Mecanismos de fertilização inferidos através do registro de cocolitoforídeos durante o Quaternário Tardio na Margem Continental Sul-Brasileira

Abstract

Mechanisms of fertilization inferred from the coccolithophorid record during the Late Quaternary in the southern Brazilian Continental Margin. This study aimed to understand which fertilization mechanisms are preponderant over oceanic primary productivity and its relationship with remarkable climatic events of the Late Quaternary in the south of the Brazilian Continental Margin. The investigation was carried out through geochemical and coccolithophorid analyzes in the SIS188 marine core, recovered from the Pelotas Basin slope at 1,514 m water depth. The record shows that productivity was related to insolation (with a predominance of the precession cycle) and atmospheric processes that influence ocean dynamics. During the glacial period (MIS 3 and 2), the highest productivity intervals were associated with the expansion of the upwelling system in the Santa Marta Cape region, driven by the northeast winds. However, the interval of greatest productivity recorded in the core is the initial Holocene, when the upwelling was attenuated. This substantial increase in productivity is attributed to lagging processes resulting from the decrease in sea level that occurred during the Last Glacial Maximum. Keywords: productivity, Pelotas Basin, upwelling, Quaternary, coccolithophorids.