The Tanami 3D model – incorporating the results of the 2005 Tanami Seismic Survey

Summary

The Tanami 3D crustal-scale model integrates geological mapping with seismic interpretation and gravity modelling in order to enhance our understanding of the 3D architecture of the region.

The Tanami Region is a multiply deformed Palaeoproterozoic terrain consisting of the predominantly turbiditic Tanami Group, the volcanically derived sedimentary and extrusive rocks of the Ware Group and the Mount Charles Formation. Thought to be underlain by Archaean basement, the region was intruded by numerous granitoid bodies during the period 1820-1790 Ma and hosts the Callie world-class and several smaller gold deposits.

The 2005 Tanami seismic survey consisted of four regional traverses. Interpreted sections show the presence of a series of crustal-penetrating structures, that appear to be fundamental to the evolution of the Tanami Region. A number of these interpreted structures appear to link the mid-crust to ‘thin-skinned’ structures within the uppermost crust. The seismic also shows the presence of a southeast-dipping suture and associated pop-up structure, separating the Tanami crust from the Arunta crust. Known ore deposits are all located in close proximity to these interpreted through-going thrust faults and the associated ramp anticlines. Gravity modelling of the southeast-trending backbone seismic traverse (05GAT1) supports the seismic interpretation.

The current 3D model was constructed using 3D GeoModeller incorporating seismic data, modelled gravity, interpreted magnetic and gravity data and geological mapping. The 3D model forms the basis of the Tanami X3D web viewing tool, which allows the model and associated data to be viewed and manipulated over the web.

Key words::

• 3D model
• gravity
• Tanami
• seismic