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.
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.
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.