Shipek bottom sampler (Shi'-pek). A commercial brand of grab sampler.
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.
mouth frame . The angulated girdle of ossicles surrounding the mouth of an asterozoan.
bütschliite (bütsch'-li-ite). A white rhombohedral mineral: K2Ca(CO3)2. It is dimorphous with fairchildite. Also spelled: buetschliite.
rhabdophane-(Nd) . A brown, pinkish, or yellowish-white hexagonal mineral of the rhabdophane group: (Nd,Ce,La)PO4•H2O.
ferrisymplesite (fer-ri-sym'-ples-ite). An poorly defined amorphous amber-brown mineral of the vivianite group: Fe3+3(AsO4)2(OH)3•6H2O(?) . Cf: symplesite.
serac (se-rac' [Pron: seh-rahk']). A jagged pinnacle, sharp ridge, needlelike tower, or irregularly shaped block of ice on the surface of a glacier (commonly among intersecting crevasses, as on an icefall), formed where the glacier is periodically broken as it passes over a steep slope. Introduced by Saussure in 1787 on the basis of snow/ice features observed along the margins of snow cap; he soon extended the term to ice features at the surface of a glacier (Carozzi, 1996). Etymol: French "sérac", a solid curdy white cheese made in the Alps and sold in quadrangular blocks, which glacial seracs resemble in appearance and shape. Both the French form and the anglicized version are in regular use. Cf: nieve penitente.
meta- (met'-a-). A prefix that, when used with the name of a sedimentary or igneous rock, indicates that the rock has been metamorphosed, e.g. metabasalt, metaquartzite.
tectonic subsidence . That part of the subsidence at a given point in a sedimentary basin caused by a tectonic driving mechanism. It is calculated by removing the component of subsidence produced by nontectonic processes such as sediment loading, sediment compaction, and changes in water depth (Biddle and Christie-Blick, 1985).
base loss . Process of base loss identified by the molecular ratio Al2O3/(CaO + MgO +Na2O + K2O). Syn: base depletion.
irtyshite (ir'-tysh-ite). An adamantine colorless hexagonal mineral: Na2(Ta,Nb)4O11 .
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