Forward modelling along the Southern Carnarvon deep seismic reflection line â?? Using gravity data to investigate seismic interpretations

Abstract

Forward modelling was undertaken to test the architecture of the Southern Carnarvon deep seismic reflection survey (11GA-SC1) interpretation against gravity data. The seismic data extends to ~60 km depth and images the crust-mantle boundary (MohoroviÄ?iÄ? discontinuity) allowing it to be incorporated in the forward modelling. Using average density values for the upper mantle, granulite to amphibolite facies mid to lower crustal rocks, and upper crustal felsic and sedimentary rocks, a model was generated which explains the observed gravity anomalies and is consistent with the seismic interpretation. This work highlighted areas where the seismically inferred models were inconsistent with the gravity data and the importance of understanding regional trends, such as those generated by the crust-mantle boundary. The modelling undertaken in this study reflects the most up to date understanding of the regional geology in this area.