熊耳山矿集区金矿控矿地质要素分析

本文统计了豫西熊耳山地区53个金矿床(点),编绘了熊耳山地区金矿床分布图。系统的野外矿床地质观察以及熊耳山地区矿床分布图都显示,该区金矿的主要控矿要素为太华群变质结晶基底、北西向和北东向断裂构造,以及燕山期酸性侵入岩。太华群处于熊耳山核部,南北两侧以不整合接触带分别与熊耳群及新生代地层相拆离。矿集区45%的金矿床分布于太华群内,从鲁山、熊耳山到小秦岭,金矿化程度增强,而太华群中的金丰度依次降底,显示太华群提供了部分成矿物质。近东西向马超营断裂为熊耳山地区一级构造单元,其北侧发育一系列北东向次级断层。区内金矿床主要分布于马超营断裂以北,明显沿北东向断层成带分布,且矿床的控矿构造也呈北东向,暗示了北东向断层的控矿特征。研究区内发育有花山、五丈山、合峪、太山庙等大花岗岩体和大量石英斑岩脉和花岗斑岩岩脉。花山岩体和五丈山岩体与地层外接触带是控制金矿床产出重要区域,36%的金矿床产出于岩体附近或角砾岩体内,小型岩脉则广泛发育于各金矿床内。本区1∶20万区域化探金含量存在七个异常区,分别与该区金矿床集中分布区相吻合。

Ore-controlling Geological Factors of Gold Deposits in the Xiong’ershan Region,Western Henan Province

This study sorted out 53 gold deposits in the Xiong’ershan region,and drew a geological map showing the distribution of the main gold deposits.Systematic field investigation and deposit distribution map suggest that the Taihua Group metamorphic basement,NW and NE trending faults and the Yanshanian period magma activities are the major ore-controlling factors for the gold deposits in this area.The Taihua Group is situated in the core of the Xiong’ershan Mountains,which is detached from the Xiong’er Group and Cenozoic strata on the south and north sides by unconformity contact zones.About 45% of the gold deposits are hosted in the Taihua Group metamorphic basement.From the Lushan,Xiong’ershan to Xiaoqinling,the gold mineralization increased,while the gold abundance decreased in the Taihua Group.These characteristics imply that the Taihua Group offered some ore-forming materials for the gold deposits in the Xiong’ershan region.The nearly EW-trending Machaoying fault is the first-order tectonic unit in the Xiong’ershan area,and there are several nearly paralleled NE-trending subordinate faults north of the Machaoying fault.Almost all of the gold deposits in this area are located to the north of the Machaoying fault,and are distributed along the NE-trending subordinate faults.Additionally,the NE-trending faults play a key role in lots of gold deposits.Intense intermediate-acidic magmatic activities in the Xiong’ershan region formed the Huashan granitic pluton,Wuzhangshan granitic pluton,Heyu granitic pluton,Taishanmiao granitic pluton,and many small quartz porphyry veins and k-feldspar granite veins in this area.Inside and outside the contact zones of these granitic plutons are significant areas for gold deposits,and small veins are developed in the gold deposits.Statistic results suggest that 36% of the gold deposits are located in the contact zones.Moreover,gold geochemical surveys at a scale of 1:200000 indicate that there are 7 gold anomaly-concentrating areas in the Xiong’ershan region,which coincide with the specific gold concentration areas,respectively.