河北省涉县符山铁矿石榴子石特征及其形成条件

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。

CHARACTERS AND GROWTH CONDITIONS OF GARNETS FROM FUSHAN IRON DEPOSIT, HEBEI PROVINCE

The present paper makes a thorough investigation of the garnets from the Fushan deposit, which is a typical one of what are generally thought to be skarn type iron deposits in North China. The garnets are mainly in the skarn, but some are also associated with dike syenite. Presented are the chemical analyese. microprobe analyses, infrared spectral data, Mossbauer spectra and homogenization temperatures. The garnets belong to the grandite series. The contents of andradite vary from almost 100% to less than 10%. The wave numbers of the major absorption bands in the infra-red spectrum vary with the percentage of andradite. Except two bands, there exist excellent linear relations between the wave number and the percentage of andradite for the other six major absorption bands. The two exceptions are the 831-856cm^-1 and 883-915cm^-1 bands. The linear relation for the former is relatively poor. For the latter, garnets rich in andradite show an excellent linear relation, but those lack of andradite deviate quite a bit. The linear relations can be used to determine the compositions of grandite garnets. Mossbauer spectra reveal that the colors of the garnets are connected with the valent states and structural sites of Fe.