• Illinois State Geological Survey Radiocarbon Dates X

      Liu, Chao-Li; Asch, D. L.; Fisher, B. W.; Coleman, D. D. (Department of Geosciences, The University of Arizona, 1992-01-01)
      The following is a partial list of samples of archaeological interest processed between February 1981 and October 1985 at the Illinois State Geological Survey (ISGS) Radiocarbon Dating Laboratory. The list contains samples from west-central Illinois that were related to projects conducted by current or former researchers at the Center for American Archeology (CAA) (formerly Foundation for Illinois Archaeology) and Northwestern University, Department of Anthropology, or, as noted, by colleagues from other institutions. Although some of the samples reported here came from non-cultural contexts and are primarily of geological significance, all were from or related to archaeological investigations.
    • Institut Royal du Patrimoine Artistique Radiocarbon Dates XIV

      Dauchot-Dehon, Michele; Van Strydonck, Mark (Department of Geosciences, The University of Arizona, 1992-01-01)
      This list contains the results of 14C determinations that we obtained in 1988 and 1989. delta-13C was measured by the Free University, Brussels. Our dating techniques have been described previously (Dauchot-Dehon & Heylen 1971; Dauchot-Dehon, Van Strydonck & Heylen 1986).
    • Isotope Dating of Pleistocene Dung Deposits from the Colorado Plateau, Arizona and Utah

      Mead, Jim I.; Agenbroad, Larry D. (Department of Geosciences, The University of Arizona, 1992-01-01)
      Identified dung and keratinous remains of large mammals are considered the most reliable materials to 14C date, when the initial question includes the application of the date to the time of local extirpation and extinction. The Colorado Plateau provides a unique preservation habitat (desiccation), found in greater abundance of deposits than anywhere else in North America. We review 20 localities from the Colorado Plateau that contain dung of megaherbivores. Seven species of herbivores were identified utilizing dung: Bison (bison), Equus (horse), “Euceratherium“ (shrubox), Mammuthus (mammoth), Nothrotheriops (ground sloth), Oreamnos (mountain goat) and Ovis (bighorn), and 79 14C dates were measured from the sites. Most sites contain additional associated 14C and U/Th dates on skeletal and botanical remains.
    • Liquid Scintillation Counter Characterization, Optimization and Benzene Purity Correction

      McCormac, F. G. (Department of Geosciences, The University of Arizona, 1992-01-01)
      In liquid scintillation counting (LSC), small variations in benzene purity can cause 14C pulse-height spectra to move with respect to the counting window. Thus, one must carefully monitor the purity of each benzene sample and apply corrections for spectral shifts. I describe here the techniques used at Queen's University Belfast for deriving correction factors for observed small variations in benzene purity. I also describe the methods used at our laboratory to fine-tune our Quantulus LS counters for high-precision dating. The tuning of the instruments minimizes the effect of fluctuations in gain that may occur during the long counting periods required for high-precision dating. Any remaining influences on efficiency owing to gain changes are corrected for, along with the purity correction, by continuous monitoring of the spectrum produced by the external source.
    • North American Archaeologist

      Department of Geosciences, The University of Arizona, 1992-01-01
    • Radiocarbon – Price List

      Department of Geosciences, The University of Arizona, 1992-01-01
    • Radiocarbon, Volume 34, Number 1 (1992)

      Department of Geosciences, The University of Arizona, 1992-01-01
    • Rehovot Radiocarbon Measurements IV

      Carmi, Israel; Segal, Dror (Department of Geosciences, The University of Arizona, 1992-01-01)
      The following list consists of dates of archaeological samples, obtained by gas-proportional counting of ethane, between 1985 and the end of 1991. During this time a close cooperation has been established with the Israel Antiquities Authority, which now has an archaeologist (D.S.) participating in the operation of the lab and serving as a liaison officer with the archaeological community.
    • Rudjer Bošković Institute Radiocarbon Measurements XII

      Srdoč, Dušan; Horvatinčić, Nada; Krajcar Bronić, Ines; Obelić, Bogomil; Sliepčević, Adela (Department of Geosciences, The University of Arizona, 1992-01-01)
      We present here radiocarbon analyses made since our previous list (Srdoč et al. 1989). Sample pretreatment, combustion and counting techniques are essentially the same as described previously (Srdoč, Breyer & Sliepčević 1971), supplemented by new techniques for groundwater processing (Srdoč et al. 1979). The calculation of ages follows conventional protocol (Stuiver & Polach 1977). These ages can be converted from the 5570-year half-life to the chronometrically more correct half-life of 5730 years by multiplying by the factor, 1.029. Ages and standard deviations of all samples are adjusted for stable isotope fractionation according to the recommendations in Stuiver and Polach (1977), except for groundwater, calcareous deposits and aquatic plants. The delta-13C values of the latter reflect the environmental conditions during their formation or growth rather than fractionation (Mook 1976; Krajcar Bronić et al. 1986; Marčenko et al. 1989). Thus, any percent modern (pMC) correction based on delta-13C values is meaningless or even misleading. Sample descriptions are prepared in collaboration with collectors and submitters. Calibrated ages were calculated using the program of Stuiver and Reimer (1987).
    • Send for a Free Sample Copy of...Quaternary International

      Department of Geosciences, The University of Arizona, 1992-01-01
    • Send for a Free Sample Copy of...Quaternary Science Reviews

      Department of Geosciences, The University of Arizona, 1992-01-01
    • University of Granada Radiocarbon Dates VI

      Gonzalez-Gomez, Cecilio (Department of Geosciences, The University of Arizona, 1992-01-01)
      This paper includes determinations of archaeological, geological, palaeobotanical and other samples from Spain, Portugal and Bolivia, measured at the University of Granada Radiocarbon Dating Laboratory, mostly from 1989 to 1990. Pretreatment of charcoal and wood samples is a standard acid-basic procedure using 8% HCl and 2% NaOH at boiling temperature. We obtain collagen from bone samples using the Longin (1971) method.
    • University of Wisconsin Radiocarbon Dates XXVII

      Prior, Christine A.; Phelps, Lori F. (Department of Geosciences, The University of Arizona, 1992-01-01)
      Procedures and equipment used in the University of Wisconsin laboratory have been described previously (Bender, Bryson & Baerreis 1965; Steventon & Kutzbach 1986). Except as otherwise indicated, wood, charcoal and peat samples are pretreated with dilute NaOH-Na4P2O7 and dilute HCl before conversion to counting gas methane; when noted, marls and lake cores are treated with acid only.