PETROGRAPHIC STUDIES AND ZIRCON ANALYSIS FROM THE SEDIMENTARY BASINS ALONG SOUTHERN MARGIN OF ARCHEAN BUNDELKHAND CRATON, CENTRAL INDIA

Abstract

Detrital zircons morphological and typological study is a well-established technique for provenance analysis of sedimentary units. It helps in constraining sediment source areas, temporal variations of sediment source and timing of tectonics related to sedimentary basin formation which further provide information related to reactivation of the cratonic margins. Internal texture and typology analyses were carried out on detrital zircons separated from quartzite rocks collected from two marginal basins - Bhopal basin and the Lalitpur basin of Vindhyan Supergroup. These marginal basins are located at the southern margin of the Bundelkhand craton, Bhopal basin being closer to the Central Indian Tectonic Zone. Petrographic analyses put the samples in quartz arenite category, some being metamorphosed into metaquartzites. Zircon typological studies indicate that the zircons separated from both Bhopal basin and Lalitpur basin were derived from granitoids of different types. This goes hand in hand with the close observation of zircon zonation patterns under Scanning Electron Microscope, which shows the presence of igneous zircons in Bhopal basin samples. This puts a question mark on the theory of a single origin of sediments in the basins. Furthermore, the study establishes the detrital zircon separation techniques and the use of zircons in studying the depositional ages and provenance of sedimentary units