Автор |
Massé, Laurent |
Автор |
Faugères, Jean‐Claude |
Автор |
Bernat, Michel |
Автор |
Pujos, Annick |
Автор |
Mézerais, Marie‐Laure |
Дата выпуска |
1994 |
dc.description |
At the northern exit of the Vema Channel, in the Southern Brazil Basin, deep currents linked with Antarctic Bottom Water flow (AABW, below 4200 m) have formed contouritic accumulations along the continental rise. Lithologic and textural investigations were carried out on a Kullenberg core in order to establish a chronology of late Pleistocene‐Holocene fluctuations in AABW flow. The core, spanning the last 600,000 years, was recovered from a field of sediment waves. The deposits consist of fine grained muds. Carbonate contents are very low because deposition takes place near the present‐day carbonate compensation depth. The core stratigraphic framework is based on calcareous nannofossil and excess <sup>230</sup>Th analyses. Two main types of facies can be identified: (1) yellowish brown muds, with frequent manganese enrichments forming dark laminae, and (2) homogeneous gray‐green muds. Two indicators of paleocurrent activity have been considered: (1) erosional sediment features that give evidence for high amplitude and short‐term current events, and (2) grain size fluctuations (percentage of panicles greater than 10 µm), indicating low amplitude and long‐term variations. Two periods can be defined. The first one (circa 600 to circa 350 kyr B.P.) is characterized by an instability in current activity, with strong flow events recorded as erosional surfaces. Long‐term fluctuations reveal the existence of several episodes of increased velocity occurring approximately every 50 kyr. The second period (350 kyr B.P. to present) is marked by globally weaker current activity and long‐term fluctuations of lower amplitude and longer duration. Maximum velocities occur preferentially during periods of climatic cooling. These fluctuations might be correlated with the 100 kyr eccentricity cycle of the Earth's orbit. |
Формат |
application.pdf |
Копирайт |
Copyright 1994 by the American Geophysical Union. |
Тема |
Sediment Waves and Sediment Drifts: Monitors of Global Changes in Deepwater Circulation |
Тема |
OCEANOGRAPHY: GENERAL |
Тема |
4267 |
Название |
A 600,000‐year record of Antarctic Bottom Water activity inferred from sediment textures and structures in a sediment core from the Southern Brazil Basin |
Тип |
article |
DOI |
10.1029/94PA01442 |
Electronic ISSN |
1944-9186 |
Print ISSN |
0883-8305 |
Журнал |
Paleoceanography |
Том |
9 |
Первая страница |
1017 |
Последняя страница |
1026 |
Выпуск |
6 |
Библиографическая ссылка |
Agrawal, Y. C., L. N.McCave, J. B.Riley, Laser diffraction size analysis, Principles, Methods and Application of Particle Size AnalysisJ.P.M.Syvitski, 119–128, Cambridge University Press, New York, 1991. |
Библиографическая ссылка |
Berger, W. H., Biogenous deep‐sea sediments: Production, preservation and interpretation, Chemical OceanographyJ. P.Riley, R.Chester, 265–386, Academic, San Diego, Calif., 1976. |
Библиографическая ссылка |
Bernat, M., T. M.Church, Uranium and thorium decay series in the modem marine environment, Handbook of Environmental Isotope Geochemistry The Marine Environment, A, 3P.Fritz, J. C.Fontes, 357–383, Elsevier Science, New York, 1989. |
Библиографическая ссылка |
Blaeser, C. R., M. T.Ledbetter, Deep sea bottom‐currents differentiated from texture of underlying sediment, J. Sediment. Petrol., 52, 755–768, 1982. |
Библиографическая ссылка |
