• Dalhousie University Natural Radiocarbon Measurement II

      Ogden, J. Gordon; Hart, W. C. (American Journal of Science, 1977-01-01)
    • Dalhousie University Natural Radiocarbon Measurements I

      Ogden, J. Gordon; Hart, W. C. (American Journal of Science, 1976-01-01)
    • Data Analysis and Calibration of Radiocarbon Dating Results from the Cemetery of the Marquises of Jin

      Lu, Xiangyang; Guo, Zhiyu; Ma, Hongji; Yuan, Sixun; Wu, Xiaohong (Department of Geosciences, The University of Arizona, 2001-01-01)
      The chronology study of the cemetery of Marquises of Jin is valuable to improving the chronological table of Marquis of Jin family. It is also helpful for improving the chronological table of the Zhou Dynasty. The samples were measured at Peking University (PKUAMS). We also made an interlaboratory check with Isotrace to ensure the accuracy. By careful analysis of archaeological information, we built different models and calibrated by OxCal. The calibration results, both sampling contexts and estimations, are in very good agreement with the historical record. Because the dates of some events correspond to the special part of the curve, the calibration gets very high precision. The calibration result of tomb M93 suggests that its host is Marquis Shangshu instead of Marquis Wen.
    • Database Management Systems, Radiocarbon, and Archaeology

      Moffett, J. C.; Webb, R. E. (American Journal of Science, 1983-01-01)
    • Dating a Chalcolithic Burial Cave in Peqi'in, Upper Galilee, Israel

      Segal, Dror; Carmi, Israel; Gal, Zvi; Smithline, Howard; Shalem, Dina (Department of Geosciences, The University of Arizona, 1998-01-01)
      In May 1995 an impressive karstic cave possessing dozens of burials dating to the main phase of the Chalcolithic Period (ca. 4500-3500 BCE) was discovered in Peqi'in in the high hills of Galilee in northern Israel. It was subsequently excavated over the course of the following months. The large amount of unique ceramic ossuaries and the variety of burial offerings shed light, for the first time, on this critical societal development period in a region where its remains have rarely been found. Although the major significance of the cave is as a mortuary center, it was also utilized in a domestic capacity some centuries previously, during the generally less familiar Early Chalcolithic Period. We present here the dating of 22 14C samples collected from these separate phases of cave use. Their interpretation should aid in understanding of the absolute dating of the Chalcolithic Period and its relation to the period preceding its inception.
    • Dating Bones near the Limit of the Radiocarbon Dating Method: Study Case Mammoth from Niederweningen, ZH Switzerland

      Hajdas, Irka; Michczyński, Adam; Bonani, Georges; Wacker, Lukas; Furrer, Heinz (Department of Geosciences, The University of Arizona, 2009-01-01)
      Preparation of bone material for radiocarbon dating is still a subject of investigation. In the past, the most problematic ages appeared to be the very old bones, i.e. those with ages close to the limit of the dating method. Development of preparative methods requires sufficient amounts of bone material as well as the possibility of verification of the ages. In the peat section at Niederweningen, ZH Switzerland, numerous bones of mammoth and other animals were found in the late 19th century. The first accelerator mass spectrometry (AMS) radiocarbon ages of those bones from 1890/1891 excavations placed the age between 33,000 and 35,000 BP. The excavations in 2003/2004 provided additional material for 14C dating. An age of 45,870 +/- 1080 BP was obtained on base (NaOH step) cleaned gelatin from mammoth bone, which was very close to the age of 45,430 +/- 1020 BP obtained for the peat layer that buried the mammoths. The 14C age of gelatin cleaned using the ultrafiltration method obtained in this study, 45,720 +/- 710 BP, is in a very good agreement with the previously obtained results. Moreover, the study shows that 3 pretreatment methods (base+Longin, Longin+ultrafiltration, and base+Longin+ultrafiltration) give ages consistent with each other and with the age of the peat section.
    • Dating Charred Soil Organic Matter: Comparison of Radiocarbon Ages from Macrocharcoals and Chemically Separated Charcoal Carbon

      Eckmeier, Eileen; van der Borg, Klaas; Tegtmeier, Ursula; Schmidt, Michael W. I.; Gerlach, Renate (Department of Geosciences, The University of Arizona, 2009-01-01)
      Radiocarbon dating of charcoal in soils is commonly used to reconstruct past environmental processes. Also microcharcoal that is chemically isolated from soil organic matter by high-energy UV photo-oxidation can be dated with 14C accelerator mass spectrometry (AMS). We compared the 14C AMS ages of 13 pairs of hand-picked macrocharcoals and microcharcoal samples separated via the UV oxidation method; both charcoal fractions were taken from the same soil samples (prehistoric pit fillings). We found that in most cases, the microcharcoal fraction yielded older ages than the single macrocharcoal pieces, and that the differences between the ages are not systematic. A reason for these age differences might be that the microcharcoal fraction consists of more stable components than macrocharcoals and thus yields older ages. Dating of microcharcoal would give a mean age of charred organic matter in soil material and the ages of the more stable compounds. Thus, 14C data obtained from the microcharcoal fraction in soils is not comparable to macrocharcoal ages and should not be used to complement existing macrocharcoal data sets.
    • Dating Grimes Graves

