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Cosmogenic ^(10)Be and ^(26)Al Chronology of the Last Glaciation of the Palaeo-Daocheng Ice Cap,Southeastern Qinghai-Tibetan Plateau 被引量:5
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作者 ZHANG Zhigang WANG Jian +2 位作者 XU Xiaobin BAI Shibiao CHANG ZhiYang 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2015年第2期575-584,共10页
The glacial landforms of the Qinghai-Tibetan Plateau (QTP) provide a unique opportunity to research hemispheric and global environmental changes. In this study, we focus on the glacial history of the palaeo-Daocheng... The glacial landforms of the Qinghai-Tibetan Plateau (QTP) provide a unique opportunity to research hemispheric and global environmental changes. In this study, we focus on the glacial history of the palaeo-Daocheng Ice Cap (p-DIC) in the southeastern QTP during the last glacial cycle. Based on field investigations, morphostratigraphy, and surface exposure dating of roche moutonnée, polished surface and moraine debris through the terrestrial cosmogenic nuclides (TCN) ^10Be and ^26Al. We identify glacial deposits of the last deglaciation, with minimum ages of 14.9±1.3-18.7±1.7 ka, the Last Glacial Maximum (LGM) of 24.7±2.2 ka, and the early part of the last glacial period (marine oxygen isotope stage (MIS) 3) of 37.1±3.4-45.2±3.9 ka. Our results show that in this region, the extent of the glacial advance during MIS 3 was larger than that during the traditional LGM (MIS 2). These ages are consistent with prior chronologies, and the ^10Be age is consistent with the ^26Al age for the same sample. Thus, these data provide reliable constraints on climate change in the QTP, during the last glaciation. 展开更多
关键词 Terrestrial cosmogenic nuclides last glaciation MIS 3 palaeo-daocheng Ice Cap Qinghai-Tibetan Plateau
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Last Deglaciation Climatic Fluctuation Record by the Palaeo-Daocheng Ice Cap, Southeastern Qinghai-Tibetan Plateau 被引量:6
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作者 ZHANG Zhigang XU Xiaobin +3 位作者 WANG Jian ZHAO Zhijun BAI Shibiao CHANG Zhi Yang 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2014年第6期1863-1874,共12页
The last deglaciation, a key period for understanding present and future climate changes, has long been the hot topic for palaeoclimatological study. The Qinghai-Tibetan Plateau(QTP) is often a target study area for... The last deglaciation, a key period for understanding present and future climate changes, has long been the hot topic for palaeoclimatological study. The Qinghai-Tibetan Plateau(QTP) is often a target study area for understanding hemispheric, or even global environment changes. The glacial landforms on the QTP provide a unique perspective for its climate change. In order to investigate the onset of the last deglaciation at the QTP and its regional correlation, the terrestrial cosmogenic nuclides(TCN) 10 Be and 26 Al surface exposure dating was chosen to date the roche moutonnée, the polished surface and the moraine debris located at the palaeo-Daocheng Ice Cap(pDIC), southeastern QTP. Our results show that the onset of the last deglaciation is at about 19 ka, followed by another warming event occurring around 15 ka in the p-DIC area. These timings agree well with other records, e.g. equivalent with a rapid sea level rise at 19 ka and the onset of B?lling warming event at about 15 ka. Thus, our new data can provide good reveal constraint on the climate evolution at the QTP. 展开更多
关键词 Terrestrial Cosmogenic Nuclides Last Deglaciation palaeo-daocheng Ice Cap Qinghai Tibetan Plateau
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暴露时间对利用原地生宇生核素估算至大侵蚀速率的影响 被引量:3
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作者 张志刚 王建 +2 位作者 徐孝彬 赵志军 白世彪 《地质论评》 CAS CSCD 北大核心 2013年第5期924-932,共9页
为了探讨不同暴露时间对利用原地生宇生核素估算地表基岩至大侵蚀速率(maximum erosion rates,指假设样品达到侵蚀平衡状态下的侵蚀速率)的差异,本文选择青藏高原东南部稻城古冰帽区至少暴露年代(minimum exposure ages,指利用宇生核素... 为了探讨不同暴露时间对利用原地生宇生核素估算地表基岩至大侵蚀速率(maximum erosion rates,指假设样品达到侵蚀平衡状态下的侵蚀速率)的差异,本文选择青藏高原东南部稻城古冰帽区至少暴露年代(minimum exposure ages,指利用宇生核素暴露测年法所估算的在不考虑侵蚀速率影响时的暴露年代)为500 ka、100ka、10 ka的样品进行估算,并对前人的研究结果进行统计。研究表明:①研究区地表基岩在500 ka尺度、100 ka尺度和10 ka尺度的至大侵蚀速率分别约为1 mm/ka、5 mm/ka和40 mm/ka,该结果与前人研究结果相一致。②文献统计显示百万年尺度和万年尺度地表岩石侵蚀速率可相差100倍。因此,基于原地生宇生核素所估算的侵蚀速率是在某个暴露时间(假设该暴露时间已达到侵蚀平衡状态)内的至大侵蚀速率,而不同的暴露时间尺度所估算的结果相差较大,因此在进行区域至大侵蚀速率对比时一定要注意样品的至少暴露年代尺度是否一致。本研究可为青藏高原地区地表侵蚀速率的研究提供参考。 展开更多
关键词 青藏高原 稻城古冰帽 原地生宇生核素 至大侵蚀速率 至少暴露年代
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