Sm-Nd signature of modern and late Quaternary sediments from the northwest North Atlantic: Implications for deep current changes since the Last Glacial Maximum
[en] Nd isotopes and Sm-Nd concentrations have been investigated in the clay size fraction of surface and late Quaternary sediments of the northern North Atlantic. Four sources of Nd have been identified in the surface sediments: (1) a radiogenic Nd typical of the Iceland volcanism; (2) a ''Pan-African'' Nd issued from eastern Greenland; (3) a ''Variscan'' Nd derived from the Arctic Ocean; (4) an old unradiogenic Nd related to the North American Shield, In the Iceland and Irminger basins, the major sources of Nd are the Variscan Nd derived from the Arctic Ocean and the Iceland Nd, except in the western Irminger Basin where the Pan-African Nd originating from eastern Greenland is dominant and labels sedimentary supplies linked to the Denmark Strait Overflow Water, Nd derived from Icelandic volcanism is never clearly dominant, even on the Reykjanes Ridge, and the Nd derived from the American Shield becomes dominant only in the Labrador Sea, Sediments lying in the pathway of the Western Boundary Undercurrent have Nd isotopic compositions which are shifted towards more radiogenic values indicating an input of material from the eastern basins, carried by this deep current. Late Quaternary sediments were cored from the southern Greenland Rise (core 90-013-013) and eastern Labrador Rise (Orphan Knell; core 91-045-094). In core 90-013-013, epsilon Nd values during the Last Glacial Maximum are as low as -20, but subsequently rose to -9 in the modern sediments, indicating that the sedimentary material during the Last Glacial Maximum was dominated by unradiogenic Nd from the North American Shield. This may be related to a lesser outflow of the Western Boundary Undercurrent, In core 91-045-094, located along the Labrador Current trajectory, a dominant supply of North American Shield Nd is recorded, perhaps originating at least partially from the Hudson Strait, The Sm-Nd data are compatible with smectite vs. illite studies at the same sites which suggest a continuous but more modest Western Boundary Undercurrent supply during Last Glacial Maximum.
Research Center/Unit :
GEOTOP
Disciplines :
Earth sciences & physical geography
Author, co-author :
Innocent, C.
Fagel, Nathalie ; Université de Liège - ULiège > Département de géologie > Argiles, géochimie et environnements sédimentaires
Stevenson, Ross
Hillaire Marcel, Claude
Language :
English
Title :
Sm-Nd signature of modern and late Quaternary sediments from the northwest North Atlantic: Implications for deep current changes since the Last Glacial Maximum
Publication date :
1997
Journal title :
Earth and Planetary Science Letters
ISSN :
0012-821X
eISSN :
1385-013X
Publisher :
Elsevier Science, Amsterdam, Netherlands
Volume :
146
Issue :
3-4
Pages :
607-625
Peer reviewed :
Peer Reviewed verified by ORBi
Funders :
CRSNG - Conseil de Recherches en Sciences naturelles et en Génie
A. Dia, B. Dupré and C.J. Allègre, Nd isotopes in Indian Ocean sediments used as a tracer of supply to the ocean and circulation paths, Mar. Geol. 103, 349-359, 1992.
D. Ben Othman, W.M. White and J. Patchett, The geochemistry of marine sediments, island arc magma genesis, and crust-mantle recycling, Earth Planet. Sci. Lett. 94, 1-21, 1989.
S.L. Goldstein and R.K. O'Nions, Nd and Sr isotopic relationship in pelagic clays and ferromanganese deposits, Nature 292, 324-327, 1981.
F.E. Grousset, P.E. Biscaye, A. Zindler, J. Prospero and R. Chester, Neodymium isotopes as tracers in marine sediments and aerosols, Earth Planet. Sci. Lett. 87, 367-378, 1988.
N. Fagel, P. Debrabant and L. André, Clay supplies in the Central Indian Basin since the Late Miocene: climatic or tectonic control?, Mar. Geol. 122, 151-172, 1994.
M. Lucotte and C. Hillaire-Marcel, Identification des grandes masses d'eau dans les mers du Labrador et d'Irminger, Can. J. Earth Sci. 31, 5-13, 1994.
M.S. Mc Cartney, Recirculating components to the deep boundary current of the northern North Atlantic, Prog. Oceanogr. 29, 283-383, 1992.
