Estructura del sur de Taiwán a partir del estudio de campos potenciales

Abstract

The Taiwan orogen forms an active mountain range that has been evolving since the Late Miocene as a result of the oblique collision between the Philippine Sea Plate and Eurasian Plate. In this context, the Eurasian Plate subdues the Philippine Sea Plate, causing an oblique collision between the N-S Luzon Arc, and the continental margin of the Eurasian Plate. Due to this configuration, some inherited structures from de continental margin are highly oblique to the structural trend of the Taiwan thrust-and-fold belt. These inherited structures comprise sub-vertical faults that are presently being reactivated and are actively involved in the evolution of the structure, seismicity and topography of Taiwan, causing transverse zones in its thrust-and-fold belt and foreland. In this research, we propose to help define the deep structure in southern Taiwan, as well as the location and geometry of these inherited faults by using analytical techniques and modelling of gravity and magnetic data. The application of analyti- cal techniques, such as horizontal derivatives or the calculation of the radial averaged power spectrum, offers data of inte- rest that helps to identify the geometry and location of basement structures in the margin and Taiwan. Forward modelling of gravity and magnetic data further contributes to provide a better-constrained quantitative approach to their depth as they provide valuable information about the top of the basement. Integration of these results with structural and seismicity data helps to define the structure of the crust, allowing us a better interpretation on the kinematics of the faults and improving our understanding of southern Taiwan and Eurasian continental margin.