Thesis: Identifying tectonic controls of reactivation through a combined fault and earthquake analysis.
The North West Shelf (NWS) of Australia includes the Bonaparte, Browse, offshore Canning and Carnarvon basins. It formed during the separation of Gondwana, through multiple rift, sag and reactivation events since the late Paleozoic (Longley et al., 2002; Heine and Müller, 2005). The western margin is now passive (Stagg et al., 1999) but changes along strike to a northern active margin due to collision between the Australian and Eurasian plates (Keep and Haig, 2010). The NWS is tectonically active with present day seismicity linked to plate margin stress (Clark et al., 2012).
This project combines Paleozoic to Neogene fault histories with earthquake analysis, to determine if the location of shallow earthquakes is linked to basement fault architecture. Analysis of fault strain indicators and maximum stress directions assist in determining tectonic controls. Structural features are mapped using 2D and 3D seismic surveys from across the four main basins, with results correlated between surveys and basins. Neotectonic investigations, focusing on relocating earthquakes and producing focal mechanism solutions, give insight into modes of present day tectonic failure.
Combining neotectonic analyses with seismic interpretation increases our knowledge of where and how basement fault morphology is controlling Neogene to present day deformation.
Why my research is important
The NWS hosts most of Australia’s major oil and gas reservoirs, and therefore the study is significant as it will provide insight for more complex trap exploration, as well increasing our understanding of present day earthquakes.