U–Pb Geochronology and Petrogenesis of Dongargarh Granite, Bastar Craton, Central India: Insights Into Crustal Growth and Critical Metals Mineralization Across Archean‐Proterozoic Transition

ABSTRACT This work presents a geochronological, geochemical, petrogenetic, and critical minerals study of Neoarchean‐Paleoproterozoic Dongargarh granite, Bastar Craton, Central India. This contribution presents major and trace element chemistry of magmatic alkali and plagioclase feldspar, biotite, magnetite, ilmenite, zircon, and allanite mineral phases in Dongargarh granite, and discusses their petrogenetic and metallogenic inferences. Zircon U–Pb geochronology reveals 2460.1 ± 5.3 Ma age of Dongargarh granite, which is corundum normative, peraluminous, sub‐alkaline, transitional to calc‐alkaline, A‐type, and predominantly anorogenic. Dongargarh granite exhibits high REE contents (ƩREE = 217–747 ppm), and LREE‐enriched REE patterns {(La/Sm) N = 7–9} with prominent negative Eu‐anomaly {(Eu/Eu*) N = 0.30–0.54}. Feldspar reveals 739°C and 374°C temperatures of crystallisation and exsolution, respectively, at near‐surface pressure. Prominent positive Eu‐anomaly exhibited by feldspar REE plots indicates their crystallisation from a low fO 2 melt. Biotite is Fe‐Ti‐rich, reveals A‐type granite affinity, and plots along the Fe 3 O 4 ‐Fe 2 O 3 buffer, which indicates high fO 2 during its crystallisation. Ti entry into biotite probably suppressed ilmenite precipitation from melt. Cu and Mo incompatibility in biotite probably led to their enrichment in residual melt. Biotites reveal two sets of LREE‐enriched REE patterns with prominent negative Eu‐anomaly. Abundance of magnetite over ilmenite indicates magnetite series affinity of Dongargarh granite. However, low CaO content (0.5–1.1 wt%) along with the presence of ilmenite indicates their low‐Ca ilmenite series affinity, which explains their high REE, Th, and Y contents. Magnetite‐ilmenite geothermometry reveals 435°C temperature and log 10 fO 2 values of −27 during their crystallisation, which corresponds to around 10 Km deep continental crust. Dongargarh granite exhibits an overall mineralogical and geochemical similarity with granites formed during last stage of Neoarchean global granite magmatism. This study concludes that the Dongargarh granite magma was generated in the lower crust through intracrustal recycling, with variable contributions from sodic orthogneisses (TTGs), paragneisses (metasediments), and upper mantle components. Magmatic allanites in Dongargarh granite are rich in REE (167818–217,910 ppm), HREE (1871–2192 ppm), and are a good source of Th (3216–5133 ppm), highlighting their potential use in clean and green energy generation and storage. Pegmatites associated with the Dongargarh granite may host Li, Sn, and rare earth metals, which highlights the importance of critical minerals exploration in the Dongargarh granite.