The Central Asian Orogenic Belt ( c . 1000–250 Ma) formed by accretion of island arcs, ophiolites, oceanic islands, seamounts, accretionary wedges, oceanic plateaux and microcontinents in a manner comparable with that of circum-Pacific Mesozoic–Cenozoic accretionary orogens. Palaeomagnetic and palaeofloral data indicate that early accretion (Vendian–Ordovician) took place when Baltica and Siberia were separated by a wide ocean. Island arcs and Precambrian microcontinents accreted to the active margins of the two continents or amalgamated in an oceanic setting (as in Kazakhstan) by roll-back and collision, forming a huge accretionary collage. The Palaeo-Asian Ocean closed in the Permian with formation of the Solonker suture. We evaluate contrasting tectonic models for the evolution of the orogenic belt. Current information provides little support for the main tenets of the one- or three-arc Kipchak model; current data suggest that an archipelago-type (Indonesian) model is more viable. Some diagnostic features of ridge–trench interaction are present in the Central Asian orogen (e.g. granites, adakites, boninites, near-trench magmatism, Alaskan-type mafic–ultramafic complexes, high-temperature metamorphic belts that prograde rapidly from low-grade belts, rhyolitic ash-fall tuffs). They offer a promising perspective for future investigations.

/pdf/tectonic-models-for-accretion-of-the-central-asian-orogenic-4rjcoan76s.pdf

Tectonic models for accretion of the Central Asian Orogenic Belt

[1] 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.

/pdf/accretion-leading-to-collision-and-the-permian-solonker-3zbth9mq3w.pdf

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

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.

/pdf/a-tale-of-amalgamation-of-three-permo-triassic-collage-2q1qk122oe.pdf

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

Paleozoic multiple accretionary and collisional tectonics of the Chinese Tianshan orogenic collage

http://sourcedb.igg.cas.cn/cn/zjrck/200907/W020101130538853730453.pdf

Middle Cambrian to Permian subduction-related accretionary orogenesis of Northern Xinjiang, NW China: Implications for the tectonic evolution of central Asia

The paper reviews and integrates new results on the evolution of the Paleo-Asian Ocean and its related geodynamics and geology of Altai-Sayan Region (ASR) in Central Asia. A revised terrane classification based on Vendian-Cambrian geodynamic units and evolution of terranes is described. Reactivated suture zones along the terrane boundaries are proposed. The obtained data suggest the important role of strike-slip deformations in the formation of mosaic-block structure of Central Asia. Those complicated and multi-stage deformations resulted from the Late Devonian-Early Carboniferous collision of Gondwana-derived terranes. The deformations reached their peak in the Late Carboniferous-Permian due to the collision of the Kazakhstan and Siberian continents. A system of sinistral strike-slip faults formed ASR along the margin of the Siberian continent as a result of the Late Carboniferous-Permian collision. The intrusion of granites occurred in East Kazakhstan and northwestern Gorny Altai in the Late Carboniferous and Permian. This resulted in the formation of the Northern Eurasia continent. Geodynamic evolution of the Paleo-Asian ocean and paleotectonics of ASR allow to recognize in the region the following five geodynamic stages: Vendian-Early Cambrian, Early Ordovician, Early-Middle Devonian, Late-Devonian-Early Carboniferous and Late Carboniferous-Early Permian times.

https://www.igm.nsc.ru/labs/lab212/~safonova/pdf/gsj-busl2001.pdf

Evolution of the Paleo-Asian Ocean (Altai-Sayan Region, Central Asia) and collision of possible Gondwana-derived terranes with the southern marginal part of the Siberian continent

https://www.igm.nsc.ru/labs/lab212/~safonova/pdf/jaes-busl2004.pdf

Late Paleozoic faults of the Altai region, Central Asia: tectonic pattern and model of formation

Late Paleozoic-Early Mesozoic Geodynamics of Central Asia

A Vendian-Cambrian Island Arc System of the Siberian Continent in Gorny Altai (Russia, Central Asia)

Fragments of Vendian-Early Carboniferous Oceanic Crust of the Paleo-Asian Ocean in Foldbelts of the Altai-Sayan Region of Central Asia: Geochemistry, Biostratigraphy and Structural Setting

K. Iwata

Papers

Evolution of the Paleo-Asian Ocean (Altai-Sayan Region, Central Asia) and collision of possible Gondwana-derived terranes with the southern marginal part of the Siberian continent

Late Paleozoic faults of the Altai region, Central Asia: tectonic pattern and model of formation

Late Paleozoic-Early Mesozoic Geodynamics of Central Asia

A Vendian-Cambrian Island Arc System of the Siberian Continent in Gorny Altai (Russia, Central Asia)

Fragments of Vendian-Early Carboniferous Oceanic Crust of the Paleo-Asian Ocean in Foldbelts of the Altai-Sayan Region of Central Asia: Geochemistry, Biostratigraphy and Structural Setting