Hostname: page-component-cd9895bd7-gbm5v Total loading time: 0 Render date: 2024-12-27T09:06:08.805Z Has data issue: false hasContentIssue false

Rates of Benthic Mixing in Deep-Sea Sediment as Determined by Radioactive Tracers

Published online by Cambridge University Press:  20 January 2017

Abstract

A series of closely spaced radiocarbon measurements on a carbonate-rich box core from the western equatorial Pacific show a mixed layer at least 7 cm thick, with 14C ages between 4000 and 5000 years, and an orderly progression of ages below this layer, indicating an average sedimentation rate of about 2 cm/103 yr. The profile can be simulated using a numerical extension of the mixing model of Guinasso and Schink (1975)and a numerical exponential mixing model. The best-fit iteration indicates an apparent mixing coefficient of K = 120 cm2/103 yr which also fits well the excess 210Pb distribution. The best-fit also indicates that a small amount of sediment was lost on the top, and that there was a reduction in sedimentation rate within the early Holocene.

Type
Original Articles
Copyright
University of Washington

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

Berger, W.H., Heath, G.R., 1968. Vertical mixing in Pelagic sediments. Journal Marine Research. 26, 2 134143.Google Scholar
Berger, W.H., Killingley, J.S., 1977. Glacial-Holocene transition in deep-sea carbonates: selective dissolution and the stable isotope signal. Science. 197, 563566.Google Scholar
Berger, W.H., Johnson, T.C., Hamilton, E.L., 1977. Sedimentation on Ontong-Java Plateau: Observations on a classic “carbonate monitor”. Anderson, N., Malahoff, A., The Fate of Fossil Fuel CO2 in the Ocean. Plenum Press, New York, 543568.Google Scholar
Broecker, W.S., Olson, E.A., 1959. Lamont radiocarbon measurements. VI. American Journal of Science Radiocarbon Supplement. 1, 111132.Google Scholar
Cook, R.B., Li, Y.-H., 1978. A model for sediment mixing. Earth and Planetary Science Letters. submitted.Google Scholar
Ekdale, A.A., Berger, W.H., 1978. Deep-sea ichnofacies: modern organism traces on and in pelagic carbonates of the western equatorial Pacific. Palaeogeography, Paleoclimatography, Palaeoecology. 23, 263278.Google Scholar
Goldberg, E.D., Koide, M., 1962. Geochronological studies of deep-sea sediments by the thoriumionium method. Geochimica et Cosmochimica Acta. 26, 417450.CrossRefGoogle Scholar
Guinasso, N.L., Schink, D.R., 1975. Quantitative estimates of biological mixing rates in abyssal sediments. Journal of Geophysical Research. 80, 30323043.Google Scholar
Hessler, R.R., Jumars, P.A., 1974. Abyssal community analysis from replicate box cores in the Central North Pacific. Deep-Sea Research. 21, 185209.Google Scholar
Nozaki, Y., Cochran, J.K., Turekian, K.K., Keller, G., 1977. Radiocarbon and 210Pb distribution in submersible-taken deep-sea cores from Project FAMOUS. Earth and Planetary Science Letters. 34, 167173.CrossRefGoogle Scholar
Peng, T.-H., Broecker, W.S., Kipphut, G., Shackleton, N., 1977. Benthic mixing in deep sea cores as determined by 14C dating and its implications regarding climate stratigraphy and the fate of fossil fuel CO2 . Anderson, N., Malahoff, A., The Fate of Fossil Fuel CO2 in the Ocean. Plenum Press, New York, 355374.Google Scholar