• A Regional Geochronological Study of Late Pleistocene Permafrost

      Kostyukevich, V. V. (Department of Geosciences, The University of Arizona, 1993-01-01)
      The use of radiocarbon dating in geocryological investigations makes it possible to establish a chronology for permafrost-geological development during the Late Pleistocene. Both global and regional time scales for the formation of Late Pleistocene permafrost have been worked out over the past 15-20 years at the Permafrost Institute of the Siberian Branch of the Russian Academy of Sciences. I present here results from study areas of northwestern Siberia and of North, Central and West Yakutia.
    • An Improved Method for Radiocarbon Dating Fossil Bones

      Arslanov, Kh A.; Svezhentsev, Yu S. (Department of Geosciences, The University of Arizona, 1993-01-01)
      We demonstrate here that the use of either the acid-alkali or Longin method alone does not fully extract contaminants from bone-collagen fractions. We present our methods and results of extracting bone collagen that involve successive use of both of these methods.
    • Dynamics of Radiocarbon in Soils

      Cherkinsky, A. E.; Brovkin, V. A. (Department of Geosciences, The University of Arizona, 1993-01-01)
      We present here a model of humus accumulation in recent soils. We have estimated the coefficients of mineralization of humus and humic acid for a typical Chemozem soil. We suggest a technique for calculating the renewal time of soil with specific activity higher than the modem standard and discuss the results for different soils.
    • Geochronology of Late Quaternary Events in Northeastern Russia

      Lozhkin, A. V. (Department of Geosciences, The University of Arizona, 1993-01-01)
      Radiocarbon-dated paleobotanical and palynological samples record complex changes of vegetation and climate in northeastern Russia during the Late Pleistocene and Holocene. Since the Kargin Interval (middle Wisconsin equivalent), which started 50 ka ago, we can distinguish two periods that were colder than the present. The Kirgilyakh was the earliest Karginsk cool period, dating to 45–39 ka BP. The second significant cool period dates to 33–30 ka BP. The boundary between the Kargin Interval and the last Late Pleistocene glaciation (Sartan, late Wisconsin equivalent) dates from 27 ka BP. The sharp change from herbaceous mossy tundra (Sartan) to light-coniferous larch forests (Holocene) in northeastern Russia dates to 12.5 ka ago. The Holocene thermal maximum, linked to the expansion of woody plants into the modern barren-ground tundra, dates from 9.5–8 ka BP.
    • Geochronology of the Holocene of the Belorussian Polessie

      Matveev, A. V.; Krutous, E. A.; Zernitskaya, V. P. (Department of Geosciences, The University of Arizona, 1993-01-01)
      We distinguished major stages of the last glaciation (Bulling, Older Dryas, Allerod, Younger Dryas) and the Holocene by radiocarbon dating and paleobotanical analyses. Our paleobotanical investigation of peatlands is well correlated with independent 14C data. We establish that the Atlantic and Subboreal stages of the Holocene have three divisions, and that the Subatlantic has two.
    • Geochronology of the Nival-Glacial Deposits of the Ukrainian Carpathian Mountains

      Kovalyukh, N. N.; Petrenko, L. V.; Kovalenko, V. V. (Department of Geosciences, The University of Arizona, 1993-01-01)
    • Geochronology of the Pleistocene and Holocene in the Fore-Urals

      Latypova, E. K.; Yakheemovich, B. L. (Department of Geosciences, The University of Arizona, 1993-01-01)
      The paper presents the results for the 14C dating obtained recently in the Laboratory of the Institute of Geology, Ufa Science Centre, Russian Academy of Science, on the basis of megafaunal bones, peats, wood and mollusk shells. Dates are reported in stratigraphic sequence from the Late Wurmian to the Holocene.
    • Late Paleolithic Chronology of the East European Plain

      Svezhentsev, Yu S.; Popov, S. G. (Department of Geosciences, The University of Arizona, 1993-01-01)
      We report 172 dates on osseous material from Paleolithic sites of the East European Plain.
    • Late Pleistocene Geochronology of European Russia

      Arslanov, Kh A. (Department of Geosciences, The University of Arizona, 1993-01-01)
      I constructed a Late Pleistocene geochronological scale for European Russia employing 14C dating and paleobotanical studies of several reference sections.
    • Mesolithic and Neolithic Habitation of the Eastern Baltic

      Liiva, Arvi; Loze, Ilze (Department of Geosciences, The University of Arizona, 1993-01-01)
      In this paper we consider the radiocarbon chronology of Mesolithic and Neolithic settlement sites in the eastern Baltic region. Dating of wood and charcoal from Estonian and Latvian sites establishes the periods (early, middle and late) within these epochs. We present 90 14C dates, as yet unpublished in RADIOCARBON, produced by laboratories in Riga, Tallin, Tartu, Leningrad and Moscow.
    • Possibilities for Detailed Dating of Peat Bog Deposits

      Punning, Jaan-Mati; Ilomets, Mati; Koff, Tiiu (Department of Geosciences, The University of Arizona, 1993-01-01)
      Geochemical and palynological data as well as radiocarbon dating were used to study the peat bog deposits in Niinsarre bog, northeast Estonia. The aim of this study was to establish criteria for determining a detailed chronology, which is important, for example, in studying paleoevents and historical monitoring. In some cases, we can use cumulative pollen data, as well as cumulative chemical and peat bulk density data.
    • Problems and Methods of Dating Low-Activity Samples by Liquid Scintillation Counting

