How an overflowing spring begins to build a terrace of "geyserite" deposits, Yellowstone Park, U.S.A.

Publication

How an overflowing spring begins to build a terrace of "geyserite" deposits, Yellowstone Park, U.S.A.

Description

You are up on one of the terraces of the Mammoth Springs, an irregular shaped hill, three hundred feet high, above the plateau by the hotel and the barracks of Fort Yellowstone. All the "rock" on which you stand here has been built up by slow deposits from the overflowing waters of the boiling hot springs. you can see here for yourself what the process is; these waters, boiling over the rim of their kettle, are trickling down over the outside, and, as they evaporate, they leave this crusty deposit behind, like salt or sugar on a cook's utensils. Ages and ages on ages this sort of thing has been going on right here. The deposits, though steadily increasing, add bulk very slowly. the material deposited is calcareous, i.e., like limestone in its nature; in this respect it differs from most of the mineral deposits around the geysers, or spouting springs, for their waters hold in solution less lime and more silica. Ripply little "terraces" of travertine, just like these have become, in the course of time, magnificently piled-up masses most picturesque to see. The rock-formation takes all sorts of beautiful colors, greens, pinks, yellows, golden-browns and reddish terracottas. Pools of hot water held in depressions of the terraces are as blue as a midsummer sky; many of them smell strongly of sulphur and soda. In some of the pools, curiously enough, gey colored water-plants (algae) grow, bathed in water at a temperature of 150° Fahrenheit. From Notes of Travel, No.13, copyright, by Underwood & Underwood.