Academic Programmes - Student Biographies

Stephen CoomberStephen Coomber

Master’s Degree Candidate
University of the Witwatersrand

I am registered in my second year of research as a Masters student at Wits University, Johannesburg, South Africa.

My thesis involves a gravity study of a region of the western Bushveld Complex, South Africa, south of the Pilanesberg intrusion. The region will soon be mined for the valuable PGE deposits in the Merensky Reef and UG2. A seismic survey in the region shows the Merensky Reef and UG2 chromitite layers are significantly higher than expected from dips in proximal outcrop. Gravity data will be used to run inversions on the density and underground topography, using programmes such as VPmg and Grav3D. The inversions will be constrained by borehole pierce-points and seismic interpretations. From this modelling, it may be possible to determine if the increased height of the chromitite layers is due to the influence of the Pilanesberg or flexure of the lithosphere (related to cooling of the Bushveld Complex).

Airborne FTG gravity data will also be used to model features such as faults and Iron-Rich Ultramafic Pegmatoids (IRUPs) in the region. A dense grid of gravity data was collected in October 2006 and, from this data, the FTG components will be calculated, upward continued and compared to the airborne FTG data.