青田县石平川钼矿围岩蚀变及其矿化特征研究

Study of the wallrock alteration and mineralization characteristics of Shipingchuan Mo deposit in Qingtian County,Zhejiang Province

浙江省石平川钼矿位于浙江东南沿海火山活动带。研究表明石平川钼矿应为典型的石英脉型钼矿;发育的蚀变类型主要有钾长石化、绢英岩化、青磐岩化(绿泥石化和绿帘石化)、泥化及碳酸盐化。其成矿阶段包括成矿早期的钾长石化阶段、硅化辉钼矿化阶段以及绢英黄铁矿化阶段。石平川钼矿矿化应始于钾长石化阶段的晚期,此时辉钼矿以浸染状形式发育;硅化辉钼矿化阶段是辉钼矿沉淀的主要阶段,此阶段辉钼矿主要以鳞片状和脉状发育于脉体中;绢英黄铁矿化阶段贡献了部分的钼,此时钼以浸染状、细脉状及网脉状发育于裂隙及早期的绢英岩化脉体内。硅化辉钼矿化阶段脉体与绢英黄铁矿化脉体的分布区域与矿体分布区域一致,表明这两个阶段贡献了石平川矿区绝大部分的钼的矿化。

The Shipingchuan Mo deposit is located in the coastal volcanic active zone within the southeast of Zhejiang Province.The research indicates that it is belonged to the typical quartz-vein type molybdenum deposit with the main wallrock alteration types of potash feldspathization,beresitization,propylitization（chloritization and epidotisation）,mudding and carbonation.The mineralization phase includes the early mineralization stages of potassium feldspathization,molybdenite silication and beresitization mineralization.The Mo mineralization should begin at the late period of the potassium mineralization stage in Shipingchuan deposit.Molybdenum minerals are developed in the disseminated form.The molybdenum silication mineralization stage is the main formation phase of molybdenite,which is mainly in the vein body as scale and vein shape.A part of molybdenum is contributed in the beresitization mineralization stage.The molybdenum minerals are developed as small and net veins,disseminated form in the fractures and beresitization veins.The distribution area of veins in molybdenite silication and beresitization mineralization stages is consistent with that of ore bodies.It is indicated that the molybdenum minerals are mainly formed in these two stages in Shipingchuan mining area.