Australian Palaeogeographic Studies—Outcomes and Future Opportunities

Abstract

Palaeogeographic maps are a key tool for integrating geological information and expanding interpretations into areas between and beyond data control using depositional, sequence stratigraphic, plate tectonic and other models. In Australia a major continent-wide palaeogeographic mapping program was undertaken in the 1980s as a co-operative endevour between government, universities and the petroleum and minerals industries. The BMR-APIRA Palaeogeographic Maps Project produced data and interpretative maps for 70 biostratigraphically controlled time-slices from the Cambrian to the Quaternary at a regional scale of 1:5 million. The overlap of source, reservoir and seal facies with structural trends mapped petroleum plays. New plays were identified in the Surat Basin and on the North West Shelf. Relationships revealed between organic geochemistry, depositional environments and paleogeography were especially powerful in predicting source rock distribution. This approach married with detailed oil family correlations matured to establish a framework of Australian petroleum supersystems. Other significant outcomes were the development of public access well databases and educational products. The Australian maps were integrated into global map series and provided evidence for new concepts such as the Pangean Monsoon and Dynamic Topography. Advances in technology, geological concepts and in knowledge of Australian basins in the past 30 years provide opportunities for producing new, more sophisticated palaeogeographic maps to underpin future exploration. For example, the original maps that were largely based on well information, could be updated with thousands of wells drilled in the past decades and extensive high quality seismic information that images entire new sedimentary basins discovered around Australia's continental margin. New seismic technologies also provide visualisations of ancient geomorphologies extracted from 3D data volumes that can be then nested within more generalised time-slice maps. Also beyond the scope of the original maps, were Proterozoic sequences that are now targeted for petroleum exploration. Advances is biostratigraphy, chemostratigraphy and isotopic dating provide improved time control for constructing new palaeographic maps back into the Neoproterozoic Centralian Superbasin sequences across much of inland Australia.

AAPG Datapages/Search and Discovery Article #90217 © 2015 International Conference & Exhibition, Melbourne, Australia, September 13-16, 2015