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.

Subscribe via EMail to the GeoWord of the Day.


revdite (rev'-dite). A colorless monoclinic mineral: Na16Si16O27(OH)26•28H2O .

dislocation climb . Movement of a dislocation to a higher or lower glide plane. Requires diffusion of atoms through the crystal lattice which is favored by deformation at high temperatures.

dislocation climb . Movement of a dislocation to a higher or lower glide plane. Requires diffusion of atoms through the crystal lattice which is favored by deformation at high temperatures.

dislocation climb . Movement of a dislocation to a higher or lower glide plane. Requires diffusion of atoms through the crystal lattice which is favored by deformation at high temperatures.

wheel . A holothurian sclerite in the form of a wheel, consisting of a hub, a rim, and spokes.

principal coordinates analysis . A Q-mode procedure in which observations are projected onto axes defined by the eigenvectors of a centered matrix of similarities between the observations. Cf: Q-mode factor analysis.

welded flow breccia . The lower part of the fragmented crust of aa and block-lava flows, where the fragments are thoroughly welded together rather than being loose as in the upper part of the crust.

paleointensity . The intensity of the ancient Earth's magnetic field, as determined by experiments on geologic materials that attempt to duplicate the magnetization acquisition process, using the correct ancient field intensity. Paleointensity values may be expressed as "virtual" dipole moments for the Earth.

bulk density . The weight of an object or material divided by its volume, including pore spaces and in situ moisture. It is identified as dry density for the weight per unit volume of a soil mass that has been oven-dried to a constant weight at 105°C.

aviolite (av-i-o'-lite). A type of hornfels whose main constituents are mica and cordierite. Rarely used. Type locality: Monte Aviolo, Italian Alps. Cf: astite; edolite.

Pages

Subscribe to GeoWord of the Day