In March 2005, Glencar Mining plc engaged Toby Davis (SRK Perth) to develop structural models for mineralisation for a number of gold prospects they had identified in their Komana Project in southwest Mali.
This project included interpretation of regional geophysical datasets and mapping prospects in 1000 sq km of tenements. Glencar wanted to design their future drilling programs around field evidence based structural models for mineralisation.
One of these prospects, Komana West, is hosted in structurally complex Birimian sedimentary rocks. A structural model for mineralisation and the deformation history of the project area was developed by mapping exposures around the deposit. One small exposure of veining illustrated the sequence of deformation that led to mineralisation.
Here it was discovered that because of the nature of the deformation preceding mineralisation, as well as that which accompanied it, a significant number of veins in the deposits would be oriented nearly perpendicular to the fabric that defined the host high strain zone. This realisation highlighted the need to change the drillhole orientation from that used by previous explorers, which may not have sampled the veins adequately.
With SRK’s input, Glencar developed a drilling strategy based on the improved understanding of the structural controls on gold mineralisation with subsequent drilling intersecting 20 m containing 55g/t Au. The Komana West deposit appears to be quite large; mineralisation has been defined over a strike length of more than 1.5 km.
Glencar’s success has also benefited the local community: Glencar has provided funds for two new nurses and two high school teachers in nearby villages – a huge boon – which will nearly double the health and education resources of the area.
