International Journal of Earth Sciences

, Volume 89, Issue 3, pp 522–532

Organic carbon isotope ratios (δ13C) of Arctic Amerasian Continental shelf sediments

  • A. S. Naidu
  • L. W. Cooper
  • B. P. Finney
  • R. W. Macdonald
  • C. Alexander
  • I. P. Semiletov
Original Paper

DOI: 10.1007/s005310000121

Cite this article as:
Naidu, A., Cooper, L., Finney, B. et al. Int J Earth Sci (2000) 89: 522. doi:10.1007/s005310000121

Abstract.

Organic matter origins are inferred from carbon isotope ratios (δ13C) in recent continental shelf sediments and major rivers from 465 locations from the north Bering-Chukchi-East Siberian-Beaufort Sea, Arctic Amerasia. Generally, there is a cross-shelf increase in δ13C, which is due to progressive increased contribution seaward of marine-derived organic carbon to surface sediments. This conclusion is supported by the correlations between sediment δ13C, OC/N, and δ15N. The sources of total organic carbon (TOC) to the Amerasian margin sediments are primarily from marine water-column phytoplankton and terrigenous C3 plants constituted of tundra taiga and angiosperms. In contrast to more temperate regions, the source of TOC from terrigenous C4 and CAM plants to the study area is probably insignificant because these plants do not exist in the northern high latitudes. The input of carbon to the northern Alaskan shelf sediments from nearshore kelp community (Laminaria solidungula) is generally insignificant as indicated by the absence of high sediment δ13C values (–16.5 to –13.6‰) which are typical of the macrophytes. Our study suggests that the isotopic composition of sediment TOC has potential application in reconstructing temporal changes in delivery and accumulation of organic matter resulting from glacial–interglacial changes in sea level and environments. Furthermore, recycling and advection of the extensive deposits of terrestrially derived organic matter from land, or the wide Amerasian margin, could be a mechanism for elevating total CO2 and pCO2 in the Arctic Basin halocline.

Arctic Amerasian shelf Sediment carbon and nitrogen isotopes 

Copyright information

© Springer-Verlag 2000

Authors and Affiliations

  • A. S. Naidu
    • 1
  • L. W. Cooper
    • 2
  • B. P. Finney
    • 1
  • R. W. Macdonald
    • 3
  • C. Alexander
    • 4
  • I. P. Semiletov
    • 5
  1. 1.Institute of Marine Science, University of Alaska, Fairbanks, AK 99775-1080, USA
  2. 2.Department of Ecology and Evolutionary Biology, 569 Dabney Hall, University of Tennessee, Knoxville, TN 37996, USA
  3. 3.Department of Fisheries and Oceans, Institute of Ocean Sciences, P.O. Box 6000, Sydney, BC V8L 4B2, Canada
  4. 4.Skidway Institute of Oceanography, 10 Ocean Science Circle, Savannah, GA 31411, USA
  5. 5.Pacific Oceanogical Institute, Far Eastern Branch Russian Academy of Sciences, 43 Battiyskaya St., Vladivostok 690041, Russia

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