Late Quaternary glaciation in the Tianshan and implications for palaeoclimatic change: a review
Authors:
Xiangke Xu, Axel Kleidon, Lee Miller, Shiqin Wang, Liqiang Wang, and Guocheng Dong
Abstract:
The Tianshan mountain range has been extensively and repeatedly glaciated during the late Quaternary. Multiple moraines in this region record the extent and timing of late Quaternary glacier fluctuations. The moraines and their ages are described in three sub-regions: eastern, central and western Tianshan. Notable glacial advances occurred during marine oxygen isotope stages (MIS) 6, 4, 3, 2, the Neoglacial and the Little Ice Age (LIA) in these subregions. Glaciers in western Tianshan advanced significantly also during MIS 5, but not in eastern and central Tianshan. The local last glacial maximum (llgm) of the three sub-regions pre-dated the Last Glacial Maximum (LGM) and occurred during MIS 4 in eastern and central Tianshan, but during MIS 3 in western Tianshan. The spatial and temporal distribution of the glaciers suggests that precipitation (as snow at high altitude) is the main factor controlling glacial advance in the Tianshan. The late Quaternary climate in the Tianshan has been generally cold–dry during glacial times and warm–humid during interglacial times. Between neighbouring glacial times, the climate has had a more arid tendency in eastern and central Tianshan. These palaeoclimatic conditions inferred from glacial landforms indicate important relationships between the mid-latitude westerly, the Siberian High and the Asian monsoon.
Reference:
- Boreas, 39(2), 215-232, 2010.
- Weblink to publisher's web page.
Figure 1: Position of the Tianshan mountain range in Central Asia and climatic systems in this region. The area enclosed by the dashed white line is the Tianshan, while the black rectangles show the three sub-regions: eastern Tianshan (ET, more details in Figs 2, 3), central Tianshan (CT, more details in Fig. 4) and western Tianshan (WT, more details in Figs 5–7). The dashed black line indicates the present northern limit of Asian monsoon precipitation (after Shi 2002). The black arrows show the directions of the climatic systems (after Lehmkuhl & Haselein 2000; Zhang et al. 2000; Yang et al. 2004; Owen et al. 2005).
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Figure 2: Geomorphological map of Quaternary glaciation in the Urumqi River Valley, eastern Tianshan. The circles with different numbers indicate the sample sites: 1 the lichen and AMS 14C samples from the LIA moraines; 2 the AMS 14C and 14C samples from the Neoglacial moraines; 3 the ESR, AMS 14C and 14C samples from the Shangwangfeng till; 4 the ESR samples from the Xiawangfeng till; and 5 the ESR samples from the Gaowangfeng till (see more in Table 1).
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Figure 3: Stratigraphical relationship between the Shangwangfeng and Xiawangfeng tills and their absolute ages.
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Figure 4: Map of glacial landforms in the Ateaoyinake River Valley, central Tianshan (after Zhao et al. 2009).
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Figure 5: Topographic map showing the studied sites in western Tianshan (adapted from online Google Map). This figure is available in colour at http://www.boreas.dk.
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Figure 6: Geomorphological map of Quaternary glaciation for (A) Gubel, (B) Ala Bash and (C) Ala Archa in western Tianshan. The legend in (A) is also used for (B), (C) and maps in Fig. 7 (modified after Koppes et al. 2008).
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Figure 7: Geomorphological map of Quaternary glaciation for (A) At Bashi, (B) Aksai, and (C) Mustyr in the western Tianshan (modified after Koppes et al. 2008).
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Figure 8: Comparison of the glaciation chronology for Tianshan with summer insolation value (Berger & Loutre 1991), major climatic changes recorded in deep-sea core (after Imbrie et al. 1984), Vostok ice core (Antarctica) (Jouzel 1994), GRIP ice core (Greenland) (Dansgaard et al. 1993) and Guliya ice core (northwestern China) (Yao et al. 2000). The grey bands show MIS durations derived from deep-sea core (Imbrie et al. 1984).
