3D Seismic Attribute Analysis for Gold Exploration and Mine Planning in the Witwatersrand Basin, South Africa

Abstract

Summary In this study, we use high-resolution 3D seismic acquired in Kloof (now Kloof-Driefontein Complex East and South Deep mines located in the West Rand goldfields of the Witwatersrand Basin (South Africa) to delineate gold reefs under the thick cover of the Transvaal and Ventersdorp Supergroups. The primary gold reserve within the KDC East mine is the Ventersdorp Contact Reef (VCR), situated at depths ranging from 0.5 km to 3.5 km beneath the surface. To the east of the West Rand Fault, lies the South Deep mine, which focuses its extraction efforts on the Upper Elsburg Reefs (UERs) and the VCR. The 3D seismic data was reprocessed in 2020 by HiSeis. This study focuses on applying seismic attributes to the reprocessed 3D seismic data for structural enhancement. It investigates the effectiveness of horizon attributes in defining the geometry of faults and gold-bearing horizons. The surface attributes utilized include influential data, dip angle, dip azimuth attributes, and the edge detection map that combines the dip and dip azimuth attributes. The preliminary analysis shows that the VCR ore body is crosscut by major faults (West Rand Fault and Wrench fault) and numerous faults of many orientations were mapped.