@misc{10481/107511,
year = {2025},
month = {9},
url = {https://hdl.handle.net/10481/107511},
abstract = {Petrology, geochemistry and geochronology of a metapelite (sillimanite-garnet-biotite-plagioclase-quartz) from the vicinity of the Archean Mercara Shear Zone in Coorg, S. India show that metamorphism at temperatures>850 °C occurred
between 2700–3300 Ma (Phase equilibria, thermobarometry, U-Pb dating of zircons and Lu-Hf dating of garnets). Subsequently, the rocks experienced thermal events at lower temperatures at 2400-2600 Ma as well as at 600-640 Ma (U-Pb
dates from rutile). There are indications of multiple episodes of metasomatic/ (high temperature) hydrothermal activity
during the Archean events. Residence of the rocks at lower temperatures between the high temperature events is indicated
by the kinetics of dissolution of zircon in melt. Taken together, this history shows that (a) P-T-t evolution in this Archean
collisional setting happened along an overall clockwise path but not in a single continuous loop - episodes at high temperatures were interspersed with residence at cooler temperatures in between, (b) subtle effects of metamorphism that
occurred at temperatures below the peak temperature could help to resolve some controversies related to tectonothermal
reconstructions in the region (e.g. whether signatures of both - amalgamation of Dharwar and Coorg cratons and activity
along an equivalent of the Betsimisaraka suture zone in east-central Madagascar may be present in the region), and (c) the
duration of high-temperature events (several 100 million years at ~800 °C) are consistent with an early Earth peel-back
style of plate tectonics, rather than modern day plate tectonics, operating in the region at the time.},
organization = {Deutsche Forschungsgemeinschaft – DFG (Schwerpunktprogramm 1833 “Building a Habitable Earth”, Project CH 166/17-1)},
organization = {Wilhelm and Günter Esser Foundation, Germany (RUB Research School) - (WS2019/20)},
organization = {Copenhagen University (Open access)},
publisher = {Springer Nature},
keywords = {Archean metamorphism},
keywords = {Zircon},
keywords = {Garnet},
title = {Timescale of evolution of a late archean collision zone from Coorg, S. India: constraints from zircon and garnet geochronology},
doi = {10.1007/s00410-025-02263-z},
author = {Basak, Sampriti and Cambeses Torres, Aitor and Chakraborty, Sumit and Gerdes, Axel and Münker, Carsten and Martinet, Ina and Dasgupta, Somnath and Bhowmik, Santanu Kumar},
}