加拿大新斯科舍省Coxheath铜钼矿区火山岩地质地球化学特征及构造环境判别  

Geological and geochemical characteristics of volcanic rocks and tectonic discrimination on Coxheath Cu-Mo deposit,Nova Scotia,Canada

作　　者：杨振军[1,2] 甘彩红[3] 张文山[2] 刘继顺[4] 高珍权[2] 

机构地区：[1]北京矿产地质研究院,北京100012 [2]中色金地资源科技有限公司,北京100012 [3]中国地质大学(北京),北京100083 [4]中南大学,长沙410083

出　　处：《矿产勘查》2015年第1期67-76,共10页Mineral Exploration

基　　金：国外矿产资源风险勘查专项(编号:10254B008)资助

摘　　要：Coxheath铜钼矿区前寒武纪火山岩广泛分布,具有玄武岩—安山岩—流纹岩的岩性组合,属钙碱性岩石系列,主量元素A/CNK比值为1.30 ～2.40、K2O/N2O小于1,微量元素亏损Ti、Nb、Ta,富集大阳离子亲石元素（LILE） Rb、K、Cs、Ba和Sr,相对富集轻稀土元素（20×10^-6～129×10^-6）,亏损重稀土元素（2.72×10^-6～9.91×10^-6）,呈现右斜式模型,负铕异常不明显,岩浆早期具有岛弧岩浆活动特征,晚期向陆缘发展,火山岩构造环境应为近陆缘的岛弧环境.The Cambrian volcanic rocks in Coxheath copper- molybdenum deposit area are widely distributed, with the lithological association of basalt- andesite - rhyolite. The volcanic rocks belongs to the calc -alkaline type, the major element ratio of A/ CNK is 1.30 - 2.40, the ratio of K2O/N2O is less than 1. The trace elements are characterized with less Ti, Nb and Ta elements, enriched Rb, K, Cs, Ba and Sr etc. large cation lithophile elements （LILE）. Relatively LREE is enriched （20 × 10^-6 - 129 × 10^-6） but loss of heavy rare earth elements （2.72 × 10^-6 - 9.91 × 10^ -6 ）. The REE curve shows it has right oblique model, and there is not obvious negative Eu anomaly. The early stage magmatic activity has the character of island arc magmatism, then it was evolved into the continental edge magmatism. All of these characteristics indicate that the tectonic environment of the volcanic rocks was close to the continental margin of the island arc environment.

关 键 词：Coxheath铜钼矿床 火山岩 构造环境 加拿大 

分 类 号：P618.65[天文地球—矿床学] P618.41[天文地球—地质学]