Tectono-climatic signatures during Late Quaternary in the Yunam basin, Baralacha Pass (upper Lahaul valley, India), derived from multi-proxy records

摘要

This study provides evidence of the monsoon record over the past 25 ka from the Kilang Sarai palaeolake which is located in NW Himalaya in the rain shadow zone of the Indian Summer Monsoon (ISM). The multi-proxy study by using geomorphology, carbon isotopes, mineral magnetism, clay mineralogy and elemental chemistry of a 8 m thick laminated lacustrine sediments indicates that the area experienced fluctuating precipitation conditions during the last 25 ka. The time period between 12 and 5 ka BP can be regarded as a very wet interval of the Last Glacial to mid Holocene due to a combined effect of ISM and Westerlies, followed by aridity after 5 ka BP. Tectonic triggers may have caused the development of terraces and closure of lake. At the millennial time scale, a correlation of precipitation and vegetational changes between our data and other records from similar geographical settings suggests that Kilang Sarai basin responded to periods of strengthening in precipitation during the Last Glacial to early Holocene. (C) 2014 Elsevier Ltd and INQUA. All rights reserved.