南海砗磲壳体成分及生物有机特征分析  

Analysis of the components and biological organic characteristics of Tridacna spp. shells from South China Sea

作　　者：梅衍俊 邵达 刘文齐[2] 杨文卿 杨仲康 谢周清 孙立广 MEI Yanjun;SHAO Da;LIU Wenqi;YANG Wenqing;YANG Zhongkang;XIE Zhouqing;SUN Liguang(Institute of Polar Environment&Anhui Key Laboratory of Polar Environment and Global Change,School of Earth and Space Sciences,University of Science and Technology of China,Hefei 230026,China;Instruments’Center for Physical Science,University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]中国科学技术大学地球和空间科学学院,极地环境研究室&极地环境与全球变化安徽省重点实验室,安徽合肥230026 [2]中国科学技术大学理化科学实验中心,安徽合肥230026

出　　处：《中国科学技术大学学报》2018年第7期550-559,共10页JUSTC

基　　金：中国科学院战略性先导科技专项(XDA11030104);国家重点基础研究发展(973)计划(2013CB955700)资助.

摘　　要：砗磲(Tridacna spp.)作为地质历史时期以来最大的海洋双壳类生物,因其碳酸盐壳体有明显的年纹层甚至日纹层,正逐渐成为一种重要的高分辨率古气候研究载体.在利用砗磲壳体进行古气候研究之前需要判断其碳酸盐壳体是否发生方解石化.对采自中国南海的5个砗磲壳体进行X射线衍射(XRD)测试,并对1个现代砗磲和1个古代砗磲进行差热-热重测试和顶空富集加气相色谱/质谱联用分析.结果显示,砗磲内壳没有发生方解石化,为文石相;主要无机成分为CaCO3,质量分数为96.5%~97.2%,有机成分质量分数在2.8%~3.5%,包括多种有机物,如十六烷及17种氨基酸.部分砗磲外壳发生了明显的方解石化.本研究提出了判别砗磲文石壳体是否方解石化的方法,并初步确定了砗磲壳体组分及含量,这是利用砗磲文石壳体研究气候环境变化的前提和依据.The largest bivalve shell in the world,the marine bivalve,Tridacna spp.,has hard and dense aragonite shells with annual or daily growth lines in its inner shell layers,and is becoming an ideal material for high-resolution paleoclimate reconstructions.However,identification of shell calcilization is necessary before using Tridacnidae as paleoclimate recorders.Five Tridacnidae specimens were collected from the South China Sea.The analysis results of X-ray diffraction(XRD),differential scanning calorimetry-thermo gravimetric analysis(DSC-TGA)and gas chromatography-mass spectrometer(GC-MS)showed that all the Tridacna spp.’s inner shells studied here are entirely made of aragonite,and shell calcilization does not occur.The main inorganic compound of the inner shells is CaCO 3,with a content between 96.5%~97.2%;the content of the organic matter,such as hexadecane and 17 kinds of amino acids,is between 2.8%~3.5%.However,calcilization takes place in some outer shell layers.This study presents a method to identify the calcilization of Tridacnidae shell,and preliminarily determines composition and content in Tridacnidae shell.Results from this study provide a basis for such reconstruction using Tridacnidae shells.

关 键 词：砗磲 南海 文石 碳酸盐 有机质 热重分析 

分 类 号：P736[天文地球—海洋地质]