RFG 2018 Conference

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.

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ice-receiving area . The portion of a surging glacier, generally near the terminus, that is periodically refilled by glacier surges.

estuary (es'-tu-a''-ry). A semi-enclosed coastal body of water that has a free connection with the open sea and within which seawater is measurably diluted with freshwater from land drainage (Pritchard, 1952). Estuaries are classified in terms of their mixing as stratified, partially stratified, well mixed, and reverse; or by their origins as bar-built, fjord, tectonic, fjard, and ria (Woodroffe, 2002). Cf: ria; branching bay; liman; fjord. Etymol: Latin aestus, "tide".

surf beat . (a) The slow variability of the height of incoming swell due to interference among swell of nearly the same period. (b) The long-period (several minutes) change in water level along the coast due to the changing height of breakers in the surf zone.

pyrometamorphism (py''-ro-met''-a-mor'-phism). (a) Metamorphic changes taking place without the action of pressure or water vapor, at temperatures near the melting points of the component minerals; it is a local, intense type of thermal metamorphism, resulting from the unusually high temperatures at the contact of a rock with magma, e.g. in xenoliths (Turner, 1948). Cf: igneous metamorphism. (b) "Metamorphism" caused by lightning strikes and burning coal seams.

S-type granitoid . A granitic rock produced by magma derived from partial fusion of metasedimentary or supracrustal origin. The term, proposed by Chappell and White in 1974, is thoroughly discussed by Clarke (1992).

oven-dry soil . Soil that has been dried at 105°C until it reaches constant mass.

beekite (beek'-ite). (a) White, opaque silica occurring in the form of subspherical, discoid, rosettelike, doughnut-shaped, or botryoidal accretions, commonly found as bands or layers on silicified fossils or along joint surfaces as a replacement of organic matter; e.g. chalcedony pseudomorphous after coral, shell, or other fossils. See also: ooloid. (b) Concretionary calcite commonly occurring in small rings on the surface of a fossil shell that has weathered out of its matrix. Named after Dr. Beek, dean of Bristol. Originally spelled: beckite.

stamen (sta'-men). That organ of a flower which produces pollen.

euosmite (eu-os'-mite). A brownish-yellow resin, with a low oxygen content and a characteristic pleasant odor, found in brown coal.

miscellaneous area . A kind of land area in a soil survey having little or no soil and thus supporting little or no vegetation without major reclamation. Includes areas such as beaches, dumps, rock outcrop, and badlands. The term is used in defining map units.


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