豫西铁炉坪银铅矿床矿脉构造解析及近矿蚀变岩绢云母40Ar-39Ar年龄测定

河南省洛宁县铁炉坪大型脉状银铅矿床地处华北陆块南缘熊耳山中生代变质核杂岩构造西部,由一组主要的NNE走向陡倾斜矿脉和一组次要的NW走向陡倾斜矿脉有规律地组成.矿脉以条带状、角砾状和晶洞-晶簇-梳状三种主要形式多阶段充填而成,按照主要矿脉的矿物共生序列可以分为四个阶段:铁镁碳酸盐阶段(I)、烟灰色石英-贱金属硫化物-银矿...

Vein Structure Analysis and 40Ar/39Ar Dating of Sericite from Sub-ore Altered Rocks in the Tieluping Large-size Ag-Pb Deposit of Western Henan Province

Abstract The large Tieluping vein-type Ag-Pb ore deposit is located in western Xiongershan metamorphic core complex, south margin of North China Craton. The main Tieluping veins present a paragenesis that can be divided into four stages: an early Fe-Mg carbonates stage (I) prior to polymetallic mineralization, a smoky gray quartz-base metal sulphide - silver minerals stage (II1), a dolomite-white quartz - coarse grained galena - silver minerals stage (II2), and a calcedony-fluorite-calcite stage (III) after the polymetallic mineralization. The ore veins reactivated and reopened the pre-existing ductile shear zones in association with brecciation and open-space filling processes. Kinematic observations demonstrate that the structure of NE ore veins underwent a sinistral and normal motion, and that the structure of NW ore veins underwent dextral and normal motion, correspondingly. 40Ar/ 39Ar dating was performed on sericite from the altered rocks close to the ore veins, which yielded a plateau ages of (134.6 ±1.2) Ma and an isochronal age of (135.3 ±2.4) Ma. This age data corresponds to the sericite 40Ar-39Ar plateau age of (134.9±0.8) Ma for Haopinggou lead-silver veins and the zircon SHRIMP U-Pb age of (133.5±1.4) Ma for Haopinggou granite porphyry in the same ore field, thus further indicates the spatial and temporal consistency of the mineralization and intrusion.