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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microlinear (mi-cro-lin'-e-ar). "Any lineation that is invisible to the unaided eye" (El-Etr, 1976, p.485).

crocydite (cro'-cyd-ite). A Migmatite with a flakelike or flufflike light-colored part (Dietrich and Mehnert, 1961). Rarely used. Var: krokydite.

Flinn diagram . A plot of maximum/intermediate stretches versus intermediate/minimum stretches used to represent three-dimensional strain (Flinn, 1962).

Flinn diagram . A plot of maximum/intermediate stretches versus intermediate/minimum stretches used to represent three-dimensional strain (Flinn, 1962).

ventifact (ven'-ti-fact). A general term introduced by Evans (1911) for any stone or pebble shaped, worn, faceted, cut, or polished by the abrasive or sandblast action of windblown sand, generally under desert conditions; e.g. a dreikanter. See also: windkanter. Syn: glyptolith; wind-worn stone; wind-cut stone; wind-polished stone; wind-grooved stone; wind-scoured stone; wind-shaped stone.

vale . (a) A lowland, usually containing a stream; e.g. the depression between two parallel cuestas. It often forms the wider and flatter part of a valley. (b) A rift valley or tectonic valley; e.g. the Vale of Arabia. (c) valley.

glacial-deposition coast (gla'-cial-de-po-si'-tion). A coast with partly submerged moraines, drumlins, and other glacial deposits.

needle tin ore . A variety of cassiterite with acute pyramidal forms.

plat [cart] . (a) A diagram drawn to scale, showing boundaries and subdivisions of a tract of land as determined by survey, together with all essential data required for accurate identification and description of the various units shown and including one or more certificates indicating due approval. It differs from a map in that it does not necessarily show additional cultural, drainage, and relief features. (b) A precise and detailed plan or map representing a township, private land claim, mineral claim, or other surveyed area, and showing the actual or proposed divisions, special features, or uses of the land. Syn: cadastral map. See also: plot.

quartzine (quartz'-ine). Chalcedony characterized by fibers having a positive crystallographic elongation (parallel to the c -axis). Also spelled: quartzin.