(Table 1) Age determinations of basement rocks of DSDP Leg 31@en

The origin and development of the Phillipine Sea have been central issues in tectonic studies of a marginal sea: the deep-sea drilling project (DSDP), Leg 31, was primarily intended to resolve the question. Unfortunately, at only two of the Leg 31 sites (292 and 296) were microfossils indicating the age of the basement recovered, so the age of the ocean basin, had to be deduced by dating the drilled basement rocks.菲律宾海（Philippine Sea）的成因与演化，长期以来都是边缘海构造研究的核心议题。深海钻探计划（Deep-Sea Drilling Project, DSDP）第31航次，最初便是为解决这一问题而实施。但遗憾的是，仅在该航次的292与296两个钻探站位中，获取到了可指示基底年代的微化石，因此该海盆的形成年代只能通过对钻探获得的基底岩石进行年代测定来推求。