oa Telfer Region FALCON Airborne Survey, Western Australia

The Telfer region in the Paterson Province consists of Proterozoic metasediments of the Yeneena Group, of lower-upper Greenschist facies. Sediment lithologies vary from siltstones to quartzites and carbonates. These are intruded by intrusive suites ranging from felsic to mafic, plutonic to hyperbyssal.

Known world-class assets include the Telfer Gold operation, and the O’Callaghan’s Tungsten resource (both 100% Newcrest owned).

The sedimentary and intrusive lithologies have considerable density contrast. These factors, combined with steeply dipping on-edge stratigraphy make the Telfer region ideal for gravity surveying.

Previous gravity coverage in the region has been a combination of small prospect scale surveys, and 1980s vintage 2 x 4 km regional helicopter surveys with barometric levelling control.

In order to get systematic gravity coverage of good resolution, a FALCON survey of 250m line spacing, 60m flight height, was flown in 2010.

The data show a number of blind felsic plutons, some intersected in drilling, some interpreted – especially associated with the O’Callaghan’s tungsten resource, and the Trotman’s Stockwork tungsten prospect. The data also outline much more clearly the NE over SW thrust faults in the region, and the late north-south transfer faults, the most well known of which is the Graben Fault through Telfer Dome.

Three dimensional gravity inversions performed over the O’Callaghan’s and Trotman’s Stockwork tungsten areas in Gocad/VPMG software have defined extra felsic intrusive targets for tungsten and gold mineralisation. Further diamond drilling will increase inversion constraints.