华北板块边缘深地壳构造岩的基本特征和变形环境

BASIC CHARACTERISTICS AND DEFORMATION CONDITIONS OF DEEP-CRUSTAL TECTONITES ON THE BORDERS OF NORTH CHINA PLATE

This paper deals with The texture and structure of three types of deepcrustal tectonites taken from the stacked zone on the northern border and the tectonic melange zone on the southern border of North China plate,and with the deformation characteristics of rock-forming minerals,variation of chemical composition of deformed minerals and neocrystals and deformation conditions for the tectonites. It emphasize3 that the ductile deformation of Pyr in tectonites is the highest deformation facies in the lower crust,where syntectonic neocrystals (or subgrains) and residual deformation crystals are the same in composition. According to the P-T conditions for formation of the neocrystals, as known from the result of triaxial-high-temperature-creep experiment of Pyr,the P-T conditions under which Pyr is deformed ductilely are higher than those for Pl, Or and Hb. It is recognized that the tectonites were formed in the lower crust or layer of granulitic facies.