湘东南汝城盆地火山岩的元素地球化学及源区性质讨论
The element geochemistry and nature of magma source of the volcanic rocks in the rucheng basin,southeastern hunan

贾大成 ¹ 胡瑞忠 ² 卢焱 ¹

文摘	湘东南汝城盆地火山岩系由辉绿岩、玄武岩和玄武质火山碎屑岩组成，属于低钾拉斑玄武岩系。玄武岩全岩K-Ar年龄为（128.4 ± 4.2） Ma，辉绿岩全岩K-Ar年龄为（112. 1 ±3.2）Ma。Rb、Ba、Th、U的富集和高场强元素Ta、Nb、Ti的亏损。强不相容元素含量的比值表明岩浆源区明显偏离原始地幔组分，具有富集型地幔的特征。岩浆源区主要受到地壳物质混杂以及来自消减残留板片析出流体的交代改造作用。
其他语种文摘	The volcanic rock series in the Rucheng basin in southeastern Hunan is composed of the basalt, diabase and basaltic pyroclastic rock. It belongs to low potassic tholeiite series. The whole rock K-Ar age of the basalt is 128.4 ± 4.2 Ma and the whole rock K-Ar age of the dibase is 112. 1 ±3.2 Ma. Based on the analysis of element geochemistry, the volcanic rock series have same magma source and the formation of the rocks is mainly in the form of partial melting. The trace elements express large-ion lithophilc elements (Rb, Ba, Th, U) enrichment and high field strength elements (Ta, Nb, Ti) depletion. The ratios of incompatible elements reflect the magma source departed from the composition of primary mantle and have the characteristics of the enriched metasomtic mantle. The magma source has been changed mainly by assimilation of the crustal matter as well as by metasomatism of the relict oceanic plate fluid or melting from pre-subduction.
来源	现代地质 ,2003,17(2):131-136 【核心库】
关键词	火山岩系 ; 元素地球化学 ; 岩浆源区 ; 汝城盆地
地址	1. 吉林大学地球探测科学与技术学院, 吉林, 长春, 130062 2. 中国科学院地球化学研究所, 贵州, 贵阳, 550002
语种	中文
文献类型	研究性论文
ISSN	1000-8527
学科	地质学
基金	中国科学院知识创新工程项目 ; 中国科学院边缘海地质与古环境开放实验室基金项目 ; 中国科学院贵阳地球化学研究所矿床地球化学中国科学院重点实验室基金
文献收藏号	CSCD:1303250