procephalic (pro-ce-phal'-ic). Pertaining to, forming, or situated on or near the front of the head; e.g. the "procephalic lobe", or anterior preoral part, of a merostome embryo.
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.
lattice row . A row of lattice points. See also: crystal axis.
hyperpycnal inflow (hy-per-pyc'-nal). Flowing water that is denser than the body of water it enters, resulting in formation of a turbidity current. Its flow pattern is that of a plane jet (Moore, Derek, 1966, p.89). Cf: hypopycnal inflow; homopycnal inflow.
pladdy (plad'-dy). A term used in Northern Ireland for a "residual island drumlin awash at high tide" (Stamp, 1961, p.365).
type area . The geographic area or region that encompass the stratotype or type locality of a stratigraphic unit or stratigraphic boundary (ISSC, 1994, p.27). Syn: type region.
brachiophore process . A distal rodlike extension of a brachiophore that possibly supported the lophophore in some brachiopods.
furrow [struc geol] . A nongenetic term used by Bucher (1933) for a depressed part of the crust of any size with a distinct linear development.
mixed-mode crack . A crack whose tip is subject to any combination of opening (mode I) displacement and shear (modes II and III) displacements.
activation [radioactivity] . The process of making a substance radioactive by bombarding it with nuclear particles. The radioactivity so produced is called induced radioactivity.
favositid (fav-o-sit'-id). Any tabulate coral belonging to the family Favositidae, characterized by massive colonies (usually without coenenchyme) of slender corallites with mural pores, short equal spinose septa, and complete tabulae. Range, Upper Ordovician to Permian, possibly Triassic.
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