小秦岭金矿田Q240控矿构造特征及深部成矿预测

摘要

The research on structure and mineralization alteration of Q240 vein in Xiaoqinling gold deposit indicates that the vein undergoes multi-stage tectonic activity transformation. In the early stage, structural belt undergone mainly left-lateral brittle ductile shear deformation, and developed NW-trending quartz vein with the structure lineation plunging toward SW. Mineralization of the vein was characterized by the rich pyrite with a strip distribution. While the later right-lateral brittle ductile shear deformation formed the NEE-trending pyrite quartz vein. By analyzing the change characteristics of three orebodies in the plane, we know that the vein is constructed by multi-superimposed tectonic hydrothermal activity and the main structure is associated with the left-lateral shear deformation, and later suffered the right-lateral deformation. The NEE-trending structure plane forms a space for mineralization. Combined with stress environment, ore control regularity and orebody lateral characteristics, we get that the ore body appear equidistant regularity in the strike and dip based on the structure alteration. According to the research, we predict three mineralization targets in the deep of Q240 vein.%对小秦岭金矿田Q240号矿脉进行构造与矿化蚀变特征分析研究，结果表明该脉体经历了多期构造活动改造。构造带早期以左行脆韧性剪切变形为主，发育北西走向石英脉，其构造线理倾伏向南西，石英脉中矿化特征以黄铁矿为主，呈条带状分布；而后期右行脆韧性剪切变形则形成北东东走向的黄铁矿石英脉。对3个矿体平面上变化特征的分析表明，矿体被多期构造-热液活动叠加，主成矿构造应该与北东走向的左行剪切变形相关，并在后期遭受了右行走滑变形改造，以北东东走向的缓倾结构面为容矿空间。结合应力环境和控矿规律以及矿体侧伏特征，依据构造蚀变特征，认为矿体在走向和倾向上均有似等距规律。据此，在Q240矿脉深部圈定出3处成矿靶区。