      Ambers, Janet (Department of Geosciences, The University of Arizona, 1998-01-01)
      More radiocarbon analyses have been produced for the Neolithic flint mines of Grimes Graves than for any other site with which the British Museum's Radiocarbon Laboratory has been involved. Despite this heavy concentration of effort, a recent review of these figures concluded that poor sample selection, combined with a lack of sufficient quality assurance procedures, severely limit the use that can be made of this database. To overcome these difficulties, a redating program has been undertaken using a carefully selected subset of the original material. In this paper I discuss the flaws in the original data set, due to both technical and sampling problems; set out ways to avoid similar problems in the future, with particular reference to quality assurance; and discuss the new results and their archaeological implications.
    • Dating Human Occupation on Diatom-Phytolith-Rich Sediment: Case Studies of Mustang Spring and Lubbock Lake, Texas, USA

      Hatté, Christine; Hodgins, Gregory; Holliday, Vance T.; Jull, A. J. Timothy (Department of Geosciences, The University of Arizona, 2010-01-01)
      The Great Plains of North America have a rich archaeological record that spans the period from Late Glacial to Historic times, a period that also witnessed significant changes in climate and ecology. Chronometric dating of archaeological sites in many areas of the Great Plains, however, is often problematic, largely because charcoal and wood--the preferred materials for radiocarbon dating--are scarce in this grassland environment with few trees. Two reference archaeological sites are studied here: Mustang Spring and Lubbock Lake, Texas, USA. We carry out a geochronological approach based on a cross-study of carbon-derived data: combustion yield, 13C, 14C age differences between high temperature and low temperature released carbon, and the 14C age itself. A study that incorporates multiple approaches is required to solve issues induced by the sedimentological context, which is rich in both freshwater diatoms and phytoliths from quite different origins. Analysis of carbon-derived data allows us to draw a succession model of dry and wet episodes and to associate it with a chronological framework. In this way, we can assert that, for the Mustang Spring site, several human occupations existed from ~11 kyr BP to ~8.7 kyr BP along the 110-cm-long series with an interruption of ~150 yr that is associated with a palustrine environment between the Plainview and Firstview occupations.
    • Dating Materials in Good Archaeological Contexts: The Next Challenge for Radiocarbon Analysis

      Boaretto, Elisabetta (Department of Geosciences, The University of Arizona, 2009-01-01)
      Radiocarbon dating has had an enormous impact on archaeology. Most of the dates are obtained using charred materials and, to a lesser extent, collagen from bones. The contexts in which charred materials and bones are found are often, however, not secure. There are 3 other datable materials that are usually in secure contexts: plaster/mortar, phytoliths, and the organic material in the ceramic of whole vessels. The plaster/mortar of walls and floors are often in very secure contexts. Phytoliths are abundant in archaeological sites and in some situations form well-defined surfaces. Whole vessels are usually found in secure contexts and their typologies are indicative of a specific period. Dating each of these materials has proved to be difficult, and solving these technical problems represents major future challenges for the 14C community. The effective use of charcoal and bone collagen for dating can also be improved by paying careful attention to the micro-contexts in which they are found, such as in clusters or as part of well-defined features. Pre-screening to identify the best preserved material can also contribute to improving the accuracy of the dates obtained. A general objective should be to have an assessment of the quality of the material to be dated so that the potentially invaluable information from outliers can be exploited.
    • Dating of Ancient Icons from Kiev Art Collections

      Kovalyukh, N.; van der Plicht, J.; Possnert, G.; Skripkin, V.; Chlenova, L. (Department of Geosciences, The University of Arizona, 2001-01-01)
      Icon painting in the Ukraine is rooted in the Byzantine culture, after the conversion to the Christian religion. During the medieval epoch, Kiev became the artistic center for highly skilled icon painters. The icons were painted on woodenboards, specially made for this purpose. Historic dating of some even well-known icons is uncertain or not precise. Here we present for the first time radiocarbon dates for selected icons. Both liquid scintillation counting (LSC) and accelerator mass spectrometry (AMS) dating methods were applied, allowing intercomparison.
    • Dating of Biodeposits of Oxalates at the Arc de Berà in Tarragona, Spain

