• Scandinavian Models: Radiocarbon Dates and the Origin and Spreading of Passage Graves in Sweden and Denmark

      Paulsson, Bettina Schulz (Department of Geosciences, The University of Arizona, 2010-01-01)
      Approximately 2700 radiocarbon results are currently available from European megalithic contexts. The interpretation of these 14C dates is often difficult. It is not easy to connect many of them from their archaeological context to the construction or the burial phase of the graves. This paper focuses on the megaliths of Scandinavia--a special megalith region--as it is the only place in Europe with 14C dates directly referable to the construction of the passage graves, the graves have good bone preservation, and new dating sequences are available. Some 188 14C results are now available from Scandinavian passage graves. In Sweden, new data suggest that these graves were built from the first half of the 35th century BC onwards. The 14C dates from birch bark as filling material between dry walls make it possible to build a sequence for the construction phase of the passage graves in Denmark from the 33rd century BC onward. With an interpretative Bayesian statistical framework, it is possible to untangle the nuances of the differences for the origin and the spreading of the megaliths in the different regions, to define, together with the archaeological remains, possible cultural-historical processes behind these phenomena and to discuss diffusion versus convergence.
    • Simple Pretreatment Method Development for Iron and Calcium Carbonate Samples

      Park, Junghun; Hong, Wan; Choi, Han Woo; Kim, Joonkon; Kim, Gi Dong (Department of Geosciences, The University of Arizona, 2010-01-01)
      Since iron artifacts generally contain trace amounts of carbon, an iron sample needs to be relatively large, as compared to other materials, and a specially designed combustion system is required. An elemental analyzer (EA) was used for the combustion of iron without any special chemical treatment. CO2 gas with 1 mg of carbon was obtained from the combustion of an iron artifact by using an EA and reduced to graphite for accelerator mass spectrometry (AMS) measurement. In this work, AMS dating results done at the Korea Institute of Geoscience and Mineral Resources (KIGAM) for several ancient iron artifacts are presented and compared with independently estimated ages. This method was found to be useful for the pretreatment of iron artifacts that contained 0.1% carbon. A simple pretreatment method using an EA was also applied to calcium carbonate (CaCO3) samples. Samples were preheated overnight at 100-300 C, without any special chemical treatment. This removed modern CO2 contamination and the background level decreased to a comparable value measured in samples treated with phosphoric acid under vacuum.
    • Spatial Distribution of ∆14C Values of Organic Matter in Surface Sediments off Saru River in Northern Japan, One Year after a Flood Event in 2006

      Nagao, Seiya; Irino, Tomohisa; Aramaki, Takafumi; Ikehara, Ken; Katayama, Hajime; Otosaka, Shigeyoshi; Uchida, Masao; Shibata, Yasuyuki (Department of Geosciences, The University of Arizona, 2010-01-01)
      Dispersion and deposition of terrestrial organic matter by flooding on the inner shelf were studied using C/N ratios, 13C, and ∆14C values of sedimentary organic matter. Surface sediment samples (top 2 cm) were collected from coastal areas near the Saru River in southwestern Hokkaido, northern Japan, 1 yr after a flood event in 2006. Riverine suspended solids were also collected at a fixed station downstream during 2006-2008. Sandy sediments were located at the front of the river mouth and the western part of the sampling area, with the 13C of organic matter ranging from -23.8 to -22.0, ∆14C of -655 to -388, and an organic carbon/total nitrogen (C/N) ratio of 5.9-7.7. On the other hand, silt and clay sediments were distributed in a restricted area 11-16 km from the river mouth, with lighter 13C (-26.7 to -24.1) and higher ∆14C (-240 to -77) of organic matter and C/N ratio (7.8-13.3). From end-member analysis, the apparently younger and less degraded organic matter in the silt and clay sediments consists mainly of terrestrial organic matter released by flood events. They remain in the depression, although most flood deposits were moved to deep-sea environments.
    • Spatial Radiocarbon and Stable Carbon Isotope Variability of Mineral and Thermal Waters in Slovakia

      Povinec, P. P.; Franko, O.; Šivo, A.; Richtáriková, M.; Breier, R.; Aggarwal, P. K.; Araguás-Araguás, L. (Department of Geosciences, The University of Arizona, 2010-01-01)
      Isotope hydrology investigations were carried out with the aim to study isotope variability in mineral and thermal waters (MTW) of Slovakia. The aquifers of MTW were formed by Triassic limestones and dolomites, which are found in the mountains as well as in the pre-Tertiary substratum of depressions and lowlands. The MTW were of artesian and/or open structures. At present, there are only boreholes available, as natural outflows have already been captured by them. Large spatial isotope variability (14C between 2 and 33.6 pMC, 18O between -11.8 and -9.8, and 13C between -12.7 and -3.4 for bicarbonates and -21 and -4.9 for free CO2) and heterogeneity of MTW was observed, indicating different origins of MTW. Corrected radiocarbon apparent ages of MTW indicate that they mostly infiltrated during the Würm and Holocene periods.
    • Spatial Variation in the Marine Radiocarbon Reservoir Effect throughout the Scottish Post-Roman to Late Medieval Period: North Sea Values (500-1350 BP)

