TITLE:
Geochronological Constraints for Boundary Shear Zones between Eastern Ghats Province and Bastar Craton: Implication for the Formation of Granulites and Their Exhumation History
AUTHORS:
Rajib Kar, Miguel Angelo Stipp Basei, Samarendra Bhattacharya, Anwesha Ghosh, Sanchari Chatterjee
KEYWORDS:
Shear Zone, Extrusion Tectonics, Exhumation, Eastern Ghats Province, Geochronology
JOURNAL NAME:
International Journal of Geosciences,
Vol.13 No.8,
August
3,
2022
ABSTRACT: 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.