南秦岭北部裂陷带铅锌矿床控矿机理  

Pb-Zn deposit ore-controlling mechanism in the ground fracture zone of Southern Qinling Mountains

作　　者：常宗东 刘玉林 董君鹏 张佳峰 CHANG Zongdong;LIU Yulin;DONG Junpeng;ZHANG Jiafeng(Baoji 717 Corps Limited of Northwest Nonferrous Geological and Mining Group,Baoji 721000,China)

机构地区：[1]宝鸡西北有色七一七总队有限公司,陕西宝鸡721000

出　　处：《西安科技大学学报》2023年第2期322-331,共10页Journal of Xi’an University of Science and Technology

基　　金：中国地质调查局项目(DD2016005213);西北有色地矿集团科技项目(XD20190023)。

摘　　要：以典型铅锌矿床为例,从岩浆侵入和铅锌矿形成的时空耦合性,控矿构造及其演化特征,矿石Rb-Sr,S,Pb同位素测试等方面分析研究南秦岭北部裂陷带铅锌矿床控矿机理。铅锌矿床受纵向褶断带与横向隆起带交汇部位形成的“成矿结”下部预测中-晚三叠世隐伏岩体斜向上涌形成的“被动”隆断带控制,岩体沿深大断裂上涌刺穿并连通上部纵向线状背斜倒转翼古道岭组灰岩与星红铺组千枚岩之间“硅钙面”附近形成的层间滑脱、负压、扩容构造带,铅锌成矿热液虹吸入负压构造空间内聚集成矿;成矿后期岩浆及构造的进一步活动,导致控矿褶断裂进一步发展和演化变形,铅锌之赋矿构造也得到再次疏通和拓展,铅锌矿体随之发生重熔、迁移、再聚集成矿。分析论证隐伏岩体涌入与铅锌矿床控矿构造的形成、发展、演化和矿体重熔、迁移、再聚集成矿的控矿机理,提出南秦岭北部裂陷带铅锌矿床成因类型和成矿模式。The typical lead-zinc deposit of Fengtai Mining Area is taken as the research object in this paper to explore the ore-controlling mechanism of the lead-zinc deposit in the north of Southern Qinling fracture zone from the magma intrusion and the spatial-temporal coupling of lead-zinc deposit formation,ore-controlling structure and its evolution characteristics,as well as Rb-Sr,S,Pb isotope tests.It is found that the Pb-Zn deposit is controlled by the“mineralized junction”formed at the intersection of the longitudinal folded fault zone,the lateral uplift belt,and the“passive”uplift zone created by the oblique up-welling of the predicted concealed-rock in Middle to Late Triassic.The up-welling of the rock body along the deep fracture pierces and connects the upper longitudinal linear back-slope inversion wing of the Gudaoling Formation limestone with the Xinghongpu Formation micro phyllite near the“silicon-calcium surface”,forming an inter-layer gliding,negative pressure,and expansion tectonic belt,and the lead-zinc mineralizing hydrothermal fluid is siphoned into the negative pressure tectonic space for mineralization.Moreover,the further activities of magma and tectonics in the late stage of mineralization contribute to the development and evolution of the ore-controlling folds and fractures,thus resulting in the reopening and expanding of the Pb-Zn ore-bearing structures and the subsequent remelting,migration and re-gathering of Pb-Zn ore bodies.This article describes and demonstrates the formation,development and evolution of ore-controlling structures and the ore body remelting,migration and re-aggregation mechanisms of ore-controlling systems,with the genesis type and ore-forming mode proposed of Pb-Zn deposits in the northern rift zone of the South Qinling Mountains.

关 键 词：南秦岭北部裂陷带 控矿机理 褶断带 隐伏岩体 负压扩容构造 

分 类 号：TD121[矿业工程—矿山地质测量]