      Russell, N.; Cook, G. T.; Ascough, P. L.; Dugmore, A. J. (Department of Geosciences, The University of Arizona, 2010-01-01)
      The marine radiocarbon reservoir effect (MRE) occurs as a spatially and temporally dependent variable owing to localized changes in oceanic water composition. This study investigates Delta-R values (deviations from the global average MRE whose Delta-R = 0) during the period 500-1350 BP for the east coast of Scotland, where a complex estuarine system exists that drains into the semi-enclosed North Sea basin. Due to the availability of suitable archaeological samples, the data set has a distinct Medieval focus that spans the area from Aberdeen in the north to East Lothian in the south. Many of the Delta-R values are not significantly different from 0 (the global average), but there are occasional excursions to negative values (max -172 +/- 20) indicating the presence of younger water. These values show greater variability compared to other published data for this general region, suggesting that considerable care must be taken when dating marine derived samples from archaeological sites on the east coast of Scotland.
    • Studies on the Preparation of Small 14C Samples with an RGA and 13C-Enriched Material

      Liebl, Jakob; Avalos Ortiz, Roswitha; Golser, Robin; Handle, Florian; Kutschera, Walter; Steier, Peter; Wild, Eva Maria (Department of Geosciences, The University of Arizona, 2010-01-01)
      The minimum size of radiocarbon samples for which reliable results can be obtained in an accelerator mass spectrometry (AMS) measurement is in many cases limited by carbon contamination introduced during sample preparation (i.e. all physical and chemical steps to which samples were subjected, starting from sampling). Efforts to reduce the sample size limit down to a few mu-g carbon require comprehensive systematic investigations to assess the amount of contamination and the process yields. We are introducing additional methods to speed up this process and to obtain more reliable results. A residual gas analyzer (RGA) is used to study combustion and graphitization reactions. We could optimize the reaction process at small CO2 pressures and identify detrimental side reactions. Knowing the composition of the residual gas in a graphitization process allows a reliable judgment on the completeness of the reaction. Further, we use isotopically enriched 13C (greater than or equal to 98% 13C) as a test material to determine contamination levels. This offers significant advantages: 1) The measurement of 12C/13C in CO2 is possible on-line with the RGA, which significantly reduces turnaround times compared to AMS measurements; 2) Both the reaction yield and the amount of contamination can be determined from a single test sample. The first applications of isotopically enriched 13C and the RGA have revealed that our prototype setup has room for improvements via better hardware; however, significant improvements of our sample processing procedures were achieved, eventually arriving at an overall contamination level of 0.12 to 0.15 mu-g C during sample preparation (i.e. freeze-drying, combustion, and graphitization) of mu-g-sized samples in aqueous solution, with above 50% yield.
    • Submarines, Quarks, and Radioisotope Dating

      Muller, R. A. (Department of Geosciences, The University of Arizona, 2010-01-01)
    • Successful AMS 14C Dating of Non-Hydraulic Lime Mortars from the Medieval Churches of the Åland Islands, Finland

      Heinemeier, Jan; Ringbom, Åsa; Lindroos, Alf; Sveinbjörnsdóttir, Árný E. (Department of Geosciences, The University of Arizona, 2010-01-01)
      Fifteen years of research on accelerator mass spectrometry (AMS) radiocarbon dating of non-hydraulic mortar has now led to the establishment of a chronology for the medieval stone churches of the land Islands (Finland), where no contemporary written records could shed light on the first building phases. In contrast to other material for dating, well-preserved mortar is abundantly available from every building stage. We have gathered experience from AMS dating of 150 land mortar samples. Approximately half of them have age control from dendrochronology or from 14C analysis of wooden fragments in direct contact with the mortar. Of the samples with age control, 95% of the results agree with the age of the wood. The age control from dendrochronology, petrologic microscopy, chemical testing of the mortars, and mathematical modeling of their behavior during dissolution in acid have helped us to define criteria of reliability to interpret the 14C results when mortar dating is the only possibility to constrain the buildings in time. With these criteria, 80% of all samples reached conclusive results, and we have thus far been able to establish the chronology of 12 out of the 14 churches and chapels, while 2 still require complementary analyses.
    • Table of Contents

