摘要
通过对辽吉朝古元古代褶皱带的构造演化分析,尤其对褶皱带南带内发育的典型构造组合及相应出现的岩浆活动、变质作用和变形作用的系统构造分析,提出岩浆核杂岩是古元古代褶皱带早期演化过程中形成的主要构造型式。岩浆核杂岩主要由3种成分、性质、特点及变质演化不同的构造单元构成,即核部岩浆杂岩、外部的滑覆体壳及其间的幔部顺层韧性剪切带。岩浆核杂岩的构造分析,揭示出它们形成于褶皱带早期阶段演化的伸展作用过程中。
A unique structural style,i.e.magmatic core complex,is recognized through an analysis of tec-toinc evolution of the Liaoming-Jilin-Korea fold belt in the eastern North China craton,especially on the basis of systematic analysis of typical structural assemblages,metamorphism,magmatism(volcanic and pluton-ic activities)and mechanisms of deformation of rocks.A magmatic core complex is composed of three parts:a magmatic core,a crust of down-dip slipping blocks in the outer part and a layered ductile shear zone in the mantle part.As the dominant structural component of the fold belt,at least20complexes are recognized in the western part of the fold belt.It is shown that magmatic core complexes are formed by regional extension during the early evolution of the fold belt.Magmatic core complex es are different in many aspects from traditional metamorphic core complexes.The extensional origin and tectonic significance of the magmatic complexes are further discussed.
出处
《地质通报》
CAS
CSCD
北大核心
2002年第4期202-206,共5页
Geological Bulletin of China
基金
国家自然科学基金项目(49872071)
中国地质调查局"华北地台成矿规律与找矿方向"课题资助。