Analysis of late Quaternary linear dune development in the Thar Desert, India

Abstract

Linear dunes are the most widespread dune type worldwide and act as important geoproxies of late Quaternary environmental change in deserts. They are less common in the Thar Desert, India than other dune types, especially parabolic forms, and to date their development history is poorly understood. Here we investigate a linear dunefield in the northern Thar through analysis of a series of excavated full dune profile sites and the application of optically stimulated luminescence (OSL) dating to provide chronometric control. Results show that linear dunes have been present since at least ~58 ka and were active throughout much of the Holocene. The early Holocene, a period marked by strong Indian summer monsoon winds (e.g., Gill et al., 2017), has been shown as the last major phase of dune accumulation recorded in all sites, with ages ranging from ~11.6–8.6 ka. Two spatially restricted records of dune accumulation have also been identified during the later part of Holocene: ~4–3 ka and ~2–1 ka, attributed to localised reworking within the dunes. The suite of luminescence ages generated from the study region confirms the principle recognised in other dunefields (e.g., the south-western Kalahari; Stone and Thomas, 2008) and theoretically (Bailey and Thomas, 2014) that age records from individual dunes are unlikely to capture the developmental history of dunefields.