云南镇沅老王寨金矿床地质特征及成因探讨

作为哀牢山金矿带北段的典型矿床,老王寨金矿床空间上位于北西向脆韧性剪切带与东西向逆冲脆韧性剪切带交汇部位,北西向脆韧性剪切带、不同时代的中酸性浅成侵入体、基性和超基性岩侵入体以及哀牢山群变质岩系与金矿体具有密切的时空及成因联系。矿石中石英的流体包裹体分析表明,金矿的成矿流体主要为中低温、低盐度的NaCl-H2O体系。结合同位素、成岩成矿年代的研究认为,成矿物质及成矿流体均主要来自深部的上地幔或下地壳,金的大规模成矿与喜山期深部岩浆作用密切相关。

Geological features and genesis of Laowangzhai gold deposit in Zhenyuan county, Yunnan

As a typical deposit in the northern Ailaoshan gold metallogenetic belt,the Laowangzhai gold deposit locates in the junction site of the NW brittle-ductile shearing belt and E-W thrusting brittle-ductile shearing belt.The NW brittle-ductile shearing belt,middle-acid intrusions and basicty-ultrabasic rocks intrusions as well as the metamorphic rocks are closely related to the formation of the deposit in both space and time.The analysis on fluid inclusions in the quartz from the gold ore indicates that the ore-forming fluid belongs to the NaCl-H2O system with low-middle temperature and low salinity.Isotopic element analysis and geochronology suggest that both ore-forming materials and fluids mainly derived from the upper mantle or lower crust.Deep magmatism in the Himalaya period played an important role in the gold mineralization in this area.