• Correcting 14C Histograms for the Non-Linearity of the 14C Time Scale

      Stolk, A.; Hogervorst, Koos; Berendsen, Henk (Department of Geosciences, The University of Arizona, 1989-01-01)
      Large numbers of 14C dates of the base and top of Holocene peat layers may be plotted in 14C histograms in order to establish statistically a chronology of periods of essentially elastic sedimentation and peat formation. Due to the non-linearity of the 14C time scale in terms of calendar years, clustering of 14C dates on random peat growth may occur. This seriously hampers the interpretation of histograms. A quantitative method and computer program were developed to correct the histograms for this effect. The correction factor that has to be applied depends on the calibration curve and the interval width of the correction parameter dy. For peat samples, an interval width of 100 14C yr and a calibration curve based on a 100-yr moving average seems to be a reasonable choice.
    • High-Resolution 14C Dating of Organic Deposits Using Natural Atmospheric 14C Variations

      Van Geel, Bas; Mook, Willem G. (Department of Geosciences, The University of Arizona, 1989-01-01)
      The occurrence of atmospheric 14C variations complicates calibration, ie, the translation of 14C ages into real calendar ages. The procedure of wiggle matching, however, allows very precise calibration, by matching known 14C variations with wiggles in the floating chronology. In principle, wiggle matching can also be applied to a series of 14C dates from organic (peat) deposits. Where, in general, 14C ages are required at short distances and on small samples, dating by 14C accelerator mass spectrometry (AMS) is required.