Facies analysis and paleosol characterization of Urucuia group in the Sao Domingos - GO region

Abstract

The Sanfranciscana basin is a wide intracratonic basin sub-divided in Abaeté sub-basin and Urucuia sub-basin which includes four Groups of Neo Paleozoic to Neo Cretaceous ages, among them there is the target of this study, the Urucuia Group (Upper Cretaceous). The Urucuia Group has the largest rock volume and areal distribution of the basin. Its rocks constitute two Formations, the basal named Posse overlaid by Serra das Araras Formation. In a continental environment where there is a few fossil contents, the paleosol study can bring important information about climatic and geomorphologic conditions, and biological activity being possible to do an environmental reconstruction. Therefore, this project aims to elaborate a paleoenvironmental model to the Upper Cretaceous of the Sanfraciscana basin through facies analysis and paleosol characterization. The fieldwork was accomplished in the outcrops of the Urucuia Group situated near to São Domingo (GO) town. Outcrop descriptions, photographic registration, and sample collection to laboratory analysis were the methodology applied. The outcrop description was made by the identification of lithologies, textures, sedimentary structures, paleocurrents, fossil content, bed geometry, as well as paleosol macromorphologic description.