Integrating global multidimensional datasets to underpin subduction process modelling during the past 60 million years

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Project Report
Understanding the initiation and processes governing subduction remains one of the greatest challenges in geodynamics. Subduction processes affect every aspect of the Earth system, from its control on the thermal and chemical state of the mantle, to its recycling of oceanic lithosphere, sediments, water and volatiles, to its affect on the atmosphere, hydrosphere, biosphere and solid Earth through earthquakes and volcanic eruptions. Moreover, subduction is generally agreed to be one of the primary driving forces of plate tectonics and mantle convection through slab pull and the addition of raw materials into the mantle. … Read more…

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GPlates News

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GPlates News Current Edition Issue 3 – March 2015 View Online newsletter GPlates News Past Editions Issue 2 – April 2014 View Online newsletter Issue 1 – October 2013 View Online newsletter Download PDF newsletter   Mailing Lists GPlates mailing lists GPlates-announce: A read-only list that you can subscribe to if you are only interested … Read more…

Constructing a tectonic framework for Ocean Drilling at high latitudes

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Project Summary
Currently a major Ocean Drilling Program (ODP) campaign south of Australia is being carried out, comprising nine drilling legs. We propose to create a tectonic and paleogeographic framework for interpreting, modelling and synthesising these data. A joint analysis of Arctic and Antarctic regions will bring together a group of researchers from the Universities of Ottawa/Canada, California at San Diego/USA and Sydney to integrate data and models for the evolution of polar ocean basins and margins. The project will strengthen our ties with centres of excellence in polar geoscience and help to maximise the return for Australia’s investment in ODP.  … Read more…

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Seafloor spreading around Australia

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(a) Abstract
The Australian Plate has undergone major changes in plate boundary geometry and relative plate velocities since the breakup of Gondwanaland. We illustrate the history of seafloor spreading around Australia by reconstructing gridded ocean floor ages and plate boundary configurations in a fixed Australian reference frame. In the Argo Abyssal Plain, seafloor spreading started at M25 dated as 154.3 Ma Late Jurassic (Oxfordian). The onset of seafloor spreading west of Australia at ~136 Ma marks the breakup between Greater India and Australia. Roughly at the same time, long-lived subduction east of Australia ceased, probably due to subduction of the Phoenix-Pacific spreading ridge, changing this plate boundary to a transform margin. … Read more…

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Numerical Modeling of Archean Tectonic Regimes by 2-Dimensional Finite Element Code

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Project Summary
Many lines of evidence suggest that heat loss from the earth should have been significantly greater in the Archean. The presence of high temperature komatiites, greater radiogenic heat production and heat from the secular cooling of the earth all imply higher mantle temperatures in the Archean. However, these lines of evidence are difficult to reconcile with Archean metamorphic PT data, diamond thermobarometry, mantle xenoliths in kimberlites, the ominous lack of minimum melting granites and estimates for crustal thickness which all suggest that geothermal gradients in the Archean, at least on the continents, were not very different from today. This paradox presents problems for reconstructing Archean tectonic processes and environments.  … Read more…

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Seafloor imaging east and south of Australia

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Project Summary
Data from three recent cruises on N.O. L’Atalante are used in collaboration with AGSO to use backscatter and bathymetry data for seafloor classification, and to reconstruct the tectonic and sedimentary history of selected areas, also based on 3.5 kHz, seismic reflection, gravity and magnetic data.

Sponsors
Australian Geological Survey Organization
Environment Australia  … Read more…

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Welcome newcomers!

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Welcome!

The Mid-Cretaceous seafloor spreading pulse: fact or fiction?

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Project Summary
A major debate in Geoscience is centred on the hypothesis that a massive pulse of rapid seafloor spreading occurred during the mid-Cretaceous (~120-80 Ma). It has been suggested that such a pulse caused prolonged magnetic field stability, large igneous provinces, a sea-level highstand, variations in atmospheric CO2 and anoxia, but doubts have been raised about its existence. We propose to test this hypothesis by creating complete palaeo-seafloor age grids for the last 130 m.y. They will serve as input for 3-D spherical convection models, whose output will be groundtruthed by plate kinematics, results from mantle tomography and by the uplift-subsidence history of cratons.  … Read more…

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