海南儋州文溪坡钨多金属矿段裂隙构造与钨富集成矿关系

Relationship Between Fracture Structure and Enrichment of Tungsten Mineralization, Danzhou Wenxipo, Hainan Province, China

通过裂隙统计和测量,分析裂隙充填物等裂隙岩相学特征,探讨裂隙构造与钨富集成矿关系。研究认为,本区裂隙分为4期,裂隙倾角(中轴夹角)分别为9°、29°、47°、69°。白钨矿主要赋存在层间裂隙中,其细脉倾角在45°左右,与地层构造变形面理大致相同,部分白钨矿细脉赋存在穿层裂隙组中,细脉倾角在60°左右。白钨矿富矿体和裂隙储矿空间受黑云母闪长岩侵入岩体控制较为明显,在黑云母闪长岩侵入岩体附近,碎裂岩化相较为强烈,平均裂隙密度达到35条/m,局部裂隙密度最高可达110条/m,白钨矿富集在黑云母闪长岩体的外接触带;裂隙充填物类型包括高温到低温矿物,其特征表明裂隙充填物具有多期次形成的特征;白钨矿富集成矿主要与电气石化和硅化密切相关,推测白钨矿富集成矿主要受黑云母闪长岩有关的岩浆热液成矿作用和裂隙密度大小耦合关系控制,本矿区新发现的钨矿具有较好找矿前景。

In this paper, relationships between fracture and mineralization regularity of tungsten were discussed. The petrographic study with statistics and fracture measuring, fissure fillings, suggests that fractures angle in this study area might be divided into four groups, i.e., 9°, 29°,47°, and 69°, respectively. The scheelite mainly occurs in the interlayer-fracture; the inclination of scheelite stringer is about 45°, which is roughly the same as stratigraphic tectonic deformation foliation, and part of scheelite stringer occurred instrata penetration fissure in the group. Rich scheelite orebody and fractured ore space controlled by biotite diorite intrusive obviously; cataclastic lithification is relatively strong near the biotite diorite intrusion, and fracture density reached 35 m-1 on average. The local fracture density can reach up to 110 m-1, and the white tungsten deposited in the outer contact zone of the biotite diorite. Filling types and characteristics of fracture show that the fracture fillings have multiphase characteristics; fissure fillings include high temperature to low temperature minerals. Microscopic identification results show that the enrichment and mineralization of scheelite are mainly related to tourmalinization and silicification closely, speculated that the enrichment and mineralization of scheelite mainly related to the magmatic hydrothermal mineralization of biotite diorite and fracture density. The discovery of tungsten ore has a large prospecting potential.