Publications
175 results found
Paul M, van de Flierdt T, Rehkamper M, et al., 2015, Tracing the Agulhas leakage with lead isotopes, Geophysical Research Letters, Vol: 20, Pages: 8515-8521, ISSN: 1944-8007
The transport of warm and salty waters from the Indian Ocean to the South Atlantic by the Agulhas Current constitutes a key return route of the meridional overturning circulation. Despite, the importance of the Agulhas Leakage on interoceanic exchange, its role on biogeochemical cycles is poorly documented. Here, we present the first lead (Pb) concentration and isotope data for surface seawater collected during the GEOTRACES cruise D357 in the Agulhas current system. Lead in surface waters of the Cape Basin is described by three distinct endmembers: the South African coast, open South Atlantic seawater, and Indian Ocean seawater. The latter stands out in its Pb isotopic composition and can be tracked within two distinct Agulhas rings. High Pb concentrations in the Agulhas rings further corroborate an Indian Ocean provenance of waters, and suggests that the Agulhas Leakage not only represents a major conduit for heat, but also for trace metals.
Jimenez-Espejo FJ, Pardos-Gene M, Martinez-Ruiz F, et al., 2015, Geochemical evidence for intermediate water circulation in the westernmost Mediterranean over the last 20 kyr BP and its impact on the Mediterranean Outflow, Global and Planetary Change, Vol: 135, Pages: 38-46, ISSN: 1872-6364
The Mediterranean Outflow (MOW) is generated by deep and intermediate waters from different basins in the Mediterranean Sea. Despite the number of studies on Mediterranean water masses, little work has been done on the source and properties of intermediate waters in the westernmost Mediterranean Sea and their links with MOW. Here we examine three marine sediment records spanning the last 20 kyr, located at key depths to trace intermediate waters along the Alboran Sea. We use a combination of redox-sensitive elements, which can serve as proxies to reconstruct variations in the water column oxygenation and the Nd isotopic composition of foraminiferal ferromanganese coatings, in order to reconstruct water mass provenance of Eastern/Western Mediterranean waters.As measured, εNd < − 9.2 and a low U/Th ratio during glacial periods can be attributed to the presence of Western Mediterranean Deep Water (WMDW) at the study sites. During deglaciation, higher Nd isotopic compositions and U/Th ratios point to an enhanced contribution of the modified Levantine Intermediate Water (LIW). The comparison between our data and other LIW and MOW records suggests that i) the lower branch of MOW is linked to WMDW during the glacial period, ii) the middle MOW branch follows LIW activity during deglaciation, while iii) the upper branch is more active during late Holocene, coinciding with LIW formation increase after sapropel deposits. This reconstruction has significant implications for an understanding of the MOW evolution.
Wilson DJ, van de Flierdt T, Bridgestock LJ, et al., 2015, Exploring Pb isotopes in deep-sea corals: measurement by TIMS and application to the deglacial Southern Ocean, 25th Annual VM Goldschmidt Conference
Murphy K, Rehkämper M, Kreissig K, et al., 2015, Improvements in Cd stable isotope analysis achieved through use of liquid–liquid extraction to remove organic residues from Cd separates obtained by extraction chromatography, Journal of Analytical Atomic Spectrometry, Vol: 31, Pages: 319-327, ISSN: 1364-5544
Organic compounds released from resins that are commonly employed for trace element separations are known to have a detrimental impact on the quality of isotopic analyses by MC-ICP-MS. A recent study highlighted that such effects can be particularly problematic for Cd stable isotope measurements (M. Gault-Ringold and C. H. Stirling, J. Anal. At. Spectrom., 2012, 27, 449–459). In this case, the final stage of sample purification commonly applies extraction chromatography with Eichrom TRU resin, which employs particles coated with octylphenyl-N,N-di-isobutyl carbamoylphosphine oxide (CMPO) dissolved in tri-n-butyl phosphate (TBP). During chromatography, it appears that some of these compounds are eluted alongside Cd and cannot be removed by evaporation due to their high boiling points. When aliquots of the zero-ε reference material were processed through the purification procedure, refluxed in concentrated HNO3 and analyzed at minimum dilution (in 1 ml 0.1 M HNO3), they yielded Cd isotopic compositions (ε114/110Cd = 4.6 ± 3.4, 2SD, n = 4) that differed significantly from the expected value, despite the use of a double spike technique to correct for instrumental mass fractionation. This result was accompanied by a 35% reduction in instrumental sensitivity for Cd. With increasing dilution of the organic resin residue, both of these effects are reduced and they are insignificant when the eluted Cd is dissolved in ≥3 ml 0.1 M HNO3. Our results, furthermore, indicate that the isotopic artefacts are most likely related to anomalous mass bias behavior. Previous studies have shown that perchloric acid can be effective at avoiding such effects (Gault-Ringold and Stirling, 2012; K. C. Crocket, M. Lambelet, T. van de Flierdt, M. Rehkämper and L. F. Robinson, Chem. Geol., 2014, 374–375, 128–140), presumably by oxidizing the resin-derived organics, but there are numerous disadvantages to its use. Here we show that liquid–liqui
