Quaternary megafans in the state of Roraima, Northern Amazonia: sedimentological, climatic and tectonic implications

• Grant number: 10/09484-2
• Support type: Regular Research Grants
• Duration: November 01, 2010 - October 31, 2013
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal researcher: Dilce de Fátima Rossetti
• Grantee: Dilce de Fátima Rossetti
• Home Institution: Instituto Nacional de Pesquisas Espaciais (INPE). Ministério da Ciência, Tecnologia e Inovações (Brasil). São José dos Campos , SP, Brazil
• Assoc. researchers: Antonio Carlos Luz Lisbôa

Abstract

Megafan consists of a large-scale depositional system with sedimentological, stratigraphic and morphological characteristics still poorly documented in both modern and ancient environments. In Brazil, the Taquari megafan in the Pantanal Matogrossense is the only known record of this type of depostional system. Preliminary analysis of remote sensing data suggests the presence of a remarkable megafans in the State or Roraima, northernmost of Amazonia Basin The goal of this project is to demonstrate the presence of two megafan systems preliminarily detected in the Branco-Negro interfluve and in the left margin of the Branco River, as well as discuss the factors that were potentially important to their development in an area today dominated by fluvial systems. The study will consist on the following phases: 1. analysis of remote sensing data, using Landsat, ALOS (Advanced Land Observing Satellite)-PALSAR (Phased Array type L-band Synthetic Aperture Radar), digital elevation model (DEM)-Shuttle Radar Topography Mission (SRTM), and drainage maps provided in digital format by SIVAM/IBGE; 2. analysis of sedimentological and stratigraphic data to be acquired from cores; 3. laboratorial analysis including total organic carbon (C), ´13C, 14C dating and optically stimulated luminescence (OSL). The presence of megafans in an area dominated by fluvial alluvial systems linked to tributaries of the Amazonas River has great implications to discuss the influence of climate and tectonics during the Quaternary of Amazonia. The results derived from this project will help to amplify the characterization of megafans, as well as understand the factors that might control their development in different geological contexts. (AU)

Scientific publications

(11)

(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)

CORDEIRO, CARLOS L. O.; ROSSETTI, DILCE F.; GRIBEL, ROGERIO; TUOMISTO, HANNA; ZANI, HIRAN; FERREIRA, CARLOS A. C.; COELHO, LUIZ. Impact of sedimentary processes on white-sand vegetation in an Amazonian megafan. JOURNAL OF TROPICAL ECOLOGY, v. 32, n. 6, p. 498-509, NOV 2016. Web of Science Citations: 8.

CREMON, EDIPO HENRIQUE; ROSSETTI, DILCE DE FATIMA; SAWAKUCHI, ANDRE DE OLIVEIRA; LISBOA COHEN, MARCELO CANCELA. The role of tectonics and climate in the late Quaternary evolution of a northern Amazonian River. Geomorphology, v. 271, p. 22-39, OCT 15 2016. Web of Science Citations: 13.

ROSSETTI, DILCE F.; COHEN, MARCELO C. L.; TATUMI, SONIA H.; SAWAKUCHI, ANDRE O.; CREMON, EDIPO H.; MITTANI, JUAN C. R.; BERTANI, THIAGO C.; MUNITA, CASIMIRO J. A. S.; TUDELA, DIEGO R. G.; YEE, MARCIO; MOYA, GABRIELA. Mid-Late Pleistocene OSL chronology in western Amazonia and implications for the transcontinental Amazon pathway. SEDIMENTARY GEOLOGY, v. 330, p. 1-15, DEC 2015. Web of Science Citations: 19.

DE OLIVEIRA CORDEIRO, CARLOS LEANDRO; ROSSETTI, DILCE DE FATIMA. Mapping vegetation in a late Quaternary landform of the Amazonian wetlands using object-based image analysis and decision tree classification. International Journal of Remote Sensing, v. 36, n. 13, p. 3397-3422, 2015. Web of Science Citations: 18.

ROSSETTI, DILCE F. The role of tectonics in the late Quaternary evolution of Brazil's Amazonian landscape. EARTH-SCIENCE REVIEWS, v. 139, p. 362-389, DEC 2014. Web of Science Citations: 16.

CREMON, EDIPO HENRIQUE; ROSSETTI, DILCE DE FATIMA; ZANI, HIRAN. Classification of Vegetation over a Residual Megafan Landform in the Amazonian Lowland Based on Optical and SAR Imagery. REMOTE SENSING, v. 6, n. 11, p. 10931-10946, NOV 2014. Web of Science Citations: 6.

ROSSETTI, DILCE F.; ZANI, HIRAN; CREMON, EDIPO H. Fossil megafans evidenced by remote sensing in the Amazonian wetlands. ZEITSCHRIFT FUR GEOMORPHOLOGIE, v. 58, n. 2, p. 145-161, JUN 2014. Web of Science Citations: 14.

ROSSETTI, D. F.; ZANI, H.; COHEN, M. C. L.; CREMON, E. H. A Late Pleistocene-Holocene wetland megafan in the Brazilian Amazonia. SEDIMENTARY GEOLOGY, v. 282, p. 276-293, DEC 30 2012. Web of Science Citations: 10.

ROSSETTI, D. F.; BERTANI, T. C.; ZANI, H.; CREMON, E. H.; HAYAKAWA, E. H. Late Quaternary sedimentary dynamics in Western Amazonia: Implications for the origin of open vegetation/forest contrasts. Geomorphology, v. 177, p. 74-92, DEC 1 2012. Web of Science Citations: 25.

ZANI, H.; ROSSETTI, D. F.; COHEN, M. L. C.; PESSENDA, L. C. R.; CREMON, E. H. Influence of landscape evolution on the distribution of floristic patterns in northern Amazonia revealed by delta 13C data. JOURNAL OF QUATERNARY SCIENCE, v. 27, n. 8, p. 854-864, NOV 2012. Web of Science Citations: 9.

ZANI, HIRAN; ROSSETTI, DILCE DE FATIMA. Multitemporal Landsat data applied for deciphering a megafan in northern Amazonia. International Journal of Remote Sensing, v. 33, n. 19, p. 6060-6075, 2012. Web of Science Citations: 13.