West Pacific and North Indian Oceans and Their Ocean-continent Connection Zones: Evolution and Debates

The Indian Ocean and the West Pacific Ocean as well as the ocean-continent connection zones in between constitute the core of "The Belt and Road" Program. In-depth scientific understanding of the natural environment, mineral resources, geo-hazard distribution, energy potential and other geoscientific problems of the region is critical for the earth science communities to well serve the urgent needs of the region. This paper mainly discusses the following key scientific issues in the West Pacific and North Indian oceans and their connection zones: 1, modern marine geodynamic problems related to the two oceans. Based on the research and development needs in the two oceans and the ocean-continent transitional zones, this item includes the following questions: (1) origin, growth, death and evolution of plates involving the two oceans, for example, ① the initial origin and process of the triangle Pacific Plate, including the origin and difference of the Galapagos and West Shatsky micro-plates; ② spatial and temporal evolution, current status and future trends of the plates in the paleo- or present Pacific Ocean and their impacts on the evolution of the East Asian Continent Domain; ③ origin and evolution of the Indian Ocean and the formation and break of related supercontinents. (2) the latest progress in the research of mid-oceanic ridges and related problems: ① the ridge- hotspot interaction and ridge accretion, the relationship between vertical accretion behavior in scales of thousands years or tens of thousands years and lateral spreading in scale of millions years at the mid-oceanic ridges aged 0 Ma; ② differences in the formation mechanisms between back-arc basin extension and normal mid-oceanic ridge spreading; ③differences between the spreading of ultra-slow Indian Ocean and rapid Pacific, differences between active and passive spreading, and the push force onto the mid-oceanic ridges; ④ mid-oceanic ridge jumping and spreading termination: causes of the intra-oceanic plate reorganization, termination, and spatial jumps; ⑤ the interaction between mantle plume and mid-oceanic ridge. (3) intra-oceanic subduction and tectonics: ① the origin of intra-oceanic arc and subduction, ridge subduction and slab windows at continental margins, transform faults and transform-type continental margin; ② origins of large igneous provinces, oceanic plateaus and seamounts chains. (4) oceanic core complex and rheology of oceanic crusts in the Indian Ocean. (5) research advances in the driving force within oceanic plates, including mantle convection, negative buoyancy, trench sunction and mid- oceanic ridge push etc. 2, ocean-continent connection zones between the two oceans, including: (1) properties of continental margin basement, for example, if the crusts of the Okinawa Trough, the Okhotsk Sea, and east of New Zealand are continental crust or oceanic crust, and the origin of micro-continent in oceans; (2) the process of ocean-continent transition and coupling, comparison of major events between the West Pacific Ocean seamount chains and continental margins, mantle exhumation and the ocean-continent transition zones, origins of transform fault within backarc basins, formation and subduction of transform-type continental margins; (3) strike-slip faulting between the West Pacific Ocean and the East Asian Continent and its temporal and spatial range and scale; (4) connection between deep and surface processes within the two oceans and their connection zones, namely the assembly among the Eurasian, Pacific and India-Australia plates and the related effect from the deep mantle, lithosphere, to crust and surface Earth system, and some related issues within the connection zones of the two oceans under the super-convergent background. 3, relationship, especially their present relationship among the Paleo- or Present Pacific plates, the Tethyan Belt, the Eurasian Plate or the plates within the Indian Ocean and their evolutionary trends. At last, this paper makes a perspective on the development of marine geology in the two oceans and one zone.