冀北北岔沟门铅锌矿床中辉钼矿的铼-锇同位素年龄  

The Re-Os isotopic age of molybdenite from Beichagoumen Ph-Zn deposit in the North China Platform

作　　者：毛德宝[1] 陈志宏[1] 钟长汀[1] 李子仪 邹晓秋[3] 

机构地区：[1]中国地质科学院天津地质矿产研究所,天津300170 [2]河北地质矿产勘查开发院,河北石家庄050081 [3]中国地质科学院岩矿测试技术研究所,北京100037

出　　处：《地球化学》2000年第2期132-135,共4页Geochimica

基　　金：国土资源部"九五"科技攻关课题!95-02-003-02

摘　　要：北岔沟门铅锌矿床是华北地台北缘中段最近发现的一个极具成矿远景的新矿床，对矿床成因和成矿规律 的研究刚刚起步。本文介绍了用同位素稀释－等离子质谱法，直接测定了矿床中辉钼矿的Ｒｅ－Ｏｓ等时线年龄，证明成 矿作用发生在燕山中晚期，其等时线年龄为（１５２ ± ３） Ｍａ。这一年龄反映了成矿与浅成花岗岩浆侵入活动有关，并为区内进一步找矿勘探提供了一定的依据。With a large scale or superlarge scale in prospecting, the Beichagoumen Ph-Zn deposit is a new explored deposit in the northern edge of North China Platform. The mineralizations occur in the contact of Mesozoic granite and volcanic-sedimentary rocks, and display obvious zonation of Cu, Mo→Pb, Zn→Pb, Zn, Ag→Ag, Pb, Zn→Ag, An from the granite in southwest to the volcanic rocks in northeast. Molybdenite is the main ore mineral in south mineralization and provides a dating tool for the minerogenetic epoch. The molybdenite Re-Os analyses use 5 - 20 mg of sample. The chemical separation procedure includes alkali fusion, extraction of Re by acetone and extraction of Os by distillation. The isotope dilution-inductively-coupled plasma mass spectrometry (ICP- MS ) is used to determine the isotope ratio. The Re-Os model ages are (136 ± 5) Ma - (180 ± 10) Ma, and the reasonable isochron age is (152 ± 3 ) Ma (Fig. 2). This result implies the mineralization may take place in the middle-late Yanshanian.

关 键 词：辉钼矿 铅锌矿床 铼-锇 同位素年龄 

分 类 号：P618.420.4[天文地球—矿床学] P618.430.4[天文地球—地质学]