Material composition characteristics of Naijtal Group in subduction accretion complex on the southern slope of East Kunlun Mountains

The formation of the East Kunlun Mountains experienced long-term tectonic evolution, collage, collision and the complex orogenic process, thus generating very complex geological structure. During its northward subduction, Ordovician-Silurian Kunduz formed typical subduction accretion complex on the southern slope of East Kunlun Mountains. In addition, the extremely complicated composition of the Naijtal Group is also the vital component in this belt. Through field investigation, the authors found that the Naijtal Group has very complicated composition, and consists of ophiolite fragments-bearing deposits, ocean mud calcium deposits, midocean ridge-ocean island deposits that contain ophiolite fragments and ocean pelitic calcareous sediments, abyssal-bathyal sediments with the characteristics of turbidite on the continental slope, foreland basin flysch sediments and volcanic island arc material composition. The contact relationships between different rock combinations are ductile shear contact after faulting, and these rocks with strong tectonic deformation have very different ages and tectonic environments. In the process of long-term subduction, different materials collaged or heaped together at the edge of the east Kunlun block in the forms of rocks with different sizes and shapes.