福建漳州复式岩体磁铁矿的成因矿物学特征

Study on the Genetic Mineralogy of Magnetites from the Zhangzhou Complex Massif in Fujian Province

漳州花岗岩岩基共分两期七次(Ⅰ-Ⅶ)侵入,是中国东南沿海燕山晚期有代表性的大型复式岩体。笔者对区内各类花岗岩磁铁矿作了较深入的矿物学工作,包括晶出产状、晶体形态、X射线衍射、红外谱学、化学成分及稀土元素地球化学等方面的研究。本文重点论述磁铁矿的标型特征及成因意义,并提出区分不同成因花岗岩类岩石磁铁矿矿物学的判别标志,结合副矿物组合及岩石化学特点,对区内早、晚两期花岗岩类的成因分别判别为I型和A型花岗岩。

The Zhangzhou granitic batholith, in which two stages and seven times of intrusions took place, is a large-scale complex massif of late Yanshanian along the coast of Southeast China. The authors made a through study on the mineralogy of magnetites from different kinds of granites in the surveyed area, including the studies of crystallization occurrence, crystal morphology, X-ray diffraction, infarred spectroscopy, chemical composition and REE geochemistry and so on. We have a discussion on the typomorphic characteristics and genetic implication of magnetites and present a mineralogical distiguishing mark of magnetites from the different kinds of granites. Finally, combined with the characteristics of the accessory mineral assemblages and pertrochemistry, it is concluded that the early and late Cretaceous granites in the surveyed area belong separatively to the I-type and A-type granites.