DOI: 10.1016/j.quascirev.2015.07.018
Scopus记录号: 2-s2.0-84938077048
论文题名: Luminescence dating of glacial deposits near the eastern Himalayan syntaxis using different grain-size fractions
作者: Hu G. ; Yi C.-L. ; Zhang J.-F. ; Liu J.-H. ; Jiang T.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2015
卷: 124 起始页码: 124
结束页码: 144
语种: 英语
英文关键词: Different grain size fractions
; Glacial sediments
; Luminescence dating
; Partial bleaching
; Southeastern Tibet
Scopus关键词: Bleaching
; Catchments
; Cleaning
; Deposition
; Deposits
; Grain size and shape
; Luminescence
; Quartz
; Sediments
; Stratigraphy
; Field observations
; Glacial sediments
; Grain size
; Last Glacial Maximum
; Luminescence dating
; Luminescence signals
; Optically stimulated luminescence
; Southeastern Tibet
; Glacial geology
; bleaching
; catchment
; cooling
; fluvial geomorphology
; glaciofluvial deposit
; grain size
; humid environment
; Last Glacial Maximum
; lithostratigraphy
; luminescence dating
; moraine
; quartz
; Quaternary
; till
; China
; Himalayas
; Xizang
英文摘要: Numerical dating of glacial deposits is important for understanding Quaternary glacial evolution. Optically stimulated luminescence (OSL) dating is one of the techniques widely used on such sediments. Owing to the short distances traveled before deposition, the incomplete bleaching of luminescence signals in glacial sediments may introduce serious dating problems vis-à-vis glacial and any associated sediments. Here, we report a comparison of OSL ages obtained from the fine (4-11μm) and medium (38-63μm) grain size fractions of quartz extracted from glaciofluvial sediments and from glacial tills in the Basongcuo catchment near the eastern Himalayan syntaxis. Initially, four glacial stages were identified based on field observations of moraine distribution and geomorpho-stratigraphic relations. A total of 39 OSL samples were then collected from glaciofluvial sand layers or lenses and from till. Quartz grains in the fine (4-11μm) and medium (38-63μm) size fractions were extracted from each sample, and dated using the single-aliquot regeneration (SAR) protocol. The modern supraglacial sediment sample was dated to ~0.2 (fine grain) to ~0.7 (medium grain) ka, suggesting that the sediment was not completely bleached on deposition. Contrary to previous experience suggesting that coarse grains are usually better bleached than fine grains prior to deposition, our results show that estimated OSL ages for fine grains are generally younger than those for medium grains. This suggests that the two fractions may have come from different sources and thus have different bleaching histories, and that fine-grained quartz may be more suitable for OSL dating of these materials. Applying the minimum age model to data from medium-grained quartz yields ages close to those obtained from fine-grained quartz, suggesting that both can be used for dating glacial advances. The OSL dates suggest that glaciers in the studied area advanced at 0.1-1.3ka, ~7.5ka and 11-13ka, and were furthest advanced between ~16 and ~30ka. The timing of the local Last Glacial Maximum (LGM) is broadly consistent throughout the eastern and central Himalaya and frequent glacial advances after the LGM. All suggest that glaciers in the humid eastern Himalayan syntaxis are sensitive to global cooling. © 2015 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/59842
Appears in Collections: 过去全球变化的重建
There are no files associated with this item.
作者单位: Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, CAS, Building 3, Courtyard 16, Lin Cui Road, Chaoyang District, Beijing, China; Key Laboratory of Earth Surface Processes, Department of Geography, Peking University, Beijing, China; Key Laboratory of Tectonics and Petroleum Resources of Ministry of Education, China University of Geosciences, Wuhan, China
Recommended Citation:
Hu G.,Yi C.-L.,Zhang J.-F.,et al. Luminescence dating of glacial deposits near the eastern Himalayan syntaxis using different grain-size fractions[J]. Quaternary Science Reviews,2015-01-01,124