Evolution of the Archean felsic crust of Singhbhum Craton, India: A reassessment

The Precambrian Singhbhum Craton and the adjoining orogenic belts of eastern India hold a history of continental crust generation by repeated emplacement and reworking of multiphase tonalite-trondjhemite-granodiorite (TTG) and granites throughout the Archean. Temporal classification of this complex Archean TTG and granite sequence have not been straightforward due to repeated magmatism that gave rise to complex intrusive relationships between the magmatic bodies, their complex tectonic juxtaposition and lack of geochronological data. Recent surge of new geochronological and isotope data has brought significantl clarity in the temporal relationships between different crustal components of this craton. In this study, geochemical data (published and new) of the TTG and granites (n = 251) with robust age reference was compiled and classified using a two-fold (viz. age and geochemistry) classification to understand the secular change of crustal composition. Herein, the Archean TTG suites were divided into four age-based groups, viz. Group-I (> ca. 3.5–3.4 Ga), II (ca. 3.4–3.3 Ga), III (ca. 3.3–3.2 Ga) and IV (更多