Abstract: The study area is located in the east China Pioneer Area of the eastern Pacific Ocean. Detailed analysis of the topography and tectonic geomorphology was carried out based on the multi-beam water depth data and single-channel seismic profiles combined with the geological setting in the Pacific Ocean. The water depth of the study area ranges between 5700 and 3800 m. The main tectonic geomorphology units in the study area are linear faulted hills and magma-type sea mountains. Linear faulted hills can be divided into west and east parts. Its size is controlled by the NNW-trending faults, and is supposed to be the result of the thermal subsidence of oceanic crust. Magma-type sea mountains, including three sub-zones, were formed by the eruption or incursion of magma deep beneath the oceanic crust. There are different sizes and shapes of sea mountains in the study area, including single peak and multi-peak mountains. The formation and evolution mechanism of oceanic morphology is discussed in this paper, and the results may contribute to the study of oceanic geomorphology and the associated dynamics.

Key words: Eastern Pacific Ocean, China Pioneer Area, tectonic geomorphology, magma activity