The acquisition and interpretation of the deep crustal seismic line 13GA-EG1 has allowed a new 3D model to be constructed for the western Gawler Craton. The new 3D model expands on the Eastern Gawler IOGC / Woomera Prohibited Area model, which sits to the north and east of this seismic line. Interpretations used to construct this model were derived from a cross-border collaborative work program between the Geological Survey of South Australia, the Geological Survey of Western Australia and Geoscience Australia, initiated by the collection of seismic line 13GA-EG1. This is the first of three models which will cover the length of the seismic line 13GA-EG1; the others being the Albany-Fraser Orogen model in Western Australia and the Coompana model which straddles the WA/SA border. These are being worked on and will be published in the coming years to produce a continuous crustal architecture and density model between the Gawler and Yilgarn Cratons.

The Burra (Burra) Mine, situated 150 km north of Adelaide within the Adelaide Geosyncline, produced 2.7 million tonnes of copper ore in two major mining phases: 1845 – 1877 and 1970 - 1981. The entire length of the pit is occupied by a diapiric body intruding the Skillogalee Dolomite and may extend up to 500 m to the west. Recognition that the porphyry and associated mineralisation are of similar age to the host Skillogalee Dolomite promotes large tracts of the Adelaide Geosyncline as prospective for similar mineralisation. The Burra mine 3D model was constructed using a georeferenced version of the original hand-drafted base map, which included elevation data points surveyed during the final phase of mining. These elevation locations and associated height data were digitised from the georeferenced map into a GIS point dataset. Borehole and survey station points were captured and saved in separate point datasets. The point dataset elevation values were transferred to the base plan polylines (where spatially coinicident), and these lines were used to generate a 3D triangular irregular network (TIN). Elevation points not spatially coincident with base plan lines were added to the TIN separately. The geology dataset was draped over the TIN in a 3D visualisation environment and was output to an Adobe 3D pdf format for display in Acrobat Reader TM.

Curnamona Province was created as a convenient way of visualising the spatial distribution and thickness of these basinal sediments. The model enables users to make estimations of vertical distances from the surface to key surfaces, including depth to top of Palaeo-Mesoproterozoic, base of Cambrian, base of Mesozoic and base of Cenozoic. The inferred forms of these key surfaces are derived from a combination of drillhole data, seismic data interpretation and aeromagnetic data modelling.