Post-depositional remanent magnetization lock-in and the location of the Matuyama-Brunhes geomagnetic reversal boundary in marine and Chinese loess sequences | |
Liu, Qingsong1,2; Roberts, Andrew P.2; Rohling, Eelco J.2; Zhu, Rixiang1; Sun, Youbin3 | |
刊名 | EARTH AND PLANETARY SCIENCE LETTERS |
2008-10-30 | |
卷号 | 275期号:1-2页码:102-110 |
关键词 | Matuyama-Brunhes boundary marine sediment post-depositional remanent magnetization (PDRM) lock-in loess paleosol |
ISSN号 | 0012-821X |
DOI | 10.1016/j.epsl.2008.08.004 |
文献子类 | Article |
英文摘要 | Bioturbation disturbs detrital magnetic particles after deposition, so accurate recording of the ancient geomagnetic field in bioturbated sediments is widely attributed to acquisition of a post-depositional remanent magnetization (PDRM) whereby the geomagnetic field exerts a torque on a magnetic particle and aligns it with the held after the final mixing event experienced by the particle. The relationship between the Matuyama-Brunhes boundary (MBB) and oxygen isotope age tie points in marine sediments has been widely used to determine the depth at which the paleomagnetic signal is locked-in. However, such analyses can be badly affected by age discrepancies among different paleoclimatic proxies and by varying isotopic compositions of seawater in different locations and from the presence of different water masses at different depths at the same location. It is therefore necessary to separately compare paleomagnetic data with respect to either benthic or planktonic foraminiferal oxygen isotope records for sites from the same water mass to avoid inadvertently introducing age differences to the analysis. When the global data set is subjected to such a rigorous analysis, few reliable data remain for the MBB. Using two complementary approaches, we estimate that the MBB is, on average, shifted <= 20 cm below its true position in marine sediments. This offset is the sum of the thickness of the bioturbated surface mixed layer, which is possibly dominant, and the PDRM lock-in depth. There is also controversy concerning observed differences in the position of the MBB relative to paleoclimatic proxies in marine sediments and Chinese loess deposits. For the Chinese loess, quartz grain size is insensitive to pedogenic alteration and is a useful parameter for determining the true position of the MBB with respect to paleoclimatic boundaries. We conclude that the MBB occurs late in marine oxygen isotope stage 19, and in the upper part of Chinese paleosol unit 58, rather than at the mid or lower part of loess unit L8. Our results require adjustment of the generally accepted positions for the MBB, and resolve a longstanding chronological conundrum for marine and Chinese loess sequences. (c) 2008 Elsevier B.V. All rights reserved. |
WOS关键词 | OXYGEN-ISOTOPE RECORDS ; ASTRONOMICAL TIMESCALE ; NORTHEAST ATLANTIC ; SEDIMENTS ; SEA ; SUSCEPTIBILITY ; DEPOSITS ; PLATEAU ; OCEAN ; MICROTEKTITES |
WOS研究方向 | Geochemistry & Geophysics |
语种 | 英语 |
出版者 | ELSEVIER SCIENCE BV |
WOS记录号 | WOS:000260993000011 |
资助机构 | European Commission(7555) ; European Commission(7555) ; Bairen Program of the Chinese Academy of Sciences ; Bairen Program of the Chinese Academy of Sciences ; NSFC(40221402) ; NSFC(40221402) ; European Commission(7555) ; European Commission(7555) ; Bairen Program of the Chinese Academy of Sciences ; Bairen Program of the Chinese Academy of Sciences ; NSFC(40221402) ; NSFC(40221402) ; European Commission(7555) ; European Commission(7555) ; Bairen Program of the Chinese Academy of Sciences ; Bairen Program of the Chinese Academy of Sciences ; NSFC(40221402) ; NSFC(40221402) ; European Commission(7555) ; European Commission(7555) ; Bairen Program of the Chinese Academy of Sciences ; Bairen Program of the Chinese Academy of Sciences ; NSFC(40221402) ; NSFC(40221402) |
内容类型 | 期刊论文 |
源URL | [http://ir.iggcas.ac.cn/handle/132A11/68774] |
专题 | 中国科学院地质与地球物理研究所 |
通讯作者 | Liu, Qingsong |
作者单位 | 1.Chinese Acad Sci, Inst Geol & Geophys, Paleomagnetism & Geochronol Lab SKL LE, Beijing 100029, Peoples R China 2.Univ Southampton, Natl Oceanog Ctr, Southampton SO14 3ZH, Hants, England 3.Chinese Acad Sci, Inst Earth Environm, State Key Lab Loess & Quaternary Geol, Xian 710075, Peoples R China |
推荐引用方式 GB/T 7714 | Liu, Qingsong,Roberts, Andrew P.,Rohling, Eelco J.,et al. Post-depositional remanent magnetization lock-in and the location of the Matuyama-Brunhes geomagnetic reversal boundary in marine and Chinese loess sequences[J]. EARTH AND PLANETARY SCIENCE LETTERS,2008,275(1-2):102-110. |
APA | Liu, Qingsong,Roberts, Andrew P.,Rohling, Eelco J.,Zhu, Rixiang,&Sun, Youbin.(2008).Post-depositional remanent magnetization lock-in and the location of the Matuyama-Brunhes geomagnetic reversal boundary in marine and Chinese loess sequences.EARTH AND PLANETARY SCIENCE LETTERS,275(1-2),102-110. |
MLA | Liu, Qingsong,et al."Post-depositional remanent magnetization lock-in and the location of the Matuyama-Brunhes geomagnetic reversal boundary in marine and Chinese loess sequences".EARTH AND PLANETARY SCIENCE LETTERS 275.1-2(2008):102-110. |
个性服务 |
查看访问统计 |
相关权益政策 |
暂无数据 |
收藏/分享 |
除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。
修改评论