甘肃阳山金矿带构造控矿机理探讨--来自方解石红色环带研究的证据

阳山金矿带内主要容矿岩石为泥盆系灰岩、千枚岩，灰岩裂隙中常发育晶形完好的方解石（冰洲石）晶簇，方解石晶体中发育明显的红色环带，利用扫描电镜及X-射线能谱成份分析结果显示红色环带方解石含微量的锰和铁，推断致色离子为Mn2＋，和Fe3＋；而Fe3＋的存在指示环带生长于金矿的主成矿期；颜色交替环带状结构发育，指示主成矿阶段流体系统进入到温度周期性升降、压力逐渐释放的开放环境。

A probe into structural ore-control mechanism in the Yangshan gold ore belt in Gansu,evidence from calcite red girdle study

Major ore-bearing rocks are Devonian limestone and phyllite in the Yangshan gold belt, and limestone frac- tures usually host calcite （Iceland spar） druses with well grown crystal forms. Red girdles are well developed in calcite crystals. SEM and X-ray energy spectrum analytical results indicated that red-girdle calcite contains trace Mn and Fe, and the color is presumably caused by Mn2＋ and Fe3＋,and Fe3＋ suggests that girdle grew in the prime gold mineraliza- tion period. The development of color alternation girdle texture shows that fluid system in the prime mineralization time goes into an open environment with periodic up and down of temperature and gradual release of pressure.