Growth of mountain belts in central Asia triggers a new collision zone in central India

I Koulakov,N Al-Arifi,S El Khrepy,T Gerya,B K Rastogi,I Medved,J R Kayal,A Jakovlev

doi:10.1038/s41598-018-29105-2

Abstract

Several unusual strong earthquakes occurred in central India along the Narmada-Son Lineament (NSL) zone, far from active plate boundaries. To understand the role of collisional processes in the origin of this seismicity, we develop a numerical thermomechanical model of shortening between the Indian Plate and Asia. We show that at the final stage of collision, the shortening rate of the high mountain areas slows. The continuing convergence of India and Asia triggers the initiation of a new collision zone in continental part of India. Various geological and geophysical observations indicate that the NSL is a weakest zone with northward thrusting of the thinner central Indian lithosphere underneath the thicker northern part of the Indian Plate. We hypothesize that the NSL was reactivated during the final stage of the India Asia convergence and it will possibly form a new mountain belt within the Indian continent.

Highlights

Most of the seismic activity in Asia occurs in highly deformed orogenic belts and is triggered by active deformations of the crust owing to India-Asia collision
The existing GPS observations directly show that the major contractional deformations of continental India are accommodated in the Narmada-Son Lineament (NSL) zone[13,14,15]
The information about the lithospheric structure may help to understand the cause of unusual tectonic activity in the intracontinental parts of India

Summary

Asia triggers a new collision zone in central India

Several unusual strong earthquakes occurred in central India along the Narmada-Son Lineament (NSL) zone, far from active plate boundaries. Many strong and moderate earthquakes in the inner parts of the Indian Plate occur along the Narmada-Son Lineament (NSL), which is one of the most prominent tectonic elements in continental India. Four years measurements at two GPS stations south of Narmada rift at Burwani in the state of Madhya Pradesh (74.90 N 22.04 E) and Sagbara in the state of Maharashtra (73.79 N 21.54 E) indicate deformation rate of more than 3 mm/yr[15] The cause of this unusual tectonic activity in intracontinental parts of India is still under debates. To understand the role of collisional processes in the origin of the recent contractional deformations at the NSL, we create a numerical thermomechanical model of shortening between the Indian Plate and Asia.

Results

Methods

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Author Contributions

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