TY - JOUR
T1 - Eastern Indian Ocean microcontinent formation driven by plate motion changes
AU - Whittaker, J. M.
AU - Williams, S. E.
AU - Halpin, J. A.
AU - Wild, T. J.
AU - Stilwell, J. D.
AU - Jourdan, F.
AU - Daczko, N. R.
PY - 2016/11/15
Y1 - 2016/11/15
N2 - 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.
AB - 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.
KW - plate tectonics
KW - rifting
KW - microcontinent
KW - mantle plume
UR - http://www.scopus.com/inward/record.url?scp=84992397369&partnerID=8YFLogxK
UR - http://purl.org/au-research/grants/arc/CE0561595
UR - http://purl.org/au-research/grants/arc/DE140100376
UR - http://purl.org/au-research/grants/arc/FL0992245
U2 - 10.1016/j.epsl.2016.09.019
DO - 10.1016/j.epsl.2016.09.019
M3 - Article
AN - SCOPUS:84992397369
VL - 454
SP - 203
EP - 212
JO - Earth and Planetary Science Letters
JF - Earth and Planetary Science Letters
SN - 0012-821X
ER -