Advertisement

Geo-Marine Letters

, Volume 16, Issue 1, pp 17–23 | Cite as

Sedimentary carbon-isotope systematics on the Amazon shelf

  • Christopher K. Sommerfield
  • Charles A. Nittrouer
  • David J. DeMaster
Article

Abstract

Sedimentary carbon systematics on the Amazon continental shelf were investigated using14C andδ13C measurements of sedimentary organic materials. Mass balance calculations indicate that the14C content of modern shelf muds results from burial of old (~ 5000 yr BP) terrestrial soil carbon and bomb-14C-enriched marine carbon, implying that most of the bomb-labeled riverine particulate carbon is not buried on the shelf. The14C signature of Amazon shelf deposits records the effects of both biogeochemical and sedimentary processes active in this dynamic environment.

Keywords

Burial Continental Shelf Soil Carbon Particulate Carbon Sedimentary Carbon 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Aller RC, Blair NE, Xia Q, and Rude PD (1996) Remineralization rates, recycling, and storage of carbon in Amazon shelf sediments. Continental Shelf Research 16Google Scholar
  2. Allison MA, Nittrouer CA, Faria LEC Jr., Silveira OM, and Mendes AC (1996) Sources and sinks of sediment to the Amazon margin: The Amapa Coast. Geo-Marine Letters 16:36–40Google Scholar
  3. Becker-Heidmann P and Scharpenseel P (1989) Carbon isotope dynamics in some tropical soils. Radiocarbon 31:672–679Google Scholar
  4. Benoit GJ, Turekian KK, and Benninger LK (1979) Radiocarbon dating of a core from Long Island Sound. Estuarine and Coastal Marine Science 9:171–180Google Scholar
  5. Berger WH and Heath GR (1968) Vertical mixing in pelagic sediments. Journal of Marine Research 26:135–143Google Scholar
  6. Berner RA (1982) Burial of organic carbon and pyrite sulfur in the modern ocean: Its geochemical and environmental significance. American Journal of Science 282:451–473Google Scholar
  7. Broecker WS, Gerard R, Ewing M, and Heezen BH (1960) Natural radiocarbon in the Atlantic Ocean. Journal of Geophysical Research 65:2903–2931Google Scholar
  8. Cai D-L, Tan FC, and Edmond JM (1988) Sources and transport of particulate organic carbon in the Amazon River and estuary. Estuarine, Coastal and Shelf Science 26:1–14Google Scholar
  9. Craig H (1953) The geochemistry of stable carbon isotopes. Geochimica et Cosmochimica Acta 3:53–92Google Scholar
  10. DeMaster DJ and Turekian KK (1987) The radiocarbon record in varved sediments of Carmen Basin, Gulf of California: A measure of upwelling intensity variation during the past several hundred years. Paleoceanography 2:249–254Google Scholar
  11. Erlenkeuser H (1976) Environmental effects on radiocarbon in coastal marine sediments. In: Proceedings of 9th International Radiocarbon Conference, Los Angeles and San Diego. Berkeley: University of California Press. pp 453–468Google Scholar
  12. Erlenkeuser H, Suess E, and Willkomm H (1974) Industrialization affects heavy metal and carbon isotope concentrations in recent Baltic Sea sediments. Geochimica et Cosmochimica Acta 38:823–842Google Scholar
  13. Gibbs RJ (1967) The geochemistry of the Amazon River system part I: The factors that control the salinity and the composition and concentration of suspended solids. Geological Society of America Bulletin 78:1203–1232Google Scholar
  14. Harkness DD, Harrison AF, and Bacon PJ (1986) The temporal distribution of bomb14C in a forest soil. Radiocarbon 28:328–337Google Scholar
  15. Hedges JL, Clark WA, Quay PD, Richey JE, Devol AH, and Santos U. de M (1986) Composition and fluxes of organic matter in the Amazon River. Limnology and Oceanography 31:717–738Google Scholar
