| 1. |
- Blaauw, Maarten, et al.
(author)
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A Bayesian framework for age-modelling of radiocarbon-dated peat deposits: case studies from the Netherlands
- 2007
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In: Radiocarbon. - 0033-8222 .- 1945-5755. ; 49:2, s. 357-367
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Journal article (peer-reviewed)abstract
- Recently, Bayesian statistical software has been developed for age-depth modeling (“wiggle-match dating”) ofsequences of densely spaced radiocarbon dates from peat cores. The method is described in non-statistical terms, and is com-pared with an alternative method of chronological ordering of 14C dates. Case studies include the dating of the start of agri-culture in the northeastern part of the Netherlands, and of a possible Hekla-3 tephra layer in the same country. We discussfuture enhancements in Bayesian age modeling.
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| 2. |
- Bonsall, Clive, et al.
(author)
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Food for Thought : Re-Assessing Mesolithic Diets in the Iron Gates
- 2015
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In: Radiocarbon. - : Cambridge University Press (CUP). - 0033-8222 .- 1945-5755. ; 57:4, s. 689-699
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Journal article (peer-reviewed)abstract
- Stable isotope ratios of carbon, nitrogen, and sulfur in human bone collagen are used routinely to aid in the reconstruction of ancient diets. Isotopic analysis of human remains from sites in the Iron Gates section of the Lower Danube Valley has led to conflicting interpretations of Mesolithic diets in this key region of southeast Europe. One view (Bonsall et al. 1997, 2004) is that diets were based mainly on riverine resources throughout the Mesolithic. A competing hypothesis (Nehlich et al. 2010) argues that Mesolithic diets were more varied with at least one Early Mesolithic site showing an emphasis on terrestrial resources, and riverine resources only becoming dominant in the Later Mesolithic. The present article revisits this issue, discussing the stable isotope data in relation to archaeozoological and radiocarbon evidence.
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| 3. |
- Dury, Jack P. R., et al.
(author)
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CONSIDERATION OF FRESHWATER AND MULTIPLE MARINE RESERVOIR EFFECTS : DATING OF INDIVIDUALS WITH MIXED DIETS FROM NORTHERN SWEDEN
- 2018
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In: Radiocarbon. - 0033-8222 .- 1945-5755. ; 60:5, s. 1561-1585
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Journal article (peer-reviewed)abstract
- Human burials from the cemetery at the Rounala church, northern Sweden, were radiocarbon (C-14) dated to shed light on the use of the cemetery. Carbon, nitrogen and sulfur stable isotope analysis of bone collagen from 19 distinct individuals indicated that these individuals had a mixed diet consisting of freshwater, marine and terrestrial resources. Dietary modeling using FRUITS was employed to calculate the contributions of the different resources for each individual. These data were then used to calculate individual Delta R values, taking into account freshwater and multiple marine reservoir effects, the latter caused by Baltic and Atlantic marine dietary inputs, respectively. C-14 dating of tissues from modern freshwater fish species demonstrate a lack of a freshwater reservoir effect in the area. Two OxCal models were used to provide endpoint age estimates. The calibrated data suggest that the site's cemetery was most likely in use already from the 14th century, and perhaps until at least the late 18th century.
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| 4. |
- Eilers, Gerriet, et al.
(author)
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The Radiocarbon Intracavity Optogalvanic Spectroscopy Setup at Uppsala
- 2013
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In: Radiocarbon. - : Cambridge University Press (CUP). - 0033-8222 .- 1945-5755. ; 55:3-4, s. 237-250
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Journal article (peer-reviewed)abstract
- Accelerator mass spectrometry (AMS) is by far the predominant technology deployed for radiocarbon tracer studies. Applications are widespread from archaeology to biological, environmental, and pharmaceutical sciences. In spite of its excellent performance, AMS is expensive and complicated to operate. Consequently, alternative detection techniques for 14C are of great interest, with the vision of a compact, user-friendly, and inexpensive analytical method. Here, we report on the use of intracavity optogalvanic spectroscopy (ICOGS) for measurements of the 14C/12C ratio. This new detection technique was developed by Murnick et al. (2008). In the infrared (IR) region, CO2 molecules have strong absorption coefficients. The IR-absorption lines are narrow in line width and shifted for different carbon isotopes. These properties can potentially be exploited to detect 14CO2, 13CO2, or 12CO2 molecules unambiguously. In ICOGS, the sample is in the form of CO2 gas, eliminating the graphitization step that h is required in most AMS labs. The status of the ICOGS setup in Uppsala is presented. The system is operational but not yet fully developed. Data are presented for initial results that illustrate the dependence of the optogalvanic signal on various parameters, such as background and plasma-induced changes in the sample gas composition.
