Petrogenesis of Meso-Neoarchean granitoids from the Chitradurga Greenstone Belt: Implications on crustal growth and reworking of the Dharwar Craton, southern India.

[Display omitted] • Granitoids of Chitradurga belt were emplaced at ∼ 3.2 Ga, ∼3.0 Ga and ∼ 2.6 Ga. • Two metamorphic events are documented at ∼ 3.0 Ga and ∼ 2.56 Ga. • Nd isotopes infer juvenile crustal addition at 3.2 Ga, reworking at 3.0 Ga and 2.6 Ga. • Role of convergent margin tectonics in the evolution of Chitradurga granitoids. The Chitradurga Greenstone Belt is one of the largest belts in the central part of the Western Dharwar Craton (WDC). We present new SHRIMP U-Pb zircon and titanite ages, whole-rock geochemical and Sm-Nd isotopic data for granitoids that developed at both its eastern and western margins, and for those that are intrusive into the belt. Western margin TTG samples yield emplacement ages ofca. 3.21 Ga and are of the high-Al TTG type characterized by weakly negative ɛNd t values. Eastern margin granite samples yield emplacement ages of ∼ 3.0 Ga and 2.56 Ga with negative ɛNd t values. The granites intrusive into the belt are of Neoarchean age (∼2.61 Ga) with more-evolved Nd isotopic signatures consistent with the involvement of older crustal material. Metamorphic events are documented at ca. 3.0 Ga and ca. 2.5 Ga. The ca. 3.0 Ga event is synchronous with the diapiric emplacement of trondhjemites and high-K granitic plutons in the WDC. The peak metamorphic event at ∼ 2.5 Ga is the major tectono-thermal event evident throughout the Dharwar Craton. Geochemical systematics imply the involvement of convergent margin tectonics in the evolution of studied granitoids. The role of horizontal tectonics in the crustal growth of WDC is evident from at least 3.2 Ga, whereas signatures for the reworking of the older crust are more prominent from ∼ 3.0 Ga. [ABSTRACT FROM AUTHOR]