A new coexisting amphibole pair was recently found in the Jianshan iron depeit,Loufan of Shanxi Province, China. Electron microprobe analysis shows that the coexisting pair is compeed of gfunerite K0.001 (Na0.027 Ca0....A new coexisting amphibole pair was recently found in the Jianshan iron depeit,Loufan of Shanxi Province, China. Electron microprobe analysis shows that the coexisting pair is compeed of gfunerite K0.001 (Na0.027 Ca0.073 Mn0.031 Fe)1.932 (Fd Mg1.964 Ti0.002Fe)2Si80.069 O22. 10 (OH )2 and ferropargasite (K0. 135 Na0.461 )0.596 (Na0.088 Ca1.853 Mn0.005Fe)2 (Mn0.005FeMg0.875 Ti0.021 Fe,Al0.812)5 (Si6.103A1. 897)8O22. 00 (OH)2. The two kinds of amphiboles occur in amphiboe schist not only as seParate phenocrySts, but also are combined to form "single-ccrystal" phenocrysts in the form of topotactic intergrowths with the common c- and b-axes. The forndary between topotactic gttinerite and ferropargaste is opti-cally and chemically sharp. In comparison with the coexisting fermmagnesan amphibole and calcic amphibole pair discovered by predecesors, the newy discovered pair has lowr Mg/Fe ratios and wider miscibility gaps.展开更多
文摘A new coexisting amphibole pair was recently found in the Jianshan iron depeit,Loufan of Shanxi Province, China. Electron microprobe analysis shows that the coexisting pair is compeed of gfunerite K0.001 (Na0.027 Ca0.073 Mn0.031 Fe)1.932 (Fd Mg1.964 Ti0.002Fe)2Si80.069 O22. 10 (OH )2 and ferropargasite (K0. 135 Na0.461 )0.596 (Na0.088 Ca1.853 Mn0.005Fe)2 (Mn0.005FeMg0.875 Ti0.021 Fe,Al0.812)5 (Si6.103A1. 897)8O22. 00 (OH)2. The two kinds of amphiboles occur in amphiboe schist not only as seParate phenocrySts, but also are combined to form "single-ccrystal" phenocrysts in the form of topotactic intergrowths with the common c- and b-axes. The forndary between topotactic gttinerite and ferropargaste is opti-cally and chemically sharp. In comparison with the coexisting fermmagnesan amphibole and calcic amphibole pair discovered by predecesors, the newy discovered pair has lowr Mg/Fe ratios and wider miscibility gaps.