Boyle, E. A., Cadmium in benthic foraminifera and abyssal hydrography: Evidence for a 41 kyr obliquity cycle, Climate Processes and Climate Sensitivity Geophys. Monogr. Ser., 29T.Takahashi, J.Hansen, 360–368, AGU, Washington, D.C., 1984. |
Библиографическая ссылка |
Ciesielski, P. P., P. M.Weaver, Neogene and Quaternary paleoenvironmental history of Deep Sea Drilling Project leg 71 sediments, southwest Atlantic Ocean, Initial Rep. Deep Sea Drill. Proj., 71, 461–477, 1983. |
Библиографическая ссылка |
Curry, W. B., G. P.Lohmann, Carbon isoiopic changes in benthic foraminifera from the western South Atlantic: Reconstruction of glacial abyssal circulation patterns, Quat. Res., 18, 218–235, 1982. |
Библиографическая ссылка |
Dowling, L. M., L. N.McCave, Sedimentation on Feni Drift and late Glacial bottom water production in the northern Rockall Trough, in Contourites and Bottom Currents, Sediment. Geol., 82, 79–87, 1993. |
Библиографическая ссылка |
Duplessy, J. C., N. J.Shackleton, R. G.Fairbanks, L. D.Labeyrie, D.Oppo, N.Kallel, Deep water source variations during the last climatic cycle and their impact on global deep water circulation, Paleoceanography, 3, 343–360, 1988. |
Библиографическая ссылка |
Ellwood, B. B., M. T.Ledbetter, Antarctic bottom water fluctuations in the Vema Channel: Effects of velocity changes on particle alignment and size, Earth Planet. Sci. Lett., 35, 189–198, 1977. |
Библиографическая ссылка |
Ellwood, B. B., M. T.Ledbetter, Paleocurrent indicators in deep‐sea sediment, Science, 203, 1335–1337, 1979. |
Библиографическая ссылка |
Faugères, J. C., La campagne BYBLOS. Rôle des courants profonds dans la sédimentation de la marge est‐brésilienne, Mem. Hors Ser. Soc. Géol. Fr., 27, 8, 1988. |
Библиографическая ссылка |
Faugères, J. C., D.A.V.Stow, Bottom‐current controlled sedimentation: A synthesis of the contourite problem, in Contourites and Bottom Currents, Sediment. Geol, 82, 287–297, 1993. |
Библиографическая ссылка |
Georgi, D. T., Circulation of bottom waters in the South Atlantic, Deep Sea Res. A, 28, 959–979, 1981. |
Библиографическая ссылка |
Hollister, C. D., I. N.McCave, Sedimentation under deep‐sea storms, Nature, 309, 220–225, 1984. |
Библиографическая ссылка |
Hogg, N., P. E.Biscaye, W.Gardner, W. J.SchmilzJr., On the transport and modification of Antarctic Bottom Water in the Vema Channel, J. Mar. Res., 40suppl, 231–263, 1982. |
Библиографическая ссылка |
Imbrie, J., J. D.Hays, D. G.Martinson, A.Mclntyre, A. C.Mix, J. J.Morley, N. G.Pisias, W. L.Prell, N. J.Shackleton, The orbital theory of Pleistocene climate: Support from a revised chronology of the marine Ol8 record, Milankovilch and Climate, Part IA. L.Berger, et al., 269–305, D. Reidel, Norwell, Mass., 1984. |
Библиографическая ссылка |
Jansen, J.H.F., A.Kuijpers, S. R.Troelstra, A mid‐Brunhes climatic event: Long‐term changes in global atmosphere and ocean circulation, Science, 232, 619–622, 1986. |
Библиографическая ссылка |
Johnson, D. A., K. A.Rasmussen, Late Cenozoic turbidite and contourite deposition in the southern Brazil Basin, Mar. Geol., 58, 225–262, 1984. |
Библиографическая ссылка |
Johnson, D. A., S. E.McDowell, L. G.Sullivan, P. E.Biscaye, Abyssal hydrography, nephelometry, currents and benthic boundary layer structure in the Vema Channel, J. Geophys. Res., 81, 5711–5786, 1976. |
Библиографическая ссылка |
Johnson, D. A., M. T.Ledbetter, L. H.Burckle, Vema Channel paleooceanography: Pleistocene dissolution cycles and episodic bottom water flow, Mar. Geol., 23, 1–33, 1977. |
