陈继平;廖群安;罗婷;张雄华;郭东宝;朱和林;柳小明;

• 1:中国地质大学地球科学学院
• 2:西北大学大陆动力学国家重点实验室

摘要(Abstract)：

磁海辉绿岩型铁矿位于塔里木北缘北山裂谷带,主要岩石类型为辉绿岩,岩石具有较高的Mg#(55.7～70.1)、中铝Al2O3(13.75～14.65)特征,Na2O/K2O(1.79～14.04)变化较大,整体属于钙碱性系列(K2O/Na2O=0.07～0.56,FeO/MgO=0.77～1.46)。稀土元素方面,磁海辉绿岩具有较高的稀土元素质量分数和δEu异常特征[w(∑REE)=88.01×10-6～213.07×10-6,δEu=0.63～1.44],球粒陨石标准化稀土元素配分模式为缓右倾型[(La/Yb)N=1.32～3.87,(La/Sm)N=1.05～2.17,(Gd/Yb)N=1.12～1.58],微量元素上选择性富集大离子亲石元素(Rb、K),亏损高场强元素(Nb、Ta)。岩浆演化过程中斜长石和单斜辉石的分离结晶作用是岩浆演化的主要机制,同时伴有较为明显的地壳混染作用。LA-ICP-MS锆石U-Pb年代学指示该辉绿岩形成于约291.9Ma,构造环境分析表明磁海辉绿岩为板内拉张环境的产物。

关键词(KeyWords)： 磁海辉绿岩;锆石U-Pb;分离结晶;同化混染;拉张环境

Abstract:

Keywords:

基金项目(Foundation): 中国地质调查局地质调查项目(1212011085469)

作者(Author): 陈继平;廖群安;罗婷;张雄华;郭东宝;朱和林;柳小明;

Email:

DOI:

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