      Arslanov, Kh A.; Tertychnaya, T. V.; Chernov, S. B. (Department of Geosciences, The University of Arizona, 1993-01-01)
      The important problem of contamination of old samples by younger 14C necessitates treatment of organic and carbonate samples to ensure more complete removal of contaminating carbon. Here we present studies of chemical procedures for the liquid scintillation method of 14C dating undertaken since 1960 in the former USSR. We discuss new procedures such as lithium carbide synthesis from charred organic samples and benzene synthesis on a V2O5.Al2O3.SiO2 catalyst, as well as memory effect in the carbide synthesis procedure and characteristics of two homemade counters.
    • Problems in Radiocarbon Dating of Soils

      Chichagova, O. A.; Cherkinsky, A. E. (Department of Geosciences, The University of Arizona, 1993-01-01)
      We discuss our progress in three principal applications of 14C dating of recent and fossil soils: 1) new methods; 2) problems of interpreting 14C soil data (e.g.,14C age of soils, age of soils, duration of humus formation, rate of carbon cycling); and 3) 14C analysis of soil organic matter (OM) in pedology and paleogeography (e.g., soil genesis and evolution, humus formation and OM metamorphosis, geochronology and stratigraphy of Late Pleistocene and Holocene sediments). We suggest exploring the above issues in the analysis of each 14C profile in conjunction with paleogeographical data, and by simulation of the carbon cycle in each type of profile.
    • Radiocarbon and 11-Year Variations of Cosmic Rays

      Burchuladze, A. A.; Pagava, S. V.; Togonidze, G. I.; Avtandilashvili, M. V. (Department of Geosciences, The University of Arizona, 1993-01-01)
    • Radiocarbon Chronology of Archaeological Sites of the Kurile Islands

      Zaitseva, G. I.; Popov, S. G.; Krylov, A. P.; Knorozov, Yu V.; Spevakovskiy, A. B. (Department of Geosciences, The University of Arizona, 1993-01-01)
    • Radiocarbon Chronology of Early Medieval Archaeological Sites in Northwestern Russia

      Popov, S. G.; Svezhentsev, Yu S.; Zaitseva, G. I. (Department of Geosciences, The University of Arizona, 1993-01-01)
      A reliable archaelogical chronology for medieval sites in northwestern Russia depends in part on a refined regional calibration scale for 14C dates. We present results of dates on tree-ring series from Novgorod that show a systematic discrepancy from European calibration curves, and that underline the need for more extensive 14C dating as the basis of an extended calibration curve for the region.
    • Radiocarbon Chronology of Paleogeographic Events of the Late Pleistocene and Holocene in Russia

      Kaplin, P. A.; Svitoch, A. A.; Parunin, O. B. (Department of Geosciences, The University of Arizona, 1993-01-01)
      14C chronology of Late Pleistocene paleogeographical events in the Black Sea-Caspian Sea region shows that the following transgressions partly correlate with each other: Karangat and Khazarian; Neo-Euxinian and Khvalyn; Holocene and Neo-Caspian. The main climatic events were synchronous in intercontinental Siberia. In the far eastern region, the Middle-Wisconsinan transgression is reflected by Chukotka and western Kamchatka terraces and by submerged ancient shorelines in Primorye.
    • Radiocarbon Dating and Tephrochronology in Kamchatka

      Braitseva, O. A.; Sulerzhitsky, L. D.; Litasova, S. N.; Melekestsev, I. V.; Ponomareva, V. V. (Department of Geosciences, The University of Arizona, 1993-01-01)
      We discuss results of 14C dates obtained from areas of young volcanoes in Kamchatka. We apply these dates to reconstructing regional volcanic activity during the Holocene.
    • Radiocarbon Dating Organic Detritus: Implications for Studying Ice Sheet Dynamics

      Punning, Jaan-Mati; Rajamäe, Raivo (Department of Geosciences, The University of Arizona, 1993-01-01)
      We present here a description of the 14C dating method used at the Institute of Geology, Estonian Academy of Science. We discuss results of geochronological studies of several stratigraphic sections, from which we estimate the age of the Late Weichselian (Late Valdaian) glacial maximum. 14C and paleobotanical data indicate that biodetrital materials comprise organic debris from various sources and suggest only a maximum age of investigated strata (16,000 BP).
    • Reconstruction of Caspian Sea-Level Fluctuations: Radiocarbon Dating Coastal and Bottom Deposits

      Karpytchev, Yu A. (Department of Geosciences, The University of Arizona, 1993-01-01)
      Owing to the large basin area of the Caspian Sea, fluctuations in its level reflect climatic changes in the northern hemisphere. To reconstruct these fluctuations, I collected mollusk shells, plant debris, carbonates and organic matter samples for 14C dating from deposits of ancient salt marshes, depressions and bars formed during significant sea-level decline. I studied the impact of eolian sedimentation via parallel dating of carbonates and other materials. The data demonstrate that sea level rises during periods of cooling and falls during warming periods; this is true for both long-term (2-2.5 ka) and short-term climatic changes.