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| 5. |
- Fontana, Sonia L.
(author)
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Radiocarbon chronologies of Holocene lacustrine sediments from the southern coast of Buenos Aires Province, Argentina
- 2007
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In: Radiocarbon. - 0033-8222 .- 1945-5755. ; 49:1, s. 103-116
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Journal article (peer-reviewed)abstract
- Two lacustrine sediment sequences, La Olla 1 and Laguna del Sauce Grande, on the southern coast of Buenos Aires Province, Argentina, were investigated for carbon reservoir effects, which may influence age-depth chronologies. Fruits of the submerged macrophyte Ruppia cf. maritima from the La Olla 1 sequence, and gastropod shells of Heleobia parchappii from the Laguna del Sauce Grande core, were radiocarbon dated. In addition, terrestrial plant remains and shells of living specimens were dated to assess the presence and magnitude of a reservoir effect. A reservoir age of about 800 14C yr is estimated for the aquatic plant samples of La Olla 1 for the early Holocene. The reservoir effect is attributed to the inwash of 14C-deficient bicarbonate from the surrounding sand dunes. The decay of marine organisms and salt spray are likely the main sources of 14C-deficient carbon. The magnitude of the reservoir effect is consistent with marine reservoir offsets reported for the region. The 14C measurements on shells of living and fossil specimens of Heleobia parchappii indicate the absence of a reservoir effect at Laguna del Sauce Grande, which may be due to the large size and shallow nature of the lake. This study shows how the reservoir ages of 2 close-by lakes in very similar geological settings can be largely different. These results have significant implications for the interpretation of 14C dates from lacustrine deposits in the region.
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| 6. |
- Larsson, Anton, 1994-, et al.
(author)
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Jordfallet at Bohus : Reinterpreting the 14C dating of a medieval landslide event
- 2022
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In: Radiocarbon. - 0033-8222 .- 1945-5755. ; 64:5, s. 1239-1255
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Journal article (peer-reviewed)abstract
- Radiocarbon (14C) dating has, since its inception, become an integral part of disciplines such as geology and archaeology, underpinning many key findings made by researchers in the past seven decades. As 14C dating develops, the need arises to revisit older findings and legacy data which may well contain laboratory errors or post-analysis misinterpretations. In this paper we examine one such finding from Sweden, namely the 1958 14C dating of the great Jordfallet (“the Earthfall”) landslide, which was published in the very first volume of Radiocarbon in 1959. We further trace how the results of this 14C dating were misunderstood in a time prior to modern radiocarbon calibration, and the impact which this mistake has had throughout academic publications, state reports and local heritage literature through the course of over sixty years. Because of this flawed interpretation the credible date of 1249 AD given to the landslide by historical sources has been overlooked. Instead, a series of dates from the mid-12th and early 13th centuries have been attributed to the landslide event based on erroneous radiocarbon analysis, a mistake which has substantial implications for the understanding of both regional and international history in medieval Scandinavia.
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| 7. |
- Levin, Maureece J., et al.
(author)
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A Partial Chronological Sequence of Human Habitation for Pingelap Atoll (Pohnpei State, Federated States of Micronesia)
- 2019
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In: Radiocarbon. - : UNIV ARIZONA DEPT GEOSCIENCES. - 0033-8222 .- 1945-5755. ; 61:3, s. 765-776
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Journal article (peer-reviewed)abstract
- Pingelap Atoll, 1.8 km(2) in area and nearly 70 km from the nearest island, presents a clear example of anthropogenic niche-building in physically isolated circumstances with limited resources. This paper presents the first radiocarbon (C-14) dates (n=8) from an archaeological project examining settlement and subsistence practices on the atoll, specifically how Pingelapese people have constructed the environment to meet their needs over centuries of occupation. These dates confirm that human occupation of Pingelap occurred by 1700-1550 cal BP (2 sigma) at the latest, only a few centuries after the earliest securely-dated settlement of high islands in the region (Kosrae and Pohnpei), and with strikingly similar timing to another atoll in the region, Mwoakilloa. Evidence of early settlement includes shell tools, ornaments, extensive marine faunal remains, and charred botanical domesticates. These preliminary data build a framework for the settlement history and environment building of Pingelap.
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| 8. |
- Lillie, Malcolm, 1963-, et al.
