黄陵背斜北缘竹园沟—下坪锌矿床Rb-Sr同位素测年及其地质意义  

Rb-Sr Dating of Sphalerite from Zhuyuangou-Xiaping Zinc Depositin Northern Margin of Huangling Anticline and Its Geological Significance

作　　者：周舟 杨朋 向萌 雷雳 艾德建 闫磊 熊渊 Zhou Zhou;Yang Peng;Xiang Meng;Lei Li;Ai Dejian;Yan Lei;Xiong Yuan(Seventh Geological Brigade of Hubei Geological Bureau,Yichang,Hubei 443100)

机构地区：[1]湖北省地质局第七地质大队,湖北宜昌443100

出　　处：《资源环境与工程》2023年第6期664-670,共7页Resources Environment & Engineering

基　　金：湖北省成矿区划与矿产前期勘查(鄂西片)(KCDZ2023-20);湖北省黄陵地区锑矿、稀土矿等关键矿产成矿规律研究及找矿预测(KJ2021-11)。

摘　　要：竹园沟—下坪锌矿床为近年来黄陵背斜北缘新发现的代表性矿床,矿体隐伏于地下,赋存于灯影组白马沱段角砾状白云岩中,呈似层状、透镜状产出,矿石矿物主要为闪锌矿、方铅矿。为确定该矿床的成矿时代并加深矿床成因认识,开展了闪锌矿Rb-Sr同位素测年工作。结果表明,该矿床闪锌矿Rb-Sr等时线年龄为(489±12)Ma,相当于早奥陶世;闪锌矿Sr同位素初始值为0.71199,指示成矿物质或成矿流体可能由基底岩石和震旦系碳酸盐岩地层共同提供。黄陵背斜北缘发育了包括竹园沟—下坪锌矿床在内的一系列中低温热液矿床(点),可能为加里东中—晚期伸展背景下强烈构造热液活动的产物。The Zhuyuangou-Xiaping zinc deposit is a representative deposit discovered in northern margin of Huangling anticline in recent years.The ore body is concealed underground and occurs in the breccia dolomite of Baimatuo Section of Dengying Formation.It is layered and lenticular,and the ore minerals are mainly sphalerite and galena.In order to determine the metallogenic age of the deposit and deepen the understanding of the genesis of the deposit,Rb-Sr isotopic dating of sphalerite was carried out.The results show that the Rb-Sr isochron age of sphalerite is(489±12)Ma,which is equivalent to the Early Ordovician.The initial Sr isotope value of sphalerite is 0.71199,indicating that the ore-forming materials or ore-forming fluids are jointly provided by basement rocks and Sinian carbonate strata.A series of medium-low temperature hydrothermal deposits(occurrences),including Zhuyuangou-Xiaping zinc deposit,are developed in northern margin of Huangling anticline,which may be the product of strong tectonic hydrothermal activity in the middle-late Caledonian extensional background.

关 键 词：Rb-Sr测年 闪锌矿 加里东期成矿活动 黄陵背斜 

分 类 号：P597.3[天文地球—地球化学] P618.43[天文地球—地质学]