Abstract
Rivers are the dominant source of many elements and isotopes to the ocean. But this input from the continents is not balanced by the loss of the elements and isotopes through hydrothermal and sedimentary exchange with the oceanic crust, or by temporal changes in the marine inventory for elements that are demonstrably not in steady state1,2,3,4. To resolve the problem of the observed imbalance in marine geochemical budgets, attention has been focused on uncertainties in the hydrothermal and sedimentary fluxes1,2,3,4. In recent Earth history, temporally dynamic chemical weathering fluxes from the continents are an inevitable consequence of periodic glaciations5,6,7,8,9. Chemical weathering rates on modern Earth are likely to remain far from equilibrium owing to the physical production of finely ground material at glacial terminations10,11,12,13 that acts as a fertile substrate for chemical weathering. Here we explore the implications of temporal changes in the riverine chemical weathering flux for oceanic geochemical budgets. We contend that the riverine flux obtained from observations of modern rivers is broadly accurate, but not representative of timescales appropriate for elements with oceanic residence longer than Quaternary glacial–interglacial cycles. We suggest that the pulse of rapid chemical weathering initiated at the last deglaciation has not yet decayed away and that weathering rates remain about two to three times the average for an entire late Quaternary glacial cycle. Taking into account the effect of the suggested non-steady-state process on the silicate weathering flux helps to reconcile the modelled marine strontium isotope budget with available data. Overall, we conclude that consideration of the temporal variability in riverine fluxes largely ameliorates long-standing problems with chemical and isotopic mass balances in the ocean.
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References
Elderfield, H. & Schultz, A. Mid-ocean hydrothermal fluxes and the chemical composition of the ocean. Annu. Rev. Earth Planet. Sci. 24, 191–224 (1996)
Galy, A., France-Lanord, C. & Derry, L. A. The strontium isotopic budget of Himalayan rivers in Nepal and Bangladesh. Geochim. Cosmochim. Acta 63, 1905–1925 (1999)
Davis, A. C., Bickle, M. J. & Teagle, D. A. H. Imbalance in the oceanic strontium budget. Earth Planet. Sci. Lett. 211, 173–187 (2003)
Holland, H. D. Sea level, sediments and the composition of seawater. Am. J. Sci. 305, 220–239 (2005)
Taylor, A. & Blum, J. D. Relation between soil age and silicate weathering rates determined from the chemical evolution of a glacial chronosequence. Geology 23, 979–982 (1995)
Blum, J. D. & Erel, Y. Rb-Sr isotope systematics of a granitic soil chronosequence: The importance of biotite weathering. Geochim. Cosmochim. Acta 61, 3193–3204 (1997)
Harlavan, Y., Erel, Y. & Blum, Y. D. Systematic changes in lead isotopic composition with soil age in glacial granitic terrains. Geochim. Cosmochim. Acta 62, 33–46 (1998)
Foster, G. L. & Vance, D. Negligible glacial-interglacial variation in continental chemical weathering rates. Nature 444, 918–921 (2006)
Dosseto, A., Bourdon, B. & Turner, S. P. Uranium-series isotopes in river materials: Insights into the timescales of erosion and sediment transport. Earth Planet. Sci. Lett. 265, 1–17 (2008)
Bell, M. & Laine, E. P. Erosion of the Laurentide region of North America by glacial and glaciofluvial processes. Quat. Res. 23, 154–174 (1985)
Thomas, M. F. & Thorp, M. B. Geomorphic response to rapid climatic and hydrologic change during the late Pleistocene and early Holocene in the humid and sub-humid tropics. Quat. Sci. Rev. 14, 193–197 (1995)
Goodbred, S. L. & Kuehl, S. A. Enormous Ganges-Brahmaputra sediment discharge during strengthened early Holocene monsoon. Geology 28, 1083–1086 (2000)
