The shear types and the ductile thinning of the ductile shear zone

Many researchers have focused their attention on the evolution of the fabric and the shear type of the shear zone. The kinematic vorticity can be estimated by using the polar Mohr method, the finite strain, the rigid grain net, the finite strain and the quartz C-fabric, and the components of simple shear and pure shear during the evolution of the ductile shear zone can also be calculated. Many facts have confirmed that the natural shear zones are always general shear zones which combines different components of simple shear and pure shear and whose values of kinematic vorticity range from 0 to 1, suggesting that the ductile thinning perpendicular to the band of the shear zone occurred. The rate of the ductile thinning during the evolution of the ductile shear zone can be estimated by the methods of the finite strain measurement and kinematic vorticity, the budding of the shear zone and the polar Mohr. Using the Louzidian ductile shear zone and Greece Hellenides Chelmos shear zone, this paper indicates that the ductile thinning really occurred in the ductile shear zone. The ductile thinning is the supplement and perfection of lithosphere thinning; at the same time, the shear types of the ductile shear zone related to the metamorphic core complex constitute an effective method to analyze the mechanism of the metamorphic core complex.