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Carbon Isotopic Changes in Benthic Foraminifera from the Western South Atlantic: Reconstruction of Glacial Abyssal Circulation Patterns

Published online by Cambridge University Press:  20 January 2017

W. B. Curry  and
G. P. Lohmann
W. B. Curry
Affiliation:
Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543
G. P. Lohmann
Affiliation:
Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543
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Abstract

Oxygen- and carbon-isotopic analyses have been performed on the benthic foraminifer Planulina wuellerstorfi in seven Late Quaternary cores from the Vema Channel-Rio Grande Rise region. The cores are distributed over the water-depth interval of 2340 to 3939 m, which includes the present transition from North Atlantic Deep Water (NADW) to Antarctic Bottom Water (AABW).

The carbon-isotopic records in the cores vary as a function of water depth. The shallowest and deepest cores show no significant glacial-interglacial difference in δ13C. Four of the five cores presently located in the NADW have benthic foraminiferal δ13C that is lower during glacial isotopic stages. Based on bathymetric gradients in δ13C, we conclude that, like today, there were two water masses present in the Vema Channel during glacial intervals: a water mass enriched in 13C overlying another water mass depleted in 13C. The largest gradient of change of δ13C with depth, however, occurred at 2.7 km, ∼ 1 km shallower than the present position of this gradient.

On the basis of paleontologic and sedimentologic evidence, we consider it unlikely that the NADW:AABW transition shallowed to this level. Reduced carbon-isotopic gradients between the deep basins of the North Atlantic and Pacific Oceans during the last glaciation suggest that production of NADW was reduced. Lower production of NADW may have modified the local abyssal circulation pattern in the Vema Channel region.

Type
Research Article
Information
Quaternary Research , Volume 18 , Issue 2 , September 1982 , pp. 218 - 235
Copyright
University of Washington

