Quaternary evolution of the Ganga River system: New quartz ages and a review of luminescence chronology

Abstract

The Ganga foreland basin is amongst the largest such basins in the world and has recently been studied by several groups. Considerable confusion on the chronology has been created on account of poorly informed interpretations. We review the existing chronological framework and add new luminescence chronometric data from the Ramnagar section along the Ganga River at Varanasi. This section is dated using the Single Aliquot Regeneration (SAR) on quartz. The age data indicated that the (1) sedimentation of this 20 m thick section started prior to 59 ka and continued at least up to 7 ka (2) ages from five samples are in stratigraphic order and confirm the ages given by Srivastava et al. (2003a) from the same section that were derived using Multiple Aliquot Additive Dose (MAAD) protocol on fine-grained feldspars and quartz (3) Quartz palaeodoses derived are as high as 186±11 Gy that can yield to OSL ages of ∼60 ka and this is in contrast to earlier suggestion of an upper bound of ∼35 ka.