论文部分内容阅读
对我国众多沉积岩系中的微细浸染型金矿床开展了较为系统的稳定同位素地球化学研究。非常分散复杂的氢氧同位素组成被认为是沉积盆地流体的一个典型特征,这是因为盆地流体中水的两个主要来源──海水和大气降水,经不同程度的水-岩反应同位素交换后又以不同比例相互混合,再加上有机物和粘土矿物的相变水在不同阶段以不同比例加入。碳氧同位素表明,本类矿床中的CO2主要由海相沉积碳酸盐经溶解过程而产生,并可能混入部分由沉积有机物质经脱羧基作用生成的CO2。结合其他地球化学研究成果,本文认为这类矿床的成矿流体与盆地沉积物的演化密切相关,很可能是由成分复杂的沉积物所决定的、混杂来源的盆地成因流体。
A systematic and stable isotope geochemistry study has been carried out on the finely disseminated gold deposits in many sedimentary rock series in China. The highly dispersed and complicated composition of hydrogen and oxygen isotopes is considered to be a typical feature of fluids in sedimentary basins because of the two main sources of water in the basin fluids - seawater and atmospheric precipitation. After varying degrees of water-rock reaction isotope exchange Mixed with each other in different proportions, and phase change water of organic and clay minerals is added at different stages in different proportions. Carbon and oxygen isotopes indicate that CO2 in this type of deposit is mainly produced by the dissolution of marine sedimentary carbonate and may be contaminated with CO2 that is partially formed by the decarboxylation of deposited organic matter. Combined with the results of other geochemical studies, we conclude that the ore-forming fluids of these deposits are closely related to the evolution of sediments in the basin and are likely to be derived from the basin-origin fluids that are complicated by the complex sediments.