植硅体14C测年研究:过去、现在与未来  

PHYTOLITH RADIOCARBON DATING :PAST,PRESENT AND FUTURE

作　　者：左昕昕 吴乃琴[3,4,5] Zuo Xinxin;Wu Naiqin(State Key Laboratory for Subtropical Mountain Ecology of the Ministry of Science and Technology and Fujian Province,Fujian Normal University,Fuzhou 350007,Fujian;School of Geographical Sciences,Fujian Normal University,Fuzhou 350007,Fujian;Key Laboratory of Cenozoic Geology and Environment,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029;University of Chinese Academy of Sciences,Beijing 100049;Institutions of Earth Science,Chinese Academy of Sciences,Beijing 100029)

机构地区：[1]福建师范大学湿润亚热带山地生态国家重点实验室培育基地,福建福州350007 [2]福建师范大学地理科学学院,福建福州350007 [3]中国科学院地质与地球物理研究所,中国科学院新生代地质与环境重点实验室,北京100029 [4]中国科学院大学,北京100049 [5]中国科学院地球科学研究院,北京100029

出　　处：《第四纪研究》2019年第1期59-66,共8页Quaternary Sciences

基　　金：国家自然科学基金项目(批准号:41771241、41430103和41830322);国家重点基础研究发展计划项目(批准号:2015CB953801)共同资助.

摘　　要：文章回顾了植硅体14C测年发展的历史,对当前其研究的现状进行了全面的总结和评述,对近年来其研究的争议进行了梳理。植硅体测年研究中存在的问题(如污染和老碳效应等)在其他材料测年过程同样存在,不能基于少量现代植物植硅体测年的异常数据而完全否定其意义。大量的测年数据显示,并不是所有的植硅体年代都偏老,相反地层中的植硅体年代与同层位其他材料的年代重合或接近。因此,在一些缺少其他有机质测年材料的地层,植硅体14C测年仍然是一种极具潜力的年代学方法,在构建一些重要环境和考古文化时间标尺上将会发挥更重要的作用。Phytolith radiocarbon dating was a long established chronological technique since 1960s. Questions about its reliability have been spiritedly discussed. In this study, we discussed the nature and status of phytolith radiocarbon dating through reviewing all previous phytolith dating studies, including techniques, approaches, tests, and application in paleoecological and archaeological research. We draw a conclusion that not all phytolith ages are questionable because of a large amount of successful dating applications in previous studies. The cumulative studies in the nature and structure of phytolith occluded carbon shed lights on that organic matter derived from photosynthesis is the main component of carbon in phytoliths. Although phytolith may trap trace of carbon absorbed by plants from the soil, this carbon fraction is too small to bias the phytolith ages. Those abnormal phytolith ages largely from the modern plants cannot be addressed by the old carbon hypothesis proposed by Santos et al. It is clearly that different phytolith extraction methods show different effects on the content as well as the nature of phytolith carbon. The rapid digestion was so harsh that it might alter the structure, nature, and yield of phytolith carbon, and finally skew the phytolith ages. The processes involved in phytolith 14C measurement, such as the increasing combustion temperature, were also be taken as the potential factor which would bias the phytolith dating results. It is plausible, however, that if the phytolith ages increase with increasing combustion temperature, because other phytolith ages encountered with the identical 14C measurement in the same Lab shown good consistence with other paired dating samples. The negative correlation between graphite and 14C age of phytolith in Santos' study imply that trace amounts of graphite produced by micro-phytolith samples(usually less than 100 mg) were more likely to be contaminated during the 14C measurement. Thus, phytolith carbon dating is an effective method that can be us

关 键 词：植硅体 放射性碳十四测年 植硅体碳 

分 类 号：Q949.714.2[生物学—植物学] Q913.84[天文地球—古生物学与地层学]