Constraining central Neo-Tethys Ocean reconstructions with mantle convection models

Nerlich, Rainer; Colli, Lorenzo; Ghelichkhan, Siavash; Schuberth, Bernhard S. A. and Bunge, Hans-Peter (2016): Constraining central Neo-Tethys Ocean reconstructions with mantle convection models. In: Geophysical Research Letters, Vol. 43, No. 18: pp. 9595-9603

Abstract

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 paleomargin 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 intraoceanic subduction zone cannot sufficiently reproduce geoid and seismic observations.

• Item Type: Journal article
• Faculties: Geosciences > Department of Earth and Environmental Sciences
• Subjects: 500 Science > 550 Earth sciences and geology
• ISSN: 0094-8276
• Language: English