wall rock

noun

, Mining.

wall rock

rock that is immediately adjacent to a mineral vein, fault, or igneous intrusion

An Americanism dating back to 1855–60

The undergrowth was very dense out to the edge of the perpendicular wall rock.

In igneous rock the ore-bearing solutions may have altered the wall rock to a dense mixture of quartz, sericite, and chlorite.

Their principal occurrence is in distinct fissure veins in igneous rocks, with more or less replacement of the wall rock.

The ore fills fissures to some extent, but is mainly a replacement of the wall rock.

In narrow lodes, some of the wall-rock must be cut away to get room for the workmen.

April 24, 2024gallimaufry

[gal-uh-maw-free ]

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