摘要
安徽北淮阳构造带的基底由一套变火山沉积岩建造 (即原称庐镇关群 )所组成。岩类学、岩石地球化学、年代学的研究表明 ,这套火山岩属碱性玄武岩系列、拉斑玄武岩系列和钙碱性玄武岩系列 ,分别形成于中元古宙陆内裂解 (扩张 )带和晚元古宙岛弧两种构造环境 ,其中以岛弧环境火山岩为主要部分 ,由此可以证明北淮阳构造带是在中元古宙陆内裂解带基础上发展起来的古弧系 。
The basement rocks that is called the Luzhenguan Group, which located in Beihuaiyang tectonic belt, is a suite of meta volcanic sedimentary rocks. The petrology, petrochemistry, chronology analysing results indicate that these meta volcanic sedimentary rocks can be divided into two series. One is tholeiite series,another is calc alkaline series. The main part of meta volcanic sedimentary rocks is calc alkaline series. The former was related with continental rifting environment in Middle Proterozoic. The latter formed under active continent margin with island arc during Late Proterozoic. The rifting type tholeiite and island arc type volcanic rocks are exposed that proves tectonic setting had changed from Middle Proterozoic to Late Proterozoic. It also proves that the basement metamorphic rocks of Beihuaiyang tectonic belt are attributed to ancient island arc type basement formed over rifting belt within the continent. Thus it belongs to continental basement.
出处
《现代地质》
CAS
CSCD
北大核心
2000年第4期401-407,共7页
Geoscience
基金
国土资源部"九五"重大基础项目!(编号 :95 0 110 2- 0 3)
关键词
基底变质岩
构造属性
北淮阳构造带
地球化学
basement metamorphic rock
attribute of tectonics
ancient island arc
continental basement
Beihuaiyang tectonic belt
Anhui Provin
