Radiocarbon
https://journals.uair.arizona.edu/index.php/radiocarbon
<div><strong>Radiocarbon</strong> is the main international journal of record for research articles and date lists relevant to <span class="style8"><sup>14</sup></span>C and other radioisotopes and techniques used in archaeological, geophysical, oceanographic, and related dating. The journal is published quarterly. We also publish conference proceedings and monographs on topics related to our fields of interest. ISSN: 0033-8222</div><div>As of 2016, Radiocarbon will be published by Cambridge University Press. Please check the Cambridge Online site for new Radiocarbon content and submit manuscripts through the new platform.</div>en-USRadiocarbon0033-8222Table of Contents
https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/18719
Mark McClure
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2015-05-282015-05-28575Editorial Board
https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/18718
Mark McClure
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2015-05-282015-05-28575Book Review: The Long and Winding Road: Review of L S Klejn. Soviet Archaeology: Trends, Schools, and History (translated by R Ireland and K Windle)
https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/18676
Yaroslav V Kuzmin
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2015-05-282015-05-28575Late Quaternary Vegetational Changes in a Marsh Forest in Southeastern Brazil with Comments on Prehistoric Human Occupation
https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/18198
<p>This article presents a palynological study carried out on a sediment core from a peat deposit in Serra de Botucatu, in São Paulo State, southeastern Brazilian Plateau. This region has been covered by grassland vegetation and forest patches throughout the recorded period. AMS radiocarbon dating plus palynological analysis of 27 samples from the sediment core allowed the recognition of several environmental changes that took place during the last 33,000 yr recorded in the core. The relationship between sedimentation rates and changes in the abundance of plants recognized through their pollen record, particularly a few important indicator species, provided the paleoenvironmental history for the Serra de Botucatu region, allowing the identification of changes in climate conditions and comparison with other regions in Brazil. One of the most remarkable features of this record is the cold and humid conditions during the Last Glacial Maximum, which diverges from previous interpretations for southeastern and southern Brazil but is in good agreement with paleoclimatic data from trace elements from cave stalagmites in SE Brazil. No indications of human impacts on the vegetation were found in this record.</p><p>DOI: <a href="/index.php/radiocarbon/article/view/18198">10.2458/azu_rc.57.18198</a></p><h1><strong> </strong></h1>Walter Mareschi BissaMauro B de Toledo
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2015-05-282015-05-28575737753Radiocarbon and Stratigraphic Chronology of Canímar Abajo, Matanzas, Cuba
https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/18313
<p>Twelve accelerator mass spectrometry (AMS) radiocarbon dates from the shell-matrix site of Canímar Abajo (Matanzas, Cuba) are reported. Eleven were obtained directly from human bone collagen in burials and one was obtained from charcoal recovered from a burial context. The site stratigraphy presents two episodes of burial activity separated by a shell midden layer. The AMS dates fall into two compact clusters that correlate remarkably well with the stratigraphy. The older burial dates to between 1380–800 cal BC (2σ) and the younger one to between cal AD 360–950 (2σ). The AMS dates are compared to eight conventional <sup>14</sup>C dates previously obtained on shell and charcoal. One of the conventional dates on charcoal (5480–5380 cal BC; 2σ) has been reported as the oldest <sup>14</sup>C date in the Caribbean region; its context and reliability are clarified. The suite of AMS dates provides one of the most reliable chronometric dating of a cultural context during this timeframe in Cuba. The correlation of <sup>14</sup>C and stratigraphy establishes a solid chronology for investigating the important economic and ritual features of Canímar Abajo.</p><p>DOI: <a href="/index.php/radiocarbon/article/view/18313">10.2458/azu_rc.57.18313</a></p>Mirjana RoksandicWilliam Mark BuhayYadira Chinique des ArmasRoberto Rodríguez SuárezMatthew C PerosIvan RoksandicStephanie MowatLuis M VieiraCarlos ArredondoAntonio Martínez FuentesDavid Gray Smith
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2015-05-282015-05-28575755763Dating the Dead: New Radiocarbon Dates from the Lower Ica Valley, South Coast Peru
https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/18343
<p>This article presents radiocarbon dates from human bone samples (<em>n</em> = 13) from seven pre-Columbian cemeteries in the Samaca and Ullujaya Basins of the lower Ica Valley, south coast of Peru, spanning from the end of the Early Horizon to the Inca Late Horizon. These contexts have been severely looted. Yet, in all cases, their putative dating by material culture remains is confirmed by these <sup>14</sup>C dates. This shows that such disturbed contexts, sadly typical of the Peruvian coast, can nonetheless still yield valuable bioarchaeological and burial practice data. These dates elaborate upon an emerging picture of the absolute dating of the cultural phases of the wider south coast region, in particular casting new light on the poorly understood Middle Horizon to Late Intermediate period transition. A paucity of archaeological data for this 3-century period has been taken as evidence of some sort of environmentally or socially induced lacuna. Instead, the <sup>14</sup>C dates presented here suggest that the basins of the lower Ica Valley were continuously occupied over this period.</p><p>DOI: <a href="/index.php/radiocarbon/article/view/18343">10.2458/azu_rc.57.18343</a></p>Lauren CadwalladerSusana Arce TorresTamsin C O'ConnellAlexander G PullenDavid G Beresford-Jones
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2