巴布亚新几内亚新生代埃达克岩及成矿意义  

Cenozoic Adakites in Papua New Guinea and Metallogetic Significance

作　　者：朱章显[1] 杨振强[1] 

机构地区：[1]宜昌地质矿产研究所,湖北宜昌443003

出　　处：《吉林大学学报（地球科学版）》2008年第4期618-623,共6页Journal of Jilin University：Earth Science Edition

基　　金：中国地质调查局项目(1212010661308)

摘　　要：根据巴布亚新几内亚地区埃达克岩地球化学特征,讨论了埃达克岩的构造环境意义。巴布亚新几内亚埃达克岩微量元素特征为高锶(一般大于596.80×10-6),在微量元素蛛网图上具有正Sr异常(Sr/Y比值平均>41.7)和明显的Nb、Th负异常。Y和重稀土元素Yb含量很低(分别为≤20×10-6和≤1.9×10-6)。Mg#值>0.45;87Sr/86Sr一般小于0.7045。巴布亚新几内亚埃达克岩主要形成于弧-陆碰撞环境的大洋岛弧和大陆边缘造山带。埃达克岩的分布区与世界级斑岩铜-金矿和浅成热泉金矿成矿带分布一致。Based on the geochemical characteristics of adakites,the significance of the Cenozoic adakites in Papua New Guinea is discussed. The resuh shows that the adakites of Papua New Guinea are characterized by high Sr content（〉596.80× 10^-6）, by strongly positive Sr anomaly peaks （average Sr/ Y ratio 〉41.7） and by apparent negative Nb and Th anomalies on the spider diagram of trace elements. However, both Y and Yb contents are very low（Y≤20×10^-6 and Yb≤1. 9×10^-6 respectively）in the adakites. Meanwhile, in adakites of Papua New Guinea, Mg^# values are 〉0.45 and ^87Sr/^86Sr values are generally d0. 704 5. The adakites of Papua New Guinea are both located at the oceanic island arc and continental margin orogens in an arc-continent collision setting. Their distribution districts contain both world-class porphyry copper-gold as well as hot-spring gold deposits.

关 键 词：埃达克岩 微量元素 弧-陆碰撞 

分 类 号：P588.1[天文地球—岩石学]