中国南方红土记录的中更新世气候转型及其环境效应  

Middle Pleistocene transition and its environmental effects revealed by red earth of South China

作　　者：熊文婷 朱丽东[1] 张晓 郭利成 叶玮[1] 熊尚发[2,4] Xiong Wenting;Zhu Lidong;Zhang Xiao;Guo Licheng;Ye Wei;Xiong Shangfa(College of Geography and Environmental Sciences,Zhejiang Normal University,Jinhua 321004,Zhejiang;Key Laboratory of Cenozoic Geology and Environment,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029;CAS Center for Excellence in Life and Paleoenvironment,Beijing 100044;College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049)

机构地区：[1]浙江师范大学地理与环境科学学院,浙江金华321004 [2]中国科学院地质与地球物理研究所,中国科学院新生代地质与环境重点实验室,北京100029 [3]中国科学院生物演化与环境卓越创新中心,北京100044 [4]中国科学院大学地球与行星科学学院,北京100049

出　　处：《第四纪研究》2020年第6期1441-1452,共12页Quaternary Sciences

基　　金：国家自然基金科学项目(批准号:41572345);中国科学院(B类)战略性先导科技专项项目(批准号:XDB26020401);中国科学院地质与地球物理研究所重点部署项目(批准号:IGGCAS-201905)共同资助。

摘　　要：中更新世气候转型(MPT)是第四纪气候变化的重要过程,主要表现为全球气候系统的主导周期由41 ka转变为100 ka,全球冰量显著增多,海洋温度下降,陆地干旱化程度显著增强。与海洋沉积记录相比,陆相沉积记录的MPT研究易受载体的连续性和分辨率限制,总体上不多,而针对中国南方红土MPT的工作就更为稀见。本文基于ESR年代学框架,对江西九江九庐(JL)红土剖面的多个环境代用指标进行主成分(PCA)分析,尝试建立JL红土剖面第四纪环境演化序列,并据此与深海氧同位素记录进行对比,结果表明JL红土剖面记录了MPT过程,其中区域气候系统的相对稳定状态在MPT后可能被打破,区域气候向着冷干方向持续发展。综合考虑本研究结果与全球气候变化背景,推测MPT时期全球冰量增加、全球变冷、西伯利亚高压增强,共同驱动着中国南方地区的更新世气候演化。The Mid-Pleistocene Transition(MPT,approximately 1.2 Ma to 0.5 Ma)was marked by fundamental changes in Earth's climate state,where the low-frequency,high-amplitude,quasi-periodic(100-ka)glacial variability emerged and characterized the Later Pleistocene and Holocene.Previously published MPT records reveal that evidences from the marine realm are abundant and high-resolution.However,discontinuity and low-resolution of the continental MPT records mainly limited the practice of further researches from land area.Moreover,only a few studies have tried to explore diverse manifestations of the Middle Pleistocene climate transition by terrestrial deposits.Consequently,further work is needed to fully understand and explore characteristics,mechanisms,and implications for MPT recorded in terrestrial deposits.In South China,red earth has been recognized as an important definition of this area,as it is covered by red soil at a large scale.Especially,red earth in South China deposited during the Quaternary period and documented the evolution of regional environment,which has enormous potential to decipher the environmental changes across the MPT.Thus,we selected the JL red earth section(29°42'N,116°02'E)located in Mount Lushan,Jiujiang,Jiangxi Province as study section,where the depth of the section is about 18.46 m.A total of 920 samples were taken at 2 cm interval from the JL red earth sections for particle size,color and magnetic susceptibility measurements.Our principal aim is to investigate the manifestations and the main causal mechanisms of the MPT based on works of ESR dating and multi-proxies analyses.A more careful analysis of chronology of our section and other red earth section in South China suggests that the chronostratigraphic framework of JL red earth section can be estimated to span ca.1200 ka to 233 ka.The multi-proxies analysis will be focused on Principal Component Analysis(PCA).Results of PCA analysis indicates that PCA F1 is a sensitive proxy for the degree of regional warming and cooling,which provides

关 键 词：红土 中更新世气候转型 主成分分析 西伯利亚高压 

分 类 号：P532[天文地球—古生物学与地层学] P534.631[天文地球—地质学]