• Journal of Natural Resources
  • Vol. 35, Issue 12, 12003064 (2020)
WANG Meng1、2、3, CHEN Shi-tao1、2、3、*, HUANG Wan-chun1、2、3, CAI Wen-qin4, GONG Qing-lin1、2、3, LIANG Yi-jia1、2、3, WANG Xian-feng5, and WANG Yong-jin1、2、3
Author Affiliations
  • 1Key Laboratory of Virtual Geographic Environment, Ministry of Education, School of Geography Science, Nanjing Normal University, Nanjing 210023, China
  • 2State Key Laboratory of Cultivation Base of Geographical Environment Evolution (Jiangsu Province), Nanjing 210023, China
  • 3Jiangsu Center for Collaborative Innovation in Geographical Environment Resource Development and Application, Nanjing 210023, China
  • 4Department of Marine Science and Engineering, Nanjing Normal University, Nanjing 210023, China
  • 5Nanyang Technological University, Earth Observatory of Singapore, Singapore 639798, Singapore
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    Abstract

    The study of various proxies of stalagmites is conducive to understand the characteristics and mechanisms of monsoon climate events comprehensively. Here, we present a high-resolution and multi-proxy stalagmite record from Yongxing Cave, Central China, spanning the interval between 65 and 35 ka B.P. based on high precision U/Th dating method and multi-proxy analyses. A total of 371 subsamples were drilled for oxygen and carbon isotopic measurements along the growth axis at a spacing of 0.5-mm-diameter carbide dental burrs. The analyses were conducted using a Finnigan MAT 253 mass spectrometer linked to a Kiel Carbonate Device at the School of Geography, Nanjing Normal University. The precision is 0.06‰ for δ18O and 0.05‰ for δ13C at the 1σ level. For the gray-level measurements, the polished surface of the studied section was scanned at a resolution of 1200 dpi using an EPSON Perfection 4990 Photo Scanner. The gray level was then obtained from the image using the Environment for Visualizing Images (ENVI 4.8) software while traversing down the growth axis. The values range between 0 and 442, with a spatial resolution of 20 μm. The experimental results show that during the period of 65-40 ka B.P., the stalagmite records of gray-level, δ13C and δ18O all presented millennial to sub-millennial changes, but the amplitude of δ13C is much smaller than that of δ18O. This indicates that the local climate indicators of δ13C, gray-level and lithology also respond to the Heinrich (H) events and Dansgaard-Oeschger (DO) events, but their sensitivities to events are different. During the H4 episode (about 40-38 ka B.P.), δ13C and the gray-level of the stalagmite showed anomalous changes. The significantly positive shift of δ13C reached an amplitude of 4.5‰ during H4, which was 2-3 times than other H events, while the gray-level presented the same characteristics to that of the DO cycles. We imply that the state of soil erosion may play an important role in such correspondence during H4. When the monsoon weakened to a certain threshold, the soil cover above the permeable cave was greatly deteriorated, thus weakening and/or preventing the infiltration ability of the soil-karst system and increasing the impurity contents in the stalagmite.

    末次冰期频现千年尺度气候突变事件,对这类事件的最初认识来源于北半球高纬地区大西洋海洋沉积[1]和格陵兰冰芯的研究[2,3]。北高纬的千年尺度气候变化已得到了众多地质记录的支持,Leuschner等[4]曾总结了全球三十余个地点的研究成果,指出在格陵兰、北大西洋、地中海、北太平洋、东亚、孟加拉湾、阿拉伯海、赤道大西洋、南极及其邻近海域都发现了类似的气候变化。在这些地质记录中,洞穴石笋记录因其高分辨率、精确定年等优点而成为了刻画千年气候突变事件的有效载体,受到越来越多的关注[5]

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    Meng WANG, Shi-tao CHEN, Wan-chun HUANG, Wen-qin CAI, Qing-lin GONG, Yi-jia LIANG, Xian-feng WANG, Yong-jin WANG. The response of stalagmite gray-level and isotopes to the climatic events during the last glacial period[J]. Journal of Natural Resources, 2020, 35(12): 3064
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    Received: May. 24, 2019
    Accepted: --
    Published Online: May. 8, 2021
    The Author Email: CHEN Shi-tao (chenshitao@njnu.edu.cn)