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Episodes 2020; 43(1): 109-123

Published online March 1, 2020

https://doi.org/10.18814/epiiugs/2020/020006

Copyright © International Union of Geological Sciences.

The Southern Granulite Terrane: A synopsis

M. Santosh

School of Earth Sciences and Resources, China University of Geosciences, Beijing, Beijing 100083, P.R. China
Department of Earth Sciences, University of Adelaide, Adelaide SA 5005, Australia; E-mail: santosh@cugb.edu.cn; msantosh.gr@gmail.com

Correspondence to:E-mail: santosh@cugb.edu.cn; msantosh.gr@gmail.com

Received: March 24, 2019; Revised: September 17, 2019; Accepted: September 17, 2019

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The Southern Granulite Terrane (SGT), the wedgeshaped southern termination of Peninsular India, is a mosaic of several crustal blocks and intervening collisional sutures/shears which developed through multiple orogenic cycles during Mesoarchean to late Neoproterozoic-Cambrian. The SGT has been the focus of global geoscience world for more than four decades mainly with regard to deep crustal processes, crustmantle architecture, polyphase structural evolution, extreme crustal metamorphism, growth and recycling of continental crust, and the assembly-evolution-disruption of supercontinents through time, among other aspects. The earliest felsic crust in the SGT includes the 3.5-Ga granitoids in the Coorg Block, followed by successive maturation stages marked by younger magmatic phases in the various blocks. The zircon δ18O values from the Coorg Block also fingerprint the emergence of continental crust above sea level in the early Earth. Multiple arc-magmatic pulses along the margins of the different crustal blocks of the SGT during Neoarchean and Neoproterozoic, together with accreted remnants of ophiolites and other oceanic components, suprasubduction zone complexes, and exhumed high- to ultrahigh-temperature metamorphic orogens suggest subduction-accretion-collision tectonics that constructed the various crustal blocks through time, and incorporated them within Precambrian supercontinent assemblies.