福建马坑铁矿辉石的成因矿物学研究

On the Genetic Mineralogy of Pyroxenes from the Makeng Iron Ore-Deposit in Fujian Province

本文研究了福建马坑铁矿床中辉石族矿物的时空分布、产状、种属及其晶体形态标型、物理标型、化学成分标型。通过不同成因的辉石(308个不同成因辉石)化学成分标型对比、图解等综合判别方法确定马坑铁矿中辉石有火山岩变质、沉积变质、接触交代和岩浆四种成因。矿体底部成矿建造为富Fe、K、Mn火山岩建造,中下部为富F、Mn硅铁质沉积建造,上部为富Ca、Mg、Mn、Fe、Si碳酸盐沉积建造。马坑矿床主矿体为海底火山沉积变质型铁矿。提出利用辉石的种属、含铁系数、化学标型判断有无矿体及其贫富的矿物学标志。

This paper focuses on the time-space distribution, occurrence, genus, crystal typomorphic characteristics, and physicochemical composition typomorphic characteristics of the pyroxenes from the Makeng Iron Ore-deposit. Bases on the analysis results of chemic composition typomorphic characteristics of the pyroxenes (from 380 samples), it is inferred that the pyroxenes were formed by volcano-metamorphism, metagenesis, contact-metasomatism and magmatism. For the metallogenic formation, there are Fe, K, Mn-rich volcanic rock formation in the base of the orebody, Fe and Mn-rich silico-ferric sedimentary formation in the middlelower part of the orebody and Ca, Mg, Mn, Fe, Si-rich carbonate sedimentary formation in the upper part of the orebody. The major orehody of the Makeng Iron Ore-deposit is of the iron ores of the sub-marine volcano sedimentary-metamorphic type. The author presented herein a mineralogical indicator which can distinguish if there exist orebodies and the Fe concentration of the ores is higher or lower according to the genus, ferriferous coefficient and chemical typomorphic characteristics of the pyroxenes.