中文摘要:为确定辽宁青城子矿集区金、银的成矿时代,分别以含金硅化岩和含银网脉状石英晶体内流体包裹体为对象,应用Rb_Sr法测得金、银成矿的等时线年龄为(233±31) Ma~(234±14) Ma;作为对Rb_Sr法测年结果的验证,又以与贵金属矿石矿物共生的热液石英为对象,用40Ar/39Ar快中子活化法测得坪年龄tp=(238.78±0.74) Ma~(238.80±0.60) Ma,等时线年龄ti=(239.46±1.13) Ma~(240.35±0.88) Ma。Rb-Sr和40Ar/39Ar两种方法的测年结果基本一致,与本区印支期岩浆活动时代〔217.6 Ma~(230.7±5) Ma〕吻合。
Abstract:Located in eastern Liaoning Province, Qingchengzi area has an age-old mining history. Within an area of about 11×9 km, there occur a lot of Pb-Zn deposits, some of which have been mined for more than one hundred years. Recently a large Au deposit (Xiaodongjiabuzi) and a large Ag deposit (Gaojiabuzi) have been discovered. All this has made the area an important target for further exploration. Samples used in this study were taken from fluid inclusions in silicified rocks (the Xiaodongjiabuzi Au deposit), and in vein quartz (the Gaojiabuzi Ag deposit). The study yielded a Rb-Sr isochron age of (233±31) Ma~(234±14) Ma. To confirm the result, the authors used hydrothermal quartz associated with ore sulfides for quick neutron activation dating. This yielded 40Ar/39Ar plateau age of (238.78±0.74) Ma~(238.80±0.60) Ma,and isochron age of (239.48±1.13) Ma~(240.35±0.88) Ma. These results coincide well with the magmatism of Later Indochina age 〔217.6 Ma~(230.7±5) Ma〕.Indochina orogeny is the major metallogenic epoch in this area, and the tectonic events and the magmatism during this period must have been the major factors responsible for the ore-forming process. In eastern Liaoning, the age of gold mineralizations shows a trend of getting younger from west to east, and from north to south.
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基金项目:国家重点基础研究发展规划项目(G1999043201)
引用文本:
薛春纪,陈毓川,路远发,李华芹.2003.辽东青城子矿集区金、银成矿时代及地质意义[J].矿床地质,22(2):177~184.2003.Metallogenic Epochs of Au and Ag Deposits in Qingchengzi Ore_clustered Area, Eastern Liaoning Province [J].Mineral Deposits22(2):177~184
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