mesofossil (mes'-o-fos-sil). A term defined by Hughes (1994) as a plant fossil of intermediate size. Ranging between megafossils (e.g., leaves) and spores or pollen, it still requires microscopic study, such as megaspores and small seeds.
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.
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.