Geochronological Constraints for Boundary Shear Zones between Eastern Ghats Province and Bastar Craton: Implication for the Formation of Granulites and Their Exhumation History  

作　　者：Rajib Kar Miguel Angelo Stipp Basei Samarendra Bhattacharya Anwesha Ghosh Sanchari Chatterjee Rajib Kar;Miguel Angelo Stipp Basei;Samarendra Bhattacharya;Anwesha Ghosh;Sanchari Chatterjee(Department of Geology, University of Calcutta, Kolkata, India;Geoscience Institute, Sao Paulo University, Sao Paulo, Brazil)

机构地区：[1]Department of Geology, University of Calcutta, Kolkata, India [2]Geoscience Institute, Sao Paulo University, Sao Paulo, Brazil

出　　处：《International Journal of Geosciences》2022年第8期593-608,共16页地球科学国际期刊（英文）

摘　　要：Shear zones in the boundary between Eastern Ghats Province (EGP) and the cratons of Singhbhum in the north and Bastar in the west provide an excellent opportunity to study the tectonics of shear zone development and its timing in relation to the evolutionary history of the granulite suites. Detailed structural, microfabric and quartz C-axis patterns revealed a high temperature shear zone, at the western boundary between EGP and Bastar Craton (BC) around Paikmal. Petrological studies in this shear zone indicated decompression coeval with stretching in the sheared granulites. Geochronological constraints provided here indicate rapid exhumation of deep seated granulites in this boundary shear zone;the timing also is late in relation to the long-lived thermal (granulite formation) event in the EGP. Additionally, our geochronological data demonstrated the ~1600 Ma event in the Eastern Ghats Belt (EGB) involving sedimentation, magmatism, metamorphism and crustal anatexis, as a significant world event.Shear zones in the boundary between Eastern Ghats Province (EGP) and the cratons of Singhbhum in the north and Bastar in the west provide an excellent opportunity to study the tectonics of shear zone development and its timing in relation to the evolutionary history of the granulite suites. Detailed structural, microfabric and quartz C-axis patterns revealed a high temperature shear zone, at the western boundary between EGP and Bastar Craton (BC) around Paikmal. Petrological studies in this shear zone indicated decompression coeval with stretching in the sheared granulites. Geochronological constraints provided here indicate rapid exhumation of deep seated granulites in this boundary shear zone;the timing also is late in relation to the long-lived thermal (granulite formation) event in the EGP. Additionally, our geochronological data demonstrated the ~1600 Ma event in the Eastern Ghats Belt (EGB) involving sedimentation, magmatism, metamorphism and crustal anatexis, as a significant world event.

关 键 词：Shear Zone Extrusion Tectonics EXHUMATION Eastern Ghats Province GEOCHRONOLOGY 

分 类 号：F42[经济管理—产业经济]