Formation of Paleo- to Meso-Archean continental crust in the western Dharwar Craton, India: Constraints from U Pb zircon ages and Hf-Pb-Sr isotopes of granitoids and sedimentary rocks

The combination of UPb zircon ages with Hf-Sr-Pb isotopes different intrusive and extrusive felsic sedimentary rocks provides constraints on the petrogenetic evolution continental crust in western Dharwar Craton, India. oldest detrital preserved formed at ?3.6 Ga represents a relic crustal material region. dominant granitoid units Craton contain grains magmatic between 3.4 3.0 that indicate formation major during this interval. Trace element abundances granitoids members intermediate to suite derived by partial melting mafic ?3.6–3.4 Ga. initial bulk rock Hf isotope compositions these are consistent their even older was slightly enriched relative depleted mantle composition. This ? < 3.8 individual grains, obtained two analytical techniques (in-situ complete dissolution followed chromatographic separation) give evidence for presence such (<3.8 Ga) immediate precursor host rocks. Such source is PbSr systematics shows no indication Eoarchean enriched/evolved Craton. thus an stage started after melting. combined geochronological isotopic suggest Mesoarchean differentiation melts from amphibolite/eclogite included increasing contributions reprocessed time interval growth younger generation mostly reworking crust. These bodies distinct petrogeneses sources, include mantle, evolved crust, became essential elements stable majority which generated