Eastern Indian Ocean microcontinent formation driven by plate motion changes

Joanne Margaret Whittaker, Simon E Williams, Jacqueline A Halpin, Toban Joseph Wild, Jeffrey Darl Stilwell, Fred Jourdan, Nathan R Daczko

Research output: Contribution to journalArticleResearchpeer-review

25 Citations (Scopus)

Abstract

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 margins, with plume-driven thermal weakening commonly inferred to facilitate calving. However, a role for plate tectonic reorganisations has also been suggested. Here, we show that a combination of plate tectonic reorganisation and plume-driven thermal weakening were required to calve the Batavia and Gulden Draak microcontinents in the Cretaceous Indian Ocean. We reconstruct the evolution of these two microcontinents using constraints from new paleontological samples, 40Ar/39Ar ages, and geophysical data. Calving from India occurred at 101–104 Ma, coinciding with the onset of a dramatic change in Indian plate motion. Critically, Kerguelen plume volcanism does not appear to have directly triggered calving. 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.
Original languageEnglish
Pages (from-to)1-10
Number of pages10
JournalEarth and Planetary Science Letters
DOIs
Publication statusPublished - 30 Sep 2016

Keywords

  • plate tectonics
  • rifting
  • microcontinent
  • mantle plume

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