摘要
我国内生金矿成因类型主要有变质热液型、岩浆热液(交代-重熔岩浆)型、火山热液型和渗滤热液型四种.我国内生金矿的成矿作用特点:①对老变质岩系有明显的依存性.金矿化具有明显的地域性;②具有交代-重熔岩浆成矿作用的独特性;③具有成矿作用的多阶段性和不同形式金矿化(充填石英脉和细脉浸染型)的垂直分带性;④具有钾长石化交代蚀变作用的广泛性;⑤具有矿源层-重熔花岗岩浆作用,韧脆性断裂构造三位一体联合控矿特点.今后应当在矿源层的地球化学特征和微量金的赋存状态方面;在解决古老矿源层与新成矿时代的时间差的成矿机理研究方面;在花岗状岩石成岩作用特点与金成矿作用之间的成因联系方面;在郯庐断裂带成生特征对我国东部地区金矿分布格局的控制作用等方面进行较深入的研究,不断建立和发展我国金矿成矿理论.
There are four Main genetic types of gold deposit in eastern China, namely metamorphic-hydrothermal, magma-hydrothermal, volcano-hydrothermal and infiltration-hydrothermal types. Among them, the major deposit of the magma-hydrothermal type is metasomatic-anatectic magma-hydrothermal-deposit.
In eastern China, vein-like and veinlet-dissemination gold deposits are mainly distributed in grano-greenstone area and upwarped district of folded area in North China platform. They are characterised mainly by 1, distinct dependence on ancient metamorphic rocks with common host rocks of amphibolite and biotite-amphibole gneiss of high amphibolite facies, 2. most deposits related with autochthonous or para-autochthonous metasomatic-anatectic magmatism, 3. vertical zonation of various gold mineralization and multiple minerogenesis, 4. widespread metasomatism of K-feldsparizaion and 5. ore-controlling of ore-source bed-granitic magmatic activity-faults in 'three to one', combination.
The following problems should be solved in future. 1. Thorough study of ore-source bed. The especial attention should be paied to occurrence of gold in ore-source bed and later geological reformation, which is an important factor to activate and migrate gold from ore-source bed. 2. Study of minerogenetic time.In the present, isotopic datings show the major minerogenectic stage of gold deposits in China is Mesozoic. How did Mesozoic geologic process lead the migration of gold from ancient ore-source bed ? Attention should be paied to study of faulting metamorphism and its evolution.3.The formation of granitoid rocks. It is probable that metasomatic-anatectic magmatism is the major power of gold minerogenesis in China. And 4. the significant gold minerogenetic areas are all distributed in the both sides of Tancheng-Lujiang fault. Therefore, it is important to study the controlling of this great fault to gold deposits in eastern China and the controlling of ancient E-W faults intersecting with the Tancheng-Lujiang fault to gold prospect areas.
关键词
变质岩
金矿床
成矿作用
mctamorphic rocks area endogenetic gold deposit