Tauxe L, Sugisaki S, Jimenez-Espejo F, et al., 2015, Geology of the Wilkes land sub-basin and stability of the East Antarctic Ice Sheet: Insights from rock magnetism at IODP Site U1361, EARTH AND PLANETARY SCIENCE LETTERS, Vol: 412, Pages: 61-69, ISSN: 0012-821X
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- Citations: 8
Wilson DJ, van de Flierdt T, Bridgestock LJ, et al., 2014, Radiogenic isotopes as paleoceanographic tracers in deep-sea corals: advances in TIMS measurements of Pb isotopes and application to Southern Ocean corals, American Geophysical Union Fall Meeting 2014
van de Flierdt T, 2014, Tina van de Flierdt, OCEANOGRAPHY, Vol: 27, Pages: 241-241, ISSN: 1042-8275
Wilson DJ, Crocket KC, van de Flierdt T, et al., 2014, Dynamic intermediate ocean circulation in the North Atlantic during Heinrich Stadial 1: A radiocarbon and neodymium isotope perspective, Paleoceanography, Vol: 29, Pages: 1072-1093, ISSN: 0883-8305
The last deglaciation was characterized by a series of millennial‐scale climate events that have been linked to deep ocean variability. While often implied in interpretations, few direct constraints exist on circulation changes at mid‐depths. Here we provide new constraints on the variability of deglacial mid‐depth circulation using combined radiocarbon and neodymium isotopes in 24 North Atlantic deep‐sea corals. Their aragonite skeletons have been dated by uranium‐series, providing absolute ages and the resolution to record centennial‐scale changes, while transects spanning the lifetime of a single coral allow subcentennial tracer reconstruction. Our results reveal that rapid fluctuations of water mass sourcing and radiocarbon affected the mid‐depth water column (1.7–2.5 km) on timescales of less than 100 years during the latter half of Heinrich Stadial 1. The neodymium isotopic variability (−14.5 to −11.0) ranges from the composition of the modern northern‐sourced waters towards more radiogenic compositions, suggesting the presence of a greater southern‐sourced component at some times. However, in detail, simple two‐component mixing between well‐ventilated northern‐sourced and radiocarbon‐depleted southern‐sourced water masses cannot explain all our data. Instead, corals from ~15.0 ka and ~15.8 ka may record variability between southern‐sourced intermediate waters and radiocarbon‐depleted northern‐sourced waters, unless there was a major shift in the neodymium isotopic composition of the northern end‐member. In order to explain the rapid shift towards the most depleted radiocarbon values at ~15.4 ka, we suggest a different mixing scenario involving either radiocarbon‐depleted deep water from the Greenland‐Iceland‐Norwegian Seas or a southern‐sourced deep water mass. Since these mid‐depth changes preceded the Bolling‐Allerod warming and were apparently unaccompanied by changes in the deep Atlantic, they may indic
Pierce EL, Hemming SR, Williams T, et al., 2014, A comparison of detrital U-Pb zircon, 40Ar/39Ar hornblende, 40Ar/39Ar biotite ages in marine sediments off East Antarctica: Implications for the geology of subglacial terrains and provenance studies, EARTH-SCIENCE REVIEWS, Vol: 138, Pages: 156-178, ISSN: 0012-8252
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- Citations: 38
Patterson MO, McKay R, Naish T, et al., 2014, Orbital forcing of the East Antarctic ice sheet during the Pliocene and Early Pleistocene, NATURE GEOSCIENCE, Vol: 7, Pages: 841-847, ISSN: 1752-0894
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- Citations: 105
Robinson LF, Adkins JF, Frank N, et al., 2014, The geochemistry of deep-sea coral skeletons: A review of vital effects and applications for palaeoceanography (vol 99, pg 184, 2014), DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY, Vol: 105, Pages: 118-118, ISSN: 0967-0645
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- Citations: 1
Murphy K, Rehkaemper M, van de Flierdt T, 2014, Comment on "The isotopic composition of cadmium in the water column of the South China Sea", GEOCHIMICA ET COSMOCHIMICA ACTA, Vol: 134, Pages: 335-338, ISSN: 0016-7037
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- Citations: 4
Henry L-A, Frank N, Hebbeln D, et al., 2014, Global ocean conveyor lowers extinction risk in the deep sea, DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS, Vol: 88, Pages: 8-16, ISSN: 0967-0637
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- Citations: 40
