The Kyushu–Palau Ridge and adjacent basins are ideal locations for investigating the formation and evolution of marginal seas and initiation of plate subduction. In this study, the tectonic–sedimentary features and crustal structure of the Kyushu–Palau Ridge and adjacent basins were investigated using newly obtained deep seismic reflection and borehole data. The initial mechanism of subduction in the West Philippine Sea and its tectonic evolution are discussed. Two sets of sedimentary strata with different provenances occur in the eastern Philippine Basin. The thickness of the lower strata is variable, and most of the sediment was sourced from island arc volcanism on the Kyushu–Palau Ridge. These strata thicken towards the Kyushu–Palau Ridge, and volcaniclastic rock aprons are developed near the foot of the Kyushu–Palau Ridge. The upper strata have a relatively uniform thickness and comprise fine-grained, deep-water marine sediments. The crustal thickness of the West Philippine and Parece Vela Basins is 6–7 km, which is similar to the global average thickness of oceanic crust. The Moho beneath the West Philippine Basin has a broad and undulating form that mimics the thickness of the oceanic crust beneath the sediments. The depth to the Moho decreases towards the Central Basin Spreading Center. The Moho beneath the Parece Vela Basin is planar, which is in contrast to the undulating nature of the oceanic crust base in this area. The West Philippine Basin may have been located at the northern margin of Australia in the Southern Hemisphere during the Mesozoic. It developed gradually in a continental margin arc as a result of Palaeogene inter-arc and oceanic extension and contains fragments of continental crust. Seismic profiles and drillhole data in the West Philippine Basin reveal that compression occurred during the Eocene. Subduction along the paleo-Izu–Bonin–Mariana arc may have been caused by the far-field effects of the India–Asia collision. Subduction was accompanied by lateral propagation and a compressive stress field until the break-up of the island arc at ca. 30 Ma.

中文翻译：

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九州-帛琉中脊及邻近盆地构造-沉积特征及俯冲起始的多道地震反射研究

九州-帕劳海岭和邻近盆地是研究边缘海的形成和演化以及板块俯冲起始的理想地点。在这项研究中，利用新获得的深部地震反射和钻孔数据研究了九州-帕劳海岭及邻近盆地的构造-沉积特征和地壳结构。讨论了西菲律宾海俯冲的初始机制及其构造演化。菲律宾盆地东部发育两套不同物源的沉积地层。下部地层的厚度变化很大，大部分沉积物来自九州-帕劳海岭的岛弧火山活动。这些地层向九州-帕劳海岭方向增厚，在九州-帕劳海岭脚附近发育火山碎屑岩裙带。上层厚度相对均匀，由细粒深水海洋沉积物组成。西菲律宾盆地和帕雷塞维拉盆地的地壳厚度为6-7公里，与全球洋壳平均厚度相似。西菲律宾盆地下方的莫霍面具有宽阔且起伏的形状，模仿沉积物下方洋壳的厚度。莫霍面的深度向中央盆地扩张中心逐渐减小。帕雷塞维拉盆地下方的莫霍面是平面的，这与该地区洋壳底部的起伏性质形成鲜明对比。中生代时，西菲律宾盆地可能位于南半球澳大利亚的北缘。由于古近纪弧间和大洋伸展，它在大陆边缘弧上逐渐发育，并含有大陆地壳碎片。西菲律宾盆地的地震剖面和钻孔数据表明，始新世期间发生了压缩。沿古伊豆-小博宁-马里亚纳弧的俯冲可能是由印度-亚洲碰撞的远场效应引起的。俯冲伴随着横向传播和压缩应力场，直到岛弧在大约 10 处破裂。30马。