Exploration For Kimberlites Through a Complex Regolith Cover - A Case Study In the Application of AEM In the Deeply Weathered Archaean Yilgarn Craton, Western Australia. Available to Purchase

Regolith electrical structures associated with a small kimberlite dyke located in the Yilgarn Craton, Western Australia are examined. This study was concerned with determining The kimberlite is hosted by a deeply weathered granitic host. The saprolite associated with the granite and the kimberlites are conductive as defined from downhole geophysical logging. The kimberlite shows as a conductor in ground EM (SIROTEM and GEM-2 systems) surrounded by a resistive host. It also shows a small conductive response in 56Khz DIGHEM data but is not apparent in lower frequency data or in SALTMAP.- a fixed wing time domain airborne EM system. The geometry of the latter suggests that any response of the kimberlite is likely to be lost in a coupling of transmitter with conductive wedges of granitic saprolite to the north and south of the blow. Stitched sections of 1D LEI's for SIROTEM, DIGHEM and SALTMAP show similar trends and suggest that the regolith electrical structure is effectively modelled as a layered earth, with some exceptions. An AEM “response map” in this area is essentially a map of the variation of regolith thickness and conductivity.