INDEX 



441 



Rocky Mountains, 143, 401 



Roman Camp Hill, 179 



Roofing-slate, 76 



Rotten-stone, 71 



Rubicelle, 8 



Ruby, 9 ; spinel-, 8 ; balas-, 8 



Russia, undisturbed palaeozoic strata in, 



107 ; ores of, 229, 234, 236 ; lakes of, 



419 

 Rutile, 7 



Saddle-reefs, 255 



Sandstone, 60, 84, 93 ; concretionary, 



123 ; columnar, 149 

 Sandstone-dykes, 211 

 Sand, volcanic, 53 ; -dunes, 391, 396 

 Sanidine, 11 

 Sapphire, 9 

 Sarawak, ores of, 266 

 Sarcen-stones, 378 

 Sardonyx, 5 

 Satin-spar, 30 

 Saussurite, 12 



Scandinavian Mountains, 407 

 Schillerisation, 49 

 Schistose structure, 74 

 Schists, 74, 88, 94 ; fossils in, 94 ; 



joints in, 150 ; ores in, 234 

 Schorl, 25 ; -granite, 42 

 Scoriae, 53 

 Scree-breccia, 57 

 Seam, 109 



Secondary enrichment of lodes, 249 

 Secondary minerals, 37 

 Secondary mountain-ranges, 401, 404 

 Secretionary ore-formations, 268 

 Secretionary structure, 124 

 Secretions in granite, 42 ; in rhyolite, 



126 

 Sections, horizontal or profile, 325 ; 



vertical, 329 

 Sedentary soils, 376 

 Sedimentary ore-formations, 269 

 Sedimentary rocks, 59 

 Segregation-veins, 208 

 Selenite, 30 

 Semi-opal, 6 

 Sepiolite, 23 

 Septaria, 121 

 Serpentine, 23, 79, 213, 221, 382 



Sewage-fields, dangers from, 365 



Sgurr Ruadh, 174 



Shale, 63 ; alum-, 63 ; arenaceous, 63 ; 



carbonaceous, 63 ; oil-, 63 

 Shear-structure, 80 

 Sheeted zones, 238 

 Sheets, intrusive. See Sills 

 Shell-marl, 70 

 Shelly limestone, 70 

 Shode-stones, 338 

 Shoots, 245 

 Siderite, 29, 236 

 Sidlaw Hills, 191 



Signs used on geological maps, 281 

 Silicates, 9 



Siliceous concretions, 120 

 Siliceous rocks, 82 

 Siliceous sinter, 6, 66 

 Sillimanite, 26 

 Sills, 192, 300 

 Silser See, 421 

 Silvaplana See, 421 

 Silver, 229, 251, 256, 260, 263, 265 

 Simple lodes, 240 

 Slates, 76, 224 

 Slaty cleavage, 224, 302 

 Slickensided stones in lodes, 245, 251 

 Slickensides, 150, 157, 171, 313 

 Smaragdite, 17 

 Soapstone, 23 

 Soda-lime-felspar rocks, 48 

 Sodalite, 14 

 Soil, 57, 282, 368 

 Soil-cap, 375 



Solenhofen limestone, 264 

 Solfataric or after-action, 266, 268, 339. 



See also Pneumatolytic action 

 Solutions, siliceous, 3 

 Soulvein, 406 



Southern Uplands, Scotland, 407 

 South Downs, 410 

 Spathic iron-ore, 68 

 Specific gravity of rocks, 89, 428 

 Specular iron, 6 



Sphaerosiderite, 29 ; nodules of, 122 

 Sphene, 25 

 Spherulite-rock, 45 

 Spherulitic structure, 34, 45 

 Spinel, 8 

 Spinelloids, 8 



