Roles of south-dipping subduction in southern Tethys in the breakup of Australia from Antarctic
Abstract
The breakup of supercontinents is influenced by multiple factors including mantle plume, subduction, orogen and so on. In this study, we focus on the breakup between Australia and Antarctic as part of the Pangea break-up using a 3D global geodynamic model. We specifically examine the possibility that mantle plumes induced by southward subduction along the southern margin of the Tethys Ocean as well as the circum-Pangea subduction girdle caused this break-up event. There are several lines of geological evidence suggesting the existence of south-dipping subduction along Tethys' southern margin. In our model, we have orogenic belts such as the Albany-Fraser and the Paterson-Petermann orogens imbedded in the Australian continent that have thin and weak lithosphere with low viscosity. In addition, we calculate melt fraction of partial melting above mantle plume(s) that weakens the lithosphere. Our model results suggest that south-dipping subduction in southern Tethys, together with circum-Pangea subduction, controlled the magnitude and location of mantle plume(s) below this part of Pangea, which in-turn led to the breakup between Australia and Antarctica.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.T43I0535L
- Keywords:
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- 1525 Paleomagnetism applied to tectonics: regional;
- global;
- GEOMAGNETISM AND PALEOMAGNETISM;
- 8121 Dynamics: convection currents;
- and mantle plumes;
- TECTONOPHYSICS;
- 8157 Plate motions: past;
- TECTONOPHYSICS;
- 8178 Tectonics and magmatism;
- TECTONOPHYSICS