天然放射性碳同位素在海洋有机地球化学中的应用

THE APPLICATION NATURALLY OCCURRED RADIOCARBON (^(14)C)IN MARINE ORGANIC GEOCHEMISTRY STUDIES

天然放射性碳 (14 C)是年代测定的有效手段 ,它在考古学和地质学的应用已有几十年的历史。过去 10年中 ,伴随着加速器质谱仪 (AMS)技术和检测灵敏度的提高 ,AMS已经能够检测少于mgC量级样品中自然丰度水平的14 C ,这大大扩展了14 C在自然科学 ,特别是地球科学研究中的应用范畴。简要评述了利用天然14 C进行海洋地球化学研究的应用 ,重点介绍了前景广阔。

Naturally occurred radiocarbon ( 14 C), as a powerful tool, has been used for decades for archeological and geological dating. Recent development and applications of Accelerator Mass Spectrometry (AMS) have made it possible to detect 14 C at its natural abundance in very limited sample sizes (<mg C). This has greatly increased the range of applications using 14 C in natural science, particularly in the Earth sciences. In this paper, we briefly reviewed the principal and some recent applications of using natural 14 C in marine geochemical studies mainly in three areas:① 14 C studies of carbon cycling in the ocean; ②Using 14 C as a tracer to determine the sources, transformation and turn over of the major organic compound classes in different organic carbon pools in the ocean; and ③ 14 C studies of compound specific biomarkers in marine sediments. These studies have shown novel results and demonstrated that natural radiocarbon measurements at compound level provide a new and sensitive tool for determining the sources, transformation and biogeochemical processes of carbon cycle in oceans in the past and at present both at large and small scales.