Библиографическая ссылка |
Johnson, T. C., E. L.Lynch, W. J.Showers, N. C.Palczuk, Pleistocene fluctuations in the Western Boundary Undercurrent on the Blake Outer Ridge, Paleoceanography, 3, 191–207, 1988. |
Библиографическая ссылка |
Jones, G. A., Advective transport of clay minerals in the region of the Rio Grande Rise, Mar. Geol., 58, 187–212, 1984. |
Библиографическая ссылка |
Jones, G. A., D. A.Johnson, Displaced Antarctic diatoms in Vema Channel sediments: Late Pleistocene/Holocene fluctuations in AABW flow, Mar. Geol., 58, 165–186, 1984. |
Библиографическая ссылка |
Keigwin, L. D., G. A.Jones, Glacial‐Holocene stratigraphy, chronology and palaeoceanographic observations on some North Atlantic sediment drifts, Deep Sea Res., 36, 845–867, 1989. |
Библиографическая ссылка |
Ledbetter, M. T., Fluctuations of Antarctic Bottom Water in the Vema Channel during the last 160,000 years, Mar. Geol., 33, 71–89, 1979. |
Библиографическая ссылка |
Ledbetter, M. T., Bottom‐current speed in the Vema Channel recorded by particle size of sediment fine‐fraction, Mar. Geol., 58, 137–149, 1984. |
Библиографическая ссылка |
Ledbetter, M. T., A late Pleistocene time‐series of bottom‐current speed in the Vema Channel, Palaeogeogr. Palaeoclimatol. Palaeoecol., 53, 97–105, 1986. |
Библиографическая ссылка |
Ledbetter, M. T., B. B.Ellwood, Variations in particle alignment and size in sediments of the Vema Channel record Antarctic BottomWater velocity changes during the last 400,000 years, Antarctic GeoscienceC.Craddock, 1033–1038, University of Wisconsin Press, Madison, 1982. |
Библиографическая ссылка |
Ledbetter, M. T., D. A.Johnson, Increased transport of Antarctic Bottom Water in the Vema Channel during the last ice age, Science, 194, 837–839, 1976. |
Библиографическая ссылка |
Ledbetter, M. T., D. F.Williams, B. B.Ellwood, Late Pliocene Climate and Southwest Atlantic abyssal circulation, Nature, 272, 237–239, 1978. |
Библиографическая ссылка |
Le Pichon, X., J.Ewing, M.Truchan, Sediment transport and distribution in the Argentine Basin, Part 2, Antarctic Bottom Current passage in the Brazil Basin, Physics and Chemistry of the Earth, 8L. H.Ahrens, et al., 29–84, Pergamon, New‐York, 1971. |
Библиографическая ссылка |
Lohmann, G. P., Abyssal benthonic foraminifera as hydrographie indicators in the western South Atlantic Ocean, J. Foraminiferal Res., 8, 6–34, 1978. |
Библиографическая ссылка |
Massé, L., Sédimentation océanique profonde au Quaternaire. Flux sédimentés et paléocirculations dans l'Atlantique Sud‐Ouest: Bassin Sud‐Brésilien et prisme d'accrétion Sud‐Barbade, Doctoral dissertation, 339 pp., Univ. of Bordeaux I, Talence, France, 1993. |
Библиографическая ссылка |
McCave, L. N., Erosion, transport and deposition of fine‐grained marine sediments, Fine‐Grained Sediments: Deep‐Water Processes and FadesD.J.W.Piper, D.A.V.Stow, 35–69, Blackwell, Oxford, 1984. |
Библиографическая ссылка |
McCave, L. N., Sedimentology and stratigraphy of box cores from the Hebble site on the Nova Scotian continental rise, Mar. Geol., 66, 59–89, 1985. |
Библиографическая ссылка |
McCave, L. N., J.P.M.Syvitski, Principles and methods of geological particle size analysis, Principles, Methods and Application of Particle Size AnalysisJ.P.M.Syvitski, 3–21, Cambridge University Press, New York, 1991. |
Библиографическая ссылка |
McCave, L. N., R. J.Bryant, H. F.Cook, C. A.Coughanowr, Evaluation of a laser diffraction size analyser for use with natural sediments, J. Sediment. Pet., 56, 561–564, 1986. |
Библиографическая ссылка |
