Prograded low-temperature alteration zones, Forrestania, Western Australia

Abstract

Zones of low-temperature metasomatism are widespread in igneous and sedimentary or metasedimentary terranes. Such zones are commonly associated with base metal and precious metal mineralization, and are readily identified by having relatively simple mineral assemblages, such as quartz-chlorite-sericite-ankerite associated with gold. However, if such zones are subjected to further metamorphism, the resulting assemblages may become more complex. This abstract discusses zones of alteration in the Forrestania greenstone belt in Western Australia, that have been further metamorphosed to amphibolite facies, with the development of complex amphibole assemblages, staurolite-bearing assemblages and calc-silicate assemblages.