崂山湾位于鲁东隆起东南胶莱坳陷的沿海一带,具特殊大地构造背景。通过该区广泛出露的煌斑岩系统的岩石学和地球化学研究,探讨其物质来源和形成过程,对于研究该区地质演化历史具有重要意义。对岩石样品进行偏光显微分析、全岩化学分析、等离子体光谱分析和等离子质谱分析,结果表明:样品具有富LILE,贫HFSE的微量元素组成和右倾型的稀土元素分布型式.略具Ce负异常。岩石地球化学特征表明,煌斑岩源于受俯冲组分改造的上地幔,源区可能因为受扬子板块向华北板块俯冲作用的影响而混染了部分壳源物质。
The Laoshan Bay is located in coastal area of Jiaolai depression that is situated at the south- east uplift of Ludong, with particular tectonic setting. It is a great significance for the geological evolu- tion of this area that systemly petrological and geochemical studies to exposed lamprophyre in a broad zone and to explore the origin and formation process of the material. Through polarized light microsco- py analysis, chemical analysis of whole-rock, ICP-MAS and ICP-AES analysis, the results show that the samples have a rich IALE, depleted HFSE trace element composition and right-wing-shaped REE distribution patterns and a slight positive Ce anomaly. All characters above show that the magma is de- rived from upper mantle altered by subduction;mantle source may be the combination of lower curst of Yangtze plate and upper mantle of North China plate. The lower crust and upper mantle of Yangtze plate have separated by high-speed subduction.