鲁西金矿成矿组分的聚集与演化

在地质研究的基础上 ,以统计分析为主要手段 ,通过对鲁西隆起区太古宙地层、中生代岩体以及不同时代金矿床化学组成的研究 ,探索了成矿组分的可能来源、演化和聚集趋势 ,提出了矿源层 (岩 )中元素成矿活度的概念及定量计算方法 .研究表明 :(1)在鲁西隆起区 ,金的初始矿源是太古宙绿岩带 ,金在其中具有双成分分布 ;(2 )从太古宙至中生代 ,虽然成矿时代不同 ,成矿作用各异 ,但各类金矿床在成矿组分上对含矿建造具有明显的继承性 ;(3)含矿建造中成矿组分超量点群与其背景点群的比例以及超量点群中成矿组分的平均质量分数在很大程度上决定了其后生热液矿床的成矿特征 .

ACCUMULATION AND EVOLUTION OF ORE-FORMING COMPOSITION OF GOLD DEPOSITS IN THE WESTERN SHANDONG UPLIFT TERRAIN

This paper addresses the possible source, evolution and accumulation patterns of the ore-forming compositions, on the basis of the geological research, the statistical analysis, and the research into the Archean strata, the Mesozoic intrusive complexes and the chemical composition of gold deposits in different ages in the western Shandong uplift terrain. Then this paper suggests the concept of and the quantitative calculation method for the ore-forming activity of the elements in the mineralized source beds (rocks). The research shows the following three points: (1) In the western Shandong uplift terrain, the initial source of the gold is the Archean greenstone belts characterized by the bimodal gold distribution. (2) A conspicuous inheritance can be observed on the ore-bearing formation in terms of the mineralized compositions of different kinds of gold deposits despite of the different ages and different mineralizations from the Archean to the Mesozoic. (3) The characteristics of epigenetic hydrothermal deposits are determined to a great extent by the ratio between the excessive population of mineralized elements and its corresponding background population in the ore-bearing formation, and also by the average content of mineralized elements in the excessive population.