Exhibits > Why
Geysers Erupt > Geyser
Ingredients > Plumbing > To Build
TO BUILD A CONE
While traveling underground through volcanic
rhyolite, the thermal water dissolves silica, then carries it to
the surface. Although some of the silica lines the underground plumbing
system, a portion may be deposited around the outside of a geyser
to form a distinctive cone. The splashing of silica-rich thermal
water may also form spiny, bulbous masses of “geyserite.”
The vents within these massive cones are often very narrow, causing the water to splash and spray as it emerges. Every splash and each eruption adds its own increment of silica, enlarging the cones as the years pass. The cones of many of Yellowstone’s geysers are hundreds of years old.
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