Abstract:

Abstract:  The paper reviewed the history and progress of research in accretionary orogenesis, and considered the accretionary orogenesis an important way of continental accretion throughout the entire earth history. We supposed that the formation and evolution of orogenic belt could be explained by the evolution of composite arcbasin systems in the active continental margins, and the formation of super orogenic system was closely related to the composite arcbasin systems formed on one or two sides of an ocean, which were controlled by the subduction of longlived oceanic lithosphere. Accretionary orogenic systems in the active continental margins were built up by a series of collision and accretionary orogenies, including arcarc and arccontinent collision, accretion of forearc and backarc subduction complex, and collage of oceanic plateaus/islands/seamounts and exotic blocks (terranes). Convergent crustal consumption zone formed when the longlived oceanic lithosphere was eventually eliminated; the super orogenic complex was formed by the interconnection of orogenic systems that were transformed from the composite arcbasin systems on both sides of longlived oceanic lithosphere. Subsequently the super orogenic system was superimposed by the continentcontinent collision orogeny and intracontinental compression/extension, which caused more complexities. The convergent crustal consumption zone, therefore, is the key to understanding the formation and evolution of orogenic systems. All kinds of orogenic processes of composite arcbasin systems in the active continental margins were actually the courses of accretionary orogenesis. The study of composite arcbasin systems is very important for subdividing the orogenic minute architecture, and also basic for understanding the components, textures and structures of orogenic systems. The postorogenic intracontinental tectonic evolution was also controlled by the evolution histories of composite arcbasin systems. The composite arcbasin systems and continental margin systems provide more comprehensive records of Wilson cycles than fossil oceanic lithosphere. According to the ideas of composite arcbasin systems, a new model for the evolution of Tethyan ocean has been proposed, that the Gangdese belt had been controlled by the subduction of the Tethyan oceanic lithosphere since the Carboniferous, then an accretionary orogeny toward the ocean took place since the Triassic, and finally the Tethyan ocean vanished at the end of the Early Cretaceous.

Key words: Key words: accretionary orogenesis; composite arcbasin systems; orogenic belt; orogenic system; the convergent crustal consumption zone; the Tethyan ocean