Melguen, M., J.Thiede, Faciès distribution and dissolution depths of surface sediment components from the Vema Channel and the Rio Grande Rise (Southwest Atlantic Ocean), Mar. Geol., 17, 341–353, 1974. |
Библиографическая ссылка |
Melguen, M., P.Debrabant, H.Chamley, H.Maillot, M.Hoffert, C.Courtois, Influence des courants profonds sur les faciès sédimentaires du Vema Channel (Atlantique Sud) à la fin du Cénozoïque, Bull. Soc. Geol. Fr., 7, 121–136, 1978. |
Библиографическая ссылка |
Mézerais, M. L., Accumulations sédimentaires profondes, par courants de turbidité (Eventail du Cap‐Ferret, Golfe de Gascogne) et par courants de fond (débouché du Chenal Vema, Bassin sud Brésilien). — Géométrie, faciès et processus d'édification, Doctoral dissertation, 301 pp., Univ. of Bordeaux I, Talence, France, 1991. |
Библиографическая ссылка |
Mézerais, M. L., J. C.Faugères, A. G.FigueiredoJr., L.Massé, Contour current accumulation off the Vema Channel mouth, southern Brazil Basin: Pattern of a "contourite fan,", Contourites and Bottom Currents Sediment. Geol., 82D.A.V.Stow, J. C.Faugères, 173–187, 1993. |
Библиографическая ссылка |
Pierre, C., C.Vergnaud‐Grazzini, J. C.Faugères, Oxygen and carbon stable isotope tracers of the water masses in the central Brazil Basin, Deep Sea Res., 385, 597–606, 1991. |
Библиографическая ссылка |
Pujos, A., J.Giraudeau, Répartition des Noelaerhabdaceae (nannofossiles calcaires) dans le Quaternaire moyen et supérieur des océans Atlantique et Pacifique, Oceanologica Acta, 164, 349–362, 1993. |
Библиографическая ссылка |
Reid, J. L., W. D.Nowlin, W. C.Patzert, On the characteristics and circulation of the southwestern Atlantic Ocean, J. Phys. Oceanogr., 7, 62–91, 1977. |
Библиографическая ссылка |
Ruddiman, W. F., A.Mclntyre, The North Atlantic Ocean during the last deglaciology, Palaeogeogr. Palaeoclimatol. Palaeoecol., 35, 145–214, 1981. |
Библиографическая ссылка |
Swithenbank, J., L. M.Béer, D. S.Taylor, D.Abott, G. C.McGreath, A laser diagnostic technique for droplet and particles distributions, in Expérimental Diagnostics in Gas Phase Combustion Systems, Prog. Astronaut. Aeronaut., 53, 421–447, 1977. |
Библиографическая ссылка |
Tappa, E., R.Thunell, Late Pleistocene glacial/interglacial changes in planktonic foraminiferal biofacies and carbonate dissolution patterns in the Vema Channel region, Mar. Geol., 58, 101–122, 1984. |
Библиографическая ссылка |
Unsold, G., Der Transportbeginn rolligen Sohlmaterials in gleichförmigen turbulenten Strömungen: eine kritische Überprüfung der Shields‐Funktion und ihre experimentelle Erweiterung auf feinstkömige, nicht‐bindige Sedimente, Doctoral dissertation, 145 pp., Univ. of Kiel, Kiel, Germany, 1982. |
Библиографическая ссылка |
Wang, H., L. N.McCave, Distinguishing climatic and current effects in mid‐Pleistocene sediments of Hatton and Gardar Drifts, NE Atlantic, J. Geol. Soc. London, 147, 373–383, 1990. |
Библиографическая ссылка |
Weber, O., E.Gonthier, J. C.Faugères, Analyse granulométrique des sédiments fins marins: Comparaison des résultats obtenus au SediGraph et au Malvern, Bull. Inst. Geol. Bassin Aquitaine, 50, 107–114, 1991. |
Библиографическая ссылка |
Williams, D. F., M. T.Ledbetter, Chronology of late Brunnes biostratigraphy and late Pliocene disconformities in the Vema Channel (SW Atlantic), Mar. Micropaleontol, 4, 125–136, 1979. |
Библиографическая ссылка |
Wright, W. R., Northward transport of Antarctic Bottom Water in the western Atlantic Ocean, Deep Sea Res., 17, 367–371, 1970. |