Abstract
Sedimentary carbon systematics on the Amazon continental shelf were investigated using14C andδ 13C 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.
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Aller RC, Blair NE, Xia Q, and Rude PD (1996) Remineralization rates, recycling, and storage of carbon in Amazon shelf sediments. Continental Shelf Research 16
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 16:36–40
Becker-Heidmann P and Scharpenseel P (1989) Carbon isotope dynamics in some tropical soils. Radiocarbon 31:672–679
Benoit GJ, Turekian KK, and Benninger LK (1979) Radiocarbon dating of a core from Long Island Sound. Estuarine and Coastal Marine Science 9:171–180
Berger WH and Heath GR (1968) Vertical mixing in pelagic sediments. Journal of Marine Research 26:135–143
Berner RA (1982) Burial of organic carbon and pyrite sulfur in the modern ocean: Its geochemical and environmental significance. American Journal of Science 282:451–473
Broecker WS, Gerard R, Ewing M, and Heezen BH (1960) Natural radiocarbon in the Atlantic Ocean. Journal of Geophysical Research 65:2903–2931
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 26:1–14
Craig H (1953) The geochemistry of stable carbon isotopes. Geochimica et Cosmochimica Acta 3:53–92
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 2:249–254
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 453–468
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 38:823–842
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 78:1203–1232
Harkness DD, Harrison AF, and Bacon PJ (1986) The temporal distribution of bomb14C in a forest soil. Radiocarbon 28:328–337
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 31:717–738
Kuehl SA, DeMaster DJ, and Nittrouer CA (1986) Nature of sediment accumulation on the Amazon continental shelf. Continental Shelf Research 6:209–225
Linick TW (1980) Bomb-produced carbon in surface waters of the Pacific Ocean. Radiocarbon 22:599–606
Longinelli A and Edmond JM (1983) Isotope geochemistry of the Amazon Basin, A reconnaissance. Journal of Geophysical Research 88:3703–3717
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 228:488–490
Nittrouer CA and DeMaster DJ (1986) Sedimentary processes on the Amazon continental shelf: Past, present and future research. Continental Shelf Research 6:5–30
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 125:177–192
Nittrouer CA, Kuehl SA, DeMaster DJ, and Kowsman RO (1986) The deltaic nature of Amazon shelf sedimentation. Geological Society of America Bulletin 97:444–458
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 68–92
Nydal RJ and Lövseth K (1983) Tracing bomb C-14 in the atmosphere 1962–1980. Journal of Geophysical Research 88:3621–3642
Östlund HG, Dorsey HG, and Rooth CG (1974) GEOSECS North Atlantic radiocarbon and tritium results. Earth and Planetary Science Letters 23:69–86
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 22:756–764
Richey JE, Hedges JI, Quay PD, Victoria R, Martinelli L, and Forsberg BR (1990) Biogeochemistry of carbon in the Amazon River. Limnology and Oceanography 35:352–371
Sackett WM (1964) The depositional history and isotopic organic carbon composition of marine sediments. Marine Geology 2:173–185
Showers WJ and Angle DG (1986) Stable isotopic characterization of organic carbon accumulation on the Amazon continental shelf. Continental Shelf Research 6:227–244
Sommerfield CK, Nittrouer CA, and Figueiredo AG (1995) Stratigraphic evidence of changes in Amazon shelf sedimentation during the late Holocene. Marine Geology 125:351–371
Stuiver M and Polach HA (1977) Discussion of14C data. Radiocarbon 19:355–363
Stuiver M and Quay PD (1981) Atmospheric14C changes resulting from fossil fuel CO2 release and cosmic ray flux variability. Earth and Planetary Science Letters 53:349–362
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 32:853–883
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Sommerfield, C.K., Nittrouer, C.A. & DeMaster, D.J. Sedimentary carbon-isotope systematics on the Amazon shelf. Geo-Marine Letters 16, 17–23 (1996). https://doi.org/10.1007/BF01218832
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DOI: https://doi.org/10.1007/BF01218832