sodicanthophyllite . A name for the theoretical Na-Mg anthophyllite end-member of the orthorhombic amphibole group: (Na,[])Mg7(Si,Al)8O22(OH)2.
GeoWord of the Day
The GeoWord of the Day is a free service of the American Geosciences Institute. All of the terms and definitions are from the Glossary of Geology, 5th Edition Revised.
aggregate (ag'-gre-gate). (a) A mass or body of rock particles, mineral grains, or a mixture of both. (b) Any of several hard, inert materials, such as sand, gravel, slag, or crushed stone, used for mixing with a cementing or bituminous material to form concrete, mortar, or plaster; or used alone, as in railroad ballast or graded fill. The term sometimes includes rock material used as chemical or metallurgical fluxstone, or filtration medium. See also: coarse aggregate; fine aggregate; lightweight aggregate.
Alpides (Al'-pi-des). A name used by Suess for the great orogenic belt or system of young folded mountains, including the Alps, that extends eastward from Spain to southeast Asia. Syn: Alpine-Himalayan belt.
natural gas . (a) Hydrocarbons that exist as a gas or vapor at ordinary pressures and temperatures. Methane is the most important, but ethane, propane, and others may be present. Common impurities include nitrogen, carbon dioxide, and hydrogen sulfide. Natural gas may occur alone or associated with oil. Syn: gas. (b) Gaseous hydrocarbons trapped in the zone of groundwater saturation, under pressure from, and partially dissolved in, underlying water or petroleum (Meinzer, 1923, p.21). Cf: subsurface air; included gas.
transformational breccia (trans-for-ma'-tion-al). A term used by Landes (1945) for a breccia occurring in a stratigraphically vertical body and cutting through a stratigraphic section, and believed to have been produced by collapse, such as above a dissolved salt bed.
total reflection . Reflection in which all of the incident wave is returned.
gold amalgam . A variety of native gold containing mercury; a naturally occurring amalgam composed of gold, silver, and mercury, the gold averaging about 40%. It is usually associated with platinum, and occurs in yellowish-white grains that crumble readily.
krinovite (kri'-nov-ite). A green triclinic meteorite mineral of the aenigmatite group: NaMg2CrSi3O10 .
krinovite (kri'-nov-ite). A green triclinic meteorite mineral of the aenigmatite group: NaMg2CrSi3O10 .
talus creep . The slow downslope movement of talus, either individual rock fragments or the mass as a whole. Cf: scree creep.
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