a. As used by drillers, a line of stakes set by an engineer or drill
foreman to be used as a guide to line up and point the drill in a specific
compass direction. A line in a survey which, being accurately determined
in length and position, serves as the origin for computing the distances
and relative positions of remote points and objects by triangulation.
See also: base line
b. A compound, e.g., lime, ammonia, or caustic alkali, or an alkaloid,
capable of reacting with an acid to form a salt either with or without
elimination of water.
c. Foundation or supporting structure on which a drill is mounted.
d. See: basal pinacoid; base course.
Dictionary of Mining, Mineral, and Related Terms