An abrupt shift in dust source on the Chinese Loess Plateau revealed through high sampling resolution OSL dating
An abrupt shift in dust source on the Chinese Loess Plateau revealed through high sampling resolution OSL dating
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高采样分辨率光释光测年揭示中国黄土高原沙尘源突变
DOI：
10.1016/j.quascirev.2013.10.014
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发表时间：
2013-12
影响因子：
4
通讯作者：
Huayu Lu
中科院分区：
文献类型：
--
作者：
Thomas Stevens;Grzegorz Adamiec;Anna F. Bird;Huayu Lu
中国黄土高原上广泛的黄土堆积物是由沙尘形成的，其来源一直存在很大争议。特别是，目前还不清楚是否源可以突然改变在个别黄土单位或是否本地的影响源可以覆盖的影响，远旅行的组成部分。黄土高原沉积物的高垂直取样分辨率（10-40 cm）光释光（OSL）测年已成功地为黄土堆积提供了详细的、独立的年龄模型。在这里，OSL的行为是用来推断在末次冰期的黄土沉积物来源的转变。光释光测年程序经常使用广泛应用的单等分再生（SAR）协议的石英颗粒。对黄土高原北部北果园剖面近45 ka沉积物的详细SAR光释光测年结果表明，该剖面沉积物的年龄呈异常增长，年龄估计值具有统计学意义。2.5 m单位，在约20 ka，与样品以上和以下相比。这些样品中的许多也未能通过内部剂量恢复测试，并显示出异常的发光信号特性。OSL衰减曲线的一阶分量的反卷积揭示了许多年龄高估的样品具有显著的超快分量。这种行为仅限于2.5米的部分，只有使用高采样分辨率发光分析才可能发现。结合重矿物，粒度和地球化学证据，这表明，在这个单元的物质来源突然转移在末次盛冰期，可能是一个本地的来源，而不是良好的混合和回收多个遥远的来源，似乎是在其他时间在现场和其他研究的黄土高原部分的情况。这种源转移的环境原因可能与末次盛冰期气候的突然变化有关，并表明末次盛冰期粉尘产生地点的高度动态性。来源的变化也增加了利用沉积物特性对黄土进行标准气候代用指标分析的复杂性。
The source of dust that forms the extensive deposits of loess exposed on the Chinese Loess Plateau is highly debated. In particular, it is not clear whether sources can change abruptly within individual loess units or whether local influences on source can override the influence of far travelled components. High vertical sampling resolution (10–40 cm) optically stimulated luminescence (OSL) dating of sediments on the Loess Plateau in China has been successful in providing detailed, independent age models for loess accumulation. Here, OSL behaviour is used to infer a shift in loess sediment source during the Last Glacial period. OSL dating procedures have often utilised the widely-applied single aliquot regeneration (SAR) protocol on quartz grains. Detailed SAR OSL dating of the last 45 ka of sedimentation at Beiguoyuan section on the north of the Loess Plateau demonstrates anomalous and statistically significant age increases and scatter in age estimates in samples from a c. 2.5 m unit at about 20 ka, compared to samples above and below. Many of these samples also fail internal dose recovery tests and show anomalous luminescence signal properties. Deconvolution of OSL decay curves into first order components reveals that many of the age-overestimating samples have a significant ultrafast component. This behaviour is restricted to the 2.5 m segment and is only likely to be uncovered using high sampling resolution luminescence analysis. Combined with heavy mineral, grain-size and geochemical evidence, this suggests that the source of material in this unit abruptly shifted at the Last Glacial Maximum, potentially to a local source rather than well mixed and recycled multiple distant sources, as appears to be the case at other times at the site and other studied sections on the Loess Plateau. The environmental causes of this source shift may be tied to abrupt climate change during the Last Glacial Maximum and demonstrate the highly dynamic nature of the locations of dust generation during the Last Glacial period. The change in source also adds complexity to standard climate proxy analyses of loess using sediment properties.
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影响因子：
2
作者：
J. Singarayer;R. Bailey
通讯作者：
J. Singarayer;R. Bailey
影响因子：
4
作者：
Y. Küster;R. Hetzel;M. Krbetschek;Mingxin Tao
通讯作者：
Y. Küster;R. Hetzel;M. Krbetschek;Mingxin Tao
DOI：
10.1016/j.palaeo.2013.04.020
发表时间：
2013-07
期刊：
Palaeogeography, Palaeoclimatology, Palaeoecology
影响因子：
--
作者：
J. Nie;Wenbin Peng;K. Pfaff;A. Möller;E. Garzanti;S. Andó;T. Stevens;A. Bird;Hong Chang
通讯作者：
J. Nie;Wenbin Peng;K. Pfaff;A. Möller;E. Garzanti;S. Andó;T. Stevens;A. Bird;Hong Chang
影响因子：
2
作者：
Zhongping Lai;H. Brückner;L. Zöller;A. Fülling
通讯作者：
Zhongping Lai;H. Brückner;L. Zöller;A. Fülling
影响因子：
5.3
作者：
Shiling Yang;Z. Ding
通讯作者：
Shiling Yang;Z. Ding