Fluvial dynamics and sedimentary deposits in the Amazon channel: providing tools to decipher the paleogeographical evolution of Amazonia and deposits of large anabranching rivers in the rock record

• Grant number: 17/06874-3
• Support type: Scholarships in Brazil - Doctorate
• Effective date (Start): October 01, 2017
• Effective date (End): March 31, 2020
• Field of knowledge: Physical Sciences and Mathematics - Geosciences
• Principal Investigator: Renato Paes de Almeida
• Grantee: Cristiano Padalino Galeazzi
• Home Institution: Instituto de Geociências (IGC). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Development of large river facies models is hampered by the lack of observations from active large river systems, especially considering bedforms that never emerge throughout the year, which account for the majority of the channel. That is particularly true for deep-channel environments, where water flows at depths of tens of meters, where conditions are extremely different from what is found in smaller systems, from which current facies models were derived. In the Amazon Basin, large-scale fluvial channels function as biogeographical barriers whose evolution through the Neogene is fundamental to understand present biodiversity. Available models for active anabranching rivers in the Amazon are based only on plan-view morphology of fluvial elements and bedforms observed in satellite imagery, integrated to observations and interpretations of related deposits exposed during low stages. Submerged bedforms are a key-element to develop large river bedforms and the present proposal intends mainly to survey with Multibeam Echo Sounder (MBES) the deep channel of selected reaches of the Amazon, in order to observe their morphology and distribution, relating them to water depth. The purpose is to integrate this data with complementary sedimentological and Ground Penetrating Radar (GPR) data from the shallow channel, which is exposed in the dry season, to compose and improve facies models of anabranching rivers. This contribution will provide tools to interpret Neogene sedimentary deposits in Amazonia, necessary to understand its paleogeographical evolution, and large anabranching rivers in the rock record. (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)

TAMURA, LARISSA N.; ALMEIDA, RENATO P.; GALEAZZI, CRISTIANO P.; FREITAS, BERNARDO T.; IANNIRUBERTO, MARCO; PRADO, ARIEL H. Upper-bar deposits in large Amazon rivers: Occurrence, morphology and internal structure. SEDIMENTARY GEOLOGY, v. 387, p. 1-17, JUN 1 2019. Web of Science Citations: 0.

DO PRADO, ARIEL HENRIQUE; DE ALMEIDA, RENATO PAES; TAMURA, LARISSA NATSUMI; GALEAZZI, CRISTIANO PADALINO; IANNIRUBERTO, MARCO. Interpretation software applied to the evaluation of shallow seismic data processing routines in fluvial deposits. BRAZILIAN JOURNAL OF GEOLOGY, v. 49, n. 2 2019. Web of Science Citations: 0.

GALEAZZI, CRISTIANO P.; ALMEIDA, RENATO P.; MAZOCA, CARLOS E. M.; BEST, JIM L.; FREITAS, BERNARDO T.; IANNIRUBERTO, MARCO; CISNEROS, JULIA; TAMURA, LARISSA N. The significance of superimposed dunes in the Amazon River: Implications for how large rivers are identified in the rock record. SEDIMENTOLOGY, v. 65, n. 7, p. 2388-2403, DEC 2018. Web of Science Citations: 4.