Tibet At Gangma Co-Ritu Area Characteristics Of Accretionary Complex And Fold Belt

The movement between the oceanic plate and the continental plate is slow and complex.During such a process of subduction and collision,the trench is slowly retrograding,and at the begin of the plate,there are scraping action,underplating,the denudation of the front and so on.These effects make the shell material on the inner wall of the trench of hyperplasia which are characterized by accretionary wedges or reduction of the formation and growth of the complex,And island arc formation and migration,in order to achieve the growth of continental crust.The Gamma-mismatched metamorphic complex is located near the Gangrnarco in the southwest of the Gemma,and is composed of basalt,conglomerate,basic rock,high-pressure metamorphic rock,marble,Metamorphic quartz sandstone and other blocks.The blocks have the characteristics of long axis orientation,and the accretionary complexs thrust the Cantor set,and the relationship with the Cantor set is the thrust.The matrix often preserves the traces of the two phases.The first deformation is dominated by single shear,forming a typical single shear structure,such as smooth cover folds,spin broken spots and so on.Sandstone and other rigid blocks and matrix together with the first phase of a single shear deformation,the formation of the accumulation of complex rocks often block-block structure.In the first stage of deformation,a large amount of fluid is accompanied by a large amount of fluid.The concrete is characterized by the development of more quartz veins with single strata deformation.The long axis of the block formed by single shear deformation tends to be stable,mainly NNW and other NWW.The second deformation is the deformation of the first phase of the deformation based on pure shear.The first phase of the formation of the bedding layer of folds,in the weak matrix in the formation of the permeability of the fold cleavage,vertical bending fold hinge North East,North West,West three dominant position.Fold the axis of the surface is mainly west,northward times.The belt is mainly composed of the Upper Carboniferous Group,the Upper Carboniferous,the Lower Permian,the Meso-Lower Permian Yulonggongba Formation and the Middle Permian Longge Formation.The clastic rocks are similar to the clastic rock types,sedimentary facies and zircons in the accretionary complex,and are subjected to different tectonic processes for the same set of geological units.The tectonic pattern of the ridge is mainly composed of the reverse fault and the associated fold,and the development of the first phase of the permeability.The pleat belt system is a set of geological units for subduction scrape adhesion type during subduction.