East Albany–Fraser Orogen 3D Geomodel 2018

Seismic and gravity sections shown within the density model of the East Albany–Fraser Orogen model.

This is a model of the tectonic elements of the Albany–Fraser Orogen at the southeast margin of the Yilgarn Craton. It uses data from the Albany–Fraser seismic survey constrained using active and passive seismic data from ALFREX and potential field data.

This project used geological and geophysical datasets to construct a regional scale 3D model of the east Albany–Fraser Orogen. The model was constructed and tested using 3D gravity forward modelling, an approach selected due to the distinct Bouguer gravity anomalies produced by the orogen. One of the main results of the 3D gravity forward modelling is that dense material is required in the zone of thickened crust that extends along the orogen margin. This material has been modelled as a dense unit in the lower crust, coincident with a non-reflective zone in deep-crustal active seismic lines, confirming results from 2D gravity forward modelling. More information can be found in GSWA Record 2020/11 and the model can be accessed via e-bookshop.

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