Mantle convection models constrain central Neo-Tethys Ocean reconstructions


A striking feature of the Indian Ocean is a distinct geoid low south of India, pointing to a regionally anomalous mantle density structure. Equally prominent are rapid plate convergence rate variations between India and SE Asia, particularly in Late Cretaceous/Paleocene times. Both observations are linked to the central Neo-Tethys Ocean subduction history, for which competing scenarios have been proposed. Here we evaluate three alternative reconstructions by assimilating their associated time-dependent velocity fields in global high-resolution geodynamic Earth models, allowing us to predict the resulting seismic mantle heterogeneity and geoid signal. Our analysis reveals that a geoid low similar to the one observed develops naturally when a long-lived back-arc basin south of Eurasia's paleo-margin is assumed. A quantitative comparison to seismic tomography further supports this model. In contrast, reconstructions assuming a single northward dipping subduction zone along Eurasia's margin or models incorporating a temporary southward dipping intra-oceanic subduction zone cannot sufficiently reproduce geoid and seismic observations.

Further Information
  author = {Nerlich, Rainer and Colli, Lorenzo and Ghelichkhan, Siavash and Schuberth, Bernhard and Bunge, Hans-Peter},
  doi = {10.1002/2016GL070524},
  journal = {Geophysical Research Letters},
  language = {en},
  number = {18},
  pages = {9595{\textendash}9603},
  title = {Mantle convection models constrain central Neo-Tethys Ocean reconstructions},
  url = {},
  volume = {43},
  year = {2016},
%O Journal Article
%A Nerlich, Rainer
%A Colli, Lorenzo
%A Ghelichkhan, Siavash
%A Schuberth, Bernhard
%A Bunge, Hans-Peter
%R 10.1002/2016GL070524
%J Geophysical Research Letters
%G en
%N 18
%P 9595–9603
%T Mantle convection models constrain central Neo-Tethys Ocean reconstructions
%V 43
%D 2016