摘要
东秦岭商丹断裂带南侧的“武关岩群”是从原泥盆系刘岭群北侧解体出来的变质沉积—火山岩系。已获得该构造岩石地层单位中斜长角闪岩（变质基性火山岩）ＳｍＮｄ同位素等时线年龄为（１３８２±３０）Ｍａ，钕同位素初始比值ＩＮｄ＝０．５１１１８６±１（２σ），εＮｄ（Ｔ）＝＋６．５１。表明武关岩群”变质岩系主体形成时代为中元古代。
The “Wuguan Group Complex' is a metamorphosed sedimentary volcanic series disintegrated from the north part of the original Devonian Liuling Group.The amphibolites (metabasic volcanic rocks) in this tectono lithostratigraphic unit have been determined to have a Sm Nd isochron age of(1382±30) Ma with I Nd =0.511186±1(2σ) and ε Nd (T)=+6.51, indicating that the bulk of the metamorphic series of the “Wuguan Group Complex' was formed in the Middle Proterozoic.This result reflects the process of tectonic development and evolution of the Qinling orogenic belt in the Middle Proterozoic.
出处
《中国区域地质》
CSCD
1997年第1期38-42,共5页
Regional Geology of China
关键词
钐
钕
同位素年龄
斜长角闪岩
武关岩群
Sm Nd age,Middle Proterozoic,amphibolite,“Wuguan Group Complex
