Advanced search
Start date

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


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)

Articles published in Agência FAPESP Newsletter about the research grant:
Articles published in other media outlets (0 total):
More itemsLess items

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)
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, . (10/09484-2, 13/50475-5)
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, . (09/00672-3, 10/09484-2)
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, . (10/09484-2)
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, . (10/09484-2)
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, . (11/23317-4, 09/00672-3, 10/09484-2)
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, . (09/00672-3, 10/09484-2)
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, . (10/09484-2)
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, . (10/09484-2, 13/50475-5)
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, . (10/09484-2, 13/50475-5)
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; et al. Mid-Late Pleistocene OSL chronology in western Amazonia and implications for the transcontinental Amazon pathway. SEDIMENTARY GEOLOGY, v. 330, p. 1-15, . (10/09484-2, 13/50475-5)
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, . (10/09484-2, 13/50475-5)

Please report errors in scientific publications list by writing to: