Plate motion changes drive Eastern Indian Ocean microcontinent formation

J M Whittaker, S Williams, J Halpin, T Wild, J Stilwell, F Jourdan, N R Daczko

Research output: Contribution to conferencePoster


The roles of plate tectonic or mantle dynamic forces in rupturing continental lithosphere remain controversial. Particularly enigmatic is the rifting of microcontinents from mature continental rifted margin -several well-studied microcontinent calving events coincide in space and time with mantle plume activity,but the significance of plumes in driving microcontinent formation remains controversial, and a role for plate-driven processes has also been suggested. In 2011, our team discovered two new microcontinents in the eastern Indian Ocean, the Batavia and Gulden Draak microcontinents. These microcontinents are unique as they are the only surviving remnants of the now-destroyed or highly deformed Greater Indian margin and provide us with an opportunity to test existing models of microcontinent formation against new observations. Here, we explore models for microcontinent formation using our new data from the Eastern Indian Ocean in a plate tectonic reconstruction framework. We use Argon dating and paleontology results to constrain calving from greater India at 101104 Ma. This region had been proximal to the active Kerguelen plume for ~30 Myrs but we demonstrate that calving did not correspond with a burst of volcanic activity. Rather, it is likely that plume-related thermal weakening of the Indian passive margin preconditioned it for microcontinent formation but calving was triggered by changes in plate tectonic boundary forces. Changes in the relative motions between Indian and Australia led to increasing compressive forces along the long-offset Wallaby-Zenith Fracture Zone, which was eventually abandoned during the jump of the spreading ridge into the Indian continental margin.
Original languageEnglish
Number of pages1
Publication statusPublished - 2016
EventFall Meeting of the American-Geophysical-Union 2016 - San Francisco, United States of America
Duration: 12 Dec 201616 Dec 2016


ConferenceFall Meeting of the American-Geophysical-Union 2016
Abbreviated titleAGU
Country/TerritoryUnited States of America
CitySan Francisco

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