Millennium-scale Climate Variations from the Record of Grain-size and CaCO3 During the Pleniglacial in the Salawusu River Valley, China
Received date: 2011-09-30
Request revised date: 2011-12-12
Online published: 2012-05-20
Copyright
The MGS2 segment of the Milangguowan stratigraphical section in the Salawusu River Valley, southeast of China’s Mu Us Desert, records 5.5 sedimentary cycles consisting of dune sands alternating with fluvial or lacustrine facieses. Based on the grain-size and CaCO3 analysis, it was found that Mz and σ appear peaks and valleys in different sedimentary facieses. CaCO3 contents range from 0 to 2.94% (average 0.39%) in the dune sands, 0.14% to 2.68% (average 1.43%) in the fluvial facieses and 0.39% to 15.57% (average 8.82%) in the lacustrine, and appear 5.5 grain-size and CaCO3 cycles similar to the sedimentary facieses changes. And the CaCO3 contents have a significant correlation with Mz. The result show that the dune sands accumulate and CaCO3 moved greatly during the periods with a strong cold-dry winter monsoon. Whereas, the fluvial or lacustrine facieses developed, silt and clay increased and CaCO3 gathered largely when the warm-humid summer monsoon strengthened. The observed climate fluctuations on millennium-scale during the Pleniglacial to the alternations attributed the strength of the East Asian winter and summer monsoons.
WANG Feng-nian , LI Bao-sheng , WANG Jiang-long , NIU Dong-feng , LI Zhi-wen , SI Yue-jun , DU Shu-huan . Millennium-scale Climate Variations from the Record of Grain-size and CaCO3 During the Pleniglacial in the Salawusu River Valley, China[J]. SCIENTIA GEOGRAPHICA SINICA, 2012 , 32(5) : 596 -602 . DOI: 10.13249/j.cnki.sgs.2012.05.596
Fig.1 The location of Salawusu River and the study area图1 米浪沟湾地层剖面位置及其所在萨拉乌苏河流域概况 |
Table 1 TL dating results of some horizons and their parameters in the MGS2表1 MGS2及相关层位的热释光年代测定值和测试参数 |
层位/样品编号 | 深度 (m) | U (10-6) | Th (10-6) | K(10-6) | 年剂量(m Gy) | 总剂量 (Gy) | TL (ka B.P.) |
---|---|---|---|---|---|---|---|
18D/TGD-627 | 8.44 | 0.92±0.05 | 6.07±0.12 | 1.91±0.015 | 2.48±0.08 | 186.20±13.96 | 9.88±0.9 |
24D/PKG586 | 10.525 | 1.834 | 8.514 | 1.140 | 2.652 | 33.562±4.774 | 14.458±0.867 |
26D/XAL895 | 11.645 | 5.5 | 4.1 | 1.70 | 3.16 | 60.806±3.21 | 19.236±1.554 |
Table 2 The ages (ka BP)of each layer in the MGS2表2 MGS2各层位年代 |
层位 | 深度(m) | 起止年龄 (ka B.P.) | 层位 | 深度(m) | 起止年龄 (ka B.P.) |
---|---|---|---|---|---|
20D | 8.99~8.76 | 11.09~10.58 | 21FL | 9.39~8.99 | 11.97~11.09 |
22D | 9.74~9.39 | 12.63~11.97 | 23FL | 10.27~9.74 | 13.90~12.63 |
24D | 10.78~10.27 | 16.47~13.90 | 25LS | 11.41~10.78 | 19.11~16.47 |
26D | 11.88~11.41 | 19.67~19.11 | 27LS | 12.10~11.88 | 20.07~19.67 |
28D | 12.50~12.10 | 20.81~20.07 | 29FL | 12.74~12.50 | 21.25~20.81 |
30D | 13.63~12.74 | 22.89~21.25 |
Fig.2 The sedimentary sequences and ages in the MGS2 of the Milanggouwan section图2 米浪沟湾剖面MGS2沉积序列与时间标尺 |
Fig. 3 CaCO3 contents and the variations in the MGS2图3 MGS2层段CaCO3含量及其变化 |
Fig. 4 The scatter of Mz(Φ)-CaCO3(%) in different sedimentary facieses of the MGS2图4 MGS2不同沉积相Mz(Φ)-CaCO3(%) |
The authors have declared that no competing interests exist.
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