| dc.description.abstract | GPS data in southwestern Taiwan show that horizontal velocity increases from north toward south. The crustal movement is thus inferred to be more active in the south. However, outcropped faults and folds become less toward south in the Tainan-Kaohsiung area based on the geological map. In addition, earthquake activity does not reflect the active crustal movement. Therefore, a change of deformation mechanism from north to south occurred in the study area.
In this study, we apply the kink method and balanced cross-section to construct four sections from the Lungchuan to Fengshan area using surface, well log, and seismic data in Tainan, Kaoshiung and Pingtung area. Our goals are to understand the subsurface structure and to document the relationship between faults and folds. Furthermore, we use stratigraphic separation diagrams to study stratigraphic separation along major faults in this area.
Results of the study indicate that :
(1)In the western Chishan fault, the basal decollement lies probably in the base of Changchihkeng Formation or the older strata. The depth to detachment is about 9 to 12 km below the sea level. However, in the Pingtung plain, the basal decollement should be placed below the Changchihkeng Formation.
(2)A different structural style occurred across the western and eastern Chishan fault.
(3)The folds in front of the Lungchuan and Gutingkeng faults are interpreted to be fold-propagation fold, and these two faults crop out the surface along the fold axis.
(4)Stratigraphic separation diagrams indicate that displacement transfer occur in this area, where crustal shortening is achieved by thrusting in the north whereas folding in the south. | en_US |