| Abstract Submission No. | ABS-4.1-0216 |
| Title of Abstract | 3-C Wide-angle Crustal Seismic Imaging of the South Rewa Basin, Central India. |
| Authors | Sudeshna Moharana*, Laxmidhar Behera |
| Organisation | CSIR-NGRI |
| Address | QR NO II/44, NGRI QUARTERS, NGRI, UPPAL Hyderabad, Telangana, India Pincode: 500007 E-mail: sudeshna.ngri19a@acsir.res.in |
| Country | India |
| Presentation | Oral |
| Abstract | A 2D-3C crustal velocity structure is derived by travel-time inversion of the first arrival seismic refraction and wide-angle reflection data along the N-S trending Hardi-Samatpur seismic profile shot across the South Rewa rift basin, located within the Son-Mahanadi rift system of Central India. Inversion of seismic data along this profile reveals an undulated granitic-gneissic basement apart from fault-bounded horst and graben features. The Vp and Vs models explain that the basin is filled with 2-3 km thick sequences of Gondwana sediments as identified by first arrival traveltime delay, which is overlain by high velocity Deccan volcanics. We also delineated a thick (6.0 km) mid-crustal low-velocity zone at a depth of 13-17 km, which would indicate fluid entrapment during its rifting episode. The high velocity mafic underplating is also seen at a depth of 28-30 km at the base of the lower crust. The Moho is delineated at a depth of 37-44 km, indicating Moho upwarping below the Narmada-Son lineament. Subsequent tectonic activities have reactivated the pre-existing faults, resulting in a complex crustal structure underneath. The evolutionary nature of the basin suggests the interplay of extensional rifting, sedimentation, magmatic activity, and later tectonic reactivation along major structural lineaments, like the Narmada-Son rift zone. The present study has offered a valuable insight into the broader geodynamic framework of Central India. |
| Keywords | 3-C; basement; mafic underplating; Moho |