Albany–Fraser Orogen magnetotelluric (MT) surveys

AlbanyFraserLocationImage
MT surveys conducted over the Albany-Fraser Orogen over the 1:500K GSWA interpreted bedrock geology map.

Albany–Fraser Orogen is located along the southern margin of the Yilgarn Craton and is host to the world-class Tropicana orogenic gold deposit and Nova–Bollinger mafic-hosted Ni–Cu deposit. Both deposits are associated with major crustal structures. With support from the Exploration Incentive Scheme (EIS), two MT surveys were conducted along four main profiles in the southern Albany–Fraser region, and along a single profile north-east of Tropicana, their locations chosen to complement the deep crustal seismic reflection lines. A combined total of 248 magnetotelluric recordings were conducted north-east of Tropicana and in the Southern Albany–Fraser Orogen during 2012 and 2013, respectively. 163 data points from the Southern Albany-Fraser were inverted with 2D and 3D algorithms to produce conductivity models of the crust and uppermost lithospheric mantle. The models reveal a resistive upper crust that is crosscut by several near-vertical low-resistivity zones, which in some cases can be correlated with the location of major shear zones. Preliminary results were presented at a workshop in 2014, with extended abstracts presented in GSWA Record 2014/6 Albany–Fraser Orogen seismic and magnetotelluric (MT) workshop 2014: extended abstracts.

Details of the processing and results can be found in GSWA Report 189 A magnetotelluric survey across the east Albany–Fraser Orogen, Western Australia.

Contact

For further information contact:
geological.survey@dmirs.wa.gov.au

3D modelling results displayed along four 2D profile traces