Architecture of pre-vegetation alluvial systems of the Tombador Formation (Mesoproterozoic, Northeastern, Brazil)

• Grant number: 11/50280-4
• Support Opportunities: Regular Research Grants
• Start date: May 01, 2011
• End date: November 30, 2014
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal Investigator: Renato Paes de Almeida
• Grantee: Renato Paes de Almeida
• Host Institution: Instituto de Geociências (IGC). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Alluvial systems are very sensitive to variations in rates of subsidence and sediment deposition, and may record the evolution of these external controls as changes in the architecture of their deposits. Facies models based on recent alluvial systems consider an important division between alluvial systems of dry and humid climates, based on considerations of variations in flow and stability of channel margins, as a function of the nature and abundance of vegetation. The study of alluvial systems formed prior to the appearance of terrestrial plants represents a great challenge and require specific facies models due to the absence of the mechanisms that link climate to depositional architecture in more recent systems. This research project aims to contribute to the development of facies models and criteria for interpreting the stratigraphic evolution of sedimentary sequences prior to the appearance of vegetation on the continents. In order to achieve this, we will study the depositional architecture and provenance of the alluvial deposits of the Tombador Formation (Mesoproterozoic), in Chapada Diamantina, Bahia, northeastern Brazil. The unit is composed of exceptionally well exposed and laterally continuous alluvial successions which have potential interest for the development of facies models for pre-vegetation rivers. Sedimentary facies, facies sequences and geometry of architectural elements will be documented and interpreted for the elaboration of specific facies models for these succession. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

DE ALMEIDA, RENATO PAES; MARCONATO, ANDRE; FREITAS, BERNARDO TAVARES; TURRA, BRUNO BOITO. The ancestors of meandering rivers. GEOLOGY, v. 44, n. 3, p. 203-206, MAR 2016. (11/50280-4)