次生石英岩型非金属矿床蚀变建造的矿物学研究

本文总结了火山成因的次生石英岩型非金属矿床中蚀变矿物的共生组合类型及在空间上的分带,主要蚀变矿物的矿物学特征(包括标型特征)及其形成与转变;指出这些特征和转变在不同方面指示成矿原岩性质,矿床形成温度,成矿溶液物化条件的变化过程。

STUDY ON ALTERATION MINERALS IN SECONDARY QUARTZITE TYPE OF NON-METALLIC DEPOSITS

There are over 45 alteration minerals in secondary quartzite type non-metallic deposits, but only 11 minerals (secondary quartz, illite, kaolinite, dickite, alunite, pyrophyllite, diaspora, andalusite, corundum, pyrite, rutile and others) can be enriched to form ore deposits. In secondary quartzite body, Al-rich alteration minerals can form a series of alteration mineral associations because of temperature gradient and other factors. The zonations of alteration mineral phases in space mainly have three types: a. vertical zonation produced by high, medium, and low-temperature Al-rich alteration minerals in the center of volcanic edifice, b.symmetrial flank zonation composed of medium, and medium-low-temperature Al-rich alteration minerals near ring fractures of volcanic edifice, c. unsymmetrial flank zonation developed by medium-low-temperature alteration minerals in periphery of resurgent volcanic dome. It is shown that the typomorphic features of main alteration minerals have practical signifcance in reflecting forming-temperature, sources of ore-forming materials, properties of primary rocks and genesis of ore deposits. The alteration minerals are mainly formed by replacing feldspar, glassic components and minor dark minerals of intermediate-acidic volcanic complex. When T, pH, Eh, fo2 and others are changed in medium solution, corundum, andalusite and diaspore will take place degressive alteration (replaced by medium, and medium-low-temperature Al-rich minerals). and medium-low-temperature alteration minerals will replace mutually.