970 
water and mud, 232; mud volcanoes, 
234; geysirs, 236; order of appearance 
of lavas, 149; relation of volcanic action 
to granite, 544, 587; relation of to meta- 
morphism, 581; distribution of in space, 
259; causes of, 260, 917 
Yoleanic action (continued), historyof, 259 ; 
evidence of this action in Archean or 
Pre-cambrian time, 260, 643; Silurian, 
260, 662, 668, 670, 671, 673, 685, 689; 
Devonian, 695, 702, 703; Old Red 
Sandstone, 260, 560, 564, 713, 715; 
Carboniferous, 208, 245, 260, 559, 564, 
567, 738, 739, 740, 743; Permian, 260, 
560, 751, 755, 756, 757; Triassic, 260, 
769; Cretaceous, 831, 833; Eocene, 858, 
Oligocene and later Tertiary, 250, 565, 
861, 877, 881, 920 
Voleanic products, 197; gases and vapours, 
198, 211, 235, 262; sublimations, 229, 
298; water, 202; lava, 203; fragmentary 
materials, 162, 205, 216, 565; preserva- 
tion of organic remains in, 207, 606 
Voleanic structure, 239, 558; cones, 239 ; 
tuff-cones, 243; mud-cones, 245; lava- 
cones, 245; cones of tuff and lava, 247; 
craters, 241, 558; heads (Vulkanische 
Kuppen), 256; necks, 143, 163, 558 ; 
bedded volcanoes (Strato-Vulkane), 248; 
dome - volcanoes, 248; submarine vol- 
canoes, 249, 439; fissure or massive type 
of eruptions, 253; plateaux, 258, 564; 
lakes, 230, 240 
Voleano, Island of, 224, 226, 235, 255, 
320 
Volga, slope of, 363 
Volkmannia, 734 
Voltzia, 761* 
Voluta, 828, 840, 841%, 
' 881 
Volwaria, 850 
Vosges, metamorphism in the, 580 
Vulcanism, 197 
Vulsella, 847 
855, 873, 875*, 
Wacke, 161 
Wadhurst Clay, 817 
Wahsatch Group, 853 
Wahsatch Mountains, granite of, 553 
Walchia, 733, 752, 792 
Waldheimia, 789, 881 
Wales, coast alluvia of, 388; erect trees in 
coal-measures of, 496; crumpled coal 
seams in, 520; coalfield of, 289, 531; 
diorite bosses of, 545 
Walkerde, 161 
Walnut, early forms of, 838, 871 
Warminster Beds, 820 
Water, present in all rocks, 298; white- 
hot water-substance in lava, 297, 262, 
296, 573; origin of, in rocks, 299 ; 
effect of infiltration of upon rocks, 72 
107, ,155, 167, 299; solvent power of 
INDEX. 
increased. by heat and pressure, 300, 
310, 312, 348, 352 ; suspends solidification 
of eruptive rocks, 301; active chemical 
solutions in, 302, 347; three forms of, 
328; circulation of over the globe, 329; 
underground circulation of, 344; hard 
and soft, 348; chemical changes caused 
by underground, 351; effects of running 
water on rocks, 371; chemical action of 
river, 364, 372; without sediment does 
not erode, 373, 394 ; effects of freezing, 
401 
Waterfalls, origin of, 375, 926 
Water-ice, 110 
Water-level, alteration of by wind, 328; 
of springs, 345 
Water-lilies, fossil, 869, 875 
Watersheds, how determined, 925; aa in 
centre of a country, 925; less permanent 
than water-courses, 925 
Waterstones, 764 
Water-vapour of the atmosphere, 31 
_ Waves caused by earthquakes, 272; by 
wind, 327, 422, 423; by tides, 419 ; 
size of, 422; force of, 423, 428; effects 
of, 428; aided by air, 429 
Wealden deposits, 815, 817, 828 
Weathered blocks are apt to be mistaken 
for erratics, 413 
Weathered crust, varying thickness of, 
334; removal of by rain, 341; possible 
source of part of Boulder-clay, 888 
Weathering, examples of, 64, 66, 69, 71, 
72, 73, 74, 75, 76, '78, 81, 95,123, 154, 
136, 178; importation of in field-geology, 
178; definition of, 333; causes of, 334; 
conditions for resisting, 335 
Weber Quartzite, 749 
Wells, why shallow or deep, 345 
Wemmelien (Systéme), 851 
Wenlock Group, 676 
Weiss-stein, 125 
Westmoreland, iron of, 68 
Westphalia, Cretaceous rocks of, 828 
Whet-slate, 122 
White as a colour of rocks, 92 
White Lias, 764 
White Mountains (New England), glacia- 
tion of, 899 
White River Group, 869 
White Sea, communication between and 
Caspian, 397 
White Prag, 576 
Wiesbaden, mineral waters of, 351 
Williamsonia, '772* 
Willow, fossil forms of, 804, 829, 839, 855, 
877 
Wind, velocity of, 318; geological effects 
of, 320; transport of seeds by, 326 
Wolf, fossil, 869, 875, 898 
Wollastonite, artificially formed, 300 
Woods (see Forests) 
Woolhope Limestone, 676 
noiastlinil 
