• AMS Dating of Human Bone from Palau: New Evidence for a Pre-2000 BP Settlement

      Fitzpatrick, Scott M. (Department of Geosciences, The University of Arizona, 2002-01-01)
      Direct dating of a human bone fragment from the Chelechol ra Orrak site (western Micronesia) has yielded one of the earliest dates for Palau thus far. This date compares well with recently collected paleoenvironmental evidence and radiocarbon dates on Babeldaob Island suggesting that settlement of the Palauan archipelago took place much earlier than previously thought.
    • Differences in 14C Age Between Stratigraphically Associated Charcoal and Marine Shell from the Archaic Period Site of Kilometer 4, Southern Peru: Old Wood or Old Water?

      Kennett, Douglas J.; Ingram, B. Lynn; Southon, John R.; Wise, Karen (Department of Geosciences, The University of Arizona, 2002-01-01)
      Consistently large differences occur in the calibrated 14C ages of stratigraphically associated shell and charcoal samples from Kilometer 4, an Archaic Period archaeological site located on the extreme south coast of Peru. A series of nine shell and charcoal samples were collected from a Late Archaic Period (approximately 6000-4000 BP) sector of the site. After calibration, the intercepts of the charcoal dates were approximately 100-750 years older than the paired shell samples. Due to the hyper-arid conditions in this region that promote long-term preservation of organic material, we argue that the older charcoal dates are best explained by people using old wood for fuel during the Middle Holocene. Given this "old wood" problem, marine shell may actually be preferable to wood charcoal for dating archaeological sites in coastal desert environments as in southern Peru and Northern Chile.
    • Reservoir Corrections for Marine Samples from the South Atlantic Coast, Santa Catarina State, Brazil

      Eastoe, C. J.; Fish, S.; Fish, P.; Gaspar, M. Dulce; Long, A. (Department of Geosciences, The University of Arizona, 2002-01-01)
      Coeval shell and charcoal from Santa Catarina State, Brazil, differ systematically in 14C content, indicating a reservoir effect in marine samples. For modern samples (AD 1939-2000) and archeological samples (2500-1595 BP), the mean 14C age difference between marine and atmospheric carbon is 220 +/20 years, the marine carbon being older. For three samples dated AD 1939-1944, a distinct reservoir correction of 510 +/10 years is also observed. The ages of archeological shell samples from Jabuticabeira may be corrected by subtracting 220 years from the apparent 14C ages.