Zircon U-Pb geochronology and Hf isotopes from granulites and gneisses from Kabbaldurga, in the Dharwar Craton, South India: implications for Mesoarchean magmatic charnockite in the crustal evolutionary trajectory

Article Type

Research Article

Publication Title

Episodes

Abstract

The Southern Granulite Terrane (Dharwar Craton), South India, is a key unit for understanding the origin of charnockite. New U-Pb and Lu-Hf analyses in zircon crystals from 16 samples representing a wide variety of lithotypes from the quarries in Kabbaldurga reveal a complex geological history in the Archean and early Paleoproterozoic. Magmatic protoliths predominantly record Paleoarchean ages between 3.4 and 3.2 Ga. Combined U-Pb and Lu-Hf signatures indicate a history of recurrent crustal anatexis, juvenile magmatic input, and felsic injections. Mesoarchaean magmatic charnockites were generated mainly from hornblende-dehydration melting of Paleoarchaean mafic rocks. In addition, Peninsular Gneissic Complex of the Dharwar Craton, commonly described as TTG suites, are likely generated by melting of hydrated basalt. The new data are consistent with the idea of a convecting magmatic cycle and also support the proposal that the southern Dharwar Craton comprises a tilted cross-section through the Archaean crust. Paleoproterozoic high-temperature event is documented here as a complex unit involving juvenile mafic magmatism, granulite facies imprints and crustal anatexis as well as felsic injections, occurring within a short time period around 2.5 Ga.

First Page

1

Last Page

20

DOI

10.18814/epiiugs/2024/024006

Publication Date

3-1-2025

Link to Full Text

Share

COinS