• Determination of 90Sr/90Y in Wheat Grains, Soil, and Deposition Samples by TBP Extraction and Cerenkov Counting

      Gertmann, Udo Ch; Tschöpp, Vlasta (Department of Geosciences, The University of Arizona, 2006-01-01)
      Within the framework of radioecological studies, 90Sr was determined in wheat grains, soil, and deposition samples. The radiochemical purification of 90Y consisted of liquid-liquid extraction by tributyl phosphate (TBP), followed by hydroxide and oxalate precipitations and, if necessary, the removal of thorium by anion exchange chromatography. The procedure proved to be very robust and reliable, having yttrium yields of 92.7 4.6% for 1-kg wheat samples, 90.9 4.2% for 50-g soil samples, and 90.6 3.2% for wet and dry deposition samples. 90Y was determined by Cerenkov counting and proportional counting. By optimizing the Cerenkov counting window, a figure of merit (FOM) of 4750 could be reached using a Quantulus 1220 system. Minimum detectable activities were in the range of 10 mBq.
    • Dilemma of Dating on Lacustrine Deposits in an Hyperarid Inland Basin of NW China

      Zhang, H. C.; Ming, Q. Z.; Lei, G. L.; Zhang, W. X.; Fan, H. F.; Chang, F. Q.; Wünnemann, B.; Hartmann, K. (Department of Geosciences, The University of Arizona, 2006-01-01)
      Conventional and accelerator mass spectrometry (AMS) radiocarbon, TL, OSL, and IRSL dating results on samples from the cores D100 and I70 from Ejina Basin, one of the most important inland basins in arid-hyperarid NW China, show that it is difficult to determine the ages of sediments at different depths. AMS ages of core D100 samples demonstrate that the sediments at depths from 10 to 90 m were formed between 14 to 30 kyr BP. The inverted ages from both the D100 and I70 cores imply that there was a strong reworking of the sediments during and after deposition processes. The inverted ages also indicate drastic fluctuations of groundwater bearing soluble organic matters, which might be related to neotectonic activities and climate changes during the period. Consequently, it is impossible to establish an accurate and reliable chronology for the cores based only on these dates. All AMS ages, if they are reliable and acceptable, indicate a high deposition rate (5~8 mm/yr), and since all TL, OSL, and IRSL ages are much older than those given by AMS, it makes these methods questionable for determining the ages of lacustrine-fluvial-alluvial deposits.
    • Erratum

      Department of Geosciences, The University of Arizona, 2006-01-01
      There is an error in the previous issue of Radiocarbon.
    • In Memoriam: Henry N. Michael (1912-2006)

      Department of Geosciences, The University of Arizona, 2006-01-01
    • New AMS 14C Dates from the Early Upper Paleolithic Sequence of Raqefet Cave, Mount Carmel, Israel

      Lengyel, György; Boaretto, Elisabetta; Fabre, Laurent; Ronen, Avraham (Department of Geosciences, The University of Arizona, 2006-01-01)
      Raqefet Cave (35 degrees 04'21"N, 32 degrees 39'17"W) is situated in the southeastern side of Mount Carmel in Israel (Figure 1) on the left bank of wadi Raqefet (230 m asl), ~50 m above the wadi bed. It is 50 m long with an area of ~500 m2 (Figure 2). Eric Higgs of Cambridge University and Tamar Noy of the Israel Museum conducted excavations at the site between 1970 and 1972 (Higgs et al. 1975). New excavations at the cave began in 2004 (Lengyel et al. 2005). Studies on the lithic archaeological remains from the 1970-1972 stratigraphic units assign Late Mousterian or Middle to Upper Paleolithic transition (layers VIII-VI in squares B-G/18-23), indeterminate early Upper Paleolithic (layer IV in squares B-G/18-23), Levantine Aurignacian (layers IV, III, and II in squares B-G/18-23), indeterminate late Upper Paleolithic (layer II in area B-G/18-23), Late Kebaran (layer I in squares B-G/18-23), Geometric Kebaran (layer VII in squares J-M/24-28), Late Natufian (layers IV-VI in squares A-H/7-17), Neolithic (I-IV in squares J-M/24-28), and Bronze Age (pits in squares A-H/7-17 and B-G/18-23) occupations (Higgs et al.1975; Lengyel 2003, 2005; Lengyel and Bocquentin 2005; Lengyel et al. 2005; Noy and Higgs 1971; Sarel 2004; Ziffer 1978a,b).
    • Radiocarbon Chronology of Prehistoric Campsites in Alpine and Subalpine Zones at Haleakalā, Maui Island, USA

      Carson, Mike T.; Mintmier, Melanie A. (Department of Geosciences, The University of Arizona, 2006-01-01)
      A chronological synthesis of prehistoric campsites in alpine and subalpine zones (~2-3 km asl) at Haleakalā, Maui Island, USA, is based on relative stratigraphy from 24 test excavations, associated artifacts of known or probable time periods, and 12 radiocarbon dates. The results indicate intensive use of the unfavorable high-altitude environment in the range of AD 1400-1600, with very limited use slightly earlier. Numerous campsites were used repeatedly near the Haleakalā crater rim and scattered on the lower western mountain slope. Prior to this time, activity in this inhospitable setting was infrequent and occurred on a small scale.
    • Response to Beavan Athfield's “Comment on ‘Diet-Derived Variations in Radiocarbon and Stable Isotopes: A Case Study from Shag River Mouth, New Zealand’”

