BIOCHRONOSTRATIGRAPHIC KNOWLEDGE EVOLUTION IN THE BRAZILIAN CRETACEOUS MARGINAL BASINS BASED ON CAKCAREOUS NANNOFOSSILS The use of the biostratigraphy effective contributes to the resolution of stratigraphic problems, allowing the strata correlation based on the use of fossils. Its use as a standard tool in the oil exploration, provided advances in the biostratigraphic concepts and the geological knowledge. Due to the difficulty in recover macrofossils in drilled samples, microfossils are the best alternative for correlations, paleoecological studies and chronostratigraphic placement of wells. Calcareous nannofossils is one of the most important groups, because of their abundance in rocks, the wide geographic distribution, rapid speciation and the laboratory procedure. This study aims to present the importance of the biostratigraphy and the evolution of the biochronostratigraphic knowledge of the Upper Cretaceous in the Brazilian marginal basins, by means of the main biostratigraphic zonations based on calcareous nannofossils. Citation: Guerra R. do M., Tokutake L. R. 2011. Evolução do conhecimento biocronoestratigráfico do Cretáceo nas bacias marginais brasileiras baseado em nanofósseis calcários.
