Speaker
Description
In this study, datasets obtained from ground magnetic and electrical geophysical surveys were integrated with existing geological datasets to map out structures in the Sefwi Belt of Southern Ghana. The magnetic data obtained were gridded and data enhancement filters were applied to the Total Magnetic Intensity (TMI) grid generated to enhance the magnetic anomalies to depth sources. The induced polarization-chargeability data were measured in the time domain. The positive anomalies on the IP-chargeability map coincided with the shears, margins, alterations and contact zones. Two Pole–dipole sections, carried out in the study area, were inverted and from the results obtained, an interpreted definitive geological map of the study area consisting of the geology, structures and hydrothermally altered zones was produced. The outcome of the electrical resistivity and IP inversions indicated that depths ranging from 50 to 200 m suggest conductive and chargeable bodies. The low-resistivity zones coincided with sheared and altered acidic meta-sediments. The geophysical signatures obtained from the enhanced magnetic data and the electrical data showed that the study area is structurally complex with a few of the structures corresponding to D1 deformation and most structures corresponding to D2 deformation. The study resulted in better illuminating geological structures and lithological boundaries, and thus has demonstrated the worth of geophysical data as an enhancement tool in mapping possible geological structures that host hydrothermal gold mineralization within the Sefwi Gold Belt of Ghana. Seven diamond drill holes were intuitively planned to test the hypothesized model and determine the depth of the resistive-chargeable anomalous units as well as litho-structural boundaries.
Summary
The research attempted to understand fully the role of geophysics, notably magnetic and electrical methods in illuminating structural complexities in the formation of ore forming minerals within the mesothermal ore deposit classification.
