
442 
Splint coal, 71 
Spotted slate, 76 
Springs, in bedded rocks, 350; in 
igneous rocks and schists, 353 ; shal- 
low and deep-seated, 355; use of, in 
field geology, 287 
Sprudelstein, 70 
Stackpolly, 406 
Stalactites, 64 
Stalagmites, 64 
Staurolite, 26 
Steatite, 23 
Step-faults, 167 
Steppes, 412; fauna of, 392 
Stilbite, 26 
Stockworks, 252, 260 
Stone coal, 71 
Stoss-seite, 314 
Strata, thinning and thickening of, 112, 
293; grouping of, 113; contempor- 
aneity of strongly contrasted, 114 
Stratification, 107, 109, II5 
Stratified rocks, 55 
Stratum, 108 
Streaky structure, 80 
Striz, glacial, 313 
Strike, 132; -faults, 162; -joints, 146 
Structural geology, 104; economic 
aspects of, 330, 347 
Subaérial rocks, 56 
Subhedral (hypidiomorphic) minerals, 
36 
- Subsequent eruptive rocks, 184 
Subsequent mountains, 405 
Subsequent valleys, 415 
Subsoil, 57, 282, 368, 376 
Substitution pseudomorphs, 38 
Succession of minerals in lodes, 249 
Sulphates, 29 
Sulphide ores, 231 
Sulphides, 27 
Sun-cracks, 118 
Superficial accumulations, 307 
Superior, Lake, 419 
Surface-creep, 129 
Surface-markings, 116 
Surface-wash, 308 
Sweden, ores of, 229, 234 
Syenite, 46, 89 
Syenitic mica-trap, 46 

INDEX 
Symmetrical folds, 135 
Symmetrical lodes, 246, 397 
Synclinal valleys, 352, 413 
Synclines, 136 
Synclinorium, 140 
Syngenetic ores, 228 
Systems of lodes, 241 
TABLELANDS, 412 
Tachylite, 51 
Talc, 23 ; -schist, 78, 88 
Tar springs, 72 
Tectonic basins, 419, 422 
Tectonic geology, 104 
Tectonic mountains, 394, 403, 407 
Tectonic valleys, 413 
Temperature, underground, 106, 145, 
270 
Terminal curvature, 129 
Terra rossa, 58, 385 
Terrestrial movements, evidence of, 102 
Tertiary deposits, 307 
Thermal metamorphism, 214, 219 
Thickening and thinning of strata, 112, 
293 
Throw of faults, 156 
Thrust-planes, 174 
Till. See Boulder-clay 
Tin-ore veins, 218 
Titanite, 25 
Toadstones, 269 
Tonalite, 48 
Topaz, 249 
Torrent-track of rivers, 417 
Torridon Mountains, 406 
Torso mountains, 407, 415 
Tourmaline, 25 ; -granite, 42 ; -hornfels, 
79 
Trachyte, 47, 86, 87, 89 
Transcurrent faults, 170 
Transported soils, 376 
Transvaal, gold of, 261 
Transverse lodes, 240 
Transverse thrusts, 170, 175 
Travelled soils, 376 
Travertine, 65 
Trees in peat, 319 
Tremolite, 16 
Troctolite, 49 
Trough-faults, 167 

