Zircon U–Pb (SHRIMP) Ages of the Jahazpur Granite and Mangalwar Gneiss from the Deoli-Jahazpur Sector, Rajasthan, NW India: A Preliminary Reappraisal of Stratigraphic Correlation and Implications to Crustal Growth

Abstract

We present high precision geochronological data from the Jahazpur granite and the associated Mangalwar gneiss from Deoli-Jahazpur-Hindoli region of the Aravalli Craton, northwestern India. These data are useful to understand the stratigraphic correlation between the basement gneiss and the low-grade supra-crustal rocks of the Hindoli-Jahazpur Group. U–Pb (SHRIMP-IIe) data from zircon suggest emplacement age of 2538 ± 5 Ma for the Jahazpur granite, whereas a similar age of 2520 ± 37 Ma is the timing of the high-grade metamorphism and anatexis of the Mangalwar gneiss. Combining these with whole rock geochemical data, we argue that the Neoarchean Jahazpur granite underwent crustal contami-nation and emplaced at the same time frame of the Berach granite. Concomitant metamorphism and granitic magmatism imply that overlying Hindoli-Jahazpur Group is younger than c. 2520 Ma. Thus, the Neoarchean Jahazpur granite and Mangalwar gneiss are constituents of the Banded Gneissic Complex which forms the basement of the Hindoli-Jahazpur supracrustal sequence.