A late Tonian plate reorganization event revealed by a full-plate Proterozoic reconstruction

Collins, Alan S.1, Blades, Morgan L.1, Merdith, Andrew S.2, Foden, John D.1

1Tectonics and Earth Systems (TES), Department of Earth Sciences, The University of Adelaide, Adelaide, SA 5005, Australia, 2EarthByte Group, School of Geosciences, The University of Sydney, Sydney, Australia

Plate reorganization events are a characteristic of plate tectonics that punctuate the Phanerozoic. They fundamentally change the lithospheric plate-motion circuit, influencing the planet’s lithosphere-mantle system and both ocean and atmospheric circulation through changes in bathymetry and topography. The development of full-plate reconstructions for deep time allows the geological record to be interrogated in a framework where plate kinematic reorganizations can be explored. Here, we interpret the geological record of the one of the most extensive tracts of Neoproterozoic crust on the planet (the Arabian-Nubian Shield) to reflect a late Tonian plate reorganization at ca. 800–715 Ma that switched plate-convergence directions in the Mozambique Ocean. This caused Neoproterozoic India to move towards both the African cratons and Australia-Mawson, instigating the closure of the intervening ocean and the future amalgamation of central Gondwana ca. 200 million years later. This plate kinematic change is coeval with constraints on break-up of the core of Rodinia between Australia-Mawson and Laurentia and Kalahari and Congo.


Biography

Alan Collins is a tectonic geologist with wide interests that diverge from a fascination of how our planet took the path it did because of plate tectonics.

About the GSA

The Geological Society of Australia was established as a non-profit organisation in 1952 to promote, advance and support Earth sciences in Australia.

As a broadly based professional society that aims to represent all Earth Science disciplines, the GSA attracts a wide diversity of members working in a similarly broad range of industries.