This paper reports original geochronological and trace-element data on basalts from the dredging sites 2776 and 2764 located in the southern part of the Central Fault in the Philippine Sea. The studies showed that the basalts from st. 2776 demonstrate chemical features of mid-ocean ridge and ocean island-arc basalts (N-MORB+OIAB), while basalts from st. 2764 show E-MORB+OIAB signatures. A comparative analysis of chemical composition of the volcanic rocks from both stations and Kyushu–Palau Ridge indicates that most of the rocks were derived from melts enriched in “subduction” and within-plate (WPB) components. However, WPB signatures occur in the rocks more frequently at the primitive mantle (PM) level and did not reach those of ocean-island alkaline basalts (OIB).

本文报道了来自菲律宾海中部断层南部挖泥场2776和2764的玄武岩原始地质年代学和微量元素数据。研究表明，圣保罗的玄武岩。2776年证明了中洋海脊和海洋岛弧形玄武岩（N-MORB + OIAB）的化学特征，而圣马丁岛的玄武岩则具有化学特征。2764显示了E-MORB + OIAB签名。对两个台站和九州-帕劳岭的火山岩化学成分的比较分析表明，大多数岩石来自富含“俯冲”和板内（WPB）成分的熔体。但是，WPB签名在原始地幔（PM）级别的岩石中发生的频率更高，但未达到海洋岛碱性玄武岩（OIB）的签名。