同构造隐伏花岗岩体及其热液成矿系统——以河南省熊耳山铁炉坪银多金属矿田为例

Syntectonic Concealed Granite Bodies and Their Hydrothermal Ore-Forming Systems:A Case Study of the Xiong'ershan Tieluping Silver Polymetallic Ore Field

以位于华北克拉通南缘的河南省熊耳山铁炉坪银多金属矿田为研究对象,通过对区内地质构造、成矿作用、物化探资料、遥感影像等综合研究,发现该矿田是一个与同构造隐伏花岗岩体有关的岩浆热液成矿系统。推测该隐伏岩体为一个东宽西窄、东厚西薄的“鞋底”状花岗质岩席,其总体空间形态与熊耳山变质核杂岩下盘的东向运动学方向密切相关。高位岩浆房的主体(隐伏岩体厚大部分)定位于故县水库以东地带。区内已发现的银、金多金属矿床主要是隐伏岩体东部主体顶上带外缘区定位的中温热液脉状矿化。推测在隐伏岩体顶上带的中南部还有三个隐伏岩钟发育部位,正是岩浆热液二次沸腾核心区域,因而是形成高温的斑岩型铜钼矿或隐爆角砾岩型钼金矿的最有利区段。

Taking the Xiong'ershan Tieluping silver polymetallic ore field on the southern edge of the North China Craton as the research object,this work conducted comprehensive research on geological structure,mineralization,physical and chemical exploration data,remote sensing images in the area.It is determined that the ore field is a magmatic hydrothermal mineralization system related to the same tectonic concealed granite body.The concealed rock mass is a shoe-shaped granite sheet which is wide in the east and narrow in the west,and thick in the east and thin in the west.Its overall spatial morphology is closely related to the eastward kinematic direction of the basement of the Xiong'ershan metamorphic core complex.The main body of the high-level magma chamber(most of the concealed rock mass is thick)is located in the area east of the Guxian reservoir.The discovered silver and gold polymetallic deposits in the area are mainly located in the outer edge of the overlying zone of the eastern main body of the concealed rock mass,with hydrothermal vein like mineralization at a moderate temperature.It is speculated that there are three concealed rock bell development areas in the central and southern parts of the top zone of the concealed rock mass,which are the core areas of secondary boiling of magmatic hydrothermal fluids,and therefore the most favorable sections for the formation of high-temperature porphyry type copper molybdenum deposits or concealed explosive breccia type molybdenum gold deposits.