• Radiocarbon, Volume 33, Number 1 (1991)

      Department of Geosciences, The University of Arizona, 1991-01-01
    • University of Rome Radiocarbon Dates XVII

      Alessio, Marisa; Allegri, Lucia; Improta, Salvatore; Belluomini, Giorgio; Cortesi, Cesarina; Manfra, Luigia; Turi, Bruno (Department of Geosciences, The University of Arizona, 1991-01-01)
      This list includes dates from Italy, Libyan Sahara, Niger and the Dahlak Islands, obtained from 1976 to 1980, using the benzene scintillation method. Chemical processing from sample to benzene follows procedures of Alessio et al (1978a). Standard pretreatment for wood and charcoal included boiling with 5-10% HCL. Pretreatment for a-labeled samples underwent leaching with 0.2N NaOH. Since the last date list, Lecroy NIM modules have replaced the original recording electronics for the liquid scintillation detection system, described in Alessio et al (1973, 1976). Benzene sample volumes up to 4.Sml, with appropriate amounts of NE 216 scintillator (Nuclear Enterprises, Ltd) yielded the best figure-of-merit (E2/B = 2300) for 2m1 benzene and an efficiency of 72%. Age calculations comply with standard Radiocarbon protocol, as Stuiver and Polach (1977) recommended, including normalization by mass spectrometrically determined delta-13C (Alessio et al 1969).
    • The 14th International Radiocarbon Conference

      Department of Geosciences, The University of Arizona, 1991-01-01
    • Radiocarbon Announces the Publication of the Following Special Issues:

      Department of Geosciences, The University of Arizona, 1991-01-01
    • Radiocarbon – Price List

      Department of Geosciences, The University of Arizona, 1991-01-01
    • Pre-Conference Workshops – May 19, 1991

      Department of Geosciences, The University of Arizona, 1991-01-01
    • North American Archaeologist

      Department of Geosciences, The University of Arizona, 1991-01-01
    • From the Editor

      Long, Austin (Department of Geosciences, The University of Arizona, 1991-01-01)
    • Conference Sessions

      Department of Geosciences, The University of Arizona, 1991-01-01
    • Associate Editors

      Department of Geosciences, The University of Arizona, 1991-01-01
    • Archaeometry

      Department of Geosciences, The University of Arizona, 1991-01-01
    • Udine Radiocarbon Laboratory Date List III

      Calligaris, Franco; Colonello, Stefano; del Fabbro, Adriano; Perrone, Serena (Department of Geosciences, The University of Arizona, 1991-01-01)
      This list includes some significant measurements carried out by CRAD Radiocarbon Laboratory from 1979 to 1985. The dates were obtained by liquid scintillation counting of benzene using the laboratory procedures described in previous lists (Barbina et al 1982: 214-216; Barbina, Calligaris & Ciuti 1979). Samples were pretreated according to generally applied methods, depending on type of material and particular archaeologic and geologic features.
    • Two Early Sites of Eastern Beringia: Context and Chronology in Alaskan Interior Archaeology

      Erlandson, Jon; Walser, Rudy; Maxwell, Howard; Bigelow, Nancy; Cook, John; Lively, Ralph; Adkins, Charles; Dodson, Dave; Higgs, Andrew; Wilber, Janette (Department of Geosciences, The University of Arizona, 1991-01-01)
    • The Radiocarbon Laboratory at the University of Barcelona

      Mestres, J. S.; García, J. F.; Rauret, Gemma A. (Department of Geosciences, The University of Arizona, 1991-01-01)
      In 1983, the University of Barcelona, the Institut d'Estudis Catalans and the Department of Culture of the Generalitat de Catalunya agreed to establish a laboratory for radiocarbon measurement at the Analytical Chemistry Department of the University of Barcelona. The liquid scintillation technique was chosen for radiocarbon counting. The counting laboratory is in the basement of a six-story building.
    • Scintillation Cocktail Optimization for 14C Dating Using the Packard 2000CA/LL and 2260XL

      Anderson, Robert; Cook, G. T. (Department of Geosciences, The University of Arizona, 1991-01-01)
      In terms of both quenching and, in particular, counting efficiency, scintillation counters employing burst counting circuitry are sensitive to changes in scintillant concentration. Our research demonstrates that there are plateau regions where neither parameter is significantly influenced by moderate changes in a cocktail containing butyl PBD and bis MSB. One of these, consisting of butyl PBD 2.8mg.g-1 and bis MSB 3mg.g-1 of benzene is recommended for these counters, as it enables open window counting efficiencies of ca 90% while exhibiting optimal resistance to quenching. A method for accurate dispensing of such small weights is also described.
    • Radiocarbon Dates for Lava Flows and Pyroclastic Deposits on São Miguel, Azores

      Moore, Richard B.; Rubin, Meyer (Department of Geosciences, The University of Arizona, 1991-01-01)
    • Łódź Radiocarbon Dates III

      Kanwiszer, Andrzej; Trzeciak, Pawet (Department of Geosciences, The University of Arizona, 1991-01-01)
    • Harwell Radiocarbon Measurements X

      Walker, A. J.; Young, A. W.; Otlet, R. L. (Department of Geosciences, The University of Arizona, 1991-01-01)
    • Harwell Radiocarbon Measurements IX

      Walker, A. J.; Young, A. W.; Keyzor, R. S.; Otlet, R. L. (Department of Geosciences, The University of Arizona, 1991-01-01)
    • Gas Proportional Versus Liquid Scintillation Counting, Radiometric Versus AMS Dating

      Theodórsson, Páll (Department of Geosciences, The University of Arizona, 1991-01-01)
      I discuss here the basis of a comparison of methods for radiocarbon dating and introduce a new index for the relative merit of a system, factor of counting capacity, that is generally more appropriate than the commonly used factor of merit. The merit of a dating system cannot be based on a single figure but other factors must also be considered. A comparison of the gas proportional, liquid scintillation and accelerator mass spectrometry technique is presented that for gas proportional counters is based on a multi-detector system rather than a single detector.