摘要
本文报导皖东地区上第三系大陆碱性玄武岩的地球化学特征和成因初探，其中８个样品的Ｎｄ、Ｓｒ同位素组成范围为．在大洋玄武岩的Ｎｄ－Ｓｒ同位素平面上，表现为从原始地幔向ＥＭＩ型地幔端元展布趋势．皖东玄武岩具有轻稀土和高度不相容性元素相对富集的微量元素丰度模式，类似于洋岛玄武岩（ＯＩＢ）．皖东玄武岩的源区可能是Ｎｄ、Ｓｒ同位素组成不均一、且富化的大陆岩石圈地幔．
The Nd and Sr isotopic compeitions of Neogene alkalic basalts from eastern Anhui,China are similar to EMI type mantle end-menber in isotopic system for oceanic basalts.The minimum Nd isotopic ratio is 0. 512408(±10) and the maximum Sr isotopic ratio is 0. 70550(±7). The basalts are chsractered as the enrichment of LREE, Rb, Ba, Nb, K etc.and were derived from the heterogeneous continental lithospheric mantle in Nd-Sr isotopic commotions. The discovery of EMI type Neogene batalts from eastern Anhui is Significant for undersinnchg of geochemistry and petrogenesis of Cenozoic basalts in the area and eastern China.
基金
国家自然科学基金
地质矿产部同位素地质开放实验室基金
关键词
碱性
玄武岩
钕同位素
锶同位素
第三纪
continental alkalic basalt
EMI type mantle
Eastern Anhui
