Tropical vegetation and climate related to Dansgaard-Oeschger cycles and Heinrich events: high resolution palynological study of environmental change in northern South America during Marine Isotope Stage 3

Abstract

High resolution paleoclimate records have revealed that during the last glacial period, the climate of the Earth was dominated by abrupt and widespread millennial-scale climatic changes, the so-called Dansgaard-Oeschger (D-O) oscillations and Heinrich events (HEs). Today, little is known about the role of the tropics in the transmission and amplification of D-O oscillations and HEs. This study is based on the palynological analysis of marine sediment core MD03-2622 from the Cariaco Basin, off Venezuela, providing insight into the response of the northernmost South American vegetation to rapid climate changes between 70 and 28 ka. This study employs pollen and spores, and organic-walled dinoflagellate cyst to (a) describe main vegetation and marine productivity changes recorded in the Cariaco Basin in relation to D-O oscillations and HEs, (b) investigate the underlying mechanisms controlling the observed changes, and (c) provide terrestrial and tropical counterparts for the vast marine and high latitude evidence of D-O and HE variability.