  16. Kuehl SA, DeMaster DJ, and Nittrouer CA (1986) Nature of sediment accumulation on the Amazon continental shelf. Continental Shelf Research 6:209–225Google Scholar
  17. Linick TW (1980) Bomb-produced carbon in surface waters of the Pacific Ocean. Radiocarbon 22:599–606Google Scholar
  18. Longinelli A and Edmond JM (1983) Isotope geochemistry of the Amazon Basin, A reconnaissance. Journal of Geophysical Research 88:3703–3717Google Scholar
  19. Meade RH, Dunne T, Richey J, Santos U de M., and Salati E (1985) Storage and remobilization of sediment in the lower Amazon River of Brazil. Science 228:488–490Google Scholar
  20. Nittrouer CA and DeMaster DJ (1986) Sedimentary processes on the Amazon continental shelf: Past, present and future research. Continental Shelf Research 6:5–30Google Scholar
  21. Nittrouer CA, Kuehl SA, Sternberg RW, Figueiredo AG and Faria LEC (1995) An introduction to the geological significance of sediment transport and accumulation on the Amazon continental shelf. Marine Geology 125:177–192Google Scholar
  22. Nittrouer CA, Kuehl SA, DeMaster DJ, and Kowsman RO (1986) The deltaic nature of Amazon shelf sedimentation. Geological Society of America Bulletin 97:444–458Google Scholar
  23. Noakes JE, Kim M, and Stipp JJ (1965) Chemical and counting advances in liquid scintillation age dating. Sixth International Conference on Radiocarbon and Tritium Dating, Pullman, Washington. pp 68–92Google Scholar
  24. Nydal RJ and Lövseth K (1983) Tracing bomb C-14 in the atmosphere 1962–1980. Journal of Geophysical Research 88:3621–3642Google Scholar
  25. Östlund HG, Dorsey HG, and Rooth CG (1974) GEOSECS North Atlantic radiocarbon and tritium results. Earth and Planetary Science Letters 23:69–86Google Scholar
  26. Richey JE, Meade RH, Salati E, Devol AH, Nordin CF Jr., and dos Santos U (1986) Water discharge and suspended sediment concentrations in the Amazon River: 1982–1984. Water Resources Research 22:756–764Google Scholar
  27. Richey JE, Hedges JI, Quay PD, Victoria R, Martinelli L, and Forsberg BR (1990) Biogeochemistry of carbon in the Amazon River. Limnology and Oceanography 35:352–371Google Scholar
  28. Sackett WM (1964) The depositional history and isotopic organic carbon composition of marine sediments. Marine Geology 2:173–185Google Scholar
  29. Showers WJ and Angle DG (1986) Stable isotopic characterization of organic carbon accumulation on the Amazon continental shelf. Continental Shelf Research 6:227–244Google Scholar
  30. Sommerfield CK, Nittrouer CA, and Figueiredo AG (1995) Stratigraphic evidence of changes in Amazon shelf sedimentation during the late Holocene. Marine Geology 125:351–371Google Scholar
  31. Stuiver M and Polach HA (1977) Discussion of14C data. Radiocarbon 19:355–363Google Scholar
  32. Stuiver M and Quay PD (1981) Atmospheric14C changes resulting from fossil fuel CO2 release and cosmic ray flux variability. Earth and Planetary Science Letters 53:349–362Google Scholar
  33. Walsh JJ, Premuzic ET, Gaffeney JS, Rowe GT, Harbottle G, Stoenner RW, Balsam WL, Betzer PR, and Macko SA (1985) Organic storage of CO2 on the continental slope off the mid-Atlantic bight, the southeastern Bering Sea, and the Peru coast. Deep-Sea Research 32:853–883Google Scholar

Copyright information

© Springer-Verlag 1996

Authors and Affiliations

  • Christopher K. Sommerfield
    • 1
  • Charles A. Nittrouer
    • 1
  • David J. DeMaster
    • 2
  1. 1.Marine Sciences Research CenterState University of New YorkStony BrookUSA
  2. 2.Department of Marine, Earth and Atmospheric SciencesNorth Carolina State UniversityRaleighUSA

Personalised recommendations