L.V. Worthington, ed., On the North Atlantic Circulation, 110 pp., Johns Hopkins Univ. Press, Baltimore, MD, 1976.
W.J.J. Schmitz and M.S. Mc Cartney, On the North Atlantic circulation, Rev. Geophys. 31, 1, 29-49, 1993.
R.R. Dickinson and J. Brown, The production of North Atlantic Deep Water: sources, rates and pathways, J. Geophys. Res. 99, C6, 12,319-12,341, 1994.
W.S. Broecker and G.H. Denton, The role of ocean-atmosphere reorganization in glacial cycles, Geochim. Cosmochim. Acta 53, 2465-2501, 1989.
C. Hillaire-Marcel, A. de Vernal, G. Bilodeau and G. Wu, Isotope stratigraphy, sedimentation rates, deep circulation, and carbonate events in the Labrador Sea during the last ∼ 200 ka, Can. J. Earth Sci. 31, 63-89, 1994.
J.S. Stoner, J.E.T. Channell and C. Hillaire-Marcel, Magnetic properties of deep-sea sediments off southwest Greenland: Evidence for major differences between the last two deglaciations, Geology 23, 241-244, 1995.
N. Fagel, C. Robert and C. Hillaire-Marcel, Clay mineral signature of the North Atlantic Western Boundary undercurrent, Mar. Geol. 130, 19-28, 1996.
M. Revel, J.A. Sinko and F.E. Grousset, Sr and Nd isotopes as tracers of North Atlantic lithic particles: Paleoclimatic implications, Paleoceanography 11, 95-113, 1996.
M. Revel, M. Cremer, F.E. Grousset and L. Labeyrie, Grain-size and Sr-Nd isotopes as tracers of paleo-bottom current strength, Northeast Atlantic Ocean, Mar. Geol. 131, 233-249, 1996.
S.G. Robinson and I.N. Mc Cave, Orbital forcing of bottom-current enhanced sedimentation on Feni Drift, NE Atlantic, during the mid-Pleistocene, Paleoceanography 9, 943-972, 1994.
G. Wu and C. Hillaire-Marcel, Accelerator mass spectrometry radiocarbon stratigraphies in deep Labrador Sea cores: paleoceanographic implications, Can. J. Earth Sci. 31, 38-47, 1994.
S.K. Chough, R. Hesse and J. Müller, The Northwest Atlantic Mid-Ocean Channel of the Labrador Sea. IV. Petrography and provenance of the sediments, Can. J. Earth Sci. 24, 731-740, 1987.
P. Richard, N. Shimizu and C.J. Allègre, 143Nd/146Nd a natural tracer: an application to oceanic basalts, Earth Planet. Sci. Lett. 31, 269-278, 1976.
D. Ben Othman, S. Fourcade and C.J. Allègre, Recycling processes in granite-granodiorite complex genesis: the Querigut case studied by Nd-Sr isotope systematics, Earth Planet. Sci. Lett. 69, 1984.
S.B. Jacobsen and G.J. Wasserburg, Sm-Nd isotopic evolution of chondrites, Earth Planet. Sci. Lett. 50, 139, 1980.
G.J. Wasserburg, S.B. Jacobsen, D.J. De Paolo, M.T. Mc Culloch and T. Wen, Precise determination of Sm/Nd ratios, Sm and Nd isotopic abundances in standard solutions, Geochim. Cosmochim. Acta 45, 2311-2323, 1981.
M.C. Stordal and G.J. Wasserburg, Neodymium isotopic study of Baffin Bay water: sources of REE from very old terranes, Earth Planet. Sci. Lett. 77, 259-272, 1986.
C. Jeandel, J.K. Bishop and A. Zindler, Exchange of neodymium and its isotopes between seawater and small and large particles in the Sargasso Sea, Geochim. Cosmochim. Acta 59, 535-547, 1995.
F. Grousset, C. Latouche and N. Maillet, Clay minerals as indicators of wind and current contribution to post-glacial sedimentation on the Azores/Iceland ridge, Clay Miner. 18. 65-75, 1983.
C.E. Jones, A.N. Halliday, D.K. Rea and R.M. Owen. Neodymium isotopic variations in North Pacific modern silicate sediment and the significance of detrital REE contributions to seawater, Earth Planet. Sci. Lett. 127, 55-66, 1994.
