海洋地质前沿2017，Vol.33Issue(6)：1-8,8.DOI:10.16028/j.1009-2722.2017.06001
西沙群岛浮岩的岩石地球化学特征及成因
PETRO-GEOCHEMISTRY AND GENESIS OF THE PUMICES AT DONGDAO OF XISHA ISLANDS
摘要
Abstract
In this paper,two pumices samples collected from the Dongdao Island are studied for petrography and mineral geochemistry.With chemical composition,the samples are defined as trachyte,and their rare earth distribution curves are both dipping rightward,with negative Eu anomalies,enriched incompatible elements,and a trace element normalized curve similar to the lower crust.The porphyritic minerals of plagioclase and pyroxene show a central melting structure,and olivine is molten.It is believed that the pumices are formed by an explosion of a short-term condensed magma chamber after the melting and pressure reduction of the crust at the Xisha block,due to the continuous spreading of the plate and the formation of the narrow trough on the west side of the Dongdao Island.The process caused the sudden release of pressure,and rapid eruption of magma along the stretching rift into the shallow water.关键词
东岛/浮岩/岩石地球化学/岩浆活动Key words
pumice/petro-geochemistry/magmatic activity/Dongdao分类
天文与地球科学引用本文复制引用
韩宗珠,吕迎秋,许红,刘明,来志庆..西沙群岛浮岩的岩石地球化学特征及成因[J].海洋地质前沿,2017,33(6):1-8,8.基金项目
南北极环境综合考察与评估专项(CHIN-ARE2016-01-02) （CHIN-ARE2016-01-02）
