Identification and evolution of tectonic units in the Philippine Sea Plate

The Philippine Sea Plate is located at the convergence zone of the Eurasian Plate, the Pacific Plate, and the Indo-Australian Plate. This paper divides the Philippine Sea Plate into two second-order tectonic units and eight third-order tectonic units by summarizing the marine geological, geophysical, and submarine geomorphological data of the Philippine Sea Plate collected for years and referring to the seafloor spreading theory and the trench-arc-basin system. The two second-order tectonic units are the West Philippine Sea block and the Izu-Bonin-Mariana arc-basin system. The former includes the West Philippine Basin, the Huatung Basin, the Daito Basin, and the Palau Basin, while the latter consists of the Kyushu-Palau Ridge, the Shikoku-Parece Vela Basin, the Izu-Bonin Arc, and the Mariana Arc. Furthermore, this study concludes that the Philippine Sea Plate has undergone three stages of tectonic evolution, namely the early stage of the evolution of marginal basins with Cretaceous basement (Early Cretaceous), the middle stage of the spreading of the West Philippine Basin (Eocene), and the late stage of the subduction of the Izu-Bonin-Mariana arc-basin system (Oligocene-present). The Kyushu-Palau Ridge is a window to discover the tectonic evolution of the Philippine Sea Plate due to its unique geographical location. (C) 2022 China Geology Editorial Office.