Structure and possible intrusive magmatic nature of the border at the south-eastern shelf of the Korean peninsula

The structure and possible intrusive nature of the Korean peninsula south-eastern shelf border dam (China-Korean shield) have been analyzed on the Bouguer anomalies map and seismic reflection data. It is characterized by the linear positive (40-60 mGal) anomaly (220+100 x 5 km) stretching as far as the Tsushima (Korean) strait. According to the seismic data, both the dam and the anomaly have appeared as a result of basic or ultra-basic rocks intrusion into the acoustical basement and Neogene-Quaternary sedimentary cover (megadike).