【摘要】 <正> 新桥铜矿是一个黄铁矿型铜矿床。六十年代初期就已经开始对它进行地质勘探,但在矿床成因上至今仍有不同看法。 近年来,作者等对该矿床和相邻矿区进行了一定的工作,特别是通过矿相鉴定和矿石物质组分的研究,获得了若干资料。本文就矿石结构、构造特征所提供的若干佐证,试对矿床的成因作一讨论。更多还原

【Abstract】 Based on the available informations on the features of ore structure and composition, the paper discusses the genesis of the pyritic copper deposits of Xinqiao region and its neibouring areas.1 . On the basis of the ore body occurance and its relation to the ore-bearing strata, trace element geochemistry and ore structures, the stratified ore body, which mainly consists of pyrite, is considered to be related to the sedimentation process. Laminated ( plicated ) structures are widely distributed, spherulite-like and concentric zonal structure have also been observed.2 . In the stratified ore bodies the contents of Co and Ni in pyrite are relatively low, Co/Ni< 1 . The contents of V2O5 and TiO2 in magnetite are lower than those in postmagmatic hydrothermal deposits.3 . The magnetite, which appeared in the stratified orebody and contact with igneous rocks, possesses hypidiomorphic crystalloblastic texture. The sedimentary siderite and its blastoolitic texture, which survived after the metamorphism, can be seen in the magnetite on the polished sections when it have eroded by HC1 acid. The transformation from the oolitic texture to the crystablastic and the change of mineral phases from siderite to magnetite reveal that these deposiits have subjected to reconstruction after the formation of the stratified orebody.4 . The quartz diorite stock cut across the stratified orebody and small vein-like orebodies occur in the intrusive contact zone. The copper contents in the orebodies increase as close to the quartz diorite stock. Authors suggest that these deposits are genetically related to the sedimentation-reconstruction type.更多还原