Calculation and Program Design for Pb-Sr-Nd-Hf Isotopic Parameters
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摘要: Pb、Sr、Nd、Hf 同位素都是放射性成因的重稳定同位素,地质过程中不发生同位素分馏,因而其同位素组成只与来源有关而与过程无关。这些同位素组成是成岩(成矿)物质来源及其构造环境判别的重要标志,特别是在研究壳幔分离与壳幔相互作用中起着不可替代的作用。由于这些参数的计算涉及相对复杂的公式推导,许多地质工作者并未系统学习过同位素地球化学理论,在对公式与参数的理解上难免会出现偏差,导致数据处理错误。本文对铅- 锶- 钕- 铪同位素的相关参数以及这些参数的计算公式作一全面的介绍,在此基础上,作者应用Excel VBA 设计了一套计算机程序。该程序界面友好、使用方便、结果可靠。Abstract: Pb, Sr, Nd and Hf isotopes are heavy stable isotopes of radioactive origin, and occurs no isotopic fractionation in geological process, so their isotopic compositions are only related to the source. Therefore, these isotopic compositions are important indicators of material source and tectonic setting, especially in the study of crust-mantle separation and interaction. Some geologists have not systematically studied the theory of isotopic geochemistry, and the calculation of the parameters of those isotopic compositions involves the relatively complex formula derivation, which inevitably leads to errors in data processing in the understanding of formulas and parameters. This paper introduced the related parameters of Pb, Sr, Nd and Hf isotopes, and the calculation formulas of these parameters. On this basis, a set of computer program is designed by using Excel VBA which is user-friendly, convenient, reliable.
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Key words:
- lead isotopes /
- strontium isotopes /
- neodymium isotopes /
- hafnium isotopes /
- isotopic parameters /
- computer program
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