Abstract:
The Wutaishan collision orogen may be divided into three tectonic slices by applying the tectonic lithologic event method;from south to north they are the forearc mélange zone,paleoisland arc system and backarc mélange zone.Five stages are proposed for the tectonic evolution of the Late Archean Wutaishan collision orogen:the ocean basin spreading stage(>2 600 Ma),stage of subduction of the southern ocean basin beneath the microcontinental blok and transformation of the microcontinental block into an island arc (2 600~2 500 Ma),stage of forearc collision backarc subduction(2 550~2 500 Ma),continent continent collisison stage(2 550~2 450 Ma),and extension stage(2 500~2 400 Ma).