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31. Reversed Fault .......
32. Single Thrust-plane
33. Section across Coal-basin of Mons (M. Bertrand)
34. Section from Quinaig to Head of Glenbeg (Geol. Survey)
35. Synclinal Double-fold ......
36. Anticlinal Double-fold
37. Diagram of Mountain Flexures ....
38. Diagram of Anticlinal Mountains ....
39. Synclinal Valley shifting toward Anticlinal Axis
40. Section across the Swiss Alps (A. Heim) .
41. Summit of Santis, East Side (A. Heim) .
42. Section across the Schortenkopf, Bavarian Alps (E. Fraas)
43. Section across the Kaisergebirge, Eastern Alps (E. Fraas)
44. Section across the Vald'Uina (Glimbel) ....
45. Sichelkamm of Wallenstadt (Heim) ....
46. Section across the Northern Limestone Alps (E. Fraas) .
47. Section across the Diablerets (Renevier) ....
48. Section across Dent de Morcles (Renevier)
49. Inversion and Overthrust in the Mountains South of the Lake of
Wallenstadt (E. Fraas, after A. Heim)
50. Symmetrical Flexures of the Jura Mountains .
51. Section across Western part of the Jura Mountains (P. Choffat)
52. Section across part of the Sandstone-zone of the Middle Carpathians
53. Section across part of the Middle Carpathians (Vacek)
54. Section across the Appalachian Ridges of Pennsylvania (H. D.
55. Unsymmetrical Folds, giving rise to Escarpments and Ridges
56. Structure of the Ardennes (after Cornet and Briart) .
57. Diagrammatic Section across a Plateau of Erosion .
58. Section across portion of Southern Uplands, showing Old Red Sandstone resting upon Plain of Erosion
59. Section from Glen Lyon to Cam Chois (Geol. Survey)
60. Section of Normal Fault......
61. Normal Fault, with High Ground on Downthrow Side .
62. Normal Fault, with High Ground on Upcast Side .
63. Faults in Queantoweep Valley, Grand Canon District (Dutton)
64. Ranges of the Great Basin (Hinman, afterGilbert: length of section,
65. Section from the Mediterranean across the Mountains of Palestine to
the Mountains of Moab (after M. Ulanckenhorn).
66. Section across the Vosges and the Black Forest (after Penck)
67. Section of Coal-measures nearCambusnethan, Lanarkshire, on a true
G8. Section on a true scale across " Tynedale Fault," Newcastle Coal-field 168
69. Section across Great Fault bounding the Highlands near Birnam,
Perthshire ........... 169
70. Section across Great Fault bounding the Southern Uplands . . 170
71. Diagram Section across Horstgebirge 170
72. Mountain of Granite 175
73. Plain of Granite overlooked by Mountains of Schists, etc. . . 176
74. Diagrammatic Section of a Laccolith showing Dome-shaped Eleva
tion of Surface above the Intrusive Rock (after G. K. Gilbert) . 177
75. View of Necks—Cores of old Volcanoes (Powell) .... 188
76. Section of Highly Denuded Volcano, Miuto Hill, Roxburgshire . 189
77. Diagrammatic Section across the Valley of the Tay, near Dundee . 190 7S. View of Mesa Verde and the Sierra el Late, Colorado (Hayden's Report for 1875) 203
7.). Wind Erosion: Table-Mountains, etc., of the Sahara (Mission de
Chadamcs) ........... 254
80. Wind Erosion: Harder Beds amongst inclined Cretaceous Strata,
Libyan Desert (J. Walther) 254
S1. Wind Erosion : Stages in the Erosion and Reduction of a Tablemountain (J. Walther) 255
82. Manganese Concretions weathered out of Sandstone, Arabah Mount
ains, Sinai Peninsula (J. Walther) 256
83. Formation of Sand-dunes 259
84. Advance of Sand-dunes ......... 259
85. Longitudinal Sections of Lake-basins on a true scale . . . 293
86. Sea-cliff cut in Horizontal Strata 3x9
87. Sea-cliff cut in Strata dipping Inland 320
88. Sea-cliff cut in Strata dipping Seaward 320
89. Sea-cliff cut in Beds dipping Seaward 323
Plate I. Joints in Granite, Glen Kunach, Cairngorm (from a photograph
by W. E. Carnegie Dickson) to face 200
Plate II. Weathering of Joints in Granite, Cairngorm Mountains (from a
photograph by W. E. Carnegie Dickson) . . . to face 202
EARLY VIEWS AS TO ORIGIN OF SURFACE-FEATURES—ROCKS AND
WHEN geologists began to inquire into the origin
vals among great successions of marine strata; in other places, limestones, evidently of oceanic origin, were found entering into the framework of lofty mountains far removed from any sea. It was these and similar striking contrasts between the present and the past which doubtless induced the belief that the earth's crust, after having passed through many revolutions more or less catastrophic in character, had at last become approximately stable—the occasional earthquakes and volcanic disturbances of recent times being looked upon as only the final manifestations of those forces which in earlier ages had been mainly instrumental in producing the varied configuration of the land. Mountains and valleys belonged to earth's Sturm und Drang period. That wild time had passed away, and nc>w-old age, with its lethargy and repose, had supefven.ecL L The tumultuous accumulations of stony clay, blocks and boulders, gravel and sand that overspread extensive areas in temperate latitudes were- T/eJieved to be the relics of the last great catastrophe-Which had affected the earth's surface. Some notable, xlisturbance of the crust, it was thought, had cause'd^ihe' waters of northern seas to rush in devastating waves across the land. When these diluvial waters finally retired, then the modern era began—an era characterised by the more equable operation of nature's forces.
But with increased knowledge these views gradually became modified. Eventually, it was recognised that no hard-and-fast line separates past and present.