Mantle Flow and Deforming Continents: From India-Asia Convergence to Pacific Subduction

Area of Science:

• Geophysics
• Tectonics
• Geodynamics

Background:

• Plate boundary interactions traditionally explain mountain belts and rift zones.
• Widespread deformation across Asia, from the Himalayas to the Japan Sea, challenges simple plate boundary models.

Purpose of the Study:

• To explain the extensive deformation in East Asia by proposing a new model for the India-Asia collision.
• To investigate the role of deep asthenospheric mantle flow in continental deformation.

Main Methods:

• Comparative analysis of tectonic and kinematic records (last 50 million years).
• Integration with seismic tomography and anisotropy models.
• Modeling deep asthenospheric mantle flow dynamics.

Main Results:

• Asthenospheric flow from the India-Asia collision extends to East Asia, influencing subduction dynamics.
• This flow drives extensional deformation over a 3,000-km region and controls compressional stresses.
• Shortening directions in deforming continents may indicate past asthenospheric flow directions.

Conclusions:

• Deep asthenospheric flow beneath continents plays a crucial role in large-scale tectonic processes.
• The India-Asia collision model highlights the significance of mantle flow in continental deformation.
• This framework offers new insights into studying past mantle flow and tectonic evolution.