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

Key words: 
• biological shell carbonate /
• carbon isotope /
• oxygen isotope /
• cross sections

Abstract: 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.