Full-fit, palinspastic reconstruction of the conjugate Australian-Antarctic margins

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AusAntCThick47Ma-1Despite decades of study the pre-rift configuration and early rifting history between Australia and Antarctica is not well established. The plate boundary system during the Cretaceous includes the evolving Kerguelen-Broken Ridge Large Igneous Province in the west as well as the conjugate passive and transform margin segments of the Australian and Antarctic continents. … Read more…

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Dynamic subsidence of eastern Australia during the Cretaceous

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Dynamic Subsidence of Eastern Australia Matthews et al (2011)During the Early Cretaceous Australia’s eastward passage over sinking subducted slabs induced widespread dynamic subsidence and formation of a large eperiogenic sea in the eastern interior. Despite evidence for convergence between Australia and the paleo-Pacific, the subduction zone location has been poorly constrained. Using coupled plate tectonic-mantle convection models, we test two end-member scenarios, one with subduction directly east of Australia’s reconstructed continental margin, and a second with subduction translated ~1000 km east, implying the existence of a back-arc basin. Our models incorporate a rheological model for the mantle and lithosphere, plate motions since 140 Ma and evolving plate boundaries. While mantle rheology affects the magnitude of surface vertical motions, timing of uplift and subsidence depends on plate boundary geometries and kinematics. … Read more…

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High resolution reconstruction of the Central and Eastern Indian Ocean

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Project Summary
Plate reconstruction models for the rifting and separation of Gondwanaland’s conjugate margins continue to be poorly constrained. We propose to develop a new, high-resolution plate model for the central and eastern Indian ocean by synthesizing old and new geological and geophysical data utilizing combined French and Australian advanced software for magnetic anomaly modeling and plate tectonic reconstructions. We will test alternative continental fit reconstruction hypotheses by using a variety of reconstructed data sets. Such a joint research is timely, as the Indian Ocean continental margins become the focus of intense oil and gas exploration.  … Read more…

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The subduction reference framework: Unravelling the causes of long-term sea-level change

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Project Summary
Sea level has fluctuated by up to 300 m through geological time, creating vast sedimentary basins and associated natural resources. We will use Earth’s subduction history as imaged by seismic tomography to establish a subduction reference framework for the past 200 million years, tracking all tectonic plates in both latitude and longitude. 4D numerical mantle-plate tectonic simulations (3D plus time) will reconstruct how the recycling of old, cold oceanic plates into the mantle have influenced surface topography and sea-level change since the breakup of the supercontinent Pangaea.  … Read more…

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Integration of plate kinematic reconstructions in geodynamic models of mantle convection

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Project Summary
Despite more than 30 years of plate tectonics research, we still do not know exactly what drives the plates or controls the time-dependence of mantle convection. Plate motions are linked to processes in the deeper Earth interior by complex, enigmatic cause-and-effect relationships. While mantle convection is generally accepted as the underlying cause of plate motions, the geometry of mantle flow and its relation to plate motions remains poorly understood. As plate tectonics is the Earth Science paradigm, breakthroughs in this field affect understanding of all branches of Earth Science including formation and distribution of natural resources, long-term climate change and natural hazards. … Read more…

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