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Paleoproductivity changes during the Late Quaternary in the southeastern Brazilian upper continental margin of the Southwestern Atlantic

Abstracts

Changes in the Brazilian continental margins oceanic productivity and circulation over the last 27,000 years were reconstructed based on sedimentological and microfaunal analyses. Our results suggest that oceanic paleoproductivity and the supply of terrigenous sediments to the Brazilian continental margin were higher during the Last Glacial Maximum (LGM) than during the Holocene. These changes may have been primarily influenced by significant sea level fluctuations that have occurred since the late Pleistocene. During the LGM, the lower sea level, higher productivity and lower sea-surface paleotemperatures may have been the result of the offshore displacement of the main flow of the Brazil Current. However, during the Holocene, the warm waters of the Brazil Current were displaced toward the coast. This displacement contributed to the increase in water temperature and prevented an increase in oceanic productivity. The decrease in terrigenous supply since the LGM could be related to the increase of the extension of the continental shelf and/or drier climatic conditions.

Foraminifera; Brazil Current; Late Quaternary; Southwestern Atlantic


Mudanças na produtividade e circulação oceânica da margem continental Brasileira foram reconstituídas a partir de análises sedimentológicas e microfaunísticas realizadas em sedimentos de um testemunho representativo dos últimos 27 000 anos. Nossos dados sugerem maior produtividade oceânica e suprimento de sedimento terrígeno na área de estudo no Último Máximo Glacial (UMG) do que no Holoceno. Estas mudanças foram principalmente influenciadas por flutuações do nível relativo do mar. Durante o UMG, num cenário de nível relativo do mar mais baixo, a maior produtividade oceânica e menor temperatura da superfície do mar, podem ter sido produtos do deslocamento para o largo da Corrente do Brasil. No Holoceno, o deslocamento para a costa das águas quentes da Corrente do Brasil contribuiu para o aumento na temperatura da água e menor produtividade oceânica. A diminuição do aporte de sedimentos terrígenos desde o UMG pode estar relacionado ao aumento da extensão da plataforma continental e/ou a condições climáticas mais secas no continente.

