Palinoestratigrafia do intervalo Alagoas da Bacia do Araripe, Nordeste do Brasil

Abstract

Any knowledge achieved about the geological history of the Araripe Basin contributes effectively for understanding the geology of the entire Northeastern Brazil. Besides the several researches concerning the rich fossiliferous content of that basin, specially of the Alagoas Stage, there are few studies focused on biostratigraphical aspects, which are especially important for understanding the geological evolution of a basin. Aiming at achieving a biostratigraphical framework to the Alagoas Stage in the Araripe Basin, palynological analyses were proceeded on 167 samples from 14 wells drilled at the Eastern portion of the Araripe Basin. The interval, composed of sandstones, microclastic sediments, limestones, and evaporites, was assigned to the Rio da Batateira and Santana Formations. The biostratigraphical analyses showed that only P-270.2 and P-280.1 subzones, from Regali & Santos (1999), are present in the studied area. Comparison of these results with data from other authors allowed to recognize correlated intervals in the Parnaíba, Grajaú, Potiguar, and Sergipe basins.