阜平岩群下部Sm-Nd同位素年龄及其地质意义  

Sm-Nd Isotope Age of the Lower Fuping Group Complex and Its Geological Significance

作　　者：沈保丰[1] 李俊建[1] 林源贤[1] 翟安民[1] 曹秀兰[1] 

机构地区：[1]中国地质调查局天津地质矿产研究所,300170

出　　处：《地质学报》2005年第6期784-789,共6页Acta Geologica Sinica

基　　金：国土资源部科技攻关项目(编号95-02-003);中国地质大调查综合研究项目(编号K1.4-3-1);国家黄金攻关项目(编号900511)等资助的成果。

摘　　要：阜平岩群主要分布在太行山北段,是我国太古宙重要的地层单元,并构成阜平深变质绿岩带的岩石组合。前人认为阜平岩群及其区域变质时代主要为新太古代。本次对阜平岩群下部含辉石斜长角闪岩Sm-Nd同位素年代学的详细研究,获得Sm-Nd等时线年龄3352±50Ma和平均模式年龄3374.5Ma,说明阜平岩群底界年龄接近3400Ma,从而也反映阜平深变质绿岩带形成在古—中太古代,是我国目前最老的绿岩带,也是世界上最古老的绿岩带之一。The Fuping Group complex is mainly exposed in the northern part of Taihang Mountain. It is an important Arehean stratum in China and consists of a rock association of the Fuping katametamorphie greenstone belt. It was recognized before that the Fuping Group complex and regional metamorphism are mainly of the Neoarehean in age. In this research, pyroxeneferous amphibolites of the lower Fuping Group complex show an Sm-Nd isoehronal age of 3352±50 Ma and an average model age of 3374 Ma, which indicates that the isotope age of the bottom boundary of the Fuping Group complex is close to 3400 Ma. This isotope age also indicates that the Fuping Group complex, as well as Fuping katametamorphic greenstone belt, belongs to the Paleo- Mesoarehean. As a result, the Fuping greenstone belt is the oldest greenstone belt in China and one of the oldest greenstone belts in the world.

关 键 词：阜平岩群 Sm—Nd同位素年龄 含辉石斜长角闪岩 深变质绿岩带 

分 类 号：P597[天文地球—地球化学]