A. Michard, P. Gurriet, M. Soudaut and F. Albarede, Nd isotopes in French Phanerozoic shales: external vs internal aspects of crustal evolution, Geochim. Cosmochim. Acta 49, 601-610, 1985.
S.L. Goldstein, R.K. O'Nions and P.J. Hamilton, A Sm-Nd isotopic study of atmospheric dust particulates from major river systems, Earth Planet. Sci. Lett. 70, 221-236, 1984.
R.K. O'Nions, P.J. Hamilton and N.M. Evensen, Variations in 143Nd/144Nd and 87Sr/86Sr ratios in oceanic basalts, Earth Planet. Sci. Lett. 34, 13-22, 1977.
A. Zindler, S.R. Hart, F.A. Frey and S.P. Jakobsson, Nd and Sr isotope ratios and rare earth element abundances in Reykjanes Peninsula basalts: evidence for mantle heterogeneitiey beneath Iceland, Earth Planet. Sci. Lett. 45, 249-262, 1979.
R.S. Cohen, N.M. Evensen, P.J. Hamilton and R.K. O'Nions, U-Pb, Sm-Nd and Rb-Sr systematics of mid-ocean ridge basalt glasses, Nature 283, 149-153, 1980.
S.R. Carter, N.M. Evensen, P.J. Hamilton and R.K. O'Nions, Basalt magma sources during the opening of the North Atlantic, Nature 281, 28-30, 1979.
C. Gariépy, J. Ludden and C. Brooks, Isotopic and trace element constraints on the genesis of the Faeroe lava pile, Earth Planet. Sci. Lett. 63, 257-272, 1983.
R.K. O'Nions, P.J. Hamilton and P.J. Hooker, A Nd isotope investigation of sediments related to crustal development in the British Isles, Earth Planet. Sci. Lett. 63, 229-240, 1983.
L. André, S. Deutsch and J. Hertogen, Trace-element and Nd isotopes in shales as indexes of provenance and crustal growth: the early Paleozoic from the Brabant Massif (Belgium), Chem. Geol. 57, 101-115, 1986.
T.C. Liew and A.W. Hofmann, Precambrian crustal components, plutonic associations, plate environment of the Hercynian Fold Belt of central Europe: indications from a Nd and Sr isotopic study, Contrib. Mineral. Petrol. 98, 129-138, 1988.
P. Matte, Tectonics and plate tectonics model for the Variscan belt of Europe, Tectonophysics 126, 329-374, 1986.
M.T. Mc Culloch and G.J. Wasserburg, Sm-Nd and Rb-Sr chronology of continental crust formation, Science 200, 1003-1011, 1978.
H. Martin, Petrogenesis of Archean trondhjemites, tonalites, and granodiorites from eastern Finland: major and trace element geochemistry, J. Petrol. 28, 921-953, 1987.
F.E. Grousset and R. Chesselet, The Holocene sedimentary regime in the northern Mid-Atlantic Ridge region, Earth Planet. Sci. Lett. 78, 271-287, 1986.
P.R. Vogt and G.L. Johnson, A longitudinal seismic reflection profile on the Reykjanes Ridge: Part I: Evidence for west-flowing bottom water, Earth Planet. Sci. Lett. 18, 45-48, 1973.
R.G. Miller, R.K. O'Nions, P.J. Hamilton and E. Welin, Crustal residence ages of clastic sediments, orogeny and continental evolution, Chem. Geol. 57, 87-99, 1986.
W.J. Schmitz and N.G. Hogg, Observations of energetic low-frequency current fluctuations in the Charlie Gibbs Fracture Zone, J. Mar. Res. 36, 725-734, 1978.
P. Henry, Etude chimique et isotopique (Nd) de formations ferrifères (banded iron formation ou BIFs) du Craton ouest-africain, Bull. Soc. Géol. Fr. 166, 3-13, 1995.
E. Boyle, Last-Glacial-Maximum North Atlantic Deep Water: on, off or somewhere in-between?, Philos. Trans. R. Soc. London A 348, 243-253, 1995.
W.F. Ruddiman and A. MacIntyre, Oceanic mecanisms for amplification of the 23,000 year ice volume cycle, Science 212, 617-627, 1981.
N. Fagel, C. Hillaire-Marcel and C. Robert, Changes in the Western Boundary Undercurrent outflow since the Last Glacial Maximum, from Smectite/Illite ratios in deep Labrador Sea sediments, Paleoceanography, in press.
