THE BOUGUER ANOMALIES AND DEPTHS OF MOHOROVICIC DISCONTINUITY IN THE SOUTH CHINA SEA REGION

The South China Sea is situated at the continsntal margin of South China.In this region,there are both continental and oceanic crusts.The values of Bouguer gravity anomalies on the continental shelf are low positive or low negative.Because the depth of the Mohorovicic discontinuity in this region is about 26-32 km below sea level,the crust belongs to the continental type.The values of Bouguer gravity anomalies in the deep-sea region are more than 250 mgal and the depth of the Moho-surface is about 10-15 km below sea level,so the crust is of oceanic type.The values of gravity anomalies and depths of the Moho-surface,obtained over the continental(and island) slope,range between those regions mentioned above,so the crust belongs to the transitional type.The continental crust is inferred to be directly in contact with the oceanic crust as a result of a lithospheric fault.