—The glacier gravings—Younger records over older: theglacier palimpsest—The dispersion of the drift—The diamonds ofthe drift—Tabulated comparison of the glaciated and nonglaciatedregions—Unassorted and assorted drift—Features into which thedrift is molded—Marginal or “kettle” moraines—Outwash plains—Pittedplains and interlobate moraines—Eskers—Drumlins—Theshelf ice of the ice age—Character profiles | [297] |
| CHAPTER XXIII |
| Glacial Lakes which marked the Decline of the Last Ice Age |
| Interference of glaciers with drainage—Temporary lakes due to ice blocking—The“parallel roads” of the Scottish glens—The glacial LakeAgassiz—Episodes of the glacial lake history within the St. LawrenceValley—The crescentic lakes of the earlier stages—The early LakeMaumee—The later Lake Maumee—Lakes Arkona and Whittlesey—LakeWarren—Lakes Iroquois and Algonquin—The NipissingGreat Lakes—Summary of lake stages—Permanent changes ofdrainage effected by the glacier—Glacial Lake Ojibway in the Hudson’sBay drainage basin—Reading references | [320] |
| CHAPTER XXIV |
| The Uptilt of the Land at the Close of the Ice Age |
| The response of the earth’s shell to its ice mantle—The abandoned strandsas they appear to-day—The records of uplift about Mackinac Island—Thepresent inclinations of the uplifted strands—The hinge lines ofuptilt—Future consequences of the continued uptilt within the lakeregion—Gilbert’s prophecy of a future outlet of the Great Lakes tothe Mississippi—Geological evidences of continued uplift—Drowningof southwestern shores of Lakes Superior and Erie—Reading references | [340] |
| CHAPTER XXV |
| Niagara Falls a Clock of Recent Geological Time |
| Features in and about the Niagara gorge—The drilling of the gorge—Thepresent rate of recession—Future extinction of the American Fall—Thecaptured Canadian Fall at Wintergreen Flats—The WhirlpoolBasin excavated from the St. David’s gorge—The shaping of theLewiston Escarpment—Episodes of Niagara’s history and their correlationwith those of the glacial lakes—Time measures of the Niagaraclock—The horologe of late glacial time in Scandinavia—Readingreferences | [352] |
| CHAPTER XXVI |
| Land Sculpture by Mountain Glaciers |
| Contrasted sculpturing of continental and mountain glaciers—Wind distributionof the snow which falls in mountains—The niches whichform on snowdrift sites—The augmented snowdrift moves down thevalley: birth of the glacier—The excavation of the glacial amphitheateror cirque—Life history of the cirque—Grooved and fretteduplands—The features carved above the glacier—The features shapedbeneath the glacier—The cascade stairway in glacier-carved valleys—Thecharacter profiles which result from sculpture by mountain glaciers—Thesculpture accomplished by ice caps—The Norwegian tind orbeehive mountain—Reading references | [367] |
| CHAPTER XXVII |
| Successive Glacier Types of a Waning Glaciation |
| Transition from the ice cap to the mountain glacier—The piedmontglacier—The expanded-foot glacier—The dendritic glacier—Theradiating glacier—The horseshoe glacier—The inherited-basin glacier—Summaryof types of mountain glacier—Reading references | [383] |
| CHAPTER XXVIII |
| The Glacier’s Surface Features and the Deposits upon its Bed |
| The glacier flow—Crevasses and séracs—Bodies given up by the Glacierdes Bossons—The moraines—Selective melting upon the glaciersurface—Glacier drainage—Deposits within the vacated valley—Marksof the earlier occupation of mountains by glaciers—Readingreferences | [390] |
| CHAPTER XXIX |
| A Study of Lake Basins |
| Fresh water and saline lakes—Newland lakes—Basin-range lakes—Rift-valleylakes—Earthquake lakes—Crater lakes—Coulée lakes—Morainallakes—Pit lakes—Glint or colk lakes—Ice-dam lakes—Glacier-lobelakes—Rock-basin lakes—Valley moraine lakes—Landslidelakes—Border lakes—Ox-bow lakes—Saucer lakes—Crescenticlevee lakes—Raft lakes—Side-delta lakes—Delta lakes—Barrierlakes—Dune lakes—Sink lakes—Karst lakes: poljen—Playa lakes—Salines—Alluvial-damlakes—Résumé—Reading references | [401] |
| CHAPTER XXX |
| The Ephemeral Existence of Lakes |
| Lakes as settling basins—Drawing off of water by erosion of outlet—Thepulling in of headlands and the cutting off of bays—Lake extinctionby peat growth—Extinction of lakes in desert regions—The rôle oflakes in the economy of nature—Ice ramparts on lake shores—Readingreferences | [426] |
| CHAPTER XXXI |
| The Origin and the Forms of Mountains |
| A mountain defined—The festoons of mountain arcs—Theories of originof the mountain arcs—The Atlantic and Pacific coasts contrasted—Theblock type of mountain—Mountains of outflow or upheap—Domedmountains of uplift; laccolites—Mountains carved fromplateaus—The climatic conditions of the mountain sculpture—Theeffect of the resistant stratum—The mark of the rift in the erodedmountains—Reading references | [435] |
| APPENDICES |
| A. The quick determination of the common minerals | [449] |
| B. Short descriptions of some common rocks | [462] |
| C. The preparation of topographical maps | [467] |
| D. Laboratory models for study in the interpretation of geological maps | [472] |
| E. Suggested itineraries for pilgrimages to study earth features | [475] |
| Index | [489] |