Foraminiferos; Corrente do Brasil; Quaternário Tardio; Atlântico Sudoeste


  • ANGULO, R. J.; SOUZA, M. C.; REIMER, P. J.; SASAOKA, S. K. Reservoir effect of the southern and southeastern Brazilian coast. Radiocarbon, v. 47, p. 6773. 2005.
  • ANGULO, R.;  LESSA, G. C.; SOUZA, M. C. A critical review of mid- to late-Holocene sea-level fluctuations on the eastern Brazilian coastline. Quat. Sci. Rev., v. 25, p. 486506. 2006.
  • ARZ, H. W.; PÄTZOLD, J.; WEFER, G. Correlated Millennial-Scale Changes in Surface Hydrography and Terrigenous Sediment Yield Inferred from Last-Glacial  arine Deposits off Northeastern Brazil. Quat. Res., v. 50, p. 157166. 1998.
  • BARBOSA, V. P. Foraminíferos Bentônicos Quaternários do talude continental da Bacia de Santos: Sistemática, Paleobatimetria e Paleoecologia 1998. 427 p.  Dissertação de Mestrado - Instituto de Geociências, Universidade Federal do Rio Grande do Sul, Rio Grande, RS.,  1998.
  • BROECKER, W. S.; PENG, T.-H. Carbon cycle: 1985Glacial to interglacial changes in the operation of the global carbon cycle. Radiocarbon, v. 28, p. 309327,  1986.
  • CAMPOS, E. J. D.; Velhote, D; Silveira, I. C. A. Shelf break upwelling driven by Brazil Current cyclonic meanders. Geophys. Res. Letts, v. 27, n. 6, p. 751-754,  2000.
  • CASTRO, B. M. Correntes e massas de água da plataforma continental norte de São Paulo 1996. 248 p. Tese de livre-docência - Instituto Oceanográfico, Universidade de São Paulo, São Paulo, SP,  1996.
  • CLAUZET, G.; WAINER, I.; LAZAR, A.; BRADY, E.; OTTO-BLIESNER, B.. A numerical study of the South Atlantic circulation at the Last Glacial Maximum. Palaeogeogr. Palaeoclimatol. Palaeoecol, v. 253, p. 509528,  2007.
  • CORRÊA, I. C. S. Les variations du niveau de la mer durant les derniers 17 500 ans BP: l'exemple de la plate-forme continentale du Rio Grande do Sul Brésil. Mar. Geol., v. 130, p. 163178, 1996.
  • EBERWEIN, A.; MACKENSEN, A. Last Glacial Maximum paleoproductivity and water masses off NW-Africa: Evidence from benthic foraminifera and stable isotopes. Mar. Micropal., v. 67, p. 87103, 2008.
  • FONTANIER, C.; JORISSEN, F. J.; LICARI, L.; ANSCHUTZ, A.; CARBONEL, P. Live benthic foraminiferal faunas from the Bay of Biscay: faunal density, composition, and microhabitats. Deep-Sea Res. I, v. 49, p.751785, 2002.
  • GIANNINI, P. C. F.; SAWAKUCHI, A. O.; MARTINHO, C. T.; TATUMI, S. H. Eolian depositional episodes controlled by Late Quaternary relative sea level changes on the ImbitubaLaguna coast (southern Brazil). Mar. Geol., v. 237, p.143168,  2007.
  • HEMLEBEN, C.; SPINDLER, M.; EERSON, O. R. Modern planktonic foraminifera New York: Springer-Verlag, 1989. 363 p.
  • HERGUERA, J. C.; BERGER, W. H. Paleoproductivity from benthic foraminifera abundance; glacial to postglacial change in the west-equatorial Pacific. Geology, v. 19, p. 11731176,  1991.
  • JACOB, J.; HUANG, Y.; DISNAR, J.-R.; SIFEDDINE, A.; BOUSSAFIR, M., ALBUQUERQUE, A. L. S.; TURCQ, B. Paleohydrological changes during the last deglaciation in Northern Brazil. Quat. Sci. Rev., v. 26, p.10041015,  2007.
  • JONES, R. W. The Challenger foramifera London: Oxford Science Publications;  The Natural History Museum;  Oxford University Press, 1994.149 p.
  • KEMLE-VON MÜCKE, S.; HEMLEBEN, C. Foraminifera. In: BOLTOVSKOY, D. (Ed.). South Atlantic Zooplankton Leiden: Backhuys Publishers, 1999. p. 43-73.
  • LEDRU, M.-P.; ROUSSEAU, D.-D.; CRUZ JR., F. W.; RICCOMINI, C.; KARMANN, I.; MARTIN, L. Paleoclimate changes during the last 100 000 yr from a record in the Brazilian Atlantic rainforest region and interhemispheric comparison. Quat. Res., v. 64, p. 444 450,  2005.
  • LOEBLICH JR., A. R.; TAPPAN, H. Foraminiferal genera and their classification PLATES  New York: Van Nostrand Reinhold,  1988.  2 v. 970 p.
  • LOUBERE, P.; FARIDUDDIN, M. Benthic Foraminifera and the Flux of Organic Carbon to the Seabed. In: SEN GUPTA, B. K. (Ed.). Modern Foraminifera. London:Kluwer Academic Press, 1999. p.181-200.
  • MACKENSEN, A.; SCHMIELD, G.; HARLOFF, J.; GIESE, M. Deep-sea foraminifera in the South Atlantic Ocean: Ecology and assemblage generation. Mar. Micropal., v.41, p. 342-358. 1995.
  • MAHIQUES, M. M.; MISHIMA Y.; RODRIGUES, M. Characteristics of the sedimentary organic matter on the inner and middle continental shelf between Guanabara Bay and São Francisco do Sul, eastern Brazilian margin. Cont. Shelf Res., v.19, p.775 798, 1999.
  • MAHIQUES, M. M.; SILVEIRA, I. C. A.; SOUSA, S. H. M.; RODRIGUES, M. Post-LGM sedimentation on the outer shelf-upper slope of the northermost part of São Paulo Bight, southeastern Brazil. Mar. Geol., v.181, p. 387-400,  2002.
