富钴结壳的10Be、26Al定年方法初步研究  

Preliminary Research on the 10Be and 26Al Dating Methods of Cobalt-Rich Crusts

作　　者：胡滢 董克君 崔丽峰[2] 杨业 张小龙 徐胜 刘丛强 HU Ying;DONG Ke-jun;CUI Li-feng;YANG Ye;ZHANG Xiao-long;XU Sheng;LIU Cong-qiang(Institute of Surface-Earth System Science,Tianjin University,Tianjin 300072,China;State Key Laboratory of Environmental Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,China)

机构地区：[1]天津大学表层地球系统科学研究院,天津300072 [2]中国科学院地球化学研究所,环境地球化学国家重点实验室,贵阳550081

出　　处：《矿物岩石地球化学通报》2020年第1期116-124,共9页Bulletin of Mineralogy, Petrology and Geochemistry

基　　金：国家自然科学基金资助项目(11775157,11575296,41603018)。

摘　　要：大洋富钴结壳的生长速率及其定年测量在研究古大洋环流、古环境及古气候变迁等方面具有重要意义,而宇宙成因核素10Be、26Al因为其测量时间尺度长、精度高,而被视为富钴结壳年代测定的最有效手段之一。本文在前人研究的基础上,对富钴结壳中10Be、26Al定年新方法进行了探究。对采自太平洋的2块富钴结壳样品进行连续的淋滤实验,并对其中1个样品CXD08-1自生相中的10Be和26Al进行分离、纯化及AMS(Accelerator Mass Spectrometry)测量分析。利用10Be浓度和10Be/9Be值计算得到CXD08-1在5~10 mm间的平均生长速率分别为(10.23-0.47^+0.52)mm/Ma和(14.25-0.89^+1.02)mm/Ma。而26Al因为大量衰变及27Al载体的加入而未得到可靠的分析结果,因此,26Al定年须进一步探索。It has been shown that the growth rate and dating of oceanic cobalt-rich crusts are significant for studying paleooceanic circulation,paleo-environmental and paleo-climatic transitions and so on.Cosmogenic nuclides of 10Be and 26Al,which have advantages of long timescale and high precision,are considered as one of the most effective methods for dating cobalt-rich crusts.Based on previous studies,new methods(10Be and 26Al)to date cobalt-rich crusts have been explored in this paper.Continuous leaching experiments of two cobalt-rich crust samples which were collected from Pacific Ocean and the 10Be and 26Al separation,purification and AMS measurement ofthe cobalt-rich crust sample CXD08-1 were carried out.The average growth rates of the 5-10 mm thick zones of the cobalt-rich crust CXD08-1,calculated by using 10Be concentrations and 10Be/9Be ratios,are(10.23-0.47^+0.52)mm/Ma and(14.25-0.89^+1.02)mm/Ma,respectively.However,no reliable result has been obtained due to the fast decay of 26Al and high 27Al concentration.Therefore,the 26Al dating method requires to be further studied in future.

关 键 词：10Be 26Al 富钴结壳 定年 

分 类 号：P736[天文地球—海洋地质]