山东栖霞地区太古宙英云闪长岩

THE ARCHAEAN TONALITES IN QIXIA AREA, SHANDONG

摘要:

通过1:5万栖霞幅地质填图,在太古界胶东群变质地层中划分出了经过变质变形的英云闪长岩体。本文论述了区内英云闪长岩的地质特征及岩石学、岩石化学、稀土元素特征和U-Pb同位素地质年龄。岩体侵入太古界胶东群,据同位素年龄初步划分为两期岩浆侵入活动,分别在28亿年和26亿年。英云闪长岩在胶东地区是首次确定,对于该区基础地质研究具有重要意义。

Abstract:

The metamorphosed and deformed tonalites are distinguished from the Archaean metamorphic strata (Jiaodong Group) by geological mapping(maP scale 1:50000)in the Qixia area. In this paper the authors discuss their characteristics in terms of geology, petrology, petrochemistry, REE and U Pb isotopic age. They intrude into the Jiaodong Group and involved in two stages of magmatism at 2.8 Ga and 2.6 Ga, respectively according to their isotopic ages. The tonalites are first identified in eastern Shandong, which i...