statistical lithofacies (sta-tis'-ti-cal). A lithofacies that grades laterally into its neighbors and whose boundaries are vertical arbitrary-cutoff planes (Weller, 1958, p.633). Cf: intertongued lithofacies.
prism [cryst] . A crystal form having three, four, six, eight, or twelve faces, with parallel intersection edges, and which is open only at the two ends of the axis parallel to the intersection edges of the faces.
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.
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.
