A Tale of Amalgamation of Three Permo-Triassic Collage Systems in Central Asia: Oroclines, Sutures, and Terminal Accretion

Wenjiao Xiao,Hanlin Chen,Min Sun,Chao Yuan,Brian F Windley,Shu Sun,Baochun Huang,Jiliang Li,Chunming Han

doi:10.1146/annurev-earth-060614-105254

Abstract

The Central Asian Orogenic Belt records the accretion and convergence of three collage systems that were finally rotated into two major oroclines. The Mongolia collage system was a long, N–S-oriented composite ribbon that was rotated to its current orientation when the Mongol-Okhotsk orocline was formed. The components of the Kazakhstan collage system were welded together into a long, single composite arc that was bent to form the Kazakhstan orocline. The cratons of Tarim and North China were united and sutured by the Beishan orogen, which terminated with formation of the Solonker suture in northern China. All components of the three collage systems were generated by the Neoproterozoic and were amalgamated in the Permo-Triassic. The Central Asian Orogenic Belt evolved by multiple convergence and accretion of many orogenic components during multiple phases of amalgamation, followed by two phases of orocline rotation.

Highlights

The key to defining the termination of accretion in an accretionary orogen is to recognize the initial magmatic processes that are generated at the time of ocean closure
Geochemical and isotopic data for magmatic rocks related to terminal collision along the Solonker-Xar Moron suture zone in the southern Central Asian Orogenic Belt (CAOB) that record such processes following closure of the PaleoAsian Ocean (Figure)
The linear generation of high Sr/Y melts along the Solonker-Xar Moron suture zone defining the onset of postsubduction processes in the southern CAOB

Summary

Introduction

The key to defining the termination of accretion in an accretionary orogen is to recognize the initial magmatic processes that are generated at the time of ocean closure. Shan Li1, Tao Wang1, Wen-Jiao Xiao2, 3, Sun-Lin Chung4, 5, Simon A. For citation: Li S., Wang T., Xiao W.-J., Chung S.-L., Wilde S.A., 2017.

Results

Conclusion