张家口梁家沟铅锌银矿床Rb-Sr和Sm-Nd等时线年龄及其地质意义  

Rb-Sr and Sm-Nd isochron ages of the Liangjiagou Pb-Zn-Ag ore deposit in Chicheng County of Zhangjiakou City and their geological implications

作　　者：李随民[1] 魏明辉[2] 李森文[2] 李紫烨[1] 李玉红[2] 韩玉丑[3] 李永峰[3] 

机构地区：[1]石家庄经济学院,河北石家庄050031 [2]河北省地矿局第三地质大队,河北张家口075000 [3]河北省地矿局,河北石家庄050081

出　　处：《中国地质》2014年第2期529-539,共11页Geology in China

基　　金：河北省国土资源厅基金项目(2012055548;2013045650)联合资助

摘　　要：张家口南部中—新元古代碳酸盐岩地层发育,赤城县梁家沟铅锌银多金属矿床产于中元古代蓟县系雾迷山组地层中,为目前在张家口南部碳酸盐岩沉积盖层中发现的典型多金属矿床。由于缺少成矿时代数据,对该类型矿床的成因长期以来存在同生沉积和后生改造两方面的争议。本文利用单矿物闪锌矿和闪锌矿与黄铁矿共生硫化物组合采用Rb-Sr等时线法测定梁家沟矿床的成矿时代分别为126 Ma和130.7 Ma;利用单矿物闪锌矿和闪锌矿与黄铁矿共生硫化物组合采用Sm-Nd等时线法测得成矿时代分别为130.5 Ma和131 Ma。两种方法测定的成矿时代十分接近,结合张家口区域地质背景,表明张家口南部碳酸盐岩地层中的多金属矿床为燕山期构造运动时期热液活动的产物。Mesoproterozoic and Epiproterozoic carbonate strata are widely distributed in southern Zhangjiakou.Located in the Wumishan Formation in Chicheng County,the Liangjiagou Pb-Zn-Ag polymetallic deposit is a typical polymetallic deposit in the carbonate sedimentary cover of southern Zhangjiakou.Due to lack of data of ore-forming epoch of the deposit,there long exist two viewpoints concerning the genesis of the deposit,i.e.,syngenetic sedimentation and epigenetic transformation.The ages of the Liangjiagou deposit were determined by the Rb-Sr isochron method for sphalerite and a group of mineral assemblage samples （pyrite and sphalerite）,and the results are 126 Ma and 130.7 Ma respectively.The ages of the Liangjiagou deposit were also determined by the Sm-Nd isochron method for sphalerite and a group of mineral assemblage samples （sphalerite and pyrite）,and the results are 130.5 Ma and 131 Ma respectively.The metallogenic epochs measured by the Rb-Sr and Sm-Nd isochron methods are very close to each other.Combined with regional geological background of Zhangjiakou,the authors hold that the mineralization resulted from hydrothermal activities in the Yanshanian tectonic movement period.

关 键 词：铅锌银多金属矿床 成矿时代 RB-SR年龄 SM-ND年龄 梁家沟 

分 类 号：P618.4[天文地球—矿床学] P597[天文地球—地质学]