      Department of Geosciences, The University of Arizona, 2010-01-01
    • Table of Contents

      Department of Geosciences, The University of Arizona, 2010-01-01
    • Table of Contents

      Department of Geosciences, The University of Arizona, 2010-01-01
    • Table of Contents

      Department of Geosciences, The University of Arizona, 2010-01-01
    • Temporal and Spatial Variations in Freshwater 14C Reservoir Effects: Lake Mývatn, Northern Iceland

      Ascough, P. L.; Cook, G. T.; Church, M. J.; Dunbar, E.; Einarsson, Á.; McGovern, T. H.; Dugmore, A. J.; Perdikaris, S.; Hastie, H.; Friðoriksson, A.; et al. (Department of Geosciences, The University of Arizona, 2010-01-01)
      Lake Mvatn is an interior highland lake in northern Iceland that forms a unique ecosystem of international scientific importance and is surrounded by a landscape rich in archaeological and paleoenvironmental sites. A significant freshwater reservoir effect (FRE) has been identified in carbon from the lake at some Viking (about AD 870-1000) archaeological sites in the wider region (Mvatnssveit). Previous accelerator mass spectrometry (AMS) measurements indicated this FRE was about 1500-1900 14C yr. Here, we present the results of a study using stable isotope and 14C measurements to quantify the Mvatn FRE for both the Viking and modern periods. This work has identified a temporally variable FRE that is greatly in excess of previous assessments. New, paired samples of contemporaneous bone from terrestrial herbivores and omnivores (including humans) from Viking sites demonstrate at least some omnivore diets incorporated sufficient freshwater resources to result in a herbivore-omnivore age offset of up to 400 14C yr. Modern samples of benthic detritus, aquatic plants, zooplankton, invertebrates, and freshwater fish indicate an FRE in excess of 5000 14C yr in some species. Likely geothermal mechanisms for this large FRE are discussed, along with implications for both chronological reconstruction and integrated investigation of stable and radioactive isotopes.
    • The 4000-Year-Old "Longshan Giant" Discovered in Shaanxi Province, China

      Yang, Yachang; Zhu, Yizhi (Department of Geosciences, The University of Arizona, 2010-01-01)
      A human skeleton of phenomenal size was uncovered during the excavation of a prehistoric site located in the city of Shangnan, Shaanxi province, China, in 2006. The skeleton dates to 4240-4100 cal yr BP, corresponding to the Longshan culture (4400-4000 yr ago). The skeletal characteristics point to a young male 16-18 yr old with a height of 193 cm. This is the tallest skeleton ever discovered in prehistoric China, and thus we name him the "Longshan Giant." The giant appears to be of the Mongoloid race and has many physical characteristics that are similar to those of modern southern Asians. Upon closer examination, 3 drilled holes of 5 cm in diameter were found in the right parietal bone of the skull. No rationale exists yet to explain the presence of these holes.
    • The Application of ICELS Systems for Radiocarbon Dating

      Tudyka, Konrad; Pazdur, Anna; Theodórsson, Pall; Michczyński, Adam; Pawlyta, Jacek (Department of Geosciences, The University of Arizona, 2010-01-01)
      Liquid scintillation counting (LSC) for radiocarbon dating is a less expensive method than accelerator mass spectrometry (AMS), provides a high degree of accuracy, and is less prone to contamination due to the larger sample sizes. However, to obtain high precision, a long counting time is needed. The Gliwice Radiocarbon Laboratory is seeking to obtain an increased counting capacity with 2-3 mL benzene samples than we presently can achieve with our 2 Quantulus systems. We are therefore investigating the possibility of using a simple, single-phototube LS system (ICELS) for dating samples younger than 5000 yr. We present the first results of this investigation, including the measurement of 3 VIRI and 3 FIRI intercomparison samples.
    • The Artemidorus Papyrus: Solving an Ancient Puzzle with Radiocarbon and Ion Beam Analysis Measurements

