Abstract:

 From the Mesozoic Andean continental margin to the presentday arcbasin system, the evolution of landform of Southeast China continental margin underwent three stages, i.e., Palaeocathysian mountains at the end of the Cretaceous, peneplain in the late Paleogene, and seabasins in the Neogene. Leveling of the Palaeocathysian mountains reduced the crustal thickness and thus decreased the imbedding depths of the Moho and increased the bouguer gravity. On the other hand, descending crustal temperature resulted in both the crystallizing of the Mesozoic crustal melting layer and the cutting down of the faults over the layer. Coupling of the above factors led to the downward movement of faultblocks in a large scale initiated in the Miocene along with development of the normal fault system in the seabasin, eruption of basaltic magma, lowering position of the Moho, and formation of the islandarc and blockmountains on the both sides of the subsiding region.

Key words:  Southeast China, continental margin, Cenozoic, tectogeomorphologic evolution