The Qiangtang basin is located between Kekexili-Jingshajiang suture belt and Bangong-Lujiang suture belt, and is divided into the north part and south part by the central uplift that has no crop out of Mesozoic strata. When the Jinshajiang Ocean was closed, the subducting plate was subducted southward. In the central part of the Qiangtang basin, the cushioning effect of the asthenosphere resulted in the thermal doming of the mantle and subsequent large-scale anatexis. Mantle source materials and antectic materials were upwelled and extruded into the middle crust, leading to the thickening of the middle crust and the heating and weakening of the middle to upper crust, and resulting in the rapid deformation (detachment) and tectonic erosion, and in the isostatic uplifting and the formation of metamorphic core complex. The upwelling of anatectic materials would further enhance the buoyant repercussion, which would combine with the side stress due from extrusion in resulting in the formation of an extension The Qiangtang basin is located between Kekexili-Jingshajiang suture belt and Bangong-Lujiang suture belt, and is divided into the north part and south part by the central uplift that has no crop out of Mesozoic strata. When the Jinshajiang Ocean was closed, the subducting Plate was subducted southward. In the central part of the Qiangtang basin, the cushioning effect of the asthenosphere resulted in the thermal doming of the mantle and subsequent large-scale anatexis. Mantle source materials and antectic materials were upwelled and extruded into the middle crust, leading to the thickening of the middle crust and the heating and weakening of the middle to upper crust, and resulting in the rapid deformation (detachment) and tectonic erosion, and in the isostatic uplifting and the formation of metamorphic core complex. The upwelling of anatectic materials would further enhance the buoyant repercussion, which would combine with the side stress due from extrusion in resulting in the formati on of an extension