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根据渤海周边的三大主要盆地中、新生代火山岩的岩石学、岩石化学、微量元素地球化学和同位素地球化学的综合分析研究表明 :1.本区中、新生代有三大火山作用时期即早中生代 (228～226.9Ma)、晚中生代 (136.0～66.3Ma)和新生代 (61.0～29.7Ma) ;2.早中生代英安岩为偏钾质酸性钠质玄武岩 ,它们均发生结晶分离作用 ;3.晚中生代火山岩微量元素分配形式和Sr、Nd同位素表明其来源于富集的岩石圈地幔 ,新生代玄武岩与OIB相似的微量元素分配模式以及亏损的Sr、Nd同位素组成 ,暗示其来源于软流圈 ;4.岩石圈 -软流圈界面在中 -新生代发生上升、回落 ,岩石圈经历拉伸和减薄过程。
According to the comprehensive analysis of Mesozoic and Cenozoic volcanic rocks in the three major basins around the Bohai Sea, the petrology, petrochemistry, trace element geochemistry and isotope geochemistry show that: 1. The Mesozoic and Cenozoic have three periods of volcanism: the Early Mesozoic (228 ~ 226.9Ma), Late Mesozoic (136.0 ~ 66.3Ma) and Cenozoic (61.0 ~ 29.7Ma). 2. Early Mesozoic dacite is a partial potassium-acid acidity basaltic rock, both of them crystallizing. The distribution patterns of trace elements and Sr, Nd isotopes of the Late Mesozoic volcanic rocks suggest that they are derived from enriched lithospheric mantle and the distribution patterns of trace elements in the Cenozoic basalts similar to OIB and depleted Sr and Nd isotopes suggest that they originated from the soft stream Circle; 4. The lithosphere-asthenosphere interface rose and fell back in the Meso-Cenozoic, and the lithosphere experienced stretching and thinning processes.