辽宁牧牛钨矿矿床成因分析

Genesis analysis of the Muniu tungsten deposit,Liaoning

牧牛钨矿的形成受断裂构造和北西向韧性剪切带控制,空间上表现为北西张开南东收敛。在牧牛钨矿区内先后发现了5条含矿石英脉,对其中的Ⅰ号和Ⅱ号含矿石英脉进行地质特征研究,发现Ⅰ号与Ⅱ号含矿石英脉都赋存于里尔峪组地层中,同受北西断裂构造控制,围岩蚀变与矿石类型具有一致性,认为Ⅰ号与Ⅱ号含矿石英脉形成于同一成矿期。对区内的花岗岩和矿体进行稀土元素分析,发现角闪花岗岩、似斑状花岗岩与Ⅰ号和Ⅱ号矿体的形成有关。通过对含钨石英脉包体测温,其成矿温度为275~425℃,得出该矿床为中—高温热液矿床。

The formation of Muniu tungsten deposit is controlled by fracture structures and NW- trending ductile shear zone; In space,the fractures open in the northwestern end and converge in the southeastern end. In the deposit area,five quartz veins containing tungsten mineralization were found. The paper carried out the geological study on No. Ⅰ and No. Ⅱ tungsten- bearing quartz veins,the result indicates that both of them occur in the Lieryu Group stratum and are controlled by fracture structures,the wall rock alteration is consistent with ore types. They were formed in the same geological period. Based on analysis of rare earth elements in the granite and orebody,it is concluded that the tungsten mineralization of No. Ⅰ and No. Ⅱ orebodies are associated with hornblende granite and porphyritic granite intrusions. By the measurement of fluid inclusion temperature in the quartz veins,it shows that the metallogenic temperature of the deposit is between 275℃ and 400℃. The conclusion is that the Muniu tungsten deposit is a mesothermal- hypothermal deposit.