SHRIMP U–Pb zircon ages of granitoids adjacent to Chitradurga shear zone, Dharwar craton, South India and its tectonic implications

Abstract

We report newly obtained U-Pb SHRIMP ages of zircons from the granitoids in the vicinity of Chitradurga shear zone of Dharwar craton, South India. The analyses yielded two different ages, an older age of ca. 3300 Ma and younger ages of~2600-2650 Ma, those suggest two major igneous activities in the study area. The former activity contemporaneous with the formation of Mesoarchean (~3.3 Ga) basement rocks (i.e., Peninsular Gneiss) and the latter reflects the Neoarchean (~2.6 Ga) regional plutonic activity in the Western Dharwar craton. Field and petrographic observations suggest that the intensity of deformation is high at the boundary between amphibolites and granitoids. Our new age dates imply that the formation of Chitradurga shear zone postdated the magmatic activity in the study area and the deformation structures possibly related to the development of Chitradurga shear zone. The area on either sides of the boundary between Eastern and Western Dharwar cratons experienced a Neoproterozoic event between 700-600 Ma indicated by prominent SHRIMP lower intercepts.

Gold, uranium, thorium, and rare earth mineralization in the Kadiri Volcanic Province of Eastern Dharwar Craton, India: An evaluation of mineralogical, textural, and geochemical attributes

“…The Dharwar Craton (DC) of southern peninsular India is one of the largest cratons (4.5 × 10 5 km 2 ) in Indian subcontinent (Figure 1) with crystalline basement ranging in age from Palaeoarchean to the Early Palaeoproterozoic (Balakrishnan, Rajamani, & Hanson, 1999; Chadwick, Vasudev, & Hegde, 2000; Naqvi, 2005; Nasheeth, Okudaira, Horie, Hokada, & Satish‐Kumar, 2015; Peucat, Mahabaleshwar, & Jayananda, 1993; Ramakrishnan & Vaidyanadhan, 2008). The abundance of greenstone belts, basement gneisses, metamorphism, and crustal thickness have categorized the DC into two distinctive sectors, namely, the Western (WDC) and the Eastern Dharwar Craton (EDC; Figure 1; Table 1; Chardon, Jayananda, Chetty, & Peucat, 2008; Gupta et al, 2003; Jayananda, Chardon, Peucat, & Capdevila, 2006; Swami Nath, Ramakrishnan, & Viswanatha, 1976) which are separated by N‐S trending Chitradurga shear zone.…”

An appraisal of geochemical signatures of komatiites from the greenstone belts of Dharwar Craton, India: Implications for temporal transition and Archean upper mantle hydration

“…The five cratonic nuclei of the Indian shield, referred to as (a) Dharwar, (b) Bastar, (c) Singhbhum, (d) Bundelkhand, and (e) Aravalli cratons, comprise the oldest surviving landmasses of the Indian sub‐continent preserving fragments of supracrustals and volcano‐sedimentary sequences of Archean greenstone belts that range in age from 3.6 to 2.7–2.5 Ga (Figure ; Manikyamba et al, ). The Dharwar Craton is among the largest cratons of the world with crystalline basement rocks ranging in age from Mesoarchean to early Palaeoproterozoic (Balakrishnan, Rajamani, & Hanson, ; Chadwick, Vasudev, & Hedge, ; Jayananda et al, , ; Jayananda, Chardon, Peucat, & Capdevila, ; Jayananda, Kano, Peucat, & Channabasappa, ; Nasheeth, Okudaira, Horie, Hokada, & Satish Kumar, ; Peucat, Bouhallier, Fanning, & Jayananda, ), covering an area of 4.5 × 105 km 2 (Ramakrishnan & Vaidyanadhan, , and references therein). The craton exposes Archean continental crust marked by a progressive transition from upper to lower crustal levels with granite–greenstone terranes grading southward into granulites (Janardhan, Newton, & FIansen, ; Jayananda et al, ; Jayananda et al, ; Swami Nath & Ramakrishnan, ).…”