Late Quaternary fluvio-aeolian interaction: palaeoenvironment and palaeoclimatic conditions in the pediment zone of Vatrak River basin, western India
Raj, Rachna; Chamyal, L.S.; Juyal, Navin; Phartiyal, Binita; Ali, S. Nawaz; Thakur, Biswajeet
published: Jun 1, 2016
manuscript accepted: Jan 19, 2016
manuscript received: Jan 31, 2015
ArtNo. ESP022006002004, Price: 29.00 €
Summary The pediment zone of the Vatrak River basin, in the north-western part of Gujarat, falls within the semi-arid southern margin of the Thar Desert. The area is covered by extensive and partially vegetated dune tops of mostly inactive aeolian landforms of diverse size and morphology. The article is focused on the understanding of terminal Pleistocene environment of the area and its possible linkage to the regional environmental changes. Detailed litho-stratigraphic studies combined with palaeoclimatic proxies like textural analysis, mineral magnetic analysis, loss on ignition data and optical chronology has improved the understanding of depositional environments prevailing in the area. The top 12 m of the exposed sediment succession depicts three major fluvial, fluvio-aeolian and aeolian facies formed by minor channelized streams, fluvio-aeolian interaction processes and aeolian dune and sand sheet deposits respectively. Proxies for palaeoclimatic interpretations aided with optically stimulated luminescence (OSL) chronology from the sedimentary record indicates that between ~55–41 ka aggradation was governed by ephemeral fluvial processes under generally semiarid conditions, followed by fluvio-aeolian processes covering an interval from ~41 ka–26 ka and dominant aeolian activity took place after ~26 ka. These facts indicate that in the area after ~41 ka, fluvial conditions dwindled and wind activity enhanced, resulting in the deposition of fluvio-aeolian sediments. A regional comparison of the data has improved our understanding about the shifts in the parameters responsible for dune formation and early Holocene incision due to a regional tectonic uplift in the area.