(author)
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Factors influencing the radiocarbon dating of human skeletal remains from the Dnieper river system : Archaeological and stable isotope evidence of diet from the Epipalaeolithic to Eneolithic periods
- 2016
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In: Radiocarbon. - : Oxford University Press. - 0033-8222 .- 1945-5755. ; 58:4, s. 741-753
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Journal article (peer-reviewed)abstract
- Recent research has identified the existence of a freshwater reservoir effect influencing the radiocarbon dating of human skeletal remains from the Dnieper region of Ukraine (Lillie et al. 2009). The current study outlines the evidence for freshwater resource exploitation throughout the period ~10,200–3700 cal BC, and presents the available evidence for the existence of dietary offsets in the 14C dates obtained. We have obtained human skeletal material from 54 Epipaleolithic to Mesolithic period individuals and 267 Neolithic to Eneolithic individuals, from 13 cemeteries, since our research in Ukraine began in 1992. Here, we present the initial results of stable isotope analysis of Eneolithic individuals from the Igren VIII cemetery alongside the Epipaleolithic to Eneolithic samples that have previously been analyzed. When contrasted against the evidence from the prehistoric fauna and fish remains studied, and modern fish species from the Dnieper region, we continue to see variability in diets at the population level, both internally and across cemeteries. We also observed temporal variability in human diets across these chronological periods. The fish samples (both archaeological and modern) show a wide range of isotope ratios for both δ13C and δ15N, which could prove significant when interpreting the dietary sources being exploited. This information directly informs the 14C dating program as an inherent degree of complexity is introduced into the dating of individuals whose diets combine freshwater and terrestrial sources in differing quantities and at differing temporal and/or spatial scales (e.g. Bronk Ramsey et al. 2014)
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| 9. |
- Lougheed, Bryan C., 1982-
(author)
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USING SEDIMENTOLOGICAL PRIORS TO IMPROVE C-14 CALIBRATION OF BIOTURBATED SEDIMENT ARCHIVES
- 2022
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In: Radiocarbon. - : Cambridge University Press. - 0033-8222 .- 1945-5755. ; 64:1, s. 135-151
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Journal article (peer-reviewed)abstract
- Radiocarbon (C-14) dating is often carried out upon multi-specimen samples sourced from bioturbated sediment archives, such as deep-sea sediment. These samples are inherently heterogeneous in age, but existing C-14 calibration techniques were originally developed for age homogeneous material, such as archaeological artifacts or individual tree rings. A lack of information about age heterogeneity leads to a systematic underestimation of a sample's true age range, as well as the possible generation of significant age-depth artifacts during periods of the Earth's history coinciding with highly dynamic atmospheric Delta C-14. Here, a new calibration protocol is described that allows for the application of sedimentological priors describing sediment accumulation rate, bioturbation depth and temporally dynamic species abundance. This Bayesian approach produces a credible calibrated age distribution associated with a particular laboratory C-14 determination and its associated sedimentological priors, resulting in an improved calibration, especially in the case of low sediment accumulation rates typical of deep-sea sediment. A time-optimized computer script (biocal) for the new calibration protocol is also presented, thus allowing for rapid and automated application of the new calibration protocol. This new calibration protocol could be applied within existing age-depth modeling software packages to produce more accurate geochronologies for bioturbated sediment archives.
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| 10. |
- Mellström, Anette, et al.
(author)
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Radiocarbon wiggle-matching of bulk sediments - how accurate can it be?
- 2013
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In: Radiocarbon. - : Cambridge University Press (CUP). - 0033-8222 .- 1945-5755. ; 55:2-3, s. 1173-1186
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Journal article (peer-reviewed)abstract
- We used the radiocarbon wiggle-match dating technique to date the varved sediments of Lake Gyltigesjön in southern Sweden with the main aim to construct an accurate chronology covering the period between about 3000 and 2000 cal BP. Wiggle-match dating was applied to bulk sediments to evaluate the possibility of constructing accurate chronologies in the absence of terrestrial plant macrofossils and when the amount of old carbon in the sediments is unknown. Facilitated by a floating varve chronology and relatively stable 14C reservoir ages, the results show the possibility to assess the contribution of old carbon solely based on the 14C wiggle-matching of bulk sediments. We confirm the wiggle-matched chronology and the 14C reservoir age of approximately 260 yr by cross-checking the results with 14C dating of macrofossils. The obtained calibrated ages based on bulk sediments have an uncertainty range of about 60–65 yr (95.4% confidence interval). This study confirms that 14C wiggle-match dating of bulk sediments is a viable tool when constructing high-resolution chronologies. The method is especially useful in Sun-climate studies since the timing between solar activity variations (expressed as 14C variations) and climate changes can be accurately determined.
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