862 ELEMENTARY GEOLOGY 
GEYSERS AND Hor SprRINGS 
Hot Springs. — In many regions of the world, warm 
or hot water rises to the surface from hot springs. 
These, though not confined to such localities, are most 
common near volcanoes, or in regions where these 
have recently been active. Some apparently reach 
deep into the earth along 
fissures (Fig. 72), while 
others originate near the 
surface. They bring up 
in solution great quan- 
tities of carbonate of 
lime, silica, and other 
mineral substances. So 
they are engaged in an 
important chemical work 
deep in the earth, and 
at the surface are de- 
positing a portion of 
their product (Figs. 33, 34, and 221). Many deposits 
of ore have been formed by the action of heated water, 
and it is probable that down in the tubes of numerous 
hot springs, deposits of valuable minerals are even now 
Fic. 220. 
The Giant Geyser, Yellowstone Park, in 
eruption. 
being made. 
Geysers. —In several widely separated regions, but 
chiefly i New Zealand, Iceland, and the Yellowstone 