Cook CP, Hill DJ, van de Flierdt T, et al., 2014, Sea surface temperature control on the distribution of far-traveled Southern Ocean ice-rafted detritus during the Pliocene, PALEOCEANOGRAPHY, Vol: 29, Pages: 533-548, ISSN: 0883-8305
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- Citations: 27
Crocket KC, Lambelet M, de Flierdt TV, et al., 2014, Measurement of fossil deep-sea coral Nd isotopic compositions and concentrations by TIMS as NdO<SUP>+</SUP>, with evaluation of cleaning protocols, CHEMICAL GEOLOGY, Vol: 374, Pages: 128-140, ISSN: 0009-2541
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- Citations: 24
Orejola N, Passchier S, Brinkhuis H, et al., 2014, Sedimentology of lower Pliocene to Upper Pleistocene diamictons from IODP Site U1358, Wilkes Land margin, and implications for East Antarctic Ice Sheet dynamics, ANTARCTIC SCIENCE, Vol: 26, Pages: 183-192, ISSN: 0954-1020
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- Citations: 13
Robinson LF, Adkins JF, Frank N, et al., 2014, The geochemistry of deep-sea coral skeletons: A review of vital effects and applications for palaeoceanography, DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY, Vol: 99, Pages: 184-198, ISSN: 0967-0645
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- Citations: 83
Margolin AR, Robinson LF, Burke A, et al., 2014, Temporal and spatial distributions of cold-water corals in the Drake Passage: Insights from the last 35,000 years, DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY, Vol: 99, Pages: 237-248, ISSN: 0967-0645
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- Citations: 30
Xue Z, Rehkaemper M, Horner TJ, et al., 2013, Cadmium isotope variations in the Southern Ocean, EARTH AND PLANETARY SCIENCE LETTERS, Vol: 382, Pages: 161-172, ISSN: 0012-821X
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- Citations: 62
Wilson DJ, Crocket KC, van de Flierdt T, et al., 2013, Deglacial ocean circulation variability in the Northwest Atlantic Ocean from neodymium isotopes and radiocarbon in deep-sea corals, 11th International Conference on Paleoceanography
Cook CP, van de Flierdt T, Williams T, et al., 2013, Dynamic behaviour of the East Antarctic ice sheet during Pliocene warmth, Nature Geoscience
Vandeginste V, John CM, van de Flierdt T, et al., 2013, Linking process, dimension, texture, and geochemistry in dolomite geobodies: A case study from Wadi Mistal (northern Oman), AAPG BULLETIN, Vol: 97, Pages: 1181-1207, ISSN: 0149-1423
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- Citations: 28
Bijl PK, Bendle JAP, Bohaty SM, et al., 2013, Eocene cooling linked to early flow across the Tasmanian Gateway, PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, Vol: 110, Pages: 9645-9650, ISSN: 0027-8424
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- Citations: 165
Griffiths JD, Barker S, Hendry KR, et al., 2013, Evidence of silicic acid leakage to the tropical Atlantic via Antarctic Intermediate Water during Marine Isotope Stage 4, PALEOCEANOGRAPHY, Vol: 28, Pages: 307-318, ISSN: 0883-8305
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- Citations: 19
Passchier S, Bohaty SM, Jimenez-Espejo FJ, et al., 2013, Early Eocene to middle Miocene cooling and aridification of East Antarctica, GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS, Vol: 14, Pages: 1399-1410
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- Citations: 42
Stocchi P, Escutia C, Houben AJP, et al., 2013, Relative sea-level rise around East Antarctica during Oligocene glaciation, NATURE GEOSCIENCE, Vol: 6, Pages: 380-384, ISSN: 1752-0894
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- Citations: 52
Houben AJP, Bijl PK, Pross J, et al., 2013, Reorganization of Southern Ocean Plankton Ecosystem at the Onset of Antarctic Glaciation, SCIENCE, Vol: 340, Pages: 341-344, ISSN: 0036-8075
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- Citations: 85
Lambelet M, Rehkaemper M, de Flierdt TV, et al., 2013, Isotopic analysis of Cd in the mixing zone of Siberian rivers with the Arctic Ocean-New constraints on marine Cd cycling and the isotope composition of riverine Cd, EARTH AND PLANETARY SCIENCE LETTERS, Vol: 361, Pages: 64-73, ISSN: 0012-821X
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- Citations: 50
Pross J, Contreras L, Bijl PK, et al., 2012, Persistent near-tropical warmth on the Antarctic continent during the early Eocene epoch, NATURE, Vol: 488, Pages: 73-77, ISSN: 0028-0836
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- Citations: 214
Tauxe L, Stickley CE, Sugisaki S, et al., 2012, Chronostratigraphic framework for the IODP Expedition 318 cores from the Wilkes Land Margin: Constraints for paleoceanographic reconstruction, PALEOCEANOGRAPHY, Vol: 27, ISSN: 0883-8305
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- Citations: 60
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