Alternative reconstructions of the Jurassic northern extent of Greater India differ by up to several thousand kilometers.We present a newmodel that is constrained by revised seafloor spreading anomalies, fracture zones and crustal ages based on drillsites/dredges from all the abyssal plains along the West Australian margin and the Wharton Basin, where an unexpected sliver of Jurassic seafloor (153 Ma) has been found embedded in Cretaceous (95 My old) seafloor. Based on fracture zone trajectories, this NeoTethyan sliver must have originally formed along a western extension of the spreading center that formed the Argo Abyssal Plain, separating a western extension of West Argoland/West Burma from Greater India as a ribbon terrane. The NeoTethyan sliver, Zenith and Wallaby plateaus moved as part of Greater India until westward ridge jumps isolated them. Following another spreading reorganization, the Jurassic crust resumed migrating with Greater India until it was re-attached to the Australian plate ~95 Ma. The new Wharton Basin data and kinematic model place strong constraints on the disputed northern Jurassic extent of Greater India. Late Jurassic seafloor spreading must have reached south to the Cuvier Abyssal Plain on the West Australian margin, connected to a spreading ridge wrapping around northern Greater India, but this Jurassic crust is no longer preserved there, having been entirely transferred to the conjugate plate by ridge propagations. This discovery constrains the major portion of Greater India to have been located south of the large-offset Wallaby- Zenith Fracture Zone, excluding much larger previously proposed shapes of Greater India.

Item Type:	Refereed Article
Keywords:	East Indian Ocean, Greater India, NeoTethys, West Australian margin, plate tectonics
Research Division:	Earth Sciences
Research Group:	Geology
Research Field:	Marine geoscience
Objective Division:	Expanding Knowledge
Objective Group:	Expanding knowledge
Objective Field:	Expanding knowledge in the earth sciences
UTAS Author:	Whittaker, J (Associate Professor Jo Whittaker)
ID Code:	84432
Year Published:	2012
Web of Science® Times Cited:	123
Deposited By:	Research Division
Deposited On:	2013-05-14
Last Modified:	2017-10-30
Downloads:	0