摘要
在众多关于黔滇桂微细浸染型（卡林型）金矿研究成果的基础上，本文通过本类型金矿含碳及有机质的特征；金能形成金属有机化合物及原子簇化合物的特征的研究。提出金以金属有机化合物形式在本区上二叠统富含生物成因有机质的煤系地层中形成预富集；在区域热变质作用中，金以气相金属有机化合物方式向上运移，蓄积在上二叠统至中三叠统各层位的背斜和穹隆部位；动力变质带的断裂活动引起物理化学突变，使金的气相金属有机化合物在构造断裂带解体、裂化从而形成了含细分散碳质的微细浸染型含金硫化物原生矿化；并探讨了主成矿期后与有机质解体有关的叠加热液活动和表生氧化作用对原生矿化的改造。
A number of Carlin type disseminated gold deposits occur in the gold mercury arsenic antimony thallium mineralized belt of the Guizhou Yunnan Guangxi triangular area On the basis of geology and experiments, this paper discussed the influence of carbonaceous and organic materials upon gold migration and deposition in these gold deposits The Upper Permian coal measure strata in this area were rich in biogenic organic materials, which might combine with such metallogenic elements as Au, Hg, Tl, As and Sb to form various types of complex organometallic compounds, thus resulting in pre enrichment of these metallogenic elements in the Upper Permian strata of this area Owing to high volatility the organogold compounds would migrate upward in the form of gaseous phase organogold compounds under the condition of regional thermometamorphism, collect in anticlines and domes of Upper Per mian to Middle Triassic strata, and usually permeate selectively among porous rocks dominated by siltstone Physical and chemical conditions changed abruptly during the fault movement which took place along the dynamic metamorphic belt, causing the resolution of gaseous phase organogold compounds Gold, together with arsenic, entered arsenopyrite and As bearing pyrite, accompanied by the cracking of organic ligand into dispersive carbon This was the main metallogenic epoch of gold deposits that formed fine disseminated carboniferous primary ores in the area Gold mainly existed in sulfide minerals in invisible negative charge state, with a small part absorbed by carbonaceous materials The disintegration product of organic materials, such as organic acid, H 2S, CO and CO 2, set off strong superimposed hydrothermal process after the main metallogenic epoch in the area Silicification and carbonatization, associated with cinnabaritization, antimonitization and realgaritization, were superimposed upon fine disseminated auriferous sulfide mineralization Limonitization and clayization in supergene leaching oxidation often further reformed the primary orebodies and formed oxidized orebodies in which gold mainly occurred as free and absorbed native gold This kind of ore is easy to be dressed
出处
《矿床地质》
CAS
CSCD
北大核心
1996年第3期193-206,共14页
Mineral Deposits
基金
国家计委国土司专项补助第30届国际地质大会科研项目
关键词
金矿床
成矿过程
微细浸染型
碳
有机质
Carlin type disseminated gold deposit, organometallic compound, gas phase migration, evolution of organic materials, metallogenic model
