A record of plume-induced plate rotation triggering seafloor spreading and subduction initiation
- 1University of Utrecht, Department of Earth Sciences, Utrecht, Netherlands (douwework@gmail.com)
- 2GFZ German Research Centre for Geosciences, Potsdam, Germany
- 3Centre of Earth Evolution and Dynamics (CEED), University of Oslo, Norway
- 4Département de Géologie et de Génie Géologique, Université Laval, Canada
- 5School of Geography, Earth and Environmental Sciences, University of Birmingham, UK
- 6School of Earth and Environmental Sciences, University of Queensland, Australia
- 7BRGM, Orléans, France
The formation of a global network of plate boundaries surrounding a mosaic of lithospheric fragments was a key step in the emergence of Earth’s plate tectonics. So far, propositions for plate boundary formation are regional in nature but how plate boundaries are being created over 1000s of km in short periods of geological time remains elusive. Here, we show from geological observations that a >12,000 km long plate boundary formed between the Indian and African plates around 105 Ma with subduction segments from the eastern Mediterranean region to a newly established India-Africa rotation pole in the west-Indian ocean where it transitioned into a ridge between India and Madagascar. We find no plate tectonics-related potential triggers of this plate rotation and identify coeval mantle plume rise below Madagascar-India as the only viable driver. For this, we provide a proof of concept by torque balance modeling revealing that the Indian and African cratonic keels were important in determining plate rotation and subduction initiation in response to the spreading plume head. Our results show that plumes may provide a non-plate-tectonic mechanism for large plate rotation initiating divergent and convergent plate boundaries far away from the plume head that may even be an underlying cause of the emergence of modern plate tectonics.
How to cite: van Hinsbergen, D. J. J., Steinberger, B., Guilmette, C., Maffione, M., Gürer, D., Peters, K., Plunder, A., McPhee, P., Gaina, C., Advokaat, E., Vissers, R., and Spakman, W.: A record of plume-induced plate rotation triggering seafloor spreading and subduction initiation, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-546, https://doi.org/10.5194/egusphere-egu21-546, 2021.