• A Study of Errors in 14C Dates of Peat and Sediment

      Olsson, Ingrid U. (American Journal of Science, 1986-01-01)
      It is a well-established fact that 14C dates from lake sediments are usually too old because of contamination with allochthonous material and/or due to discrete reservoir effects. The latter can occur in soft water lakes and may be examined by the 14C measurement of aqueous plants or the carbon dissolved and suspended in the water column. Some plants assimilate CO2 from the sediment. Their 14C activity is then dependent on the sediment accumulation rate and nutrients stored in the root system may also contribute misleading results. If water is filtered through ultra-fine membranes and then treated chemically, several fractions can be isolated for dating. The present study shows that the 14C activity of such fractions varies widely but with the weighted mean indicating an overall deficiency. Even the water from a raised bog evidences a 14C deficiency relative to contemporary atmospheric CO2. Charcoal from an archaeologic site and peat from corresponding layers in a nearby bog have yielded significantly different ages. The fact that the Cladium peat was from a very calcareous area is significant. The risk of contamination by younger root material is also documented.
    • delta-13C and Diet: Analysis of Norwegian Human Skeletons

      Johansen, Olav Sverre; Gulliksen, Steinar; Nydal, Reidar (American Journal of Science, 1986-01-01)
      The relationship between 13C content of human bone and the marine fraction in the individual diet is well established. In the present investigation human skeletons from inland and coastal areas in Norway were analyzed. Both regional and chronologic differences are revealed, and larger variability than expected at specific sites indicate more complex cultural adaptations than earlier recognized. Extremely high delta-13C values, comparable with those obtained from Eskimo sites, are found for material from Early Stone Age fishing/hunting communities.
    • The Power of 14C Measurements Combined with Chemical Characterization for Tracing Urban Aerosol in Norway

      Currie, L. A.; Klouda, G. A.; Schjoldager, Jorgen; Ramdahl, Thomas (American Journal of Science, 1986-01-01)
      Changing fuel patterns and increased awareness of health effects from combustion aerosols have generated considerable interest in the use of 14C as a biogenic-fossil aerosol source discriminator. Prior studies in the US demonstrated the importance of 14C measurement for estimating the wood-burning contribution to urban aerosols. The present work treats a specific air-pollution problem in the town of Elverum, Norway where large wintertime concentrations of aerosol carbon and polycyclic aromatic hydrocarbons (PAH) were suspected to come from residential woodl combustion (RWC). The problem was significant in that up to 50 micrograms/m3[C] and 490 micrograms/m3[PAH] were found during pollution episodes. Samples collected during two winters were analyzed for C, C, PAH, and several elements in the fine fraction (<3 micrometers) aerosol. Source apportionment based on these species indicated an average of ca 65% RWC-carbon (14C), ca 5% fine particle mass from motor vehicles (Pb), but negligible contributions from heavy fuel oil (Ni, V). Patterns of 14C and total C, examined as a function of temperature and PAH, indicated large increases in RWC aerosol on the coldest days, and a major RWC contribution to the PAH fraction. Patterns with inorganic species implied multiple tracer sources, and one important case of long-range transport.
    • The Prehistoric Expansion of Farming Into "Arctic" Norway: A Chronology Based on 14C Dating

      Johansen, Olav Sverre; Vorren, Karl-Dag (American Journal of Science, 1986-01-01)
      Palynologic and archaeologic studies using 14C dating indicate that elements of farming were introduced even further north than the Arctic Circle during the Neolithic period, ca 4000 BP. A second stage with heavier reliance on farming and with probable establishment of permanent farmsteads is dated to 2000-2500 BP.
    • The Value of 210Pb in Dating Scandinavian Aquatic and Peat Deposits

      El-Daoushy, Farid (American Journal of Science, 1986-01-01)
      Sediment and peat chronologies have been further improved allowing alternative radiometric methods to complement 14C dating. Lacustrine and coastal marine sediments as well as peat deposits in various parts in Scandinavia are studied using 137Cs, 210Pb, 14C and other methods primarily to evaluate the 210Pb but also to extend the 14C chronology. The sampling sites have various sources of input and are characterized by different geochemical, depositional, and post-depositional conditions.
    • University of Lund Radiocarbon Dates XIX

      Håkansson, Sören (American Journal of Science, 1986-01-01)
    • University of Lund Radiocarbon Dates XVIII

      Håkansson, Sören (American Journal of Science, 1986-01-01)