Numerical modelling of an evolving gold-lode system: Structural and lithological controls on ore-shoot formation in the Magdala goldmine, western Victoria

Abstract

Variable distribution of elevated gold grades in the Magdala Central Lode system is controlled by preferential and localised reactivation of pre-existing faults in a progressively rotating stress field. Populations of slickenline lineations on fault surfaces in combination with extension vein arrays associated with the faults indicate Central Lode formed initially during southwest-northeast compression, but was subsequently locally reactivated during east-west compression on lower angle fault segments to produce a series of ore-shoots within the overall lode system. A series of 2D cross-section numerical models have been used to examine how deformation and fluid flow are portioned at differe..