Figure 1
Tectonic setting of the study area displaying the major structural boundaries and outline of the Otway Basin. The east-dipping Moyston Fault represents a major crustal-scale boundary between the older Delamerian and younger Lachlan orogenic belts. The Otway Basin is a large, Late Jurassic rift basin that trends predominantly NW–SE and covers both onshore and offshore South Australia/Victoria as well as offshore Tasmania. Red triangles indicate volcanic centres of the Newer Volcanics Province3. The Mt Gambier subprovince (circled) can be further subdivided into the Mt Burr Group (NW) and the Mt Gambier/Mt Schank group (SE). All MT and GDS data shown were used in the 3D inversion. Yellow circles—broadband MT sites as part of this paper, white circles—previously collected broadband MT, blue diamonds—AusLAMP and other long-period MT, orange squares—geomagnetic depth soundings. Visualisation created using the free and open source QGIS v3.22.8 (https://qgis.org).