      Girbal, J.; Prada, J. L.; Rocabayera, R.; Argemi, M. (Department of Geosciences, The University of Arizona, 2001-01-01)
      This research stems from an earlier study of the lichen covering with oxalate deposits at the Arc de Berà monument. The initial objective of dating these biodeposits opened up other questions concerning the structure of these deposits and how they were formed. Some dating results gave an absolute age greater than the monument itself, which posed various hypotheses on the possible ageing mechanisms.
    • Dating of Cremated Bones

      Lanting, J. N.; Aerts-Bijma, A. T.; van der Plicht, J. (Department of Geosciences, The University of Arizona, 2001-01-01)
      When dating unburnt bone, bone collagen, the organic fraction of the bone, is used. Collagen does not survive the heat of the cremation pyre, so dating of cremated bone has been considered impossible. Structural carbonate in the mineral fraction of the bone, however, survives the cremation process. We developed a method of dating cremated bone by accelerator mass spectrometry (AMS), using this carbonate fraction. Here we present results for a variety of prehistoric sites and ages, showing a remarkable success rate for this method.
    • Dating of Groundwater Recharge in Two Small Adjacent Aquifers in Israel and Their Initial 14C Activities

      Guttman, J.; Kronfeld, J.; Carmi, I. (Department of Geosciences, The University of Arizona, 2011-01-01)
      Radiocarbon and tritium determinations were carried out in 2 adjacent small aquifers in Israel. These aquifers have small storage capacities and good hydraulic properties. Darcy calculations suggest that the aquifers contain young waters, ~50 yr in age. 14C concentrations in the Pleistocene aquifer are between 23-60 pMC, with the lowest activity related to contamination by petroleum-based fertilizers with no 14C. 14C concentrations in the Judea Group aquifer range from 62 to 95 pMC. An apparent difference of ~1000 yr is indicated for the average recharge age between the 2 aquifers. The tritium data suggests that the water in both aquifers is quite young. The 1000-yr difference is an artifact of initial isotopic fractionation differences through the unsaturated zone as established elsewhere for these 2 aquifers. When these individual fractionation factors (0.54 for the Pleistocene and 0.62 for the Judea Group) are used, it is revealed that both aquifers contain young water, in agreement with the Darcy calculation, which was recharged at the beginning of the period of thermonuclear atmospheric testing in the early 1960s.
    • Dating of Holocene Stratigraphy with Soluble and Insoluble Organic Fractions at the Lubbock Lake Archaeological Site, Texas: An Ideal Case Study

      Haas, Herbert; Holliday, Vance; Stuckenrath, Robert (American Journal of Science, 1986-01-01)
      The Lubbock Lake site, on the Southern High Plains of Texas, contains one of the most complete and best-dated late Quaternary records in North America. A total of 117 14C dates are available from the site, determined by the Smithsonian and SMU Laboratories. Of these dates, 84 have been derived from residues (humin) and humates (humic acids) of organic-rich marsh sediments and A horizons of buried soils. Most of the ages are consistent with dates determined on charcoal and wood, and with the archaeologic and stratigraphic record. The dates on the marsh sediments are approximate points in time. Dates from the top of buried A-horizons are a maximum for burial and in many cases are close to the actual age of burial. Dates from the base of the A-horizons are a minimum for the beginning of soil formation, in some cases as much as several thousand years younger than the initiation of pedogenesis. A few pairs of dates were obtained from hurnin and humic acid derived from split samples; there are no consistencies in similarities or differences in these age pairs. It also became apparent that dates determined on samples from scraped trench walls or excavations that were left open for several years are younger than dates from samples taken from exactly the same locations when the sampling surfaces were freshly excavated.
    • Dating of Lake and Loess Sediments

      Beer, Juerg; Sturm, Michael (Department of Geosciences, The University of Arizona, 1995-01-01)
      Lake and loess sediments represent archives that record important information about the local, regional and global climate conditions in the past. Lake sediments consist of autochthonous particles formed by biogeochemical processes within the lake and allochthonous particles brought into the lake from the catchment area. After deposition, the stratigraphy of the sediment can be altered by chemical, physical and biological processes. Under favored conditions, the sediment shows individual annual layers (varves), which can be used to date the sediment. Other dating methods are based on radioactive decay (14C, 210Pb) or on time markers such as tephra layers, deposits of natural catastrophes, e.g., floods, or radioactivity, e.g., emissions from a nuclear power plant.
    • Dating of Late Pleistocene Tree-Ring Series from Japan

