---

Zircon U-Pb-Hf isotopes constraints on the petrogenesis of Neoarchean granitic rocks from the Northeastern part of the Eastern Dharwar Craton, Southern India.

This study provides new petrographic, bulk rock geochemical, and in-situ zircon U-Pb-Hf isotopic data on 2.53–2.50 Ga high-K calc-alkaline granitoids from the Nizamabad region, the northeastern part of the Eastern Dharwar Craton (EDC). Three granitoids are identified: Hornblende-biotite granite (HBG), Biotite granite (BTG), and Monzogranite (MG). The HBG and MG indicate a high-K mafic source similar to Archean sanukitoids, while BTG and MG are derived from reworked tonalites and metagreywackes.

Zircon Hf isotopic compositions reveal two-end member sources (sediment metasomatized mantle and heterogenous crustal rocks, and variable interaction between the two). The study proposes a two-stage Neoarchean geodynamic evolution model for the EDC, with 2.70–2.56 Ga bimodal volcanics, and granitoids representing arc magmatism in the first stage and high-K calc-alkaline granitoids from continent-continent collision in the second stage.

A simplified cartoon depicting the two-stage tectonic model for the Neoarchean geodynamic evolution of the Eastern Dharwar Craton.

---