High resolution spectral sensing, or hyperspectral surveying, can be used in diamond exploration to locate kimberlites where kimberlites are exposed or weathered in areas of residual soil. Presence of other ultramafic rocks and amphibolites produce similar spectral targets but analysis by experienced spectral geologists and advanced data processing reduces the number of non-kimberlite anomalies.
The original HyMap scanner was commissioned by De Beers for this purpose. Over 25 kimberlites (both pipes and dykes) have been discovered in the last 10 years at a relatively low cost compared to other methodologies. Most exceeded 1 hectare and required minimal follow-up for confirmation and were located within 6 months of completion of the survey. Therefore, in suitable areas, hyperspectral surveys are competitive and cost-effective kimberlite exploration technique, comparable in price to high-resolution aeromagnetic surveys but with significantly lower follow-up costs. The ratio of targets to kimberlite discovery is similar to that of aeromagnetic surveys and is dependent on the geological conditions within the survey area.
