内蒙古喀喇沁变质核杂岩及其隆升机制探讨

Harkin metamorphic core complex in Inner Mongolia and its upwelling mechanism.

内蒙古喀喇沁地区的变质核杂岩是由韧性变形的太古宙、元古宙变质岩系组成的核 ;由脆 -韧性变形和经受了低压变质的中侏罗统地层组成的中间层 ;由少量脆性变形和未变质的上侏罗 -下白垩统地层和岩体组成盖层。变质核杂岩的组成与结构显示了它对称伸展和不对称隆升的特征 ,130～ 10 0 Ma是其快速隆升的时期。从该区长期的热演化历史以及同构造的岩浆活动来看 ,可以认为喀喇沁变质核杂岩是地幔热隆及岩浆侵入引起地壳伸展的典型实例。

The metamorphic core complex in Harkin area, Inner Mongolia is studied. Its core consist of Archaeozoic and Proterozoic metamorphic complexes undergoing ductile deformation, Its median layers Middle Jurassic undergoing plastic deformation with low-pressure metamorphism, and Its overlays Upper Jurassic - Low Cretaceous and mass of magmatic rocks underwent minor brittle deformation without metamorphism. The composition and texture of the metamorphic core complex show features of symmetrical extension and asymmetric uplifting and a rapid uplifting period within 130 to 100 Ma. In light of long run thermal evolution of the concerned area, the Harkin metamorphic core complex can be considered as a typical example of crust extension caused by thermal upwelling of mantle and intrusion of magma. The Harkin area can become a window to look into the structure and evolution of the North China lithosphere.