Structural Analysis and Deformation Phases of the Buqingshan Tectonic Melange Belt in the Southern Margin of East Kunlun

The Buqingshan tectonic melange was formed in the northward subduction process of oceanic lithosphere plate, which played an important role in the tectonic mélange of the southern margin of the East Kunlun.Through using the structure and lithology double geological mapping method, the Buqingshan tectonic mélange from Delisitan to Gerizhuotuo has been mapped with a large scale. After carrying out the study on material composition and deformational-metamorphic characteristics of the outcrops, the tectonic mélange has been divided into two parts, i.e., matrix with strong deformation and rock blocks with weak deformation, by combining with the study of the microstructures under the microscope. Based on the study on the geometry and kinematics between matrix and rock blocks of these tectonic mélange,the truncated relationship and tectonic association of the different geological bodies have been analyzed. As a result, 4 phases of deformation have been recognized and the relative deformation sequence of the Buqingshan tectonic mélange has been tentatively established, which provides new evidence for the study of tectonic evolution process of East Kunlun.