首页 | 期刊介绍 | 编委会 | 道德声明 | 投稿指南 | 常用下载 | 过刊浏览 | In English
引用本文:
【打印本页】   【HTML】   【下载PDF全文】   查看/发表评论  下载PDF阅读器  关闭
←前一篇|后一篇→ 过刊浏览    高级检索
本文已被:浏览 109次   下载 10  
分享到: 微信 更多
铁锰结壳年代学方法及其应用
方志浩1, 屠霄霞1,2, 乔志国1, 周怀阳1
1.同济大学;2.浙江万里学院
摘要:
铁锰结壳记录了丰富的古海洋和古气候信息,要分析这些信息,必须先确定各壳层的生长年龄。目前主要使用的定年方法有:Be同位素定年、U系同位素定年、Os同位素定年、经验公式法、古地磁地层学方法和古生物地层学方法等。每种定年方法均各有利弊,其中10Be是年龄小于10 Ma结壳的最佳定年方法;U系同位素定年精度高,但定年范围小于0.5 Ma;Os同位素定年时间尺度长,且可以判断沉积间断,但需要有区域的海水Os同位素演化曲线;Co经验公式因为简单易行,是结壳估算年龄最为常用的方法,但它无法判断沉积间断,在使用时需特别谨慎,应确保经验公式适用于所研究的样品;如果结壳厚度大、生长速率较快且不存在沉积间断,古地磁地层学方法可以快速地进行定年;此外,如果结壳中古生物化石较多,可考虑采用古生物地层学方法。在分析铁锰结壳年代学方法利弊基础上,本文利用U系定年法、古地磁地层学法和经验公式计算法相结合的方法对南海铁锰结壳进行定年,最终提出目前铁锰结壳较优的定年方法。
关键词:  铁锰结壳  生长速率  同位素定年  经验公式法  古地磁地层学方法
DOI:
分类号:
基金项目:国家自然科学基金项目(面上项目,重点项目,重大项目)
Review and application of dating methods of Ferromanganese Crusts
Fang Zhihao1, Tu Xiaoxia1,2, Qiao Zhiguo1, Zhou Huaiyang1
1.Tongji University;2.Zhejiang Wanli University
Abstract:
Deep sea ferromanganese nodules and crusts are suggested as recorders of paleoceanographic events. To analysis the paleoceanographic events recorded by the nodules and crusts, the age of each layers must be determined first. The main dating methods used so far including: 10Be dating, U-series dating, Os isotope dating, empirical equation, magnetic stratigraphy and biological stratigraphyet al. Every dating method has its advantages and disadvantages. 10Be dating is the best method to determine the age of the crusts younger than 10Ma. U-series dating has the best accuracy, but the dating time scale is only 0.5Ma. Os isotope dating could get a long time scale, and also could determine the sedimentation hiatus, but the 187Os /188Os seawater curve of the local ocean should be got first. Empirical equation is simple and easy, and it is the most common used method for age estimate. But it could not determine the sedimentation hiatus. Special care should be taken to ensure that the empirical formula is suitable for the sample. Magnetic stratigraphy can be used to date the thick and fast-growth crusts without sedimentation hiatus. Biological stratigraphy is an effective method to date the nodules and crusts with more fossils. Based on the analysis of advantages and disadvantages of dating methods of ferromanganese crusts ,the U-series dating method, paleomagnetostratigraphy method and empirical formula calculation method are used to date the ferromanganese crusts of the South China Sea. Finally, a better dating method for ferromanganese crusts is proposed.
Key words:  ferromanganese crusts  growth rate  isotopic dating  empirical equation  magnetic stratigraphy
版权所有 《海洋科学》编辑部 Copyright©2008 All Rights Reserved
主管单位:中国科学院 主办单位:中国科学院海洋研究所
地址:青岛市南海路七号  邮编:266071  电话:0532-82898755  E-mail:marinesciences@qdio.ac.cn
技术支持:北京勤云科技发展有限公司