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References

Belanger, P.E. Curry, W.B. Matthews, R.K. (1981). Core-top evaluation of benthic foraminiferal isotopic ratios for paleo-oceanographic interpretations. Palaeogeography, Palaeoclimatology, Palaeoecology 33. 205–220.CrossRefGoogle Scholar
Broecker, W.S. (1974). Chemical Oceanography Harcourt, Brace Jovanovich, New York.Google Scholar
Broecker, W.S. (1982). Glacial to interglacial changes in ocean chemistry. Progress in Oceanography 11. 151–197.Google Scholar
Corliss, B.H. (1979). Recent deep-sea benthonic foraminiferal distribution in the southeast Indian Ocean: Inferred bottom water routes and ecological implications. Marine Geology 31. 115–138.CrossRefGoogle Scholar
Curry, W.B. Lohmann, G.P. (1981). Glacial abyssal circulation in the deep western North Atlantic recorded by benthic foraminiferal isotopic changes in KN31-GPC9. Geological Society of America, Abstracts with Programs 13. 435.Google Scholar
Deuser, W.G. Hunt, J.M. (1969). Stable isotope ratios of dissolved inorganic carbon in the Atlantic. Deep-Sea Research 16. 221.Google Scholar
Duplessy, J.-C. Cherrouard, L. Vila, F. (1975). Weyl's theory of glaciation supported by isotopic study of Norwegian core K11. Science 188. 1208–1209.Google Scholar
Duplessy, J.-C. Lalou, C. Vinot, A.C. (1970). Differential isotopic fractionation in benthic foraminifera and paleotemperatures reassessed. Science 168. 250.CrossRefGoogle ScholarPubMed
Duplessy, J.-C. Moyes, J. Pujol, C. (1980). Deep water formation in the North Atlantic Ocean during the last ice age. Nature (London) 286. 479–482.Google Scholar
Emiliani, C. (1955). Pleistocene temperatures. Journal of Geology 63. 538–578.Google Scholar
Emiliani, C. (1966). Paleotemperature analysis of Caribbean cores P6304-8 and P6304-9 and a generalized temperature curve for the past 425,000 years. Journal of Geology 74. 109–125.CrossRefGoogle Scholar
Graham, D.W. Corliss, B.H. Bender, M.L. Keigwin, L.D. (1981). Carbon and oxygen isotopic disequilibria of Recent deep-sea foraminifera. Marine Micropaleontology 6. 483–497.CrossRefGoogle Scholar
Johnson, D.A. (1982). Abyssal teleconnections: Interactive dynamics of the deep ocean circulation. Palaeogeography, Palaeoclimatology, Palaeoecology 38. 205–220.CrossRefGoogle Scholar
Johnson, D.A. Ledbetter, M. Burckle, L.H. (1977). Vema Channel paleo-oceanography: Pleistocene dissolution cycles and episodic bottom water flow. Marine Geology 23. 1–33.Google Scholar
Johnson, D.A. Peters, C.S. (1979). Late Cenozoic sedimentation and erosion on the Rio Grande Rise. Journal of Geology 87. 371–392.Google Scholar
Jones, G.A. (1977). Clay minerals as an indicator of fluctuations in North Atlantic Deep Water. EOS 58. 416(abstract).Google Scholar
Kroopnick, P. (1974). Modeling the dissolved O2-CO2-13C system in the eastern equatorial Pacific. Deep-Sea Research 21. 211–217.Google Scholar
Kroopnick, P. (1980). The distribution of 13C in the Atlantic Ocean. Earth and Planetary Science Letters 49. 469–484.Google Scholar
Kroopnick, P. Weiss, R.F. Craig, H. (1972). Total CO2, 13C and dissolved oxygen-18O at Geosecs II in the North Atlantic. Earth and Planetary Science Letters 16. 103–110.Google Scholar
Ledbetter, M.T. (1979). Fluctuations of Antarctic Bottom Water velocity in the Vema Channel during the last 160,000 years. Marine Geology 33. 71–89.Google Scholar
Ledbetter, M.T. Johnson, D.A. (1976). Increased transport of Antarctic Bottom Water in the Vema Channel during the last ice age. Science 194. 837–839.Google Scholar
Lohmann, G.P. (1978). Abyssal benthonic foraminifera as hydrographic indicators in the western South Atlantic Ocean. Journal of Foraminiferal Research 8. 6–34.CrossRefGoogle Scholar
Ninkovich, D. Shackleton, N.J. (1975). Distribution, stratigraphic position, and age of ash layer L in the Panama Basin region. Earth and Planetary Science Letters 27. 20–34.CrossRefGoogle Scholar
Reid, J.L. Nowlin, W.D. Patzert, W.C. (1977). On the characteristics and circulation of the south-west Atlantic Ocean. Journal of Physical Oceanography 7. 62–91.Google Scholar
Sackett, W.M. Eckelmann, W.R. Bender, M.L. Bé, A.W. (1965). Temperature dependence of carbon isotope composition in marine plankton and sediments. Science 148. 235.Google Scholar
Schnitker, D. (1974). West Atlantic abyssal circulation during the past 120,000 years. Nature (London) 248. 385–387.Google Scholar
Schnitker, D. (1979). The deep waters of the western North Atlantic during the past 24,000 years, and the initiation of the Western Boundary Undercurrent. Marine Micropaleontology 4. 265–280.CrossRefGoogle Scholar
Shackleton, N.J. (1967). Oxygen isotope analyses and Pleistocene temperature reassessed. Nature (London) 215. 15–17.Google Scholar
Shackleton, N.J. 1977a. Tropical rainforest history and the equatorial Pacific carbonate dissolution cycles. Fate of Fossil Fuel CO2 in the Oceans. Andersen, N.R. Malahoff, A. Plenum, New York. 401–427.Google Scholar
Shackleton, N.J. 1977b. The oxygen isotope stratigraphic record of the late Pleistocene. Philosophical Transactions of the Royal Society of London B 280. 169–182.Google Scholar
Shackleton, N.J. Opdyke, N.D. (1973). Oxygen isotope and paleomagnetic stratigraphy of equatorial Pacific core V28-238: Oxygen isotope temperatures and ice volumes on a 105 Quaternary Researchyear and 106 year scale 3. 39–55.Google Scholar
Streeter, S.S. (1973). Bottom water and benthonic foraminifera in the North Atlantic-Glacial-interglacial contrasts. Quaternary Research 3. 131–141.Google Scholar
Streeter, S.S. Shackleton, N.J. (1979). Paleocirculation of the deep North Atlantic: 150,000 benthic foraminifera and oxygen-18year record of Science 203. 168–171.Google Scholar
Williams, D.F. Sommer, M.A. Bender, M.L. (1977). Carbon isotope compositions of Recent planktonic foraminifera of the Indian Ocean. Earth and Planetary Science Letters 36. 391–403.Google Scholar
Williams, D.F. Ledbetter, M.T. (1979). Chronology of Late Bruhnes biostratigraphy and Late Cenozoic disconformities in the Vema Channel. Marine Micropaleontology 4. 125–136.Google Scholar
Woodruff, F. Savin, S.M. Douglas, R.G. (1980). Biologic fractionation of oxygen and carbon isotopes by Recent benthic Foraminifera. Marine Micropaleontology 5. 3–11.Google Scholar