  • MAHIQUES, M. M.; TESSLER, M. G.; CIOTTI, A. M.; SILVEIRA, I. C. A.; SOUSA, S. H. M.; FIGUEIRA, R. L.; TASSINARI, C. C. G.; FURTADO, V. V.; PASSOS, R.F. Hydrodynamically-driven patterns of recent sedimentation in the shelf and upper slope off southeast Brazil. Cont. Shelf Res., v. 24, p. 1685-1697,  2004.
  • MAHIQUES, M. M.; FUKUMOTO, M. M.; SILVEIRA, I. C. A.; FIGUEIRA, R. C. L.; BÍCEGO, M. C.; LOURENÇO, R.A.; SOUSA, S.H.M. Sedimentary changes on the Southeastern Brazilian upper slope during the last 35 000 years. An. Acad. Bras. Cienc., v.79,  n. 1, p. 171-181,  2007.
  • MARTIN, L.; SUGUIO, K.; FLEXOR, J. N. Hauts niveaux marins pleistocenes du litoral bresilien. Palaeogeogr. Palaeoclimatol. Palaeoecol., v. 68, n.  3, p. 231239,  1988.
  • MARTINS , V.; DUBERT, J.; JOUANNEAU , J.; WEBER, O.; SILVA, E. F.; PATINHA, C.; DIAS, J. M. A.; ROCHA, F. A multiproxy approach of the Holocene evolution of shelfslope circulation on the NW Iberian Continental Shelf. Mar. Geol., v. 239, p.118, 2007.
  • MIX, A. C. Influence of productivity variations on long-term atmospheric CO2 . Nature, v.337, p. 541-544, 1989.
  • MIX, A. C.; BARD, E.; SCHNEIDER, R. Environmental processes of the ice age: land, oceans, glaciers (EPILOG). Quat. Sci. Rev, v.20, p.627-657, 2001.
  • MOLLENHAUER, G.; SCHNEIDER, R. R.; JENNERJAHN, T.;  MÜLLER, P. J.; WEFER, G. Organic carbon accumulation in the South Atlantic Ocean: its modern, mid-Holocene and last glacial distribution. Glob. Planet. Change, v. 40, p. 249266,  2004.
  • MOREY, A. E.; MIX, A. C.; PISIAS, N. G. Planktonic foraminiferal assemblages preserved in surface sediments correspond to multiple environmental variables. Quat. Sci. Rev., v. 24, p. 925-950,  2005.
  • MURRAY, J.W. Ecology and palaeoecology of benthic foraminifera New York: Longman Scientific & Technical, 1991. 397 p.
  • SARNTHEIN, M.; WINN, K.; DUPLESSY, J.-C.; FONTUGNE, M.R. Global variations of surface ocean productivity in low and mid latitudes: Influence on CO2 reservoirs of the deep ocean and atmosphere during the last 21,000 years.  Paleoceanography, v.3, n. 3, p. 361399, 1988.
  • SCHMIEDL, G.; MACKENSEN, A. Late Quaternary paleoproductivity and deep water circulation in the eastern South Atlantic Ocean: Evidence from benthic foraminifera. Palaeogeogr. Palaeoclimatol. Palaeoecol, v. 130, p. 43-80, 1997.
  • SCHMIEDL, G.; DE BOVÉE, F.; BUSCAIL, R.; CHARRIÈRE, B.; HEMLEBEN, C.; MEDERNACH, L.; PICON, P. Trophic control of benthic foraminiferal abundance and microhabitat in the bathyal Gulf of Lions, western Mediterranean Sea. Mar. Micropal., v. 40, n. 3, p.167-188, 2000.
  • SILVEIRA, I. C. A.; SCHIMIDT, A. C. K.; CAMPOS, E. J. D.; GODOI, S. S.; IKEDA, Y. A Corrente do Brasil ao largo da costa Leste Brasileira. Rev. Bras. Oceanogr., v. 48, n. 2, p. 171- 183, 2000.
  • SYLVESTRE, F. Moisture Pattern During the Last Glacial Maximum in South America. In: VIMEUX F. et al. (Ed.). Past climate variability in South America and surrounding regions: From the Last Glacial Maximum to the Holocene, v. 14:  Developments in Paleoenvironmental Research. New York: Springer-Verlag,  2009,  p. 3-28.
  • TOLEDO, F. A. L.; CACHÃO, M.; COSTA, K. B.; PIVEL, M. A. G. Planktonic foraminifera, calcareous nannoplankton and ascidian variations during the last 25 kyr in the Southwestern Atlantic: A paleoproductivity signature? Mar. Micropaleont., v. 64, p.6779,  2007a.
  • TOLEDO, F. A. L., COSTA, K. B., PIVEL, M. A. G. Salinity changes in the western tropical South Atlantic during the last 30 kyr. Glob. Planet. Change, v.57, p.383395, 2007b.
  • TOLEDO, F. A. L.; COSTA, K. B.; PIVEL, M. A. G.; CAMPOS, E. J. D. Tracing past circulation changes in the western south Atlantic based on planktonic foraminifera. Rev. Bras. Paleontol., v. 11, n. 3, p.169-178. 2008.
  • VAN MORKHOVEN, F. P. C. M.; BERGGREN, W. A.; EDWARDS, A. S. Cenozoic cosmopolitan deep-water benthic foraminifera. Bull Cent.  Rech.  Explor.-Prod.  Elf- Aquitaine,  421 p.,  1986.
  • VIANA, A. R.; FAUGÈRES, J.-C.; STOW, D. A. V. Bottom-current-controlled sand deposits a review of modern shallow- to deep-water environments. Sedim. Geo., v. 115, p. 133-157,  1998.
  • WOLLENBURG, J. E.; KUHNT, W. The response of benthic foraminifers to carbon flux and primary production in the Arctic Ocean. Mar. Micropal., v. 40, p. 189-231, 2000.
  • ZEMBRUSCKI, S. G. Geomorfologia da margem continental sul brasileira e das bacias oceânicas adjacentes. In: CHAVES, H. A. F. (Ed.).  Geomorfologia da margem continental brasileira e das bacias oceânicas adjacentes. Rio de Janeiro: PETROBRAS-CENPES-DINTEP BRAZIL, 1979.  Série Projeto REMAC, v. 7, p. 129-177.

Publication Dates

  • Publication in this collection
    23 Aug 2010
  • Date of issue
    2010

History

  • Reviewed
    15 Oct 2009
  • Received
    06 June 2009
  • Accepted
    06 May 2010
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