Late Neoarchean growth of the Bastar craton and early Cambrian accretion of the Eastern Ghats Belt, India: Linking the India-Australia-Antarctica terminal accretions during Gondwanaland assembly
Abstract
The Eastern Ghats Belt (India) is centrally located within a string of multi-continent Cambrian peri-orogens formed during the terminal assembly of East Gondwanaland. However, the timing of the accretion, Tonian versus early Cambrian, between the Eastern Ghats Belt and the Indian landmass remains contentious. We address the issue by combining field geology/microstructures, whole-rock geochemistry and U-Pb-Hf (zircon) isotope systematics in the Western Charnockite Zone (WCZ), which is wedged between the Eastern Ghats Province (EGP) to the east and the Bastar Craton to the west. The WCZ crustal domain, comprising differentiated syn-collisional magmatic charnockites, was derived by partial melting of 3.76-3.66 Ga mafic precursors. The WCZ emplaced at ~2.61 Ga and deformed at granulitefacies conditions at ~2.53 Ga, later experienced amphibolite-facies syn-shearing metamorphism at ~2.47 Ga.
In the EGP, multiply deformed high-Mg-Al granulites, characterised by high-T metamorphism at ~2.53 Ga and ~0.93 Ga, were intruded by ~0.93 Ga blastoporphyritic granitoids; however, Cambrian dates are lacking. However, adjacent to the WCZ, the EGP blastoporphyritic granitoids were deformed at high-T conditions (~0.5 Ga). In contact with EGP, ~2.45 Ga cratonic granitoids intrusive into 3.51-3.45 Ga basement gneisses exhibit ~0.5 Ga syn-shearing anatexis.
The ~2.6 Ga WCZ, derived from Meso/Eoarchean protoliths, led to eastward growth of the Bastar Craton. The Tonian-aged EGP accreted with the Archean WCZ/Bastar Craton composite along a ~0.5 Ga accretion zone characterized by prograde high-T metamorphism manifested by hornblende decomposition to two-pyroxene + plagioclase symplectites. The accretion of the WCZ/Bastar Craton with the EGP, in relation to the Indo-Antarctic Cambrian accretion, occurred as part of the global-scale terminal assembly of Gondwanaland.
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BibTeX
@article{sequeira2026late,
title = {{Late Neoarchean growth of the Bastar craton and early Cambrian accretion of the Eastern Ghats Belt, India: Linking the India-Australia-Antarctica terminal accretions during Gondwanaland assembly}},
author = {Nicole Sequeira and Nathan Cogne and Ellen Kooijman and Aman Kushwaha and S Rekha and Rabi Patra and Abhijit Bhattacharya},
journal = {Geoscience Frontiers},
year = {2026},
month = sep,
doi = {10.1016/j.gsf.2026.102452},
url = {https://insu.hal.science/insu-05735642v1},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - JOUR
TI - Late Neoarchean growth of the Bastar craton and early Cambrian accretion of the Eastern Ghats Belt, India: Linking the India-Australia-Antarctica terminal accretions during Gondwanaland assembly
AU - Nicole Sequeira
AU - Nathan Cogne
AU - Ellen Kooijman
AU - Aman Kushwaha
AU - S Rekha
AU - Rabi Patra
AU - Abhijit Bhattacharya
PY - 2026
DA - 2026/09/02
JO - Geoscience Frontiers
DO - 10.1016/j.gsf.2026.102452
UR - https://insu.hal.science/insu-05735642v1
AB - The Eastern Ghats Belt (India) is centrally located within a string of multi-continent Cambrian peri-orogens formed during the terminal assembly of East Gondwanaland. However, the timing of the accretion, Tonian versus early Cambrian, between the Eastern Ghats Belt and the Indian landmass remains contentious. We address the issue by combining field geology/microstructures, whole-rock geochemistry and U-Pb-Hf (zircon) isotope systematics in the Western Charnockite Zone (WCZ), which is wedged between the Eastern Ghats Province (EGP) to the east and the Bastar Craton to the west. The WCZ crustal domain, comprising differentiated syn-collisional magmatic charnockites, was derived by partial melting of 3.76-3.66 Ga mafic precursors. The WCZ emplaced at ~2.61 Ga and deformed at granulitefacies conditions at ~2.53 Ga, later experienced amphibolite-facies syn-shearing metamorphism at ~2.47 Ga. In the EGP, multiply deformed high-Mg-Al granulites, characterised by high-T metamorphism at ~2.53 Ga and ~0.93 Ga, were intruded by ~0.93 Ga blastoporphyritic granitoids; however, Cambrian dates are lacking. However, adjacent to the WCZ, the EGP blastoporphyritic granitoids were deformed at high-T conditions (~0.5 Ga). In contact with EGP, ~2.45 Ga cratonic granitoids intrusive into 3.51-3.45 Ga basement gneisses exhibit ~0.5 Ga syn-shearing anatexis. The ~2.6 Ga WCZ, derived from Meso/Eoarchean protoliths, led to eastward growth of the Bastar Craton. The Tonian-aged EGP accreted with the Archean WCZ/Bastar Craton composite along a ~0.5 Ga accretion zone characterized by prograde high-T metamorphism manifested by hornblende decomposition to two-pyroxene + plagioclase symplectites. The accretion of the WCZ/Bastar Craton with the EGP, in relation to the Indo-Antarctic Cambrian accretion, occurred as part of the global-scale terminal assembly of Gondwanaland.
SN - 1674-9871
ER -