河南万家楼矿区综合地球物理特征及找矿方向

Comprehensive geophysical characteristics and prospecting direction of Wanjialou mining area in Henan province

河南万家楼矿区位于东秦岭-大别造山带中段,平天贩韧性剪切带两侧,在中生代伸展拉张构造环境和灵山岩体深部熔浆流体顶托的共同作用下,早期的构造软弱带为含矿熔浆-流体的溢出提供了通道,在温度、压力等急剧变化的混沌边界形成破碎带蚀变岩型、接触带型矿床和斑岩型类矿床。高温流体携带的铁磁性矿物及其热冷却过程中的剩磁,为磁测在宏观上判别有利成矿的构造活动带提供了物性基础;EH4连续电导率剖面仪在探测地质构造和区分电阻率不大的地层中具有较高的分辨率,可进一步验证、指示深部隐伏岩体分布及侵入机制。这里根据地面高精度磁测和EH4电磁测深反演结果,对矿区内的电、磁异常进行了综合研究,在透岩浆流体成矿理论框架下,探讨了本区的成矿模式和找矿方向,并成功圈定出找矿靶区,为下一步该地区相同成矿地质条件下的找矿应用提供了重要参考。

Wanjialou mining area in Henan province is located in the middle section of the East Qinling-Dabie orogenic belt,which is on both sides of the Pingtianfan ductile shear zone.Under the joint action of the Mesozoic extensional tectonic setting and the deep magmatic fluid support of the Lingshan rock mass,the early structure weak zone provides a channel for the overflow of the ore-melting-fluid,forming broken belt altered rock type,contact belt type as well as porphyry type deposit in the chaotic boundary with sharp changes of temperature and pressure.Ferromagnetic minerals carried by high-temperature fluids and remanence during thermal cooling provide a physical basis for magnetic surveying to determine the favorable tectonic activity belts in the macroscopic.EH4 continuous conductivity profiler has high resolution in detecting geological structures and distinguishing formations with low resistivity.This can further verify and indicate the distribution and intrusion mechanism of deep concealed rock masses.Based on the ground high-precision magnetic survey and EH4 electromagnetic sounding inversion results,a comprehensive study on electrical and magnetic anomalies in the mining area was carried out.Finally,under the framework of permeable magmatic fluid mineralization theory,the discussion of the metallogenic model and prospecting direction,successfully identified the ore-forming target of Wanjialou mining area.It provides an important reference for the prospecting application under the same metallogenic geological conditions in the next step.