Browsing Radiocarbon, Volume 40, Number 3 (1998) by Authors
INTCAL98 Radiocarbon Age Calibration, 24,000-0 cal BPStuiver, Minze; Reimer, Paula J.; Bard, Edouard; Beck, J. Warren; Burr, G. S.; Hughen, Konrad A.; Kromer, Bernd; McCormac, Gerry; van der Plicht, Johannes; Spurk, Marco (Department of Geosciences, The University of Arizona, 1998-01-01)The focus of this paper is the conversion of radiocarbon ages to calibrated (cal) ages for the interval 24,000-0 cal BP (Before Present, 0 cal BP = AD 1950), based upon a sample set of dendrochronologically dated tree rings, uranium-thorium dated corals, and varve-counted marine sediment. The 14C age-cal age information, produced by many laboratories, is converted to 14C profiles and calibration curves, for the atmosphere as well as the oceans. We discuss offsets in measured 14C ages and the errors therein, regional 14C age differences, tree-coral 14C age comparisons and the time dependence of marine reservoir ages, and evaluate decadal vs. Single-year 14C results. Changes in oceanic deepwater circulation, especially for the 16,000-11,000 cal BP interval, are reflected in the Δ14C values of INTCAL98.
Radiocarbon Calibration by Means of Mass Spectrometric 230Th/234U and 14C Ages of Corals: An Updated Database Including Samples from Barbados, Mururoa and TahitiBard, Edouard; Arnold, Maurice; Hamelin, Bruno; Tisnérat-Laborde, Nadine; Cabioch, Guy (Department of Geosciences, The University of Arizona, 1998-01-01)As first shown by Bard et al. (1990a), high-precision 230Th-234U ages can be used successfully to calibrate the radiocarbon time scale beyond the high-precision tree-ring calibration that now reaches 11,900 cal BP (Kromer and Spurk 1998). Using mass spectrometric techniques, we measured 14C and 230Th ages on new samples collected from boreholes drilled off the islands of Tahiti and Mururoa (French Polynesia) in order to complement the database previously obtained on Barbados corals (Bard et al. 1990a, 1993).