Publication Name: Eastern Australian Basins Symposium 2001
Authors: S. Chantraprasert, K.R. McClay and C. Elders
Date Published: November 2001
Number of Pages: 34
Reference Type: Magazine Article
Abstract:
2D and 3D seismic data from the western Otway basin, South Australia have been used to analyse the 3D geometries of the Late Jurassic- Early Cretaceous rift fault systems in the central Penola Trough. NW and WNW striking rift fault systems in the central Penola Trough, developed in response to NNE-SSW directed regional extension. The major northeast and southwesterly-dipping fault systems initially developed as individual segments that overlapped in relay ramp structures. With increased extension segment linkage occurred producing kinks in the fault traces and leaving residual displacement minima in the overall elliptical fault displacement profiles. The displacement profiles and 3D visualisations of the major faults indicate that they grew by segment linkage in a fashion that was probably similar to numerical fault growth models. Relay ramps display skewed displacement profiles similar to those produced in numerical models of overlapping fault systems. The 3D seismic surveys include two complex accommodation zones within the central Penola Trough. These are relatively elevated zones of complex overlapping faults similar in style to accommodation zonesfound in analogue models of rift systems. No strike-slip transfer or oblique-slip transfer faults were found within this part of the Otway basin.