Volcanic arc — Mariana Islands, an oceanic island arc A volcanic arc is a chain of volcanoes positioned in an arc shape as seen from above. Offshore volcanoes form islands, resulting in a volcanic island arc. Generally they result from the subduction of an… … Wikipedia
Mount Edziza volcanic complex — Mount Edziza, one of the main volcanoes of the Mount Edziza volcanic complex Elevation … Wikipedia
2004 and later volcanic activity of Mount St. Helens — The 2004 and later volcanic activity of Mount St. Helens has been documented as a continuous eruption with a gradual extrusion of magma at the Mount St. Helens volcano in Washington, United States. Starting in October 2004 and ceasing in January… … Wikipedia
Geology of the Lassen volcanic area — The geology of the Lassen volcanic area presents a record of sedimentation and volcanic activity in the area in and around Lassen Volcanic National Park in Northern California, U.S.. The park is located in the southernmost part of the Cascade… … Wikipedia
Pine Ridge Indian Reservation — Wazí Aháŋhaŋ Oyáŋke Pine Ridge Agency Reservation Badlands in the no … Wikipedia
tumulus — (pl. tumuli) A small dome or mound on the surface of a lava flow formed by the buckling of the congealing crust near the edge of a flow caused by differences in flow rates of the cooler crust above and the hotter, more fluid lava below.… … Glossary of landform and geologic terms
Earth Sciences — ▪ 2009 Introduction Geology and Geochemistry The theme of the 33rd International Geological Congress, which was held in Norway in August 2008, was “Earth System Science: Foundation for Sustainable Development.” It was attended by nearly… … Universalium
Europe — /yoor euhp, yerr / for 1; /yoo roh pee, yeuh / for 2, n. 1. a continent in the W part of the landmass lying between the Atlantic and Pacific oceans, separated from Asia by the Ural Mountains on the E and the Caucasus Mountains and the Black and… … Universalium
cave — cavelike, adj. /kayv/, n., v., caved, caving. n. 1. a hollow in the earth, esp. one opening more or less horizontally into a hill, mountain, etc. 2. a storage cellar, esp. for wine. 3. Eng. Hist. a secession, or a group of seceders, from a… … Universalium
Silurian Period — Interval of geologic time, 443–417 million years ago. The third period of the Paleozoic Era, the Silurian follows the Ordovician Period and precedes the Devonian. It marks the first appearance of land plants and jawed fishes. The continents were… … Universalium