      Anderson, A.; Higham, Thomas (Department of Geosciences, The University of Arizona, 2006-01-01)
      Beavan Athfield (2006) has commented on our recent paper in this journal (Higham et al. 2005). In our opinion, both in her response and in Beavan Athfield (2004) she misrepresents the evidence and conclusions presented by Anderson (2000). She claims (Beavan Athfield 2006:117) that Andersons (2000) Figure 6, which is reproduced as Beavan Athfields (2004) Figure 1, shows that ages of ancient rat bone gelatin in 1995-1996 (NZA numbers 4000-6000) were exclusively earlier than about 1000 BP, while those from 1997 onward (NZA numbers 7000+) were exclusively later than about 1000 BP. Beavan Athfield asserts that this is the result of Anderson (2000) ignoring 9 published accelerator mass spectrometry (AMS) results from 1995-1996 that were younger than about 900 BP. These would be serious claims of poor scholarship, were they substantiated, but in fact, Anderson (2000, 2004) never asserted that the AMS results were distributed so exclusively, nor did he fail to take account of all published results.
    • Seoul National University Accelerator Mass Spectrometry (SNU-AMS) Radiocarbon Date List I

      Kim, J. C.; Youn, M. Y.; Kim, I. C.; Park, J. H.; Song, Y. M.; Kang, J.; Cheoun, M. K. (Department of Geosciences, The University of Arizona, 2006-01-01)
      The accelerator mass spectrometry facility at Seoul National University (SNU-AMS) began functioning in December 1998 and was first reported at the Vienna AMS conference in October 1999 and at the 17th International Radiocarbon Conference in Israel in June 2000. At the Vienna conference, we reported our accelerator system (Kim et al. 2000) and details of the basic sample preparation system (Lee et al. 2000), such as the combustion line to produce CO2 ; the catalytic reduction line for the graphitization of CO2 ; and the pretreatment procedures for wood, charcoal, and peat samples. The recent progress of the AMS facility (Kim et al. 2001) and the extension of the sample pretreatment system to iron and bone samples were reported at the 17th International Radiocarbon Conference (Cheoun et al. 2001). In the meantime, extensive testing of accuracy and reproducibility has been carried out, and ~1000 unknown archaeological and geological samples have been measured every year. In this report, the archaeological, geological, and environmental data carried out in 1999 are presented in terms of yr BP.
    • Seoul National University Accelerator Mass Spectrometry (SNU-AMS) Radiocarbon Date List II

      Kim, J. C.; Youn, M. Y.; Kim, I. C.; Park, J. H.; Song, Y. M.; Kang, J. (Department of Geosciences, The University of Arizona, 2006-01-01)
      The accelerator mass spectrometry facility at Seoul National University (SNU-AMS) began functioning in December 1998 and was first reported at the Vienna AMS conference in October 1999 and at the 17th Radiocarbon Conference in Israel in June 2000. At the Vienna conference, we reported our accelerator system (Kim et al. 2000) and the basic sample preparation system (Lee et al. 2000), including the combustion line to produce CO2 ; the catalytic reduction line for the graphitization of CO2 ; and also pretreatment procedures for wood, charcoal, and peat samples. Recent progress of the AMS facility (Kim et al. 2001) and extension of the sample pretreatment system to iron and bone samples were reported at the 17th Radiocarbon Conference (Cheoun et al. 2001). In the meantime, extensive testing of accuracy and reproducibility has been carried out, and ~1000 unknown archaeological and geological samples have been measured every year. A report of data carried out in 1999 is presented by Kim et al. (this issue). In this report, the archaeological, geological, and environmental data carried out in 2000 are presented in terms of yr BP.
    • The 3MV Multi-Element AMS in Xi'an, China: Unique Features and Preliminary Tests

      Zhou, Weijian; Zhao, Xiaolei; Xuefeng, Lu; Lin, Liu; Zhengkun, Wu; Peng, Cheng; Wengnian, Zhao; Chunhai, Huang (Department of Geosciences, The University of Arizona, 2006-01-01)
      A 3MV multi-element accelerator mass spectrometer (AMS) has been installed in Xian, China, and preliminary tests have been completed. The results of both background and precision tests for 4 nuclides are 3.1 x 10^-16, 0.2% (14C); 1.8 x 10^-14, 1.4% (10Be); 2.3 x 10^-15, 1.14% (26Al); and 2.0 x 10^-14, 1.75% (129I). The unique features of this facility are the newly developed ion source accepting solid and CO2 samples; the specially designed low-energy injector, including a beam blanking unit and Q-snout; the acceleration tube structure with the combined magnetic and electrostatic suppression; and the function of the slit stabilization in the post-acceleration system. These features are discussed in terms of the end-users point of view.