论与斑岩矿床有关的矿化角砾岩成因类型及其地质意义

伴随有各类矿化角砾岩的斑岩矿床是深成源岩在浅成-超浅成条件下侵位-矿化的产物。本文详细阐述了与斑岩矿床有关的各类矿化角砾岩的地质特征、成因分类和识别标志,并从中国独特的构造环境出发,对与矿化角砾岩有关的各种地质现象作了初步剖析,指出矿化角砾岩的形成从根本上讲是深成岩浆侵位的多旋回性造成的,以岩浆水为主体的热流体是含矿斑岩体系从封闭环境转为开放环境的主要动力条件。因此,矿化角砾岩不仅是金属元素的原始富集条件,而且是重要的找矿标志之一。我国与斑岩矿床有关的矿化角砾岩的主要成因类型为爆破角砾岩、侵入角砾岩、火山角砾岩等。多种角砾岩的叠加现象十分明显,热液交代角砾岩的叠加作用为矿化过程的指示标志.

On The Genetic Classification Of Mineralized Breccias Related To Porphyry Deposits And Its Geological Significance

Porphyry deposits associated with various mineralized breceias result from the emplacement and mineralization of the hypogene magma under the hypergene-upperhypergene conditions. In this paper, geological characteristics, genetic classification and recognition indicators of the mineralized breccia related to porphyry deposits are discussed in detail, and some geological features having to do with the mineralized breccia are tentatively analysed in the light of the specific tectonic setting of China. It is considered that the mineralized breccias were formed fundamentally as a result of the polycyclic emplacement of the hypogene magma, and that the thermal fluids with the magmatic water as the main component seem to be the main dynamic condition for the conversion of the ore-bearing porphyry system from a confined environment to an open environment. Thus, the existence of mineralized breccias acts not only as the initial concentration condition of metallic elements but also as one of the important ore prospecting indicators. There are three genetic types of mineralized breccia related to porphyry deposits in China, i.e. explosive, intrusive and volcanic breccia. The superposition of various breccias is quite odvious, and the superposed hydrothermal metasomatic breccia serves commonly as an important indicator of the ore-forming process.