Survey and integration of outcrop, core and well data for the interpretation of paleogeography, stratigraphy and sedimentary sources of Cretaceous-Cenozoic section from Amazon Basin.

Abstract

The Amazonas Basin is an intracratonic basin with paleozoic to cenozoic sedimentation, which covers part of the Brazilian states of Amazonas, Pará, Rondônia and Amapá. The most significant basin sedimentary package is the Alter do Chão Formation, from Cretaceous to Cenozoic age. Although the existing studies, there is no consensus regarding the lithostratigraphic subdivision, composition, provenance, age, paleocurrent patterns and depositional model active in the Alter do Chão Formation. The study of sandy dominantly sequences of this interval is extremely important for understanding the evolution of drainage patterns in the region and their response in relation to Andean tectonic events and local subsidence. In addition, these sandstones form the Alter do Chão Aquifer, whose understanding of the depositional model will provide a basis for carrying out studies that enable the efficient exploration of the aquifer and minimize the chances of water contamination. For the resolution of the uncertainties addressed, studies on a regional scale will be carried out, including sedimentological and architectural outcrops survey, paleocurrent analysis, petrographic analysis, geochemical and isotopic analysis, analysis of data from ANP wells and core description. The present project aims to support the interpretations of descriptions obtained in the core to be drilled and aggregate them with the data obtained in wells and outcrops, with the main objective of understanding the paleogeographic evolution of the Alter do Chão Formation.