| Abstract Submission No. | ABS-3.1-0076 |
| Title of Abstract | Deciphering Metasomatism and Seismic Quiescence: Implications for Intraplate Earthquakes in the Dharwar Craton |
| Authors | PALLAVI TRIPATHY* |
| Organisation | NATIONAL CENTRE OF SEISMOLOGY NEW DELHI |
| Address | NATIONAL CENTRE OF SEISMOLOGY MAUSAM BHAWAN LODHI ROAD NEW DELHI NEW DELHI, DELHI, India Pincode: 110003 E-mail: ptripathyncs@gmail.com |
| Country | India |
| Presentation | Oral |
| Abstract | The Dharwar Craton in southern India, one of the oldest Archean continental blocks, has long been viewed as geologically stable. Yet, seismic observations from the region reveal alternating phases of quiet intervals and bursts of intraplate earthquakes. These patterns of seismic quiescence and reactivation point toward a more dynamic lithosphere than previously assumed. One mechanism that may explain this behavior is lithospheric metasomatism, where fluids or melts infiltrate the mantle root, altering its composition and reducing its mechanical strength. This study explores the relationship between metasomatic modification of the lithosphere and the occurrence of seismic quiescence in the Dharwar Craton. Seismological techniques¿including receiver function analysis, shear-wave splitting, and tomography¿are applied to characterize crustal and mantle structures. In parallel, isotopic and trace-element data from xenoliths and volcanic rocks are evaluated to detect metasomatic signatures. Comparative results suggest that the Western Dharwar Craton maintains a thick and rigid lithosphere, sustaining long periods of quiescence, while the Eastern Dharwar Craton is underlain by thinner, chemically modified lithosphere that experiences episodic quiet phases interrupted by localized earthquake clusters. By integrating seismic imaging with geochemical evidence, this work highlights how metasomatism contributes to weakening cratonic lithosphere and influences cycles of quiescence and intraplate seismicity. The findings provide new insights into stress accumulation and release in continental interiors, with implications for seismic hazard assessment in regions traditionally considered stable. |
| Keywords | Seismology Seismotectonics Intraplate seismicity Archean cratons Dharwar Craton Seismic quiescence Lithospheric metasomatism Earthquake hazard assessment |