ABSTRACT
Several orogenic belts transecting south-eastern Asia are the sites of former convergent plate margins although there have been varying interpretations of the collisional framework of individual continental blocks, styles of convergence at these zones and the timing of respective collisions. A comprehensive tectonic study of eastern China, Mongolia and the southern Soviet Far East indicates the collision of the South China Block with a combined North China-Northeast China Fold Zone Block in the late Triassic-early Jurassic, their collective suturing to Eurasia in the late Jurassic-early Cretaceous, followed by the Sikhote Alin-Japan Block in the mid to late Cretaceous. The evidence is as follows: (a) A linear belt of late Triassic-early Cretaceous granites and granodiorites trends east from the Qinlingshan through the Dabieshan to the Huaiyang massif. Ophiolites, flysch, subduction zone melange, a paired metamorphic belt indicating north-dipping subduction and marine strata of Carboniferous to late Triassic age from the Qinlingshan define the suture between the North and South China Blocks; (b) A sinuous belt of ultramafics, blueschists, silicic to intermediate magmatism and west-and north-vergent folds and thrusts trend from the west margin of Ordos Basin through central Inner Mongolia and along the east Great Khingan Range to the Amur River. Coupled with a mid Jurassic-early Cretaceous unconformity a suturing of eastern Chinese blocks Eurasia along this zone is suggested; (c) A fold and thrust belt with ultramafics, flysch, blueschists and subduction zone melange along the Ussuri River in northeast China indicates the suturing of the Sikhote Alin-Japan Block to Eurasia along a west-dipping subduction zone in the mid to late Cretaceous. Similarly, a comprehensive tectonic study of southern China and Southeast Asia has revealed a complex regional mosaic of suture-bounded terrains which nucleated about the eastern, western and southern margins of the Yangtze Craton during the late Triassic and early Jurassic. The evidence is as follows: (d) A north-south trending belt of ophiolites, blueschists, calc-alkaline volcanics and subduction melange including granites, granodiorites and strongly deformed marine strata all of late Triassic age exposed in the Longmenshan of Sichuan merge with the Kekexilishan ophiolite zone into the Ailaoshan-Tengtaiohe ophiolite and blueschist belt in central Yunnan along which the Songban-Ganzi Complex and the Shan-Thai-Malaya Block join the Craton; (e) A southeastern prolongation of the Ailaoshan-Tengtiaohe belt bifurcates into the southeast-trending Konvoi zone of northern Vietnam and the north-south trending Pak Lay-Luang Prabang zone of Laos and Thailand. Zones of ophiolite, calc-alkaline volcanics and strong late Triassic deformation, they separate the Indosinia and Shan-Thai Malaya Blocks from the Craton respectively; and (f) A northeast-southwest trending belt of ultramafics, pillow lavas and strongly deformed Triassic marine rocks extends from the Guangxi-Guizhou border to just south of Nanjing, on-strike with coeval porphyry copper deposits (the Kweichow Geosyncline of Fromaget, 1935) is considered by Hsu (1981) as a suture between the Craton and a strip of terrain herein known as the Cathaysian Arc.
These findings differ significantly from previous interpretations of a late Paleozoic consolidation of south-eastern Asia as well as the existence of a true Pangaea.

Klimetz, M.P., 1983. The Pre-Tertiary geology and Mesozoic tectonic evolution of Eastern China, Southeast Asia and adjacent regions. Unpublished MSc. thesis, State University of New York at Albany. 216 pp., +xii; 14 folded plates (maps, charts)
University at Albany Science Library call number:  SCIENCE Oversize (*) QE 40 Z899 1983 K55

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