摘要
鞍山陈台沟地区出露有大量太古宙花岗质岩石和变质层状岩系,是研究太古代地壳形成与演化的经典地区之一。通过对该区岩石单元、构造特征研究,较系统地划分了岩石单元,具体分析了各单元组构及构造变形特征。细粒奥长花岗质糜棱岩、似斑状花岗质糜棱岩和中--细粒花岗质片麻岩具有古太古代花岗质岩石的特点,共同经历地壳中--深部层次的韧性变形改造。细粒奥长花岗岩为中太古代岩浆事件的产物,表现为非透入性的变形方式和部分韧--脆性形变组构。鞍山群层状变质岩石主要记录了新太古代中--浅部地壳层次的强烈变形事件。中粗粒白云母花岗岩就位,标志早期不同的构造变形作用在新太古代末期基本结束。在此基础上,讨论了本区太古宙地壳的形成与演化过程。
Mass of Archean granite rocks and metamorphic layered sequence exposed in Chentaigou area of Anshan are typical for studying Archean crustal formation and evolution. We systematically divide the rock units and analyse their rock fabric and structural deformation characteristics of the Archean rocks, with focusing on their compositions and structural features, in the Chentaigou area. Fine-grained trondhjemitic mylonite, porphyritic granitic mylonite and medium-fine grained granitic gneiss have the characteristics of the Paleoarchean granitic rocks, and underwent ductile deformation of middle-deep crust level. Fine-grained trondhjemite is a product of the Meso- archean magmatic events, showing impervious deformation and partial of ductile-brittle deformation fabric. Metamorphic layered rocks of the Anshan Group mainly recorded the Neoarchean strong deformation event of middleshallow crust level. The intrusion of the medium-coarse grained muscovite granite marked the end of early-phase different structural deformation processes in the Late Neoarchean. The formation and evolution of the Archean crust in the Chentaigou area are also discussed.
出处
《世界地质》
CAS
CSCD
2013年第2期191-199,共9页
World Geology
基金
中国科学院岩石圈演化国家重点实验室项目(Z1005)
国家自然科学基金项目(41172170)联合资助
关键词
花岗岩
组构
构造演化
太古宙
陈台沟
鞍山
granite
fabric
structural evolution
Archean
Chentaigou
Anshan
