黄伟^1,,
董进国^2,,
1. 宜春学院, 江西 宜春 336000
2. 南通大学地理科学学院, 江苏 南通 226007

基金项目: 国家自然科学基金项目（批准号：41877287、41472317和41102216）资助


详细信息

作者简介: 黄伟, 男, 30岁, 讲师, 第四纪地质学专业, E-mail:weihuang@jxycu.edu.cn

通讯作者: 董进国, E-mail:dongjinguo1111@163.com

中图分类号: P597⁺.2;P532

收稿日期:2020-01-20
修回日期:2020-04-30
刊出日期:2020-07-30

Characteristics of CIS13 event recorded by a high resolution stalagmite δ¹⁸O in Shanxi Province, China

Huang Wei^1,,
Dong Jinguo^2,,
1. Department of Geographical Science, Yichun University, Yichun 336000, Jiangxi
2. School of Geographical Science, Nantong University, Nantong 226007, Jiangsu


More Information

Corresponding author: Dong Jinguo,E-mail:dongjinguo1111@163.com

MSC: P597⁺.2;P532

--> Received Date: 20 January 2020
Revised Date: 30 April 2020
Publish Date: 30 July 2020


摘要
摘要:文章基于山西黎城白云洞高分辨率石笋（BY2）δ¹⁸O记录，重建了53.82~47.41 ka B.P.东亚夏季风演化历史。BY2δ¹⁸O值在52.2 ka B.P.和49.5 ka B.P.前后显著偏负，指示两次夏季风显著增强阶段，分别对应于格陵兰冰芯记录的DO14和DO13事件。山西白云洞石笋清晰记录了CIS13事件"双峰"结构，与NGRIP冰芯记录相对应，反映了东亚季风边缘区对北大西洋海-气耦合振荡，以及ITCZ南北移动引起的雨带范围变化的敏感响应。但BY2 δ¹⁸O记录的CIS13事件转换过程较NGRIP缓慢，其中开始过程呈现"三相位"变化特征：即亚洲夏季风提前出现缓慢增强趋势、在达到水热阈值条件后表现出与格陵兰温度的同步快速爆发、最后仍持续增强直至峰值；这与热带大西洋和印度洋海盆岩芯反照率记录相似，可能与南大洋越赤道气流以及ITCZ持续北移有关。另一方面，千年尺度事件和百年-年代际振荡幅度分别高达5 ‰和2 ‰，明显较东亚季风区其他石笋δ¹⁸O记录大，尤其是在百年-年代际尺度上呈现出"高频、大幅"的变化特征；表明其敏感响应于不同时间尺度气候波动。功率谱结果表明，其具有明显的50 a、60 a和206 a变化周期，可能受到太阳活动和海洋水文变化的双重影响。
关键词: 石笋δ¹⁸O/
白云洞/
东亚夏季风/
DO/CIS事件/
“双峰”结构

Abstract:Rapid millennial-scale climate oscillations during the last glaciation, associated with Dansgaard-Oeschger (DO) events, are the most interesting focus. The detailed features for some of them, however, are still open discussion. Here we reconstructed the evolution history of the East Asian summer monsoon (EASM) during the time interval of 53.82~47.41 ka B.P. (including DO14 and DO13 events), based on absolute-dated and high-resolution (24 a average) δ¹⁸O record of a stalagmite from North China. In this study, we mainly focus on the detailed features of DO13 event and associated mechanisms.
Baiyun Cave (36°40'N, 113°24'E) is located 30 km from northern Licheng County, Shanxi Province. The entrance of Baiyun Cave is large, about 500 m long, and the passageway is rich in carbonate landscape, mainly including stone flower, claw stone and stone dam. Vegetation overlying the cave are mainly composed of shrubs and trees. The temperature and humidity in-situ is 11℃ and 80%, respectively. Controlled by the EASM, the annually-average rainfall in this region is approximately 530 mm, with rainy season from May to October, which accounts for 87% of the total precipitation. Stalagmite BY2 was collected from a rock dam, 200 meters away from the entrance of cave. It is 137 mm in length, and the top and bottom diameters are uniform. The cut and polished profile shows that the lithofacies is opaque milky white to yellowish-brown, with clearly visible growth layers, which is arranged in an approximate straight line within a certain distance from the central deposition position.
Six subsamples were collected along the deposition layer with 0.9-mm-diameter carbide dental drill for U/Th dating, and each powder amount is about 50 mg. The measurements were performed by multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS), Fisher Thermo-Neptune. For stable isotopic measurements, 268 subsamples were taken with 0.5-mm-diameter carbide dental drill along the growth axis with powder masses varying between 50 μg and 100 μg. Sampling interval varies from 0.5 mm to 1.0 mm, corresponding to a temporal resolution of mainly ranging from 10 a to 30 a. The analysis was conducted by Finnigan-MAT 253 mass spectrometer fitted with a Kiel Carbonate Device.
The tendency of BY2 δ¹⁸O is gradually increasing, varying from -8.5 ‰ to -1.0 ‰. The δ¹⁸O values are significantly negative surrounding 52.2 ka B.P. and 49.5 ka B.P., with the amplitude of 3 ‰, indicating two significant intensification periods of summer monsoon, and most likely corresponding to DO14 and DO13 events recorded by Greenland ice core, respectively. The stalagmite in Shanxi clearly records the Chinese interstadial (CIS) 13 event with "twin peaks" structure, which mirrors the NGRIP ice core record. And it therefore reflects the sensitive response of the East Asian monsoon (EAM) margin to the North Atlantic Ocean-atmosphere coupling oscillation and the rain belt range variation caused by the north-south movement of the intertropical convergence zone (ITCZ). However, the CIS13 event transition processes recorded by BY2 are slower than that of NGRIP. Specifically, the starting process of summer monsoon presents three stages, which are similar to the reflectance records from the tropical Atlantic and Indian Ocean basins, and may be related to the cross-equatorial airflow in the southern ocean and the continuous northward movement of the ITCZ.
On the other hand, the range of millennial-scale events and century-decadal oscillations was up to 5 ‰ and 2 ‰, respectively, which was significantly larger than that recorded by other stalagmites within EAM region. Especially for it remarkably displays "high frequency and large amplitude" characteristics on the century-decadal timescales. It thus demonstrates that the BY2 record-based EASM is sensitive to climate fluctuations on different timescales. The results of power spectrum show that it has obvious change periods of 50 a, 60 a and 206 a, which may be influenced by both solar activity and ocean hydrology. Among, the origin signature of solar output is possibly amplified by the oceanic temperature and salinity oscillators, associated with formation of the north Atlantic deep water.
Key words:stalagmite δ¹⁸O/
Baiyun Cave/
East Asian summer monsoon/
DO/CIS event/
"twin peaks" structure



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