陈剑舜^1,,
段福才^1,,,
朱丽东^1,,,
周汪洋¹,
陈仕涛²,
王权³,
邵庆丰²
1. 浙江师范大学地理与环境科学学院, 浙江 金华 321004
2. 南京师范大学地理科学学院, 江苏 南京 210023
3. 重庆师范大学地理与旅游学院, 重庆 401331

基金项目: 国家自然科学基金项目（批准号：41602181、41572340和41572345）、浙江省自然科学基金项目（批准号：LY19D020001）、重庆市教育委员会科学技术研究项目（批准号：KJQN201900536）、中国科学院地球环境研究所黄土与第四纪地质国家重点实验室开放基金项目（批准号：SKLLQG1922）和重庆师范大学基金项目（批准号：19XLB010）共同资助


详细信息

作者简介: 陈剑舜, 男, 24岁, 硕士研究生, 自然地理学专业, E-mail:chenjs02@foxmail.com

通讯作者: 段福才, E-mail:fcduan@foxmail.com; 朱丽东, E-mail:zhulidong@zjnu.cn

中图分类号: P597⁺.2;P532

收稿日期:2019-12-12
修回日期:2020-03-19
刊出日期:2020-07-30

Millennial-scale oscillations during early MIS 4 documented by a stalagmite record from Hubei Province, Central China

Chen Jianshun^1,,
Duan Fucai^1,,,
Zhu Lidong^1,,,
Zhou Wangyang¹,
Chen Shitao²,
Wang Quan³,
Shao Qingfeng²
1. College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, Zhejiang
2. College of Geography, Nanjing Normal University, Nanjing 210023, Jiangsu
3. School of Geography and Tourism, Chongqing Normal University, Chongqing 401331


More Information

Corresponding authors: Duan Fucai,E-mail:fcduan@foxmail.com ; Zhu Lidong,E-mail:zhulidong@zjnu.cn

MSC: P597⁺.2;P532

--> Received Date: 12 December 2019
Revised Date: 19 March 2020
Publish Date: 30 July 2020


摘要
摘要:高精度定年的石笋记录有助于校正冰芯时标和理解千年尺度事件的驱动机制。基于湖北永兴洞YX288石笋5个高精度²³⁰Th年龄和264组氧同位素数据，重建了MIS4早期东亚季风水文循环演化过程。结合同一洞穴YX46记录，发现两条记录在重叠时段的波动特征高度一致，清晰地记录了持续时间较长的DO19.1事件和持续极短的DO19.2事件。石笋记录显示DO19.2和DO19.1事件的开始时间分别为约72.06 ka和69.40 ka，结束时间依次为约69.85 ka和69.03 ka，在误差范围内与格陵兰NGRIP冰芯AICC2012时标一致。这两个事件的持续时间依次约为2200 a和360 a。在DO19.2事件期间，石笋记录的东亚季风较为稳定，显著不同于格陵兰冰芯记录的温度持续下降的特征。这一季风稳定状态与南北两极间温度差的稳定波动特征较为一致，这也得到反映热带辐合带位置变化的Cariaco盆地反照率记录的支持，表明南北半球的温度变化对亚洲季风的综合影响。
关键词: 高分辨率/
石笋/
MIS4早期/
DO19/
东亚季风

Abstract:The stalagmite YX288 was obtained from Yongxing Cave (31°35'N, 111°14'E; 800 m above sea level), approximately 80 km east of Sanbao Cave (31°40'N, 110°26'E), Hubei Province, Central China. The cave is about 500 m in length, and overlain by about 50 m of Silurian limestone. The vegetation above the cave is dense, primarily covered with perennial woody plants and shrub herbaceous plants. The cave has a narrow entrance, thus the cave temperature and relative humidity is close to 14℃ and 100%, respectively. The site is dominated by East Asian monsoon. The annual atmospheric temperature is approximately 8℃, and annual precipitation ranges from 1500~2000 mm. More than 50% of the annual precipitation falls in the summer seasons from June to August. The YX288 stalagmite is 264 mm in length and its diameter ranges from 53 mm to 80 mm. when halved and polished, the stalagmite shows a yellowish-brown color over the whole section. The upper section is darker and more transparent than the lower part. The lithological characteristics are homogeneous, and the overall texture is compact and only a small part of the pores developed.
The dating subsamples and stable isotope subsamples were drilled along the growth axis with 0.9 mm and 0.5 mm hand-held carbide dental drill, respectively. The 5 subsamples for U/Th date analyses, weighing about 40 mg, were measured by inductively coupled plasma mass spectrometry (ICP-MS) on a Finnigan-MAT Element at the Isotope Laboratory of Nanjing Normal University. Uncertainties in the U-Th isotopic data and ²³⁰Th dates are calculated at the 2σ level. For stable isotopic measurements, a total of 364 subsamples, about 30 μg each, was drilled at 1-mm intervals. Oxygen isotopic analysis was conducted on a MAT-253 mass spectrometer fitted with a Kiel Carbonate Device in that Isotope Laboratory. Precision of δ¹⁸O is ±0.06 ‰, at the 1-sigma level.
The YX288 δ¹⁸O record generally shows a "W" shape. The record shows a similar pattern and amplitude with YX46 record in the same cave. The two records clearly document the Dansgaard/Oeschger (DO) events 19.1 and 19.2 (hereafter DO19.1 and DO19.2), with the duration of 360 a and 2200 a, respectively. The onsets of DO19.2 and DO19.1 are dated to ca. 72.06 ka and 69.40 ka, respectively. The terminations of them are dated to ca. 69.85 ka and 69.03 ka, respectively. The timings of the onsets and terminations are in agreement with those in Greenland ice core records on the AICC2012 timescales. During the DO19.2 interval, stalagmite records are relatively stable, different from the gradually decreasing process of the Greenland temperature. The stable condition in the stalagmite records is coherent with the temperature gradient between Greenland and Antarctic. This coherence is supported by the displacement of the Intertropical convergence zone recorded in the Cariaco Basin. The agreement indicates a combined impact of the Greenland and Antarctic climate on the EASM.
Key words:high resolution/
stalagmite/
early MIS4/
DO19/
East Asian Summer Monsoon



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