Palynologie et géochimie de haute resolution dans le NW de la Colombie:indicateurs climatiques pour les tropiques

This research investigates a continuous, Lateglacial-Holocene, sedimentary sequence cored in wet zone of the Páramo de Frontino at an altitude of 3460m amsl. This high plateau at the northwestern termination of the Colombian Western Cordillera is strategically situated close to the Pacific and Atlantic oceans, where it is susceptible to receive dry influences from the Caribbean zone, meanwhile it is exposed on its western side to the influence of El Niño. The investigated section is 14 meters thick. Both geochemistry (fluorescence X) and palynology have been used as paleoecological tools. Variations in the concentration of Fe and Ti are a proxy which provides a direct, high-resolution measure of rainfall and runoff from local watersheds. Palynology provides a proxy for vegetation changes which can be related to temperature and water level variations in the wet zone.