The axial ridge of the South China Sea: a Seabeam and geophysical survey

Abstract

Observations from the 1985 R/V Charcot cruise Nanhai were used to document NW-SE spreading in the 150-200km wide axial region of the South China Sea (SCS). The data include Seabeam and single channel seismic profiles, complemented by magnetic and gravity anomalies. Detailed surveys were performed on both sides of the ridge to examine the structural fabric. Side scan sonar data is also presented, as well as results from dredges and cores. These observations imply that the last stage of spreading in the SCS basin was oriented NW-SE, and created oceanic crust transected by numerous tranform faults trending SW-SE in the central area. Two alternative kinematic interpretations for the evolution of the basin are presented. -from Authors