Case Studies - Mineral Exploration

Ethiopia- Adola Area Mapping

The geology overlay shows apparent contacts mapped from the radiometric and apparent resistivity data, with the rock types identified from geology maps published by the Ethiopian Institute of Geological Surveys.

Combining geophysical methods enhances the interpretation beyond a simple sum of the parts. The border facies of the Gariboro massif (Bgg), a granite-gneiss, shows a similar radiometric response to the graphitic shist/quartzite unit (Grs), but the graphitic shist unit is clearly much more conductive on the resistivity map. Conversely, the granites (Gg) and biotite gneisses (Bg) are indistinguishable on the resistivity map, but definitely appear different on the radiometric survey. The olivine basalt is mapped by both the resistivity (lower resistivity) and by the radiometrics (high thorium).

This integrated approach demonstrates a powerful method of combining geophysical data with geologic data for mapping. The geology provides positive rock identification at outcrop locations (outcrops). The geophysical data can be used to extend the geologic observations to map the extents of the units.

This data is shown courtesy of the Ethiopian Institute of Geological Surveys. The data can be acquired through the EIGS.