Diamonds

Geophysics for Diamonds

Stephen Mudge has been applying a variety of geophysical techniques to diamond exploration in Australia since the early 1980s. In addition, a range of data-processing techniques have been developed and tested in an attempt to detect the variable geophysical responses of kimberlite pipes and their host environments.

The fastest and most cost-effective geophysical method for broad- area exploration for kimberlite pipes is surveying with low-level, high-resolution aeromagnetics. Specialised data processing techniques are applied to the aeromagnetic data using TargetMap^TM in order to resolve the magnetic responses of the kimberlite pipes and the structures that maybe associated with the intrusion of the pipes.

Airborne electro-magnetics (EM) is also a fast and often effective geophysical method for broad-area exploration for kimberlite pipes. A variety of airborne EM systems are available and have been applied to map electrical conductivity sometimes associated with the weathered upper portions of the pipes. In all cases, specialised data processing techniques are applied to the electro-magnetic data using TargetTEM^TM in order to resolve the subtle conductive responses of the weathered pipes.

Details of TargetMap^TM and TargetTEM^TM can be found elsewhere on this web site. A number of airborne transient electro-magnetic (TEM) surveys from Australia and Canada, using the GEOTEM, MEGATEM, TEMPEST, HOISTEM and AeroTEM systems, have been processed with TargetTEM^TM to detect and map conductivity associated with kimberlite pipes. The magnetic data from these and other surveys have been reprocessed with TargetMap^TM.