Accretion leading to collision and the Permian Solonker suture, Inner Mongolia, China: Termination of the central Asian orogenic belt

Abstract

The Solonker suture records the termination of the central Asian Orogenic Belt (CAOB). However, tectonic development of the Solonker suture is poorly understood. We report new field data for the Ondor Sum melange in the Ulan valley, and present a new evaluation of the orogenic belt extending from the southern Mongolia cratonic boundary to the north China craton within the context of a new geological framework and tectonic model, which incorporates relevant data from the literature. The southern accretionary zone between the north China craton and the Solonker suture is characterized by the Mid‐Ordovician‐Early Silurian Ulan island arc‐Ondor Sum subduction‐accretion complex and the Bainaimiao arc. This zone was consolidated by the Carboniferous‐Permian when it evolved into an Andean‐type magmatic margin above a south dipping subduction zone. The northern accretionary zone north of the Solonker suture extends southward from a Devonian to Carboniferous active continental margin, through the Hegenshan ophiolite‐arc accretionary complex to the Late Carboniferous Baolidao arc associated with some accreted Precambrian blocks. This northern zone had consolidated by the Permian when it developed into an Andean‐type magmatic margin above a north dipping subduction zone. Final subduction of the central Asian ocean caused the two opposing active continental margins to collide, leading to formation of the Solonker suture in the end‐Permian. Predominant northward subduction during final formation of the suture gave rise in the upper northern plate to a large‐scale, postcollisional, south directed thrust and fold belt in the Triassic‐Jurassic. In summary, the CAOB underwent three final stages of tectonic development: early Japanese‐type accretion, Andean‐type magmatism, and Himalayan‐type collision.

The Permian–Triassic granitoids in Bayan Obo, North China Craton: A geochemical and geochronological study

“…10), which is consistent with their post-collisional characteristics. It is also consistent with the previous studies on the Bayan Obo REE deposit (Ling et al, 2013), i.e., plate subduction during the closure of the Palaeo-Asian Ocean started in the Neoproterozoic (Khain et al, 2003) and lasted until the Carboniferous/Permian (Xiao et al, 2003).…”

Late Triassic high-Mg andesite/dacite suites from northern Hohxil, North Tibet: Geochronology, geochemical characteristics, petrogenetic processes and tectonic implications

“…further suggested that the Late Triassic-Late Jurassic collision between the southern Kunlun and Northern Qiangtang active margins possibly generated a collisional complex including two forearc basins and their accretionary complexes. This kind of collision is typical in accretionary orogens, which can be found in modern examples like the Molucca Sea (Hall, 2002) and their ancient counterparts such as Inner Mongolia (Xiao et al, 2003), the Kelameili suture between the Northern Tianshan arcs and the East Junggar arcs (Xiao et al, 2004), and the Mongol-Okhotsk suture (Tomurtogoo et al, 2005). Therefore, we suggest that the northern Hohxil high-Mg andesites and dacite suites, occurring just south of the Anyimaqen-Kunlun-Muztagh suture, were most likely generated in a forearc setting (Fig.…”

Exhumation of the Dahinggan Mountains, NE China from the Late Mesozoic to the Cenozoic: New evidence from fission-track thermochronology

“…1a). Since the Late Paleozoic, it has undergone long-term plate subduction and continent-arc and/or microcontinent-continent collisions before the ultimate collision between the North China-Mongolian Block and the Siberian Craton (Zhao et al, 1990(Zhao et al, , 1994Sengör et al, 1993;Van der Voo et al, 1999;Xiao et al, 2003;Jia et al, 2004;Li, 2006). Consequently, widespread Phanerozoic granitoids were formed in NE China and along the north margin of North China Block (Wu et al, 2000(Wu et al, , 2003(Wu et al, , 2005Jahn et al, 2001;Sun et al, 2001;Meng, 2003;Hong et al, 2004).…”