冲绳海槽中部的火山口

PRELIMINARY STUDY ON VOLCANIC CRATER IN THE MIDDLE OKINAWA TROUGH

冲绳海槽位于中国东海大陆架的东部,与东海陆架相连,是一个新生的孤后盆地,海底火山活动和地震频繁,断裂体系十分发育,沉积了十分丰富的火山碎屑沉积物,根据海底沉积物中的浮岩与磁铁矿含量变化,结合水深资料推测了海底火山口的位置,结果表明Z 14—5测站(27°18′N、127°12′E)附近是一个火山口。

The Okinawa Trough is a back-are basin located in the eastern East China Sea shelf, and it is thought to be in a nascent rifting stage of back-arc spreading. In the Okinawa Trough, volcanic activities and earthquakes occur frequently, many faults are in the Trough, and also there is abundant pyroclastic sediment. On the basis of the content of pumice and magnetite in marine sediments and combining with the data of water depth, the study result shows that, there is a volcanic crater near core Z 14-5（27°18′N.127°12′E）.