The manifestation of the Younger Dryas event in the East Asian summer monsoon margin: New evidence from carbonate geochemistry of the Dali Lake sediments in northern China
The manifestation of the Younger Dryas event in the East Asian summer monsoon margin: New evidence from carbonate geochemistry of the Dali Lake sediments in northern China
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新仙女木事件在东亚夏季风边缘的表现：中国北方大理湖沉积物碳酸盐地球化学的新证据
DOI：
10.1177/0959683618761542
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Yue Jiaojiao
中科院分区：
文献类型：
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作者：
Fan Jiawei;Xiao Jule;Wen Ruilin;Zhang Shengrui;Wang Xu;Cui Linlin;Liu Yanhong;Li He;Yue Jiaojiao
现代东亚夏季风北方边缘新仙女木事件（YD）的过程和机制至今仍有争议。本研究提供了新的高分辨率（~25年）记录的元素和稳定同位素的<38-µm方解石从沉积物柱样的大理湖，以研究在末次冰期-间冰期过渡的东亚夏季风边缘的气候变化。大理湖沉积物中的<38 µm方解石呈立方体或菱面体，这意味着它们主要由湖泊水体中沉淀的内生方解石组成。高值的Ca和Mg浓度的内生方解石被解释为强烈的蒸发和低溶解CO2浓度的湖水与高区域温度。内生方解石的δ 13 C和δ 18 O值同时升高，是由于该地区高温或少雨导致蒸发加剧的结果。这些数据表明，在15，500 - 12，800和11，550 - 10，000 cal. yr BP之间，大理湖地区的气候相对温暖和潮湿，而在12，800 - 11，550 cal. yr BP之间，气候寒冷和干燥。此外，在12,800 - 11,550 cal. yr BP期间，大理湖地区温度变化的不稳定性，在年龄不确定性范围内，可以对应于北方高纬度地区发生的YD冷反转。北大西洋地区与东亚夏季风边缘的大气耦合是影响YD事件期间大理湖区气候变化的主导型。
The processes and mechanisms of the Younger Dryas (YD) event in the modern northern margin of the East Asian summer monsoon (EASM) are still heatedly debated. This study presents new high-resolution (~25 years) records of elements and stable isotopes of <38-µm calcites from a sediment core from Dali Lake in order to investigate the climatic change in the EASM margin at the last glacial–interglacial transition. The <38-µm calcites in the Dali Lake sediments are cubical or rhombohedral, implying that they are predominated by endogenic calcites precipitated within the water body of the lake. High values of Ca and Mg concentrations of the endogenic calcites are interpreted as strong evaporation and low dissolved CO2 concentration of the lake water related to high regional temperature. Concurrent increases in δ13C and δ18O values of the endogenic calcites are interpreted as the result of intensified evaporation associated with high temperature or low precipitation in the region. These data indicate that the climate in the Dali Lake region was relatively warm and wet from 15,500 to 12,800 and from 11,550 to 10,000 cal. yr BP, and cold and dry from 12,800 to 11,550 cal. yr BP, which was generally supported by the evidence from the data of sedimentary organic matter from the same sediment core. In addition, the abruptness of the temperature change in the Dali Lake region from 12,800 to 11,550 cal. yr BP could be corresponded, within age uncertainties, to the YD cold reversal occurring over northern high latitudes. The atmospheric coupling between the North Atlantic region and the EASM margin was proposed as the dominant pattern influencing the climatic change in the Dali Lake region during the YD event.