Mapping the Chronostratigraphy of Australia with EGGS: New Data in the Eastern Resources Corridor

As part of the first phase of the Exploring for the Future (EFTF) program, depth estimates have been compiled across the North Australian Craton (NAC) in the Estimates of Geological and Geophysical Surfaces (EGGS) database. These depth estimates are ultimately intended to be used to build national-scale models of Australia’s geological cover sequences. EGGS contains depth estimate points of chronostratigraphic era boundaries derived from multiple geological and geophysical datasets. This includes points from the interpretation of airborne electromagnetic (AEM) and magnetotelluric (MT) datasets, as well as from magnetic modelling. Surface and solid geology maps, and formation tops data for groundwater, petroleum and mineral boreholes are linked with the Australian Stratigraphic Units Database (ASUD) to provide chronostratigraphic context for the depth estimates. Following on from work completed across the NAC, the structure of the EGGS database has been re-designed to better enable users to extract additional key information required to build 3D models, and abide by the FAIR (Findable, Accessible, Interoperable, Reusable) data principles. For example, EGGS now identifies points associated with a significant (era-scale) chronostratigraphic unconformity – such as where the Cenozoic overlies Paleozoic or older rocks – enabling better interpolation between points in gridded cover surfaces. We are extending our EGGS coverage to the south, along the Eastern Resources Corridor, including over the Cooper Basin. Newly added data from this area includes magnetic depth estimates from targeted magnetic inversion modelling, interpretation of the AusAEM Eastern Resources Corridor survey data, and compilation of well formation tops across South Australia, Victoria and New South Wales. These data will be used to generate a 3D depth to cover model over the Eastern Resources Corridor and contribute towards building a national-scale geological architecture model. This Abstract was submitted/presented to the 2022 Central Australian Basins Symposium IV 29-30 August (https://agentur.eventsair.com/cabsiv/).