Quartz OSL dating of sand dunes in Ghaggar Basin, northwestern India

Abstract

Several studies have used luminescence dating to investigate sand mobilization activity in extreme western areas and the southern margin of the Thar Desert, India. However, room exists for a chronology of sand profiles for the northern margins of the Thar Desert. The Ghaggar River flood plain at Rajasthan, northwestern India, in the northern margin of the Thar Desert, is bordered by sand dunes. Elucidation of the environmental changes of the Ghaggar Basin requires knowledge of many aspects of sand dune formation. We measured optically stimulated luminescence (OSL) using the single aliquot regenerative-dose (SAR) protocol for sand of eight palaeo-dunes and two flood silts of both sides of the present Ghaggar Basin and Chautang Basin flood plains. Their OSL ages were obtained respectively, as 15–10 ka or 5 ka, and 9–8 ka. Results of this study reinforce the hypothesis that sand dune deposition had started or had already been completed by 15‐10 ka. Aeolian deposition was subdued by enhanced moisture during 9–8 ka. Our interpretation is that, at least since 5 ka, the scale of the flood plain of the Ghaggar River has remained equivalent to that of the present day.