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根据精密回声测深仪(PDR)、单道水枪及气枪、多道气枪、质子硅力仪、三分全磁力仪及打捞器的详细测量结果,揭示出位于所研究区域的冲绳海槽轴部的中央地堑由五部份组成.这些地堑全部呈雁行排列.伊平星地堑(Iheya Graben)是最明显的.没有发现存在着与雁行式地堑相连的转换断层的证据.在这些地堑的轴邵新近发现了一个玄式岩海岭及一些海底丘.从这些中部海底丘和海岭采集到榄橄玄武岩样,为钾氮法年龄低于1 Ma的岛弧型高铝玄武岩.在附近还采集到一些流纹岩.英安岩和少量的英安质安山岩,它们的年龄低于1 Ma(钾氮法和裂变径迹年龄),为双模式火山作用结果.因此,岩石学方面的证据并不支持存在着洋壳的观点,而表明中部冲绳海精是一个扩张应力场.可以断定中布冲绳海槽处于大陆边缘的早期扩张过程的裂谷阶段.
Detailed measurements of the precision echo sounder (PDR), single-channel water gun and air gun, multi-channel air gun, proton-silicon force meter, Of the central graben consists of five parts, all of which are geese arranged in geese and the Iheya Graben is the most obvious, with no evidence of conversion faults associated with the geese cuttings. Shale Shao Shao recently discovered a porphyry rock Ridge and a number of seabed mound from these central seabed mound and Ridge collected Olive basalts, potassium-nitrogen method for the age of less than 1 Ma Island arc-shaped high-alumina basalts in the vicinity Some rhyolite, dacite and a small amount of quartzitic andesite are also collected and their age below 1 Ma (potassium-nitrogen and fission-track ages) is the result of dual-mode volcanism. Therefore, The evidence does not support the existence of the oceanic crust and suggests that the central Okinawa sea fines is an expanding stress field, and the rift stage of the early expansion of the Okinawa Trough in the margin of the continental margin may be concluded.