The Southwest Margin is a section of the continental margin off Australia’s western coast. It includes the Paleozoic to Mesozoic Southern Carnarvon, Perth and Mentelle basins, as well as the Naturaliste and Wallaby plateaus. While several smaller hydrocarbon discoveries have been made onshore, the offshore region remains underexplored. Recent studies, however, indicate there is potential for new petroleum discoveries in many of these frontier areas (Nicholson et al 2008; Borissova et al 2010; Jones et al 2011).
Despite the new geological insights gained from these studies, depth-to-basement and basement structure and composition beneath the Southwest Margin sedimentary basins remain poorly understood. The extent of exposed basement outcrop is limited, only a few wells intersect basement and, in many areas, the basement horizon cannot be resolved using seismic data. An understanding of basement is however important when conducting basin studies, as the basement of any basin provides the foundation onto which sediment fill is deposited. As tectonic stresses are applied to a region, the rheology and mechanical behaviour of the basement influences how the crust deforms. Hence, variations in basement strength, composition and structure significantly influence the resulting basin geometry, patterns of sediment deposition and basement derived heatflow. All of these factors fundamentally affect the generation and preservation of hydrocarbon resources. Read More
