Hostname: page-component-586b7cd67f-rdxmf Total loading time: 0 Render date: 2024-11-20T07:21:35.495Z Has data issue: false hasContentIssue false

Radiocarbon and Stable Isotope Evidence for Changes in Sediment Mixing in the North Pacific over the Past 30 kyr

Published online by Cambridge University Press:  16 November 2017

Kassandra M Costa*
Affiliation:
Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA Department of Earth and Environmental Sciences, Columbia University, New York, NY 10027, USA
Jerry F McManus
Affiliation:
Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA Department of Earth and Environmental Sciences, Columbia University, New York, NY 10027, USA
Robert F Anderson
Affiliation:
Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA Department of Earth and Environmental Sciences, Columbia University, New York, NY 10027, USA
*
*Corresponding author. Email: [email protected].

Abstract

Deep-sea sediment mixing by bioturbation is ubiquitous on the seafloor, and it can be an important influence on the fidelity of paleoceanographic records. Bioturbation can be difficult to quantify, especially in the past, but diffusive models based on radioactive tracer profiles have provided a relatively successful approach. However, a singular, constant mixing regime is unlikely to prevail in a region where dynamic oceanographic changes in the bottom water environment are a consequence of paleoclimatic variability. In this study, foraminiferal stable isotopes, radiocarbon (14C) dating, and 230Th fluxes are utilized to understand the sediment mixing history in the easternmost region of the North Pacific. In the uppermost sediment, a 12,000-yr offset between planktonic foraminifera species N. incompta and G. bulloides is observed that coincides with age plateaus at 2000–2500 yr for N. incompta and 15,000–16,000 yr for G. bulloides despite coincident glacial-interglacial shifts in δ18O of benthic species. These age plateaus, particularly for G. bulloides, are a result of changing foraminiferal abundance related to assemblage shifts and carbonate preservation changes since the last glacial period, providing a window into the extent of mixing in the past. The 14C and stable isotope results can be simulated using an iterative model that couples these changes in foraminiferal abundance with variability in mixing depth over time. The best-fit model output suggests that the deepest, or most intense, mixing of the past 30,000 yr (30 kyr) may have occurred during the Holocene. Even though changes in mixing affect the 14C and δ18O of planktonic species that have dramatically varying abundance, substantial age control is nevertheless provided by δ18O measurements on the more consistently abundant benthic foraminifera Uvigerina, thus allowing the construction of a reliable chronology for these cores.

Type
Research Article
Copyright
© 2017 by the Arizona Board of Regents on behalf of the University of Arizona 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Anderson, DM. 2001. Attenuation of millennial-scale events by bioturbation in marine sediments. Paleoceanography 16(4):352357. DOI: 10.1029/2000PA000530.Google Scholar
Bacon, MP. 1984. Glacial to interglacial changes in carbonate and clay sedimentation in the Atlantic Ocean estimated from 230Th measurements. Isotope Geoscience 2:97111.Google Scholar
