dataset: TEUMOTWTWT

Otway Basin Top Eumeralla Two Way Time Structure Map using sun shading. Sun angle 80, azimuth 35 and vertical exaggeration 10. Pixel colours indicate red shallow (0ms), purple deep (4813ms) This image is a TWT structure map for the top of the Eumeralla Formation (Top Otway Group) based on extensive regional mapping done by Minerals and Petroleum Victoria, Primary Industries and Resources South Australia, Origin Energy and Cooper (1995b). The main features to note in this image are: 1) the regional dip of the top of the Eumeralla Formation in the western and central parts of the basin; 2) the large depression to the southwest of the Tartwaup-Mussel Hingeline; 3) the intensity of faulting at the top Eumeralla level; and 4) the N-S oriented trough (Shipwreck Trough) to the southwest of the Otway Ranges. Several structural features are visible in this image. These include the Crayfish, Mumbannar, Mussel and Prawn platforms; the Shipwreck and Voluta troughs, the Bridgewater Arch, and the Port Campbell Embayment. The faulting visible at the Top Eumeralla Formation level is largely a response of the Late Cretaceous rift event. Most of the faulting associated with this event is located to the south of the Tartwaup-Mussel Hingeline in the Voluta Trough. The faults are largely oriented NW-SE with down-to-the-south throws. The Tartwaup- Mussel Hingeline shows up particularly well in this image as a series of enechelon, down-to-the-south faults, with individual throws of up to 2 seconds TWT. The fault system is concave to the southwest. The northern end of the Shipwreck Trough starts to splay to the NW and NE, and spreads out onshore where it has a semi-circular, bowl-shaped appearance open to the south. This image is extracted from Petroleum Atlas of Victoria Figure C23 (November 2001) The entire report may be downloaded ( at no cost ) from https://gsv.vic.gov.au/searchAssistant/document.php?q=parent_id:43977