Deep Lithospheric Root of Dharwar Craton Inferred from Seismology.
Abstract
We investigate the lithosphere-asthenosphere system beneath a 200 km long corridor at the Eastern Dharwar Craton, South India, covering 3.2-2.5 billion years old craton and its diamondiferous kimberlite province (1.1 billion years) with high-resolution shear wave velocity image computed at ~15 km spacing through joint inversion of receiver function and surface wave phase dispersion data. Both the geological domains have an average ~170-180 km thick craton lithosphere with a velocity of 4.7-4.8 km/s, similar to what is inferred by the kimberlite xenoliths data. Our result suggests no major thermal alteration to the lithosphere of the Eastern Dharwar craton despite being affected by kimberlite volcanism, Marion mantle plume, and fast motion of the Indian plate for 140 million years. The lithosphere-asthenosphere boundary is 50 km wide with a velocity drop of ~2%, suggesting moderately low viscosity (velocity) asthenosphere below the high viscosity (velocity) craton consistent with the continental undertow model.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2022
- Bibcode:
- 2022AGUFM.T11D..05C