华北陆块东段常发沟斑岩铜矿的成矿地质过程与成矿模式

The Changfagou Cu deposit, as a medium-scale porphyry Cu deposit discovered in the eastern North China craton. However, previous studies on the deposit are relatively poor. There are some doubts about the deposit, such as the character and evolution of ore-forming fluid and source of ore-forming fluid. So in order to provide a basis for recognition of these problems, we chose Changfagou Cu deposit as research object. Based on the field and indoor work, we plan use the cathodoluminescence technologies analysis the quartz, used routine techniques, we test temperature, salinity of the fluid inclusions in the quartz phenocryst of the ore-related porphyry,“quartz eyes”/comb quartz, different veins, quartz of different mineralization stage, and carry out EPMA, H-O isotopic analysis of magmatic mineral and altered minerals of different mineralization stage. Combined the test results, we hope can inverting the evolving processes of magma and ore-forming fluid, confirm the source of ore-forming fluid. Based on the above studies, the comparison with those of the same type abroad, build a metallogenic model of the porphyry Cu deposit, which provides theoretical basis for the exploration and the mineral resource prediction.

常发沟矿床为华北陆块东段新近探明的一座中型斑岩铜矿床。但该矿床研究程度较低，矿床成矿流体性质与演化特征、成矿流体来源等科学问题尚未理清。本申请拟以常发沟铜矿床为解剖对象，在详尽的野外和室内工作基础上，运用阴极发光对石英矿物进行研究；利用包裹体常规技术对成矿斑岩石英斑晶、“石英眼”/梳状石英、不同脉系及不同成矿阶段石英的流体包裹体进行温度、盐度测试；对不同阶段岩浆矿物、蚀变矿物进行电子探针及氢-氧同位素测试，为反演常发沟铜矿床岩浆-流体演化过程，查明成矿流体来源提供科学依据。在上述研究基础上，与国内外同类研究作对比，建立适于该区斑岩铜矿的成矿模式，该研究成果将为区域同类型矿床的找矿勘查工作和矿产资源预测提供理论依据。

常发沟矿床为华北陆块东段新近探明的一座中型斑岩铜矿床。但该矿床研究程度较低，矿床成矿流体性质与演化特征、成矿流体来源等科学问题尚未理清。本项目围绕矿床开展矿床地质特征、流体演化、成矿物质来源等关键科学问题进行研究。通过野外地质特征、矿相学、矿物穿插关系等证据，将成矿过程划分为4个阶段：石英-黄铁矿阶段；石英-辉钼矿阶段；石英-多金属硫化物阶段；石英-碳酸盐阶段；通过不同阶段矿物流体包裹体温度和成分、H-O同位素，含矿斑岩和硫化物S-Pb同位素研究，厘定成矿流体为高温高盐度流体，总体属于H2O–NaCl–CO2体系，早期成矿流体以岩浆水为主，后期有大气降水加入。查明了成矿物质来源为地幔和地壳的混合源。流体沸腾作用是常发沟铜矿床成矿的重要机制。与朝鲜及邻区铜矿对比研究，结果表明中朝边界铜矿成岩成矿均发生在早白垩世，成岩成矿作用与古太平洋俯冲板块后撤密切相关。