High-resolution, short-range, in-mine geophysical techniques for the delineation of South African orebodies

Abstract

The economic horizons of the two major precious metal ore deposits of South Africa, the Bushveld Complex (platinum) and the Witwatersrand Basin (gold), exhibit remarkable lateral continuity on a regional scale. Consequently, the geometry of the respective planar orebodies is relatively easy to predict ahead of mining. On a local, in-mine scale, however, the geometry of these orebodies is far less predictable because of the presence of disruptive geological features such as faults, rolls, terraces, potholes, dykes, and iron-rich ultramafic pegmatite (IRUP) bodies. The occurrence of these features compromises mine planning, production and safety. This paper illustrates how the integrated use of three high-resolution geophysical techniques can provide valuable geological and rock engineering information ahead of mining, making mining operations more cost effective and safe. The geophysical techniques considered are electrical resistance tomography (ERT), borehole radar, and ground penetrating radar (GPR).