河蚬壳体不同断面碳、氧同位素研究

生物壳体碳酸盐的稳定氧、碳同位素已经被广泛地应用在古气候、古环境研究中，在生物壳体就位分析中，壳体不同断面上同位素的差异将影响对壳体同位素所指示的环境意义的判断，从而对利用其提取气候环境信息造成不利影响。本文对河蚬壳体不同断面碳氧同位素进行了研究，结果表明:河蚬壳体碳同位素变化序列在不同断面上不存在显著差异，因此在做碳同位素时间序列研究时可以不考虑不同断面差异的问题，在取样过程中可以通过延长取样的长度来获得足够量的样品进行碳同位素的测定；而氧同位素变化序列在不同断面上存在差异，因此在进行壳体就位分析研究时，选取不同断面上氧同位素变化序列对研究结果影响较大，存在壳体断面选择的问题，而在取样过程中取样的长度应控制在一定范围内，避免同一生长环上距离较远位置粉末的混合。文中最后根据壳体不同断面同位素差异确定了在壳体就位分析中如何选取研究断面。

Carbon and Oxygen Isotopic Study on Different Cross-sections of Corbicula

The stable oxygen and carbon isotope of biological shell carbonate have been extensively applied in the palaeo-climatology and palaeo-environmental research.When measured the isotope composition of shell in situ,the different isotope composition between different shell cross sections will affect the environment significance judgement of shell isotope and have the adverse effect on the environment information extraction.This article has investigated carbon and oxygen isotope of the corbicula shell,the results shows that the carbon isotope profiles not obvious change in different cross sections,therefore it can not consider the difference between cross sections,and can extend the length of sample path in the sample process to obtain the enough powder to determine the carbon isotope.However,the oxygen isotope profiles exist difference between cross sections,so it should consider the difference oxygen isotope composition between cross sections,and in the sample process,the length of sample path should control in certain scope.Finally,according to the isotope difference between cross sections,the article had determined how to select the study cross section during the analysis of the shell.