Grotesque shapes of geyserite among the pools of "Biscuit Basin," Yellowstone Park, U.S.A.
figureposted on 21.05.2019, 00:00 by No Author
You are in the region known as the Upper Geyser Basin and over at the west side of Firehole River. All these curious knobs and ridges of geyserite or sinter have been formed by slow degrees from the deposit of mineral matter which had been held in solution by the waters boiling up and over flowing from hot springs near by. The clear, shallow pools that you see here now filling all the intermediate hollows are very hot and beautifully blue in color. The blueness comes not from the reflection of the sky, but from the presence of certain microscopic forms of water plants that thrive in the extraordinarily high temperature. The "biscuits" themselves are grayish brown as if they had been given an extra hard bake; here and there they take an olive hue. They are amorphous (noncrystalline) silica and very hard. Thin crusts of similar deposits cover the ground out there beyond the pools and crunch under the foot like crusty snow. Scientists estimate that the stuff is deposited at the rate of about 1-30 of an inch in a year. Tourists are not allowed to break up these picturesque knobs for cabinet specimens or souvenirs. The government wisely prohibits all such injury to the Park wonders, so there is no danger that the place will be robbed of its charms, which nature took centuries to produce. From Notes of Travel, No.13, copyright, by Underwood & Underwood.