      Fedi, M. E.; Carraresi, L.; Grassi, N.; Migliori, A.; Taccetti, F.; Terrasi, F.; Mandò, P. A. (Department of Geosciences, The University of Arizona, 2010-01-01)
      Ancient papyrus manuscripts are one of the most fascinating sources for reconstructing not only ancient life habits but also past literature. Recently, an amazing document has come to the fore due to the heated debates it raised: the so-called Artemidorus papyrus. It is a very long scroll (about 2.5 m) composed of several fragments of different sizes, with inscriptions and drawings on both sides. On the recto of the document, a text about geography and some drawings of heads, feet, and hands are present, while on the verso there are many sketches of animals, both real and fantastic. Its importance in classical studies comes from the fact that some scholars claim that it is the first known transcription of a relatively large fragment by the Greek geographer Artemidorus. However, other scholars think that the papyrus is a fake, drawn in the 19th century AD by a well-known forger. In order to overcome all possible ambiguities, the papyrus has been studied not only on the basis of historical and paleographic criteria but also by scientific techniques. We have contributed to the knowledge about the papyrus by radiocarbon dating the document and by analyzing the composition of the ink using ion beam analysis (IBA). Results are compatible with the scroll being an ancient manuscript: accelerator mass spectrometry (AMS) 14C measurements have dated the papyrus to a period between the 1st century BC and 1st century AD, while IBA measurements have pointed out the use of an organic (carbon-based) ink, which was typical of ancient Roman and Greek times. Details of the measurements are presented to emphasize the importance of combining AMS and IBA results.
    • The Carbon Origin of Structural Carbonate in Bone Apatite of Cremated Bones

      Van Strydonck, M.; Boudin, M.; Mulder, G. (Department of Geosciences, The University of Arizona, 2010-01-01)
      In order to reveal a possible carbon exchange between carbon dioxide of the fuel and the bone apatite during the cremation process an experiment was set up using fossil fuel. Two setups were constructed, one using natural gas and one using coal. In both experiments, a carbon substitution in the apatite was revealed.
    • The Chronology of Pleistocene Modern Humans in China, Korea, and Japan

      Keates, S. G. (Department of Geosciences, The University of Arizona, 2010-01-01)
      The chronological status of Pleistocene fossils of early modern humans in the People's Republic of China is based almost exclusively on indirect dating of the stratigraphic context and faunal and radiocarbon dating of associated or supposedly associated archaeological specimens. A similar pattern is observed in Korea and Japan. This paper examines the 14C and other dating techniques of early modern humans in East Asia to gain a more complete and up-to-date understanding of their chronology.
    • The Effect of Storage on the Radiocarbon, Stable Carbon and Nitrogen Isotopic Signatures and Concentrations of Riverine DOM

      Gulliver, P.; Waldron, S.; Scott, E. M.; Bryant, C. L. (Department of Geosciences, The University of Arizona, 2010-01-01)
      Chemical preservatives (e.g. mercuric chloride) are routinely added to freshwater samples to prevent biological activity compromising the isotopic signature of dissolved organic matter (DOM) with time. However, alternative preservation methods are needed due to regulations restricting the use of preservatives with potentially adverse environmental and health impacts, rendering such additions unviable. This study investigates whether a non-chemical storage method is sufficient to maintain the radiocarbon and stable carbon and nitrogen signatures of freshwater DOM from a low order river system draining a peaty catchment. Some 50 L of stream water were collected in 1 plastic carbuoy and, within 24 hr, 1-L aliquots were transferred to acid-washed plastic bottles. Five aliquots were analyzed immediately to determine the baseline values for 14C (pMC), 13C (VPDB), 15N (AIR), %C (mg L-1), and %N (mg L-1). Of the remaining subsamples, 20 were frozen and a further 20 refrigerated at 4 C. After 7, 30, 90, and 180 days, 5 frozen and 5 refrigerated aliquots were analyzed in the same manner as the baseline aliquots. Analysis of the results shows that there is no statistically significant interaction between the variables storage method or length of storage for any of the determinants. Storage method has a statistically significant effect on 14C (pMC) and [C] (mg L-1). Length of storage has a statistically significant effect on 13C (VPDB), [C] (mg L-1), and [N] (mg L-1) values. Neither storage method nor length of storage appear to have a statistically significant effect on 15N (AIR) values.
    • The Effects of Rainfall on Carbon Isotopes of POC in the Teshio River, Northern Japan

      Aramaki, T.; Nakamura, Y-H.; Uchida, M.; Shibata, Y. (Department of Geosciences, The University of Arizona, 2010-01-01)
      During a rainfall event in early September 2006, the transport behavior of particulate organic carbon (POC) in a small river (Teshio River, northern Japan) with alluvial plain and forest characteristics was investigated chiefly with carbon isotopes. The radiocarbon (∆14C value) of POC varied widely from -56 at the beginning of the rain event to -10 at peak rainfall. The ∆14C values have a positive correlation with C/N ratios and a negative correlation with 13C values except for the data from when both turbidity and water level were at their maximums due to rainfall. These results indicate that the sources of organic matter in the river come from the surface layer of soil as the water level rises during a rainfall event.