辽北龙岗地区太古宙变质深成岩中岩浆岩构造的识别

RECOGNITION OF STRUCTURES IN MAGMATIC ROCKSOF ARCHEAN METAMORPHOSED PLUTONITEIN LONGGANG AREA, NORTH LIAONING

辽北地区是我国太古宙变质岩发育区,近些年来,对该区各类深成岩浆岩的识别是太古宙地质研究的重要突破。由于受到下地壳环境强塑性变形和变质的改造,深成岩浆岩的构造识别,需要进行多方面的综合地质研究才能完成。在分期分阶段形成的太古宙变质深成侵入体中,可以识别出大量的岩浆构造,包括不同类型片麻岩之间所形成的穿切构造和赋存于片麻岩中的岩浆流面构造、结晶面构造。

North Liaoning is one of areas in China where Archean metamorphosed rocks developed well In recent years,the recognition of plutonite in the area is an important breakthough in the field of Archean geology study Owing to strong plastic deformation and metamorpism in the lower crust,the recognition of structures in the plutonitic magmatic rocks needs comprehensive geological studies in many aspects In North Liaoning,from multiphase and multistage Archean metamorphosed plutonite intrusive bodies,a great deal of magmatic structures can be recognized,which is roughly devided into 3 types:magmatic structure, shell structure and intruding deformation structure The first includes magmatic flow face structure,magmatic crystal face structure,magmatic welding structure and magmatic cross cutting structure The third includes fault structure,intruding foliation and intruding ductile deformation belts Above mentioned magmatic intrusive structures can be found in magmatic rocks of defferent structure levels in the lower crust,which all formed under strong ductile and high pressure conditions in the wall rocks