VMS and Ni-Cu exploration using an integrated geophysical and drilling method

Summary This case study illustrates the use of an exploration method that leverages modern exploration techniques for deep-seated VMS and Ni-Cu deposits in a 978 km2 survey area in the highly prospective Areachap Belt, South Africa. The exploration method comprises the use of a high power helicopter TEM (“HTEM”) system, a large fixed loop TEM (“FLTEM”) ground system and drilling that are employed in a staged process to keep down risks and costs and more importantly to optimize the chances of discovering viable economic mineral resources. Based on the HTEM survey 19 high priority VMS targets were detected for ground follow up with FLTEM. The FLTEM data confirmed all of these targets, and 2D plate modelling refined the parameter for optimal drilling of the targets. The first result of the drilling campaign led to the discovery of a significant Ni-Cu deposit. The prospect of this case study is that the employed method may be useful for certain types of mineral exploration. Provided that the electrical conductivity contrast between the mineralisation and the host rock is sufficient then the use of HTEM and FLTEM is a viable choice. The staged exploration process ensures that potential resources are detected and that risks and costs at each step are kept down.