摘要
根据地质体系多源多汇的特点,引进了一种新的定量地球化学理论模型,适用于模拟稳定同位素和微量元素在具有多个物质来源和多种分馏途径的地质体系中的变化规律。运用本文多源多汇模型研究岩浆同化-分异结晶过程中微量元素和稳定同位素的行为,所得的结果与前人AFC模型结果一致。运用此多源多汇模型对岩浆水与大气水混合过程中结晶出的石英进行模拟计算,发现其氧同位素组成随着结晶温度的降低而变大。大气中甲烷的产生和消耗有多种途径,是一种多源多汇体系,运用此模型研究它的碳同位素组成,发现其值随着甲烷总量的增多而变大。多源多汇模型不仅从更高的层次上包含了简单分馏模式、多元混合模式和AFC模式,而且可以研究这些模式不能解决的复杂地球化学过程。
Geochemical systems are commonly of multiple sources and multiple sinks, but they are normally dealt with separately. This paper introduces a new quantitative model that is capable of simulating the variation of trace elements and stable isotopes in geochemical systems with multiple sources and multiple sinks. When the model is applied to study the behaviors of trace elements and stable isotopes in the assimilated fractional crystallization process, the results are consistent with the previous AFC model. When the model is applied to simulate the oxygen isotope variation in quartz that was crystallized by mixing between meteoric water and magmatic water, it is found that its δ 18O value becomes larger with a decrease in crystallization temperature. The generation and consumption of atmospheric methane have various ways, often with multiple sources and multiple sinks. The present model is applied to study the carbon isotope variation in the atmospheric methane. The results show that δ 13C value becomes larger with increasing methane. The model for the multiple sources and multiple sinks not only outlines the simple fractionation model, multi component mixing model and AFC model at a higher level, but also can be used to study complex geochemical processes that cannot be dealt with by these separated models.
出处
《地球化学》
CAS
CSCD
北大核心
2003年第4期297-305,共9页
Geochimica
基金
国家自然科学基金(40033010)
中国科学院知识创新工程项目(KZCX2-107)
