Cost‐effective in‐mine seismic experiments to image platinum deposits and associated geological structures at Maseve platinum mine, South Africa

Abstract

The detection of mineral deposits and their related geological structures is of great importance to the mining industry as structures (such as dykes and faults) can affect the safety, cost and efficiency of mining. With the goal of testing cost-effective seismic methods for mineral exploration and mining, active and passive seismic experiments were conducted at Maseve platinum mine in the Bushveld Complex (South Africa) in 2020. The experiments involved surface-passive (using 5 Hz wireless nodes; single vertical component) and in-mine active reflection seismic surveys (using 4.5 Hz land streamer and 5 kg sledgehammer) to image geological structures and delineate economic platinum-group elements bearing Merensky and Upper Group-2 chromitite layers (known as reefs). This paper presents only the results from the in-mine active seismic experiments. The in-mine seismic surveys consisted of seven 2D reflection seismic profiles in the development tunnels, which were located ∼550 m below ground surface and a few tens of metres above known mineralizations: the Upper Group-2 and Merensky Reef. The data were carefully processed to enhance the reflections and suppress noise generated by mine infrastructure (e.g., equipment and ventilation). We successfully imaged the Merensky Reef and Upper Group-2 orebodies approximately 55 m and 124 m below the tunnel floor, respectively, and delineated faults and dykes that crosscut them. Furthermore, the seismic data reveal relatively strong amplitude and faulted reflections below the Upper Group-2 that may represent deeper chromitite-enriched orebodies. However, the economic value of these horizons can only be confirmed through drilling. The processed seismic data were combined with borehole data, synthetic modelling and geological models to constrain the interpretation. This study encourages the use of in-mine seismics for future mineral exploration, mine development and planning.

Detailed study of structure and composition of waterproof strata by mine seismic survey at the Verkhnekamskoye salt deposit

“…The world practice of studying mineral occurrences on the whole and salts in particular commonly uses geophysics, both electromagnetic [5,6] and seismic methods [7][8][9][10][11][12]. The geophysical methods to solve ore provblems are widely applied both in Russia [13][14][15][16][17] and in the near abroad countries [18][19].…”

Multi‐geophysical methods for characterizing fractures in an open pit mine, western Bushveld Complex, South Africa

“…Prior to data acquisition, appropriate acquisition parameters need to be assessed, together with the expected response of the target through forward modelling. Forward modelling can also assist in validating the interpretation of the dataset and provide information for mineral exploration and risk assessment (Malehmir et al., 2013; Manzi et al., 2017; Maries et al., 2020; Rapetsoa et al., 2022).…”