In collaboration with colleagues at the National Taiwan University, Drs. W.S. Chen and Y.G. Chen, we have been studying the foreland basin deposits of Taiwan using sequence stratigraphy, magnetostratigraphy, seismic data, and petrofacies to provide a framework to evaluate eustatic and tectonic controls on sedimentation in an active collisional foreland basin. Our analysis of the Pliocene-Pleistocene deposits of the Taiwan foreland basin has several implications for understanding the stratigraphic evolution of collisional marine foreland basins. Deposition in the Taiwan foreland basin appears to have been punctuated by at least five episodes of erosion and major valley incision. Recognition of these major erosional episodes in the Taiwan foreland basin suggests that the basin cannot be easily described using the traditional two-stage model of foreland basin development. In this model there is an early "underfilled" stage when sediment is trapped locally in the basin, and a later "overfilled" stage when sediment can bypass the basin. In the case of the Taiwan foreland basin, large volumes of sediment were eroded from within the foreland basin and transported to more distal parts of the foreland basin or to depocenters outside the foreland basin system during all stages of basin development. Another interesting aspect of our study is the distribution of well-developed unconformities along the side of the Taiwan foreland basin adjacent to the thrust belt (i.e., the proximal side). Many previous studies of foreland basins suggest that high rates of subsidence and abundant sediment supply along the proximal margins of foreland basins result in a relatively complete stratigraphic record with only minor unconformities. In the case of the Taiwan foreland basin, in contrast, several major regional unconformities are well developed along the proximal margin and much of the stratigraphic record has been eroded. The recognition of major unconformities is important from an exploration perspective because it suggests the possibility of stratigraphic traps associated with incised-valley deposits, and low-stand deltaic and submarine fan deposits.

Steeply dipping Pleistocene strata of the foreland basin.	Holocene anticline in Taiwan basin.

Temple in Taiwan.	Tea fields of central Taiwan.	Tending fields in central Taiwan. Thrust sheet in background.

Angular unconformity in Plio-Pleistocene strata, Taiwan. Person in lower left.	Country home in central Taiwan.

Fault scarp in 1999 Taiwan earthquake.	Fault scarp in 1999 Taiwan earthquake.	Fault scarp in 1999 Taiwan earthquake.