The Geologic Phenomena At Yellowstone National Park

excerpt
If from a topographic and picturesque point of view, the Yellowstone plateau is endowed with everything: rocks, rivers, lakes, high peaks, endless forests, rich pastures, from a geological point of view it is almost unique: some of the mountains I have mentioned are made of crystalline schist, especially gneiss, on which Paleozoic deposits lie (Tetons); others belong to the Mesozoic age (Wind River Range and Absaroka); others are made of granite, gneiss and various archaic and Precambrian schist (Snowey Range); others are made of archaic deposits on which Paleozoic and Mesozoic deposits lie (Gallantin Mountains). All these mountains display enormous eruptive rocks that jut out, rocks such as andesite, rhyolite, basalt; but the quantity of matter thrown out during the eruptions was so large that the fluid rhyolite, after having gone round the feet of the mountains, whose margins it limits, poured inside and gathered there forming deposits of more than 600 m in thickness (e.g. Obsidian Cliff). The volcanic activity of this plateau continues to this day. You may come across a hot spring every step you make, you may find yourself in front of a hot muddy volcano, fumaroles, sulphatars and dozen of geysers every turn you take. There are no less than 3500 geysers, hot springs, hot muddy volcanoes, fumaroles and even sulphatars.Those who visit this place are thrilled by the deafening sound of geysers, by the sharp whistle of fumaroles and by the smell of sulfur given off by the sulphatar; all these, together with the heat and the fear of sinking at each wrong step, make you believe that you are in hell. It is certain that if the Antiquity had known it, the entrance to hell would have been situated on this very plateau, not on the Etna…Until twenty-seven years ago, this region, which is very interesting from all points of view, was known only to the natives of America, the "redskin" Indians, who used to walk around here in order to admire the beautiful landscape, the geological phenomena, which they undoubtedly attributed to Gods, and to hunt bison and beavers living on this high and isolated plateau. The members of these species must have been very numerous, if we judge by the traces they left. In the Beaver Lake, for example, one can see the remains of the beautiful lacustrine lairs of these industrious animals, which have retired to more hidden places nowadays because of the road built along this lake; it is almost sure fact that when prehistoric people left their caves and their tree hollows, they built their houses after the models offered by the dwellings of the beavers.Extraordinary Journeys, CD Press, 2001


by Gregoriu Ştefănescu