wall-rock alteration

wall-rock alteration

[′wȯl ¦räk ‚ȯl·tə′rā·shən]
(geology)
Alteration of wall rock adjacent to hydrothermal veins by the fluid responsible for formation of the mineral deposit.
References in periodicals archive ?
The most obvious of these features include (1) ages of 28-31 million years (Ma) determined on early vein and wallrock hydrothermal muscovite (sericite) (Silberman, 1995), similar to those at Climax (Wallace, 1995), (2) the presence of pebble dikes or breccias in Buckskin Gulch, (3) scattered quartz-orthoclase pegmatite bodies (containing rare molybdenite) that are most likely Tertiary in age, (4) abundant amounts of fluorite, topaz and hubnerite (geochemically anomalous concentrations of Mn, Mo, F, W), (5) wall-rock alteration types including widespread quartz-sericite-pyrite, propylitic, and early stage fluorite-rich hydrothermal muscovite (associated with hubnerite-pyrite-quartz veins) greisen-type alteration, (6) isolated, thin quartz-pyrite Mo[S.
The nature, extent, and intensity of wall-rock alteration and the extent of widespread stockwork or disseminated type mineralization in the altered wall rocks at these Ace properties is not known and may be critical.
Most deposits exhibit minimal wall-rock alteration.