THERMAL HISTORY, EXHUMATION, UPLIFT AND LONGTERM LANDSCAPE EVOLUTION OF THE WESTERN SOUTH ATLANTIC PASSIVE CONTINENTAL MARGIN, BRAZIL

Passive continental margins are important geoarchives related to mantle dynamics, the breakup of continents, lithospheric dynamics and other processes. The aim of the study is to quantify the temperature, exhumation, rock and surface uplift, and long-term dynamic topography evolution of the western South Atlantic passive continental margin (WASPCM) in the states of Paraná and Santa Catarina (Central Brazil) along different transects. Special emphasis were put on old reactivated fracture zones. Therefore several transects were sampled perpendicular and parallel to the margin in a high resolution with altitudes from sea level up to 1400 m a.s.l. All togesther around 100 samples comprising sandstone, volcanic rock, granite, gneiss, were taken and proceeded to reveal apatite and zircon for apatite and zircon fission track and (U-Th-Sm)/He. Together with t-T path modelling these data are used to determine the dynamic topography evolution. The continental margin process-response systems are caused by the interaction between endogenic and exogenic forces that are related to the rift - drift “passive” continental margin evolution of the South Atlantic. Since the Lower Creatceous the data show three exhumation events with fast movements of blocks cutted by old major fracture zones. Compared to the old term "passive" continental margin these new data represent a complex and active evolution of the Southeastern passive continental margin in Central Brazil until today.