Gold, Nickel, Base Metals etc.
Geophysics for Gold, Nickel, Base metals etc.
Stephen Mudge has been applying a variety of geophysical techniques to exploration for many types of gold, copper-gold, base metal, copper, lead, zinc, nickel, manganese, chromite, iron ore, tin, tungsten and platinum-group-element deposits (PGEs) since the mid 1970s. In addition, a range of data-processing techniques have been developed and tested in an attempt to detect the geophysical responses associated with the various types of deposits.
The fastest and most cost-effective geophysical method for broad- area exploration and geological mapping is surveying with low-level, high-resolution aeromagnetics and radiometrics. Radiometric surveying is highly effective for mapping gamma-ray radiation from outcropping geology, some types of alteration systems, and uranium deposits.
Conventional data-processing techniques (such as channel ratios, ternary plots etc.) applied to the uranium, potassium, thorium and total-count radiometric channels are very effective for resolving subtle radiometric responses. They are very useful aids for surface geological mapping and target identification.
Specialised data-processing techniques are applied to the aeromagnetic data using TargetMapTM in order to resolve the magnetic responses of the various mineral deposits, the different rock types comprising the host environment, and the structures in the surrounding rocks.
Airborne electro-magnetics (EM) is also a fast and often effective geophysical method for broad-area exploration and geological mapping. A variety of airborne EM systems are available and have been applied to map electrical conductivity associated with some types of mineral deposits and to assist with geological mapping. In all cases, specialised data-processing techniques are applied to the electro-magnetic data using TargetTEMTM in order to resolve the subtle conductive responses of the various mineral deposits, their host rocks and associated structures.
A number of airborne transient electro-magnetic (TEM) surveys from Australia, Canada and Africa (using the GEOTEM, MEGATEM, TEMPEST, HOISTEM, QUESTEM, AeroTEM and VTEM systems) have been processed with TargetTEMTM to detect and map electrical conductivity associated with the various types of mineral deposits and their host rocks. The magnetic data from these and other surveys have been reprocessed with TargetMapTM.
Details of TargetMapTM and TargetTEMTM can be found elsewhere on this web site. This includes a number of examples of reprocessed total-magnetic-intensity data and multichannel TEM data from a variety of mineral deposits and geological environments in Australia.