摘要
宝兴厂斑岩铜钼金矿床是三江成矿带上与富碱斑岩有关的典型斑岩型矿床,产出于金沙江-哀牢山深大断裂带中部东侧。宝兴厂矿床铜、钼、金、铁等各类型矿化皆有发育,具有复杂的岩浆活动及热液演化。矿区岩浆岩主要为喜马拉雅期富碱复式岩体,包括正长斑岩、石英二长斑岩、花岗斑岩和斑状花岗岩等,具有多期次侵入特征。铜钼矿体主要分布于花岗斑岩和斑状花岗岩内部,铁金矿体主要分布于岩体内外接触带上,矿体呈脉状、透镜状或似层状。热液蚀变由内向外分带显著,依次为钾硅酸盐化（黑云母化）、绢云母化、青磐岩化（绿泥石-绿帘石化）,局部黏土化。本文通过系统的野外观测、详细的岩芯编录以及全面的岩相学观察,依据矿物共生组合、矿化热液脉体穿切关系及蚀变特征,将宝兴厂矿床内主要矿化脉体分为3类：A脉、B脉及D脉。通过对3类脉体内石英中流体包裹体的显微测温工作和成矿流体物理化学条件计算,剖析了成矿流体演化特征,探讨了成矿作用过程与成因机理。A脉与钾长石化和黑云母化蚀变关系密切,多为不规则脉状,宽约1~5mm,矿物组合一般为石英±钾长石±黑云母±少量黄铜矿±少量黄铁矿。石英多呈他形细粒,少量黄铁矿、黄铜矿沿石英颗粒边界呈浸染状产出。脉体中常含有黑云母、钾长石,两侧常见钾长石蚀变晕。A脉中一般没有矿化。B脉宽约15~30mm,矿物组合一般为：石英±辉钼矿±黄铜矿±黄铁矿。靠近脉壁的石英多为他形细粒,向中心转变为长柱状垂直于脉壁对称生长。硫化物呈线状分布于脉体的中心或边缘。B脉一般没有蚀变,偶见少量的绿帘石化-绿泥石化。D脉与绿泥石化-绢云母化关系密切,脉体规则连续,脉体宽度变化范围大,为1~30mm。矿物组合一般为石英±绿泥石±黄铁矿±少量黄铜矿。石英数量较少,多呈半自形-他形
The Baoxingchang Cu-Mo-Au deposit, tectonically occurring in the east-central part of the Jinshajiang-Ailaoshan suture zone, is one of the typical alkali-rich porphyry deposits in the Sanjiang metallogenic belt. The Cu, Mo, Au and Fe are lhe principal ore-metals developed commonly in the Baoxingchang deposit. Igneous rocks are mainly comprised of Himalayan alkali-rich complex, including syenitic porphyry, quartz monzonite porphyry, and porphyritic granite. Most Cu-Mo orebodies occur within the granitic rocks, while the Fe-Au orebodies distribute along the interface between the granitic rocks and sedimentary rocks, and also these orebodies occur mainly as vein-, lens- and stratoid-shape. Based on the field observation, hydrothermal alteration can be divided into four zones, zoning from proximal to distal as potassium-silicification （biotitization） zone, locally clayization zone, sericitization zone and propylitization zone. Three main types of hydrothermal veins have been identified： A-type, B-type and D-type veins based on its mineral assemblages, cutting relationship and alteration features. A-type veins with width of 1 ~ 5mm, occurred as irregular shape, are characterized by biotitization, K-feldsparization, and weak mineralization. Quartz, K-feldspar, biotite, less chalcopyrite and pyrite are the major mineral assemblages in this type of vein. Besides, K-feldspar alteration halo is commonly observed on both sides of A-type veins. B-type veins with a width of 15 -30mm, having cut through the A-type veins, have a straight contact with the wall rocks and no alteration halos were observed beside them. Mineral assemblages are mainly quartz, molybdenite, chalcopyrite and pyrite. Quartz developing close to the edge of veins are fined-grained and anhedral, and elongated and symmetrically grow vertically to vein-wall in the center of veins, while the sulfides are hnearly distributed in the center or edge of veins. D-type veins varying from 1 ~ 30mm in width and cutting through the earlier ore veins, are character
出处
《岩石学报》
SCIE
EI
CAS
CSCD
北大核心
2014年第9期2644-2656,共13页
Acta Petrologica Sinica
基金
国家重点基础研究发展规划(2009CB421008)
北京市优秀博士学位论文指导老师科研项目(20111141501)
中国地质调查局地质调查项目(12120114013501)
高等学校学科创新引智计划(B07011)联合资助
关键词
斑岩铜钼金矿床
矿化脉体
流体包裹体
宝兴厂
滇西
Porphyry Cu-Mo-Au deposit
Mineralized veins
Fluid inclusions
Baoxingehang deposit
Western Yunnan
