Research paper OSL and ESR dating of glacial deposits and its implications for glacial landform evolution in the Bogeda Peak area, Tianshan range, China Jingdong Zhao a, * , Zhongping Lai a, b , Shiyin Liu a , Yougui Song c , Zhongqin Li a , Xiufeng Yin a a State Key Laboratory of Cryospheric Sciences, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, PR China b Luminescence Dating Group, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008, PR China c State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710075, PR China article info Article history: Received 17 October 2011 Received in revised form 11 March 2012 Accepted 12 March 2012 Available online 17 March 2012 Keywords: OSL dating ESR dating Glacial landform Bogeda Peak area Tianshan range abstract The Bogeda Peak area is the largest center of modern glaciation in the eastern Tianshan range in China. Four moraine complexes and associated fluvioglacial deposits are well preserved in the valleys, indi- cating multiple Quaternary glaciations in this region. Optically stimulated luminescence (OSL) and electron spin resonance (ESR) dating were used to determine the ages of the glacial tills and associated sediments in the Gubanbogeda and Heigou valleys. A total of eighteen samples were collected from moraines and fluvioglacial deposits. Fourteen samples were dated using OSL with a single-aliquot regenerative-dose (SAR) protocol, and the other four samples were analyzed by ESR dating of germanium (Ge) centers in quartz grains, which are sensitive to both sunlight and grinding. The results indicate that the fluvioglacial deposits are more suitable for OSL dating than the tills. Most ages show good agreement with the geological setting and field investigations, and the OSL and ESR ages are consistent with each other for the samples collected from the fourth set of moraines. Based on the ages as well as geomorphic and stratigraphic, the first and second moraine complexes of the Bogeda Peak area were deposited during the Little Ice Age (LIA) and Neoglaciation respectively. The low and high glacial terraces of the third set of moraines in the Gubanbogeda and Heigou valleys were deposited during marine oxygen isotope stages (MIS) 2 and 4. The fourth set of moraines has MIS 6 ages associated with the penultimate glaciation. Crown Copyright Ó 2012 Published by Elsevier B.V. All rights reserved. 1. Introduction Mountain glaciers are sensitive climatic markers that usually advance or retreat rapidly with changes in temperature and/or precipitation. The response of these glaciers to climate directly influences glacial erosion, sediment transport and deposition. As a result, spectacular landscapes have been produced in areas of mountain glaciations, and these landscapes contain important information on past climate change and landform evolution. Successions of multiple moraines that record glacial advance and retreat are common, providing a potential opportunity to investi- gate the nature of past glacier fluctuations as a part of paleo- environmental reconstructions. In tectonically active regions, these studies can also provide potential information on the history of uplift (Shi et al., 2006). Dating glacial landforms is a fundamental component for studying the landform evolution and for paleoenvironmental reconstructions. In recent decades, several new dating techniques, including cosmogenic radionuclides (CRN: e.g., Koppes et al., 2008; Li et al., 2011), electron spin resonance (ESR: e.g., Zhou et al., 2002; Yi et al., 2002; Zhao et al., 2006, 2010) and optically stimulated luminescence (OSL: e.g., Owen et al., 2002; Spencer and Owen, 2004; Ou et al., 2010), have been developed, refined and widely applied, and these dating techniques can potentially provide constraints on the ages of glacial sediments and landforms. This has allowed conventional mapping and relative dating studies to be augmented by quantitative dating techniques, which has allowed for significant advances in research on Quaternary glaciation in China (Shi et al., 2006, 2011). The Tianshan range is a major, tectonically active mountain system in Central Asia. During Quaternary glacialeinterglacial cycles, the Tianshan range was extensively and repeatedly glaci- ated, and landforms from multiple glaciations are well preserved in valleys, basins and on piedmonts. Studies of these landforms can provide insight into temporal and spatial variation of glacier extent * Corresponding author. E-mail address: jdzhao@lzb.ac.cn (J. Zhao). Contents lists available at SciVerse ScienceDirect Quaternary Geochronology journal homepage: www.elsevier.com/locate/quageo 1871-1014/$ e see front matter Crown Copyright Ó 2012 Published by Elsevier B.V. All rights reserved. doi:10.1016/j.quageo.2012.03.004 Quaternary Geochronology 10 (2012) 237e243