The prototype of a high resolution electromagnetic geophysical system for applications in the mineral exploration of massive sulphide mineralisation at depths from 200 to 1000m has been developed and tested under the Controlled Source Electro-Magnetic Mapping (CESMM) Project. The system is based on the theory of controlled source magneto-tellurics, and the application of GPS clocks and other innovative technical modifications permit accurate resolution of deep structures.
After processing of the results, the data are displayed as 2D profiles, plan view for specific depths and 3D visualisation. The data derived from field testing over massive sulphide mineralisation in southern Spain demonstrate the resolution of known mineralisation at depths of 800m beneath a near-surface conductive layer, and provide additional information regarding the distribution of the geological structures and lithologies.
Is is concluded that the CSEMM system could be usefully applied to the definition of drill targets for deeply buried mineralisation.
The discovery of new base metal resources in Europe will depend on development of sophisticated geophysical techniques, and their application to metallogenetic studies and exploration target definition.
Computer based laboratory simulation studies of the Controlled Source Electromagnetic Mapping (CSEMM) system demonstrate that concealed stratabound base-metal mineralisation could be detected at a depth of up to 1000 m below surface. The technique is expected to provide increased depth penetration (>250m ), enhanced resolution of conductivity contrasts, and reduction of cultural noise effects. The aim of this multidisciplinary project is to develop the geophysical instrumentation and software, and then to test it in the field over known deposits and geologically favourable situations within Europe. GIS-based software will be developed so that the results can be integrated with detailed geological data, and modelled for the potential application to mineral exploration, metallogenic basin analysis and refining current or deposit models.
The proposers include companies active in the research and development of geophysical instrumentation, mineral exploration management and geological research, and mining companies with active exploration and mining interests in the EC.
Funding SchemeCSC - Cost-sharing contracts