Structural Features Offshore West Hengchun Peninsula in Southern Taiwan

This study integrates and analyzes the marine geologic and geophysics data offshore west Hengchun peninsula for the purposes of investigating the distribution and activities of structures in the study area, especially on faults, diapirs, and anticlines. We have analyzed seafloor morphology and numerous seismic reflections profiles to construct a structural map of the area offshore West Hengchun Tableland, west Hengchun peninsula. The regional structures are rather complex, including strike-slip faults, reverse faults, normal faults, dispirs and a potential sliding sub-surface beneath seabed. Some faults may connect to the onshore faults. Based on regional tectonic setting and specific seismic reflection profile images, we suggest that the main structure in the region offshore-onshore West Hengchun Tableland is an anticline structure. After the anticline was formed, extension developed in the axial part of the anticline and normal faults formed, the west limb slid westward while the top of the anticline formed a rift valley which is the current Upper Hongtsai Canyon.