f Dighem Resistivity Techniques Applied To The Detection Of Intrusive Dykes Within Coal Seams

The DIGHEMv airborne HEM system has been<br>widely used:<br>1 to aid geological mapping,<br>1 for groundwater exploration,<br>• for the detection of kimberlites,<br>• as an alteration mapping tool in gold<br>prospecting<br>• and also to find and delineate diamondiferous<br>gravels.<br>To our knowledge, this system has not previously<br>been applied for the detection of dykes<br>transecting coal seams.<br>The DIGEMv system has been used at the Avmin<br>- Forzando Coal mine in order to detect non<br>magnetically susceptible dykes. The survey was<br>carried out by Geodass Pty Ltd in conjunction<br>with DIGHEM/ CGG.<br>The Forzando Coal mine is located in the Bethal<br>district in Mpumalanga.<br>Dykes intruding into coal cause major mining<br>problems and can also reduce the coal reserves by<br>burning of the coal seams in the vicinity of the<br>dyke.