sediments of volcanic origin
91Baltic Shield — The Baltic Shield (sometimes referred to as the Fennoscandian Shield) is located in Fennoscandia (Norway, Sweden and Finland), northwest Russia and under the Baltic Sea. The Baltic Shield is defined as the exposed Precambrian northwest segment of …
92Geology of the Grand Teton area — The geology of the Grand Teton area consists of some of the oldest rocks and one of the youngest mountain ranges in North America. The Teton Range, mostly located in Grand Teton National Park, started to grow some 9 million years ago. An older… …
93Lake — For other uses, see Lake (disambiguation). Oeschinen Lake in the Swiss Alps A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the… …
94Permian Period — Interval of geologic time, 290–248 million years ago. The last of the six periods of the Paleozoic Era, it follows the Carboniferous Period. During the Permian, the continents joined to form a single supercontinent, Pangea. Hot, dry conditions… …
95Cretaceous–Tertiary extinction event — Artist s rendering of bolide impact Badlands nea …
96Clastic rock — A thin section of a clast (sand grain), derived from a basalt score. Vesicles (air bubbles) can be seen throughout the clast. Plane light above, cross polarized light below. Scale box is 0.25 mm Clastic rocks are composed of fragments, or clasts …
97Devonian Period — Interval of geologic time from 417 to 354 million years ago; it was the fourth period of the Paleozoic Era. During the Devonian, a giant continent was situated in the Southern Hemisphere (see Gondwana), and other landmasses were located in the… …
98Earth, geologic history of — Introduction evolution of the continents, oceans, atmosphere, and biosphere. The layers of rock at the Earth s surface contain evidence of the evolutionary processes undergone by these components of the terrestrial environment during the… …
99Olympus Mons — This article is about the volcano on Mars. For other uses, see Olympus (disambiguation). Olympus Mons Wide view of the Olympus Mons aureole, escarpment and caldera Coordinates …
