北秦岭西段普洛河地区煌斑岩脉地球化学特征及成岩构造环境  

Geochemical characteristics of lamprophyres and diagenetic tectonic setting in Puluohe area of the western part,north Qinling

作　　者：王凯 胡海燕 刘坤鹏 WANG Kai;HU Hai-yan;LIU Kun-peng(No.203 Research Institute of Nuclear Industry,Xianyang 712000;School of Jewelry,Shaanxi Institute of International Trade&Commerce,Xi’an 712064)

机构地区：[1]核工业二○三研究所,咸阳712000 [2]陕西国际商贸学院,西安712064

出　　处：《矿产勘查》2019年第12期2906-2912,共7页Mineral Exploration

基　　金：中国核工业地质局铀矿地质项目(编号:201620,201621)资助

摘　　要：文章以北秦岭西段普洛河地区煌斑岩脉为研究对象,在研究其地球化学特征的基础上,探讨其成岩构造环境。该区煌斑岩脉Si 含量为50. 74%56. 12%;具有高Al、低Na、K的特征;稀土总量为较低(152. 02285. 2)×10-6;稀土配分模式为右倾轻稀土富集型(La/Yb)N=10. 6918. 50,(La/Sm)N=3. 034. 51,(Gd/Yb)N=2. 673. 73,显示煌斑岩脉轻、重稀土元素分馏明显,且分馏程度基本一致;富集元素Rb、Ba、U、Pb,亏损元素Nb、Ta、Sr;属板内碱性玄武岩系列,且形成于板内拉张环境。The lamprophyres of the puluohe area in the western part of the northern Qinling are studied. Based on the study of their geochemical characteristics,discussing its diagenetic tectonic setting in this paper. The Si O2 content of lamprophyres in this area varies from 50. 74% to 56. 12%;It is characterized by high Al,low Na,K and a lower total REE content 152. 02×10-6 285. 2×10-6;The ∑REE is relative low with the right type of LREE distribution patterns( La/Yb)N= 10. 69 18. 50,( La/Sm)N= 3. 03 4. 51,( Gd/Yb)N= 2. 67 3. 73,It shows that REEs fractionate is evident and its fractionation degree is basically the same.The enriched elements Rb,Ba,U,Pb,and the depleted elements Nb,Ta,and Sr indicates that the lamprophyres belong to the alkaline basalts formed in an intraplate extensional environment.

关 键 词：煌斑岩脉 地球化学特征 成岩构造环境 普洛河地区 

分 类 号：P581[天文地球—岩石学]