Hinderer, M. Late Quaternary denudation of the Alps, valley and lake fillings and modern river loads. Geodinam. Acta 14, 231–263 (2001)
Hodell, D. A., Mueller, P. A., McKenzie, J. A. & Mead, G. A. Strontium isotope stratigraphy and geochemistry of the late Neogene ocean. Earth Planet. Sci. Lett. 92, 165–178 (1989)
Oxburgh, R., Pierson-Wickmann, A.-C., Reisberg, L. & Hemming, S. Climate-correlated variations in seawater 187Os/188Os over the past 200,000 yr: Evidence from the Cariaco Basin, Venezuela. Earth Planet. Sci. Lett. 263, 246–258 (2007)
Palmer, M. R. & Edmond, J. M. The strontium isotope budget of the modern ocean. Earth Planet. Sci. Lett. 92, 11–26 (1989)
Tipper, E. T. et al. The magnesium isotope budget of the modern ocean: Constraints from riverine magnesium isotope ratios. Earth Planet. Sci. Lett. 250, 241–253 (2006)
Gaillardet, J., Dupré, B., Louvat, P. & Allègre, C. J. Global silicate weathering and CO2 consumption rates deduced from the chemistry of large rivers. Chem. Geol. 159, 3–30 (1999)
Clark, P. U. et al. The middle Pleistocene transition: Characteristics, mechanisms and implications for long-term changes in atmospheric CO2 . Quat. Sci. Rev. 25, 3150–3184 (2006)
Anderson, S. P. Biogeochemistry of glacial landscape systems. Annu. Rev. Earth Planet. Sci. 35, 375–399 (2007)
White, A. F. & Brantley, S. L. The effect of time on the weathering of silicate minerals: Why do weathering rates differ in the laboratory and the field? Chem. Geol. 202, 479–506 (2003)
Porder, S., Hilley, G. E. & Chadwick, O. A. Chemical weathering, mass loss, and dust inputs across a climate by time matrix in the Hawaiian Islands. Earth Planet. Sci. Lett. 258, 414–427 (2007)
Millot, R., Gaillardet, J., Dupré, B. & Allègre, C. J. The global control of silicate weathering rates and the coupling with physical erosion: New insights from rivers of the Canadian Shield. Earth Planet. Sci. Lett. 196, 83–98 (2002)
West, A. J., Galy, A. & Bickle, M. Tectonic and climatic controls on silicate weathering. Earth Planet. Sci. Lett. 235, 211–228 (2005)
Henderson, G. M., Martel, D. J., O'Nions, R. K. & Shackleton, N. J. Evolution of seawater 87Sr/86Sr over the last 400 ka: The absence of glacial/interglacial cycles. Earth Planet. Sci. Lett. 128, 643–651 (1994)
Peucker-Ehrenbrink, B. & Blum, J. D. Re-Os isotope systematics and weathering of Precambrian crustal rocks: Implications for the marine osmium isotope record. Geochim. Cosmochim. Acta 62, 3193–3203 (1998)
Petit, J. R. et al. Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica. Nature 399, 429–436 (1999)
Teagle, D. A. H., Bickle, M. J. & Alt, J. C. Recharge flux to ocean-ridge black smoker systems: A geochemical estimate from ODP Hole 504B. Earth Planet. Sci. Lett. 210, 81–89 (2003)
Nielsen, S. G. et al. Hydrothermal fluid fluxes calculated from the isotopic mass balance of thallium in the ocean crust. Earth Planet. Sci. Lett. 251, 120–133 (2006)
Stoll, H. M. & Schrag, D. P. Effect of Quaternary sea-level cycles on Sr in seawater. Geochim. Cosmochim. Acta 62, 1107–1118 (1998)
Acknowledgements
We thank H. Pälike, M. Palmer, C. Hawkesworth, T. Elliott, D. Schmidt, M. Gutjahr and M. Andersen for reading and improving an earlier version of this paper, and J. Phillips for help with a statistics problem. This work was done while D.V. held a Blaustein Visiting Research Professorship at Stanford.
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Vance, D., Teagle, D. & Foster, G. Variable Quaternary chemical weathering fluxes and imbalances in marine geochemical budgets. Nature 458, 493–496 (2009). https://doi.org/10.1038/nature07828
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DOI: https://doi.org/10.1038/nature07828
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