中国黄土磁性地层研究进展与展望  

Progress and outlooks on magnetostratigraphy of Chinese loess

作　　者：陈天然 肖国桥[1,2] 林欣如 潘卿 CHEN Tianran;XIAO Guoqiao;LIN Xinru;PAN Qing(Hubei Key Laboratory of Critical Zone Evolution,School of Geography and Information Engineering,China University of Geosciences,Wuhan 430078,China;State Key Laboratory of Biogeology and Environmental Geology,China University of Geosciences,Wuhan 430078,China;Planetary Environmental and Astrobiological Research Laboratory,School of Atmospheric Sciences,Sun Yat-Sen University,Zhuhai 519000,China)

机构地区：[1]中国地质大学(武汉)地理与信息工程学院,流域关键带演化湖北省重点实验室,武汉430078 [2]中国地质大学(武汉)地球科学学院,生物地质与环境地质国家重点实验室,武汉430078 [3]中山大学大气科学学院,行星环境与宜居性研究实验室,珠海519000

出　　处：《海洋地质与第四纪地质》2024年第2期1-15,共15页Marine Geology & Quaternary Geology

基　　金：国家自然科学基金“基于地磁场相对古强度构建早更新世黄土年代标尺”(42272217)。

摘　　要：中国黄土是最重要的第四纪陆相气候记录之一,磁极性地层是建立第四纪黄土年代框架的主要方法之一。本文总结了中国黄土所记录的布容/松山(Brunhes/Matuyama)、加拉米诺(Jaramillo)、奥尔都维(Olduvai)和松山/高斯(Matuyama/Gauss)等几个作为主要定年依据的极性倒转界限的研究结果,并将黄土记录的这些界限位置与深海记录进行了对比。结果发现,不同黄土剖面所记录的各地磁极性倒转界限的位置并不一致,其差异可超过一个黄土-古土壤旋回,且不能用lock-in效应、气候和沉积速率差异、黄土地层划分差异来解释。这些地磁极性界限位置的差异指示极性界限附近的黄土可能经历了不同程度的重磁化。同时,这些差异也导致了不同研究者基于磁极性地层所建立的轨道尺度的黄土年代标尺与深海氧同位素记录的对比存在较大分歧。未来对黄土所记录的地磁场相对古强度(RPI)的研究可望为识别极性倒转界限的真实位置提供依据,并最终解决中国黄土与深海记录轨道尺度对比方案的分歧。The Chinese loess is one of the most important terrestrial records of the Quaternary climate changes.Magnetostratigraphy is one of the primary methods for establishing the chronological framework of the Quaternary loess.The measured positions of the Brunhes/Matuyama,Jaramillo,Olduvai,and Matuyama/Gauss polarity reversal boundaries in Chinese loess were summarized and compared against corresponding marine records.It was found that the positions of each polarity reversal boundary are inconsistent among different loess sections,and the difference spanned more than one loess-paleosol cycle.This discrepancy cannot be attributed to the lock-in effect,regional climate,sedimentation rate or different loess stratigraphic divisions.This may indicate that the polarity reversal boundaries recorded by loess deposits had probably experienced significant remagnetization,leading to a large discrepancy between loess geochronometer in magnetostratigraphy at orbital scale and marine oxygen isotope records by different researchers.In the future,studies shall focus more on the relative paleointensity(RPI)of loess to confirm the true position of each polarity reversal boundary and ultimately resolve the discrepancy in the comparison scheme between Chinese loess data and deep-sea sediment record.

关 键 词：黄土 第四纪 磁性地层 重磁化 地磁场相对古强度 

分 类 号：P534.63[天文地球—第四纪地质学]