Research Projects

The Eastern Ghats Mobile Belt (EGMB) is surrounded by Archaean Cratons namely Dharwar Craton in the SW, Bastar Craton in the west, and NW and North Odisha-Singhbhum Craton (NOSC) in the north. The contact between EGMB and the cratons is tectonic in nature and is marked by shear zones namely Terrane Boundry Shear Zone (TBSZ). The NW margin is marked by a westerly vergent thrust, called the Lakhna thrust, which is associated with several nappes namely Sinapalli, Lathore and Turekela nappes. The nappes have overthrusted the Bastar craton for several kilometer from its root zone. Therefore the NW front appears like a salient structure similar to the Phanerozoic thrust belt. The recess is associated with the Paikamal lateral ramp (Fig.1b). The Paikamal lateral ramp continues eastward to join with the Mahanadi shear zone of the EGMB, which is parallel and close to the northern margin of the EGMB. Similarly, there are other salient and recess structures on the NW and W front of the EGMB and these structures are cross-cut by strike-slip shear zones (Fig.1c&d). Therefore, the northern margin of the EGMB with the North Odisha Singbhum Craton is marked by a set of strike-slip shear zones (Fig.1c). These are Barakot, Riyamal, Kerajang, Angul, and Mahanadi shear zones. This set of shear zones probably joins with the Sukinda thrust that occurs in the east. Thus the strike-slip shear zones represent a transition zone between the NW boundary thrust and the Sukinda thrust. The transfer zone encloses slices off part of the mobile belt and craton, which is included under Rengali Province. The focus of this proposal is to study the kinematic and strain pattern of Barakot, Sukinda, Riyamal, and Kerajang shear zones between Kamakhyanagar to Jaraka (Fig.1c). The significance of this study lies in the fact that these shear zones constitute the strike-slip shear and the strain analysis will throw light on the tectonics of juxtaposition Archaean and Proterozoic terranes in the eastern part of the Indian shield. There are multiple phases of nepheline syenite intrusion. They will be distinguished based on tectonic and magmatic fabric. Besides, the nepheline syenite will be geochemically analysed to know if there is variation in their geochemistry amongst different phases. REE and other trace elements will help in plotting discriminatory diagrams to know the tectonic setting. Monazite geochronology will be carried out to date individual phases of nepheline syenite intrusion. That will help in finding the timing of folding, strike slip shearing. Further, pseudotachylite veins intruded along fractures in Mahanadi area marking Pan-African event. The Gondwana basins are marked by basin margin faults as Talchir basin by Angul and Kerajang shear zones. The basin formation and sedimentation may be related to the stress system along the shear zones. Further, the study bears significance for the neotectonics activity in the Mahanadi area that creates seismicity.