Stratigraphic architecture of the Albian fluvial deposits of the São Mateus Formation base, north of the Espírito Santo Basin

Abstract

The alluvial deposits from the São Mateus Formation (Albian of the Espírito Santo Basin) consist of important reservoirs. However, there are few studies detailing the stratigraphy of this stratigraphic range. Consequently, this paper presents a study at the high-resolution stratigraphic subdivision of the basal section consists predominantly of alluvial deposits. Against the difficulties presented for the stratigraphic correlation of these deposits, the strategy of correlation was the subdivide of the succession alluvial in stratigraphic cycles. This method is based on the variation in the ratio between the rates of creation of accommodation and supply sediment (A: S) that directly controls the degree of amalgamation of sandstone bodies of the fluvial channels. Therefore, six cycles were defined composed internally for systems tracts of high and low accommodation. These cycles reflect the structuring of the amalgamation disposition of the fluvial channels with the deposits external to the channels through the ratio between the accommodation rate (A) and the sedimentary influx rate (S) forming cycles.