| Abstract Submission No. | ABS-2.1-0207 |
| Title of Abstract | Deep Crustal Study in the Indian Shield: A Review |
| Authors | PSHSN Dattatreya *, Biswajith Mandal, Prakash Kumar |
| Organisation | CSIR-NGRI |
| Address | 15-24, Swaroop nagar, Uppal, Medchal- Malakajgiri Hyderabad, Telangana, India Pincode: 500039 E-mail: dattacss@hotmail.com |
| Country | India |
| Presentation | Poster |
| Abstract | Controlled Source Seismology (CSS), employing artificially generated seismic energy to record near-vertical reflections, refractions, and wide-angle signals, has emerged as a key approach for imaging both shallow and deep crustal structures of the Indian Shield. Analyses of historical and recent CSS datasets have greatly enhanced our understanding of the geodynamic framework and tectonic evolution of major geological provinces, including the Southern Granulite Terrain (SGT), Dharwar Craton, Aravalli-Delhi Fold Belt, Central Indian Tectonic Zone (CITZ), Kutch Basin, and the northwestern Himalaya. In the SGT, a four-layered crustal model reveals a 5-7 km thick low-velocity zone and an overall crustal thickness of about 45 km with a 3-4 km Moho uplift, indicating Proterozoic compression and subsequent Phanerozoic reactivation. The Dharwar Craton exhibits Moho depths increasing from ~35 km to ~42 km and a high-velocity lower crust (7.0-7.1 km/s) up to 10 km thick. Across the CITZ, an ~8 km Moho offset beneath the Central Indian Suture and opposing dipping reflections signify block heterogeneity and suture reactivation. The Bastar Craton shows a Moho depth of ~48 km, while the Aravalli�Delhi Fold Belt demonstrates a five-layered crustal configuration with listric faulting and lower crustal velocities up to 7.3 km/s. The Kutch Basin presents Mesozoic rift-related structures, including sub-horizontal reflectors down to ~15 km and domal features within a 33-35 km thick crust. In contrast, the northwestern Himalaya exhibits significant crustal thickening, with the Moho deepening from ~45 km to ~76 km near Nanga Parbat, reflecting intense shortening and uplift. Collectively, CSS investigations highlight that the Indian Shield's crustal evolution is shaped by cyclic processes of compression, rifting, and crust-mantle interactions from the Precambrian to the Cenozoic, offering crucial insights into regional geodynamics and resource potential for minerals. |
| Keywords | SGT, Dharwar Craton, Aravalli-Delhi Fold Belt, CITZ, Kutch Basin, Northwestern Himalaya, Moho offset, crust-mantle interactions |