Abstract:

In the middle section of the Himalaya belt, lenticular or pudding granulites are exposed  intermittently in some weak strained areas, while the country rocks have been strongly deformed, as indicated by their mylonite foliations and schistosity. Due to the strongly ductile shear deformation and obviously controlled by the ductile shear zone,  some mylonite occurs with the characteristics as shear lens shaped, stripy distributing and local concentrating.The granulite can be sorted into four types according to the mineral assemblage, and among which, the primary minerals such as orthopyroxene, clinopyroxene, plagioclase, hornblende and garnet show the characteristics of kinked, flatten, elongating, subgrain, marginal dynamic recrystallization and other strongly plastic deformation micro-structures. The study make it clear that the output of here granulite has relationship with the intrusion of the remelting granite and the movement of the STDS. So it can be considered that during the continental dynamic course of absolutely-temperature and dropping-pressure when Himalaya orogenic belt fast uplifting and orogen,  the lower crust basic granulite quickly move up to the earth’s surface, as the same time, the lower crust laminar flow and the action of orogenic belt uplifting-detachment-orogen leads to the granulite facies metamorphism.

Key words: deformation , metamorphism, granulite, tectono-emplacement, orogen, Himalaya