      Van der Plicht, J.; Imamura, M.; Sakamoto, M. (Department of Geosciences, The University of Arizona, 2012-10-15)
      We have radiocarbon dated series of tree rings from 2 fossil trees (named ND-113 and the Fuji tree) buried in fossil volcanic avalanche deposits in Japan. They are dendrochronologically floating, dating beyond the tree-ring part of the 14C calibration curve. The trees show about 350 and 400 annual rings, respectively, which are dated in intervals of 2 to 10 yr. Both sequences are wiggle-matched to the calibration curve IntCal09. This resulted in an age range of 16,534–16,204 cal BP for ND-113, and 23,678–23,290 cal BP for the Fuji tree.
    • Dating of Prehistoric Burial Mounds by 14C Analysis of Soil Organic Matter Fractions

      Kristiansen, Søren M.; Dalsgaard, Kristian; Holst, Mads K.; Aaby, Bent; Heinemeier, Jan (Department of Geosciences, The University of Arizona, 2003-01-01)
      Dating of prehistoric anthropogenic earthworks requires either excavation for archaeological artifacts or macroscopic organic matter suitable for 14C analysis. Yet, the former, in many cases, is undesirable and the latter is difficult to obtain. Here we present a soil science procedure, which has the potential to overcome these problems. It includes careful sampling of buried former soil surfaces, acid-alkali-acid fractionation of soil organic matter (SOM), and subsequent 14C AMS dating. To test the procedure, soil from one of the largest known burial mounds in Scandinavia, Hohoj, and 9 other Danish burial mounds were sampled. The 14C dates from extracted SOM fractions were compared to reference ages obtained by other methods. We show that humic acid fractions in 7 of the 10 mounds had the same age as the reference, or were, at maximum, 280 yr older than the reference ages. The best age estimates were derived from an organic-rich layer from the upper cm of buried soil or sod. Differences among SOM fraction ages probably indicate the reliability of the dating. Hohoj dated to approximately 1400 BC and, thus, was up to 500 yr older than other dated Scandinavian mounds of comparable size. The remaining investigated burial mounds were dated to between 1700 and 1250 BC. We conclude that combined sampling of buried soil surfaces, SOM fractionation, and 14C analysis allows for dating of archaeological earthworks when minimal disturbance is required, or if no macroscopic organic remains are found.
    • Dating of the Cultural Layers from Vilnius Lower Castle, East Lithuania: Implications for Chronological Attribution and Environmental History

      Mažeika, J.; Blaževičius, P.; Stančikaitė, M; Kisielienė, D. (Department of Geosciences, The University of Arizona, 2009-01-01)
      Complex interdisciplinary studies carried out in the territory of the Vilnius Lower Castle, E Lithuania, were used to construct a chronological framework based on radiocarbon data and archaeological information. Bulk samples (wood and sediment) were collected from an approximately 3-m core that crossed cultural layers and underlying strata. 14C dates indicate that the underlying bed possibly formed during the 6th century AD, although no archaeological finds were discovered there. Paleobotanical (pollen and plant macrofossil) investigations reveal evidence of agriculture that points to the existence of a permanent settlement in the area at that time. The chronological data indicates a sedimentation hiatus before the onset of the deposition of the cultural layer in the studied area. The 14C dates showed that the formation of the cultural bed began during the late 13th-early 14th centuries AD, that is, earlier than expected according to the archaeological record. The ongoing deposition of the cultural beds continued throughout the middle to latter half of the 14th century AD as revealed by the archaeological records and confirmed by well-correlated 14C results. After some decline in human activity in the middle of the 14th century AD, a subsequent ongoing development of the open landscape, along with intensive agriculture, points to an increase in human activity during the second half of the 14th century AD. The first half of the 15th century AD was marked by intensive exploitation of the territory, indicating a period of economic and cultural prosperity. The chronological framework indicates that the investigated cultural beds continued forming until the first half of the 16th century AD.
    • Dating of the Old Bridge in Mostar, Bosnia and Herzegovina

      Obelić, Bogomil; Krajcar Bronić, Ines; Barešić, Jadranka; Peković, Zeljko; Milošević, Ante (Department of Geosciences, The University of Arizona, 2007-01-01)
      The famous single-arch stone bridge over the Neretva River in Mostar, Bosnia and Herzegovina, was built in 1557-1566 by the order of Ottoman Sultan Sleyman the Magnificent. During the reconstruction of the Old Bridge, which was destroyed during the war in 1993, remnants of 2 older wooden bridges were found at the same location. Six wood and 2 charcoal samples were dated using the radiocarbon method. Wood samples with visible tree rings were taken for dendrochronological dating. The results point to several periods of construction and repairs to the bridge and the towers at each end, spanning from the 12th to 18th century. Calibrated 14C and dendrochronological ages were in good agreement.