冀中黄骅坳陷古近纪火山岩地球化学特征及大地构造意义

Geochemical Characteristics and Tectonic Implications of paleogene Volcanic Rocks in Jizhong-Huanghua Sag

摘要:

冀中、黄骅坳陷的火山岩主要发育于古近纪的断陷期，分为EkEs4,Es2Es3，Es1Ed三期。火山岩的岩石系列主要为碱性玄武岩系列，古近纪晚期逐渐向拉斑玄武岩过渡；稀土元素特征同大陆裂谷碱性玄武岩的配分模式一致，为轻稀土富集型。通过岩石地球化学特征分析和大地构造讨论，阐释了研究区古近纪火山活动的构造背景和成因机制。

Abstract:

olcanic rocks in Jizhong-Huanghua sag mainly developed during the faulting period of Paleogene and can be divided into three periods as Ek-Es4, Es2-Es3 and Es1-Ed. The volcanic rocks are alkaline basalt series and transited gradually to tholeiite series in late Paleogene. REE characteristics are LREE-rich type which is in accordance with the distribution pattern of alkali-basalt of continental rift . Through analysis on geochemical characteristics and tectonic discussion, tectonic setting and genetic mechanism of the Paleogene volcanic activities in study area have been explained.