The area in western Taiwan and the Taiwan Strait is a foreland basin resulted from the flexure of the Eurasian plate caused by loading of the Taiwan mountain belt. The basin is formed since the overriding of Luzon volcanic arc of the Philippine Sea plate on top of the rifted continental margin of Eurasian plate in late Miocene (˜ 6.5 Ma). In central Taiwan, the foreland sequence is up to 5 km in thickness and exhibits a deepening followed by shallowing upward succession. The basal deepening trend (˜ 6.5-3 Ma) reflects the growing and advancing loads of the proto-Taiwan mountain belt with sediments sourced mostly from continental interior (i.e. China) and paleo-environments evolved from fluvial to outer shelf settings; the upper shallowing and coarsening upward succession (˜3 Ma to present-day) records the rapid growth and denudation of the orogenic belt and filling-up of the foreland basin with paleo-environments evolved from outer shelf to braided river settings. Notably, the presence of the spectacular upper Pleistocene, ˜1 km-thick succession of braided-river conglomerates (Hoyenshan Member of the Toukoshan Formation) at the top of the foreland basin indicates a delicate balance between basin subsidence and sediment supply during the latest stage of foreland basin development.