Vertical extensional strain as a guide to gold-bearing veins within reverse-oblique fault-fracture meshes and dilational step-overs at the Darlot and Centenary gold deposits, Yilgarn Craton, Western Australia

摘要

The Archaean Darlot and Centenary gold deposits in the southern Yandal greenstone belt, Western Australia, contain over 39 t of gold. Gold occurs in veins and associated hydrothermal alteration ha-los within and adjacent to brittle-(ductile), reverse-oblique fault zones. Measurement of vein distribution at the Centenary deposit delineates a northwest-trending, about 300 m wide zone of anomalous extension interpreted as a dilational step-over within a north-striking, moderate to steeply (40-70°) west-dipping fault system. This zone contains gold-bearing veins on fault-fracture meshes.