Glossary of volcanic terms. - University of Wisconsin Oshkosh. G. J. Hudak. 2001.
mountain — mountainless, adj. /mown tn/, n. 1. a natural elevation of the earth s surface rising more or less abruptly to a summit, and attaining an altitude greater than that of a hill, usually greater than 2000 ft. (610 m). 2. a large mass of something… … Universalium
Mesoplates — The concept of mesoplates was introduced as a heuristic for characterizing the motion of lithospheric plates relative to the sublithospheric source region of hotspot volcanism (Pilger, 2003). W. Jason Morgan (1972), originally suggested that… … Wikipedia
plate tectonics — plate tectonic, adj. Geol. a theory of global tectonics in which the lithosphere is divided into a number of crustal plates, each of which moves on the plastic asthenosphere more or less independently to collide with, slide under, or move past… … Universalium
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
Plate tectonics — The tectonic plates of the world were mapped in the second half of the 20th century … Wikipedia
metamorphic rock — Any of a class of rocks that result from the alteration of preexisting rocks in response to changing geological conditions, including variations in temperature, pressure, and mechanical stress. The preexisting rocks may be igneous, sedimentary,… … Universalium
Oceanic trench — Oceanic crust is formed at an oceanic ridge, while the lithosphere is subducted back into the asthenosphere at trenches. The oceanic trenches are hemispheric scale long but narrow topographic depressions of the sea floor. They are also the… … Wikipedia
earth — /errth/, n. 1. (often cap.) the planet third in order from the sun, having an equatorial diameter of 7926 mi. (12,755 km) and a polar diameter of 7900 mi. (12,714 km), a mean distance from the sun of 92.9 million mi. (149.6 million km), and a… … Universalium
North America — North American. the northern continent of the Western Hemisphere, extending from Central America to the Arctic Ocean. Highest point, Mt. McKinley, 20,300 ft. (6187 m); lowest, Death Valley, 276 ft. (84 m) below sea level. 400,000,000 including… … Universalium
tectonic basins and rift valleys — ▪ landform Introduction landforms characterized by relatively steep, mountainous sides and flat floors. The steep sides are created by displacement on faults such that the valley floor moves down relative to the surrounding margins, or,… … Universalium
