【摘要】 符山铁矿是所谓“邯邢式”铁矿中较典型的中等矿床,石榴子石作为主要的矽卡岩矿物,其成分变化较大,物理性质有较大差异,反映了形成时物理、化学条件的不同。本文对石榴子石进行了矿床矿物学研究,总结了该矿区石榴子石的特点及其变化规律,并讨论了不同石榴子石的形成条件以及和成矿的关系。更多还原

【Abstract】 The present paper makes a thorough investigation of the garnets from the Fushan deposit, whichis a typical one of what are generally thought to be skarn type iron deposits in North China. Thegarnets are mainly in the skarn, but some are also associated with dike syenite. Presented are thechemical analyese. microprobe analyses, infrared spectral data, Mossbauer spectra and homogenizationtemperatures. The garnets belong to the grandite series. The contents of andradite vary from almost 100% toless than 10%. The wave numbers of the major absorption bands in the infra-red spectrum varywith the percentage of andradite. Except two bands, there exist excellent linear relations between thewave number and the percentage of andradite for the other six major absorption bands. The twoexceptions are the 831--856cm^-1 and 883--915cm^-1 bands. The linear relation for the former isrelatively poor. For the latter, garnets rich in andradite show an excellent linear relation, but thoselack of andradite deviate quite a bit. The linear relations can be used to determine the compositionsof grandite garnets. Mossbauer spectra reveal that the colors of the garnets are connected with the valent states andstructural sites of Fe. Green garnets have only a Fe³⁺（Y） doublet. When a Fe²⁺（X） doubletappears, the garnets become red-brown or purple, the more the Fe²⁺（X） doublet appears, the garnetsbecome red-brown or purple, the more the Fe²⁺（X）, the darker the color. The Mossbauer spctrumof a melanite is complicated with four doublets. The dark color of melanite is proposed to beassociatcd with the interaction between Fe²⁺（X） and Fe³⁺（Z）. Because of the substitutionFe³⁺（Z）+Ti⁴⁺（Y） （ ? ） Si⁴⁺（Z）+M³⁺（Y）, more TiO₂ brings more Fe³⁺（Z）. So melanites getdarker with increasing TiO₂. The garnets are divided into six groups. They are different in composition and character and areformed at different stages. Their growth conditons are discussed. The purple garnet with strong zoning and strong birefringence is an indjcator of ore bodies.更多还原