The Discovery of Magnesioferrite from Au (Fe, Cu) Magnesian Skarn Deposits and Study of the Magnesioferrite-Magnesiomagnetite Series

作     者：ZHAO Yiming ZHANG Yinan BI Chengsi GUO Lihe 

作者机构：Institute of Mineral Deposits Chinese Academy of Geological Sciences 26 Baiwanzhuang Rd. Beijing 100037 

出 版 物：《Acta Geologica Sinica(English Edition)》 (地质学报（英文版）)

年 卷 期：1998年第72卷第4期

页      面：382-391页

核心收录：

学科分类：070902[理学-地球化学] 0709[理学-地质学] 07[理学] 

基　　金：This research was supported by the National Natural Science Foundation of China grant 49573184 

主　　题：magnesioferrite magnesiomagnetite Au (Fe Cu) magnesian skarn Anhui Shaanxi 

摘      要：Abstract: Magnesioferrite, a rare metasomatic mineral, was discovered for the first time in China from the Qinlou Au (Fe, Cu) magnesian skarn deposit, Sanpu, Huaibei, Auhui Province, and the Mulonggou Fe (Mo, Cu) magnesian skarn deposit, Luonan County, Shaanxi Province. In this paper, the geological setting, mineral associations, chemical composition, some physical properties, X-ray powder diffraction data and infrared spectroscopy of magnesioferrite and magnesiomagnetite are discussed. Magnesioferrite contains 17.66%–13.48% of MgO. Its main associated minerals are clinohumite, chondrodite, serpentine, calcite and magnesiomagnetite. The density of magnesioferrite is 4.537–4.720, reflectances in percent are: 17.8–18.1, hardness is 838–900 kg/mm2, and the cell parameter ao = 8.371–8.379 ?. A systematic study of the magnesioferrite-magnesiomagnetite-magnetite series suggests that along with the increase of magnesioferrite molecules in the mineral, the density, reflectances and cell parameters decrease correspondingly, the hardness heightens, and the infrared absorption spectral band becomes wider. The authors consider that magnesioferrite is a product of contact metasomatism between hypabyssal intermediate-acid intrusions and dolomitic marble. It was formed in shallow exocontact zones under relatively oxidized conditions.