Bard, E, Arnold, M, Duprat, J, Moyes, J, Duplessy, J-C. 1987. Reconstruction of the last deglaciation: deconvolved records of δ18O profiles, micropaleontological variations, and accelerator mass spectrometric 14C dating. Climate Dynamics 1:101112.Google Scholar
Barker, S, Broecker, W, Clark, E, Hajdas, I. 2007. Radiocarbon age offsets of foraminifera resulting from differential dissolution and fragmentation within the sedidmentary bioturbated zone. Paleoceanography 22(2):111. DOI: 10.1029/2006PA001354.Google Scholar
Behl, RJ, Kennett, JP. 1996. Brief interstadial events in the Santa Barbara basin, NE Pacific, during the past 60 kyr. Nature 379(6562):243246. DOI: 10.1038/379243a0.Google Scholar
Bemis, BE, Spero, HJ, Bijma, J, Lea, W. 1998. Reevaluation of the oxygen isotopic composition of planktonic foraminifera: experimental results and revised paleotemperature equations. Paleoceanography 13(2):150160.Google Scholar
Benninger, LK, Aller, RC, Cochran, JK, Turekian, KK. 1979. Effects of biological sediment mixing on the 210Pb chronology and trace metal distribution in a Long Island Sound sediment core. Earth and Planetary Science Letters 43:241259.CrossRefGoogle Scholar
Berger, WH. 1970. Planktonic foraminifera: selective solution and the lysocline. Marine Geology 8:111138.Google Scholar
Berger, WH, Heath, GR. 1968. Vertical mixing in pelagic sediments. Journal of Marine Research 26(2):134143.Google Scholar
Berger, WH, Johnson, RF. 1978. On the thickness and the 14C age of the mixed layer in deep-sea carbonates. Earth and Planetary Science Letters 41(2):223227 DOI: 10.1016/0012-821X(78)90012-2.Google Scholar
Boudreau, BP. 1994. Is burial velocity a master parameter for bioturbation? Geochimica et Cosmochimica Acta 58(4):12431249.Google Scholar
Broecker, W, Clark, E. 2001. An evaluation of Lohmann’s foraminifera weight dissolution index. Paleoceanography 16(5):531534.Google Scholar
Broecker, W, Mix, A, Andree, M, Oeschger, H. 1984. Radiocarbon measurements on coexisting benthic and planktic foraminifera shells: potential for reconstructing ocean ventilation times over the past 20,000 years. Nuclear Instruments and Methods in Physics Research B 5(2):331339. DOI: 10.1016/0168-583X(84)90538-X.CrossRefGoogle Scholar
Broecker, W, Barker, S, Clark, E, Hajdas, I, Bonani, G. 2006. Anomalous radiocarbon ages for foraminifera shells. Paleoceanography 21(2):15. DOI: 10.1029/2005PA001212.Google Scholar
Broecker, WS, Klas, M, Clark, E, Trumbore, S, Bonani, G, Wolfli, W, Ivy, S. 1990. Accelerator mass spectrometric radiocarbon measurements on foraminifera shells from deep-sea cores. Radiocarbon 32(2):119133.Google Scholar
Broecker, WS, Klas, M, Clark, E, Bonani, G, Ivy, S, Wolfli, W. 1991. The influence of CaCO3 dissolution on core top radiocarbon ages for deep-sea sediments. Paleoceanography 6(5):593608 DOI: 10.1029/91PA01768.CrossRefGoogle Scholar
Broecker, WS, Clark, E, Lynch-Stieglitz, J, Beck, W, Stott, LD, Hajdas, I, Bonani, G. 2000. Late glacial diatome accumuation at 9°S in the Indian Ocean. Paleoceanography 15:348352.CrossRefGoogle Scholar
Brunelle, BG, Sigman, DM, Jaccard, SL, Keigwin, LD, Plessen, B, Schettler, G, Cook, MS, Haug, GH. 2010. Glacial/interglacial changes in nutrient supply and stratification in the western subarctic North Pacific since the penultimate glacial maximum. Quaternary Science Reviews 29(19–20):25792590. DOI: 10.1016/j.quascirev.2010.03.010.CrossRefGoogle Scholar
Bush, SL, Santos, GM, Xu, X, Southon, JR, Thiagarajan, N, Hines, SK, Adkins, JF. 2013. Simple, rapid, and cost effective: a screening method for 14C analysis of small carbonate samples. Radiocarbon 55(2):631640.CrossRefGoogle Scholar
Cheng, H. et al. 2013. Improvements in 230Th dating, 230Th and 234U half-life values, and U-Th isotopic measurements by multi-collector inductively coupled plasma mass spectrometry. Earth and Planetary Science Letters 371–372:8291. DOI: 10.1016/j.epsl.2013.04.006.Google Scholar
Cochran, JK. 1985. Particle mixing rates in sediments of the eastern equatorial Pacific: evidence from 210Pb, 239,240Pu and 137Cs distributions at MANOP sites. Geochimica et Cosmochimica Acta 49(1982):11951210.Google Scholar
Cook, MS, Keigwin, LD, Sancetta, CA. 2005. The deglacial history of surface and intermediate water of the Bering Sea. Deep Sea Research II 52:21632173. DOI: 10.1016/j.dsr2.2005.07.004.Google Scholar
Costa, K, McManus, J. 2017. Efficacy of 230Th normalization in sediments from the Juan de Fuca Ridge, northeast Pacific Ocean. Geochimica et Cosmochimica Acta 197:215225. DOI: 10.1016/j.gca.2016.10.034.Google Scholar
Costa, KM, McManus, JF, Boulahanis, B, Carbotte, SM, Winckler, G, Huybers, P, Langmuir, CH. 2016. Sedimentation, stratigraphy and physical properties of sediment on the Juan de Fuca Ridge. Marine Geology 380:163173.CrossRefGoogle Scholar
Coulbourn, WT, Parker, FL, Berger, WH. 1980. Faunal and solution patterns of planktonic foraminifera in surface sediments of the North Pacific. Marine Micropaleontology 5:329399.CrossRefGoogle Scholar
Crusius, J, Pedersen, TF, Kienast, S, Keigwin, L, Labeyrie, L. 2004. Influence of northwest Pacific productivity on North Pacific Intermediate Water oxygen concentrations during the Bolling-Allerod interval (14.7–12.9 ka). Geology 32(7):633636. DOI: 10.1130/G20508.1.CrossRefGoogle Scholar
Darling, KF, Wade, CM. 2008. The genetic diversity of planktic foraminifera and the global distribution of ribosomal RNA genotypes. Marine Micropaleontology 67(3–4):216238. DOI: 10.1016/j.marmicro.2008.01.009.Google Scholar
Davies, MH, Mix, AC, Stoner, JS, Addison, JA, Jaeger, J, Finney, B, Wiest, J. 2011. The deglacial transition on the southeastern Alaska Margin: meltwater input, sea level rise, marine productivity, and sedimentary anoxia. Paleoceanography 26(2):118. DOI: 10.1029/2010PA002051.Google Scholar
Demaster, DJ, Cochran, JK. 1982. Particle mixing rates in deep-sea sediments determined from excess 210Pb and 32Si profiles. Earth and Planetary Science Letters 61:257271.Google Scholar
Erez, J. 1978. Vital effect on stable-isotope composition seen in foraminifera and coral skeletons. Nature 273(5659):199202. DOI: 10.1038/273199a0.CrossRefGoogle Scholar
Ericson, DB. 1959. Coiling direction of Globigerina pachyderma as a climatic index. Science 130(3369):219220.Google Scholar
Ezard, THG, Edgar, KM, Hull, PM. 2015. Environmental and biological controls on size-specific δ13C and δ18O in recent planktonic foraminifera. Paleoceanography 30:151173. DOI: 10.1002/2014PA002735.Google Scholar
Fleisher, MQ, Anderson, RF. 2003. Assessing the collection efficiency of Ross Sea sediment traps using 230Th and 231Pa. Deep Sea Research, Part II, Topical Studies in Oceanography 50:693712.Google Scholar
Francois, R, Frank, M, Rutgers van der Loeff, M, Bacon, MP. 2004. 230Th normalization: an essential tool for interpreting sedimentary fluxes during the late Quaternary. Paleoceanography 19(1):PA1018. DOI: 10.1029/2003PA000939.Google Scholar
Goreau, TJ. 1980. Frequency sensitivity of the deep-sea climatic record. Nature 287:620622 DOI: 10.1038/287620a0.CrossRefGoogle Scholar
Guinasso, NL, Schink, DR. 1975. Quantitative estimates of biological mixing rates in abyssal sediments. Journal of Geophysical Research 80:30323043.CrossRefGoogle Scholar
Henderson, GM, Anderson, RF. 2003. The U-series toolbox for paleoceanography. Reviews in Mineral Geochemistry 52:493531.Google Scholar
Higgins, SM, Anderson, RF, Marcantonio, F, Schlosser, P, Stute, M. 2002. Sediment focusing creates 100-ka cycles in interplanetary dust accumulation on the Ontong Java Plateau. Earth and Planetary Science Letters 203:383397. DOI: 10.1016/S0012-821X(02)00864-6.Google Scholar
Jaccard, SL, Galbraith, ED. 2012. Large climate-driven changes of oceanic oxygen concentrations during the last deglaciation. Nature Geoscience 5(2):151156. DOI: 10.1038/ngeo1352.Google Scholar
Jaccard, SL, Galbraith, ED, Frolicher, TL, Gruber, N. 2014. Ocean (de)oxygenation across the last deglaciation: insights for the future. Oceanography 24(3):162173. DOI: 10.5670/oceanog.2011.65.Google Scholar
Karlin, R, Lyle, MW, Zahn, R. 1992. Carbonate variations in the northeast Pacific during the late Quaternary. Paleoceanography 7(1):4361.Google Scholar
Keigwin, LD. 1998. Glacial-age hydrography of the far northwest Pacific Ocean. Paleoceanography 13(4):323339.Google Scholar
Keigwin, LD, Schlegel, MA. 2002. Ocean ventilation and sedimentation since the glacial maximum at 3 km in the western North Atlantic. Geochemistry, Geophysics, Geosystems 3(6) 10.1029/2001GC000283. DOI: 10.1029/2001GC000283.CrossRefGoogle Scholar
Keir, RS. 1984. Recent increase in Pacific CaCO3 dissolution: a mechanism for generating old 14C ages. Marine Geology 59(1–4):227250. DOI: 10.1016/0025-3227(84)90095-1.Google Scholar
Keir, RS, Michel, RL. 1993. Interface dissolution control of the 14C profile in marine sediment. Geochimica et Cosmochimica Acta 57(15):35633573. DOI: 10.1016/0016-7037(93)90139-N.Google Scholar
Kienast, SS, Kienast, M, Mix, AC, Calvert, SE, François, R. 2007. Thorium-230 normalized particle flux and sediment focusing in the Panama Basin region during the last 30,000 years. Paleoceanography 22(2). DOI: 10.1029/2006PA001357.CrossRefGoogle Scholar
Kohfeld, KE, Chase, Z. 2011. Controls on deglacial changes in biogenic fluxes in the North Pacific Ocean. Quaternary Science Reviews 30(23–24):33503363. DOI: 10.1016/j.quascirev.2011.08.007.Google Scholar
Kozdon, R, Ushikubo, T, Kita, NT, Spicuzza, M, Valley, JW. 2009. Intratest oxygen isotope variability in the planktonic foraminifer N. pachyderma: real vs. apparent vital effects by ion microprobe. Chemical Geology 258(3–4):327337. DOI: 10.1016/j.chemgeo.2008.10.032.Google Scholar
Laepple, T, Huybers, P. 2014. Ocean surface temperature variability: large model-data differences at decadal and longer periods. Proceedings of the National Academy of Science U.S.A 111(47):1668216687. DOI: 10.1073/pnas.1412077111.CrossRefGoogle ScholarPubMed
Lam, PJ, Robinson, LF, Blusztajn, J, Li, C, Cook, MS, M cmanus, JF, Keigwin, LD. 2013. Transient stratification as the cause of the North Pacific productivity spike during deglaciation. Nature Geoscience 6(8):622626. DOI: 10.1038/ngeo1873.CrossRefGoogle Scholar
Leuschner, DC, Sirocko, F, Grootes, PM, Erlenkeuser, H. 2002. Possible influence of Zoophycos bioturbation on radiocarbon dating and environmental interpretation. Marine Micropaleontology 46:111126.Google Scholar
Lisiecki, LE, Stern, JV. 2016. Regional and global benthic d18O stacks for the last glacial cycle. Paleoceanography 31. DOI: 10.1002/2016PA003002.Google Scholar
Lohmann, G. 1995. A model for variation in the chemistry of planktonic foraminifera due to secondary calcification. Paleoceanography 10(3):445457.CrossRefGoogle Scholar
Löwemark, L, Grootes, PM. 2004. Large age differences between planktic foraminifers caused by abundance variations and Zoophycos bioturbation. Paleoceanography 19(2):19. DOI: 10.1029/2003PA000949.Google Scholar
Löwemark, L, Werner, F. 2001. Dating errors in high-resolution stratigraphy: a detailed X-ray radiograph and AMS-14C study of Zoophycos burrows. Marine Geology 177(3–4):191198. DOI: 10.1016/S0025-3227(01)00167-0.Google Scholar
Lund, DC, Mix, AC, Southon, J. 2011. Increased ventilation age of the deep northeast Pacific Ocean during the last deglaciation. Nat. Geosci. 4(11):771774. DOI: 10.1038/ngeo1272.Google Scholar
Manighetti, B, McCave, IN, Maslin, M, Shackleton, NJ. 1995. Chronology for climate change: developing age models for the Biogeochemical Ocean Flux Study cores. Paleoceanography 10(3):513525.Google Scholar
Marcantonio, F, Anderson, RF, Higgins, SM, Stute, M, Schlosser, P, Kubik, PW. 2001. Sediment focusing in the central equatorial Pacific Ocean. Paleoceanography 16(3):260267.Google Scholar
Marchitto, TM, Curry, WB, Lynch-stieglitz, J, Bryan, SP, Cobb, KM, Lund, DC. 2014. Improved oxygen isotope temperature calibrations for cosmopolitan benthic foraminifera. Geochimica et Cosmochimica Acta 130:111. DOI: 10.1016/j.gca.2013.12.034.Google Scholar
McDonald, D. 1993. The late Quaternary history of primary productivity in the Subarctic East Pacific. University of British Columbia.Google Scholar
McManus, JF, Anderson, RF, Broecker, WS, Fleisher, MQ, Higgins, SM. 1998. Radiometrically determined sedimentary fluxes in the sub-polar North Atlantic during the last 140,000 years. Earth and Planetary Science Letters 155:2943.Google Scholar
McManus, JF, Oppo, DW, Cullen, JL. 1999. A 0.5-million-year record of millennial-scale climate variability in the North Atlantic. Science 283(5404):971975.Google Scholar
Mekik, F. 2014. Radiocarbon dating of planktonic foraminifer shells: a cautionary tale. Paleoceanography 29(1):1329. DOI: 10.1002/2013PA002532.CrossRefGoogle Scholar
Mekik, FA, Anderson, RF, Loubere, P, François, R, Richaud, M. 2012. The mystery of the missing deglacial carbonate preservation maximum. Quaternary Science Reviews 39:6072. DOI: 10.1016/j.quascirev.2012.01.024.Google Scholar
Mitchell, NC, Huthnance, JM. 2013. Geomorphological and geochemical evidence (230Th anomalies) for cross-equatorial currents in the central Pacific. Deep Sea Research Part I Oceanography Research Papers 78:2441 DOI: 10.1016/j.dsr.2013.04.003.Google Scholar
Mollenhauer, G, Eglinton, TI, Ohkouchi, N, Schneider, RR, Muller, PJ, Grootes, PM, Rullkötter, J. 2003. Asynchronous alkenone and foraminifera records from the Benguela upwelling system. Geochimica et Cosmochimica Acta 67(12):21572171. DOI: 10.1016/S0016-7037(00)00168-6.Google Scholar
Mollenhauer, G, Kienast, M, Lamy, F, Meggers, H, Schneider, RR, Hayes, JM, Eglinton, TI. 2005. An evaluation of 14C age relationships between co-occurring foraminifera, alkenones, and total organic carbon in continental margin sediments. Paleoceanography 20(1):112. DOI: 10.1029/2004PA001103.Google Scholar
Mollenhauer, G, McManus, JF, Benthien, A, Müller, PJ, Eglinton, TI. 2006. Rapid lateral particle transport in the Argentine Basin: molecular 14C and 230Thxs evidence. Deep Sea Research. Part I. Oceanography 53(7):12241243. DOI: 10.1016/j.dsr.2006.05.005.CrossRefGoogle Scholar
Mollenhauer, G, McManus, JF, Wagner, T, McCave, IN, Eglinton, TI. 2011. Radiocarbon and 230Th data reveal rapid redistribution and temporal changes in sediment focussing at a North Atlantic drift. Earth and Planetary Science Letters 301(1–2):373381. DOI: 10.1016/j.epsl.2010.11.022.Google Scholar
Nozaki, Y, Horibe, Y, Tsubota, H. 1981. The water column distributions of thorium isotopes in the western North Pacific. Earth and Planetary Science Letters 54(2):203216. DOI: 10.1016/0012-821X(81)90004-2.Google Scholar
Ohkouchi, N, Eglinton, TI, Keigwin, LD, Hayes, JM. 2002. Spatial and temporal offsets between proxy records in a sediment drift. Science 298(5596):12241227.Google Scholar
Okazaki, Y, Timmermann, A, Menviel, L, Harada, N, Abe-Ouchi, A, Chikamoto, MO, Mouchet, A, Asahi, H. 2010. Deepwater formation in the North Pacific during the Last Glacial Termination. Science 329(5988):200204.Google Scholar
Oppo, DW, McManus, JF, Cullen, JL. 1998. Abrupt climate events 500,000 to 340,000 years ago: evidence from subpolar North Atlantic sediments. Science 279(5355):13351338. DOI: 10.1126/science.279.5355.1335.Google Scholar
Peng, TH, Broecker, WS. 1984. The impacts of bioturbation on the age difference between benthic and planktonic foraminifera in deep sea sediments. Nuclear Instruments and Methods in Physics Research B 5(2):346352. DOI: 10.1016/0168-583X(84)90540-8.CrossRefGoogle Scholar
Peng, TH, Broecker, WS, Berger, WH. 1979. Rates of benthic mixing in deep-sea sediment as determined by radioactive tracers. Quaternary Research 11(1):141149 DOI: 10.1016/0033-5894(79)90074-7.CrossRefGoogle Scholar
Pflaumann, U. et al. 2003. Glacial North Atlantic: sea-surface conditions reconstructed by GLAMAP 2000. Paleoceanography 18(3):1065. DOI: 10.1029/2002PA000774.Google Scholar
Praetorius, SK, Mix, AC, Walczak, MH, Wolhowe, MD, Addison, JA, Prahl, FG. 2015. North Pacific deglacial hypoxic events linked to abrupt ocean warming. Nature 527(7578):362366. DOI: 10.1038/nature15753.Google Scholar
Rae, JWB, Sarnthein, M, Foster, GL, Ridgewell, A, Grootes, PM, Elliott, T. 2014. Deep water formation in the North Pacific and deglacial CO2 rise. Paleoceanography 29:123. DOI: 10.1002/2013PA002570.Google Scholar
Reimer, PJ. et al. 2013. Intcal13 and Marine13 radiocarbon age calibration curves 0–50,000 years cal BP. Radiocarbon 55(4):18691887.Google Scholar
Ruddiman, WF, Glover, L. 1972. Vertical mixing of ice rafted volcanic ash in North Atlantic sediments. Geological Society of America Bulletin 83(9):28172836.Google Scholar
Ruddiman, WF, McIntyre, A. 1981. The North Atlantic Ocean during the last deglaciation. Palaeogeography, Palaeoclimatology, Palaeoecology 35:145214.Google Scholar
Ruddiman, WF, Molfino, BE, Esmay, A, Pokras, E. 1980. Evidence beating on the mechanism of rapid deglaciation. Climate Change 3:6587.Google Scholar
Shackleton, NJ. 1973. Attainment of isotopic equilibrium between ocean water and the benthonic foraminifera genus Uvigerina: isotopic changes in the ocean during the last glacial. Proceedings Colloques Internationaux. Centre National de La Recherche Scientifique. p 203–9.Google Scholar
Skinner, LC, Shackleton, NJ. 2004. Rapid transient changes in northeast Atlantic deep water ventilation age across Termination I. Paleoceanography 19(2):112. DOI: 10.1029/2003PA000983.Google Scholar
Spero, HJ. 1998. Life history and stable isotope geochemistry of planktonic foraminifera. In Norris R, Corfield RM, editors. Isotope Paleobiology and Paleoecology. Volume 4. Paleontological Society Papers. p 736.Google Scholar
Stuiver, M, Reimer, PJ. 1993. Extended 14C database and revised Calib 3.0 14C age calibration program. Radiocarbon 35(1):215230.Google Scholar
Suman, DO, Bacon, MP. 1989. Variations in Holocene sedimentation in the North American Basin determined from 230Th measurements. Deep Sea Research 36(6):869878.Google Scholar
Tetard, M, Licari, L, Beaufort, L. 2017. Oxygen history off Baja California over the last 80 kyr: a new foraminiferal-based record. Paleoceanography. 246264. DOI: 10.1002/2016PA003034.Google Scholar
Trauth, MH. 2013. TURBO2: A MATLAB simulation to study the effects of bioturbation on paleoceanographic time series. Computers & Geosciences 61:110. DOI: 10.1016/j.cageo.2013.05.003.Google Scholar
Uchida, M, Shibata, Y, Ohkushi, K, Yoneda, M, Kawamura, K, Morita, M. 2005. Age discrepancy between molecular biomarkers and calcareous foraminifera isolated from the same horizons of Northwest Pacific sediments. Chemical Geology 218(1–2):7389. DOI: 10.1016/j.chemgeo.2005.01.026.Google Scholar
Waelbroeck, C, Duplessy, JC, Michel, E, Labeyrie, L, Paillard, D, Duprat, J. 2001. The timing of the last deglaciation in North Atlantic climate records. Nature 412(6848):724727. DOI: 10.1038/35106623.Google Scholar
Wheatcroft, RA, Jumars, PA, Smith, CR, Nowell, ARM. 1990. A mechanistic view of the particulate biodiffusion coefficient: step lengths, rest periods and transport directions. Journal of Marine Research 48(1):177207. DOI: 10.1357/002224090784984560.Google Scholar
Wycech, J, Clay Kelly, D, Marcott, S. 2016. Effects of seafloor diagenesis on planktic foraminiferal radiocarbon ages. Geology 44(7):551554. DOI: 10.1130/G37864.1.Google Scholar
Yarincik, KM, Murray, RW, Lyons, TW, Peterson, LC, Haug, GH. 2000. Oxygenation history of bottom waters in the Cariaco Basin, Venezuela, over the past 578,000 years: results from redox-sensitive metals (Mo, V, Mn, and Fe). Paleoceanography 15(6):593604.Google Scholar
Žarić, S, Donner, B, Fischer, G, Mulitza, S, Wefer, G. 2005. Sensitivity of planktic foraminifera to sea surface temperature and export production as derived from sediment trap data. Marine Micropaleontology 55(1–2):75105. DOI: 10.1016/j.marmicro.2005.01.002.Google Scholar
Zheng, Y, Van Geen, A, Anderson, RF, Gardner, JV, Dean, WE. 2000. Intensification of the northeast Pacific oxygen minimum zone during the Bolling-Allerod warm period. Paleoceanography 15(5):528536.Google Scholar
Supplementary material: File

Costa et al. supplementary material

Costa et al. supplementary material 1

Download Costa et al. supplementary material(File)
File 944.8 KB
Supplementary material: File

Costa et al supplementary material

Costa et al supplementary material 1

Download Costa et al supplementary material(File)
File 4.6 MB