

434 INDEX 
Crush-breccia, 81, 170. See Breccia 
Crustal movements, slowly effected, 
175, 403; a cause of jointing, 153; 
influence of, on coast-lines, 423 
Cryptocrystalline structure, 36, 43, 44 
Crystalline igneous rocks, 40 
Crystalline schists, 88 
Crystallites, 34 
Cumberland, ores of, 259, 269 
Current-bedding, 115 
Current marks,‘116 
Curvature of strata, 127, 133 
Curve of erosion, 417 
Cycle of erosion, 401, 404, 412, 414, 
422 
DACITE, 49 
Danube, River, 391, 411 
Dead Sea, 4.19 
Deep leads, 234 
Deflation, 58, 369 
Deformation-mountains, 396; -valleys, 
413 
Deformation of crust, slowly effected, 
175, 403 
Deltas, 116, 411, 417 
Dendrites, 123 
Denudation, 239, 250, 309, 391, 398, 
410. See also Erosion 
Depth of lodes, 239 
Derbyshire, lead ore of, 269 
Derivative rocks, 55 ; soils from, 383 
Desquamation of rock-surfaces, 152, 
369 
Determination of rocks in the field, 81 
Devitrification, 35, 36, 45 
Diabase, 50 
Diagonal bedding, 115 
Diallage, 18 
Dichroite, 25 
Diorite, 48, 86, 89; orbicular, 48, 124 ; 
soils derived from, 380 
Dip, 127, 427 
Dip-faults, 158 
Dip-joints, 146 
Dip-slope, 296 
Dirt-bed of Portland, 100 
Disease in relation to geological con- 
ditions, 366 
Disintegration of rocks, 368 
Dislocation-mountains, 401 ; -valleys, 
413 
Dislocations, See Faults 
Disseminations, 261 
Dissolution-basins, 420 
Divergent lodes, 242 
Dolerite, 50, 89 
Dolomite (mineral) 29; (rock), 65, 82, 
124 
Downs, North and South, 410 
Downthrows, 155 
Drainage, natural underground, 350 : 
sewerage, 364; streams and rivers, 
415 
Drift soils, 376, 385 
Drumlins, Drums, 312, 317 
Druse and drusy cavities, 125, 246 
Dry valleys, 414 
Dunderlandstal, ores of, 235 
Dunes, 391, 396 
Dunite, 52 
Dura Den, 263 
Dust, 58, 376, 391 
Dykes, 197, 198, 202, 211, 301 ; com- 
posite, 206 ; effect of, on underground 
circulation of water, 356 
Dynamo-metamorphism, 223 
EARTHQUAKES a cause of jointing, 154 
Eclogite, 79 
Economic geology, 330 
Effusive eruptive rocks, 208 
Eifel, crater-lakes of the, 420 
Elzolite, 14 ; -syenite, 46 
Elements, 31 
Elk Mountains, laccoliths of, 191 
Embankments, foundations of, 349 
Emery, 9 
Enclosures in minerals, 4, 37 
End of coal, 146 
Endogenous veins, 207 
Endomorphs, 6, 37 
Engadine, lakes of, 421 
Engineering and geological structure, 
340 
Enstatite, 18 
Eocene, climate of, 99; contrast be- 
tween deposits of, in London Basin 
and in Switzerland, 107 
Epidote group, 24 

