a. A regional-scale strike-slip fault, e.g., the San Andreas rift in
California, with offset measured in hundreds of kilometers. AGI
b. A trough or valley formed by faulting.
c. In quarrying, a direction of parting in a massive rock, such as
granite, at approx. right angles to the grain. CF:
grain; hard way.
d. A narrow cleft, fissure, or other opening in rock (such as in
limestone), made by cracking or splitting. AGI
e. A planar property whereby granitic rocks split relatively easily in a
direction other than the sheeting (parallel to the surface of the Earth.)
f. A term used in slate quarrying to describe a second direction of
splitting less pronounced than slaty cleavage and usually at right angles
g. In sedimentary rocks, the horizontal plane of stratification, or the
bed of the rock. Stauffer
h. An obscure foliation, either vertical (or nearly so) or horizontal,
along which a rock splits more readily than in any other direction.
Syn: fault tracei. A crack, such as in the mid-ocean ridges. MacCracken
Dictionary of Mining, Mineral, and Related Terms