Petrofacies and tectonic setup of Kaimur Group of rocks, Son Valley, India

Abstract

The paper embodies results of petrofacies and detrital mineralogical aspects of Scarp and Dhandraul sandstones of Upper Kaimur Group, Son Valley. These sandstones are medium to coarse grained and moderately to well sorted. The constituent mineral grains are subangular to subrounded. These sandstones consisting of various types of quartz, rock fragments, mica, feldspar and heavy minerals. The plots of petrofacies in Qt–F–L, Qm–F–Lt, Qp–Lv–Ls and Qm–P–K ternary diagrams reveal that these sandstones belong to the continental block, recycled orogen, rifted continental margin tectonic regime and maturity and stability of the source region. These sandstones were derived from Palaeoproterozoic and Mesoproterozoic granite, granodiorite, gneiss and metasedimentary rocks of Mahakoshal Group and Chotanagpur granite–gneiss. The sediment composition extensively modified during weathering warm humid climate at the surface area and weathering during transport before burial thereby providing mineralogical maturity to the Upper Kaimur Sandstone.