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Sciences in Cold and Arid Regions 2013, 5(2): 0211–0219 DOI: 10.3724/SP.J.1226.2013.00211
OSL chronology and paleoclimatic implications of paleodunes in the middle and southwestern Qaidam Basin, Qinghai-Tibetan Plateau LuPeng Yu 1,2,3, ZhongPing Lai 3,4*, Ping An 1 1. Qinghai Geological Survey Institute, Xining, Qinghai 810012, China 2. State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an, Shaanxi 710075, China 3. State Key Laboratory of Cryospheric Sciences, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou, Gansu 730000, China 4. CAS Key Laboratory of Salt Lake Resources and Chemistry, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining, Qinghai 810008, China *Correspondence to: Dr. ZhongPing Lai, Professor of Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences. No. 320, West Donggang Road, Lanzhou, Gansu 730000, China. Tel: +86-931-4967348; E-mail:
[email protected];
[email protected] Received: October 22, 2012
Accepted: January 16, 2013
ABSTRACT Aeolian sediments are widely distributed in the Qaidam Basin, northeastern Qinghai-Tibetan Plateau (QTP). The paleodunes are mainly located at the southeastern, middle and southwestern Qaidam Basin. However, ages of paleodunes in the middle and southwestern Qaidam Basin have not been well studied, although they are close to and might connect to the evolution of salt lakes in the central basin. In this study, we use single aliquot regeneration (SAR) protocol of Optically Stimulated Luminescence (OSL) to date the dune sand in these two regions. The results show that: (1) Sand accumulation in these regions started at ca. 4–3 ka and lasted to ca. 0.5 ka when they were stabilized, due to the arid climate in the late Holocene. (2) The underlying fluvial sand was formed during deglaciation at 12.6±0.8 ka. (3) The stabilization periods of the paleodunes correspond to stages of glacier advance in the northeastern QTP, during which lower temperatures caused the decrease of evaporation and increase of the effective moisture, leading to an increase of vegetation cover and stabilization of the dunes. Keywords: Qaidam Basin; aeolian sediments; paleodunes; Luminescence dating; Holocene climate
1 Introduction The 700-km-long and up to 300-km-wide Qaidam Basin (QB, Figure 1b), one of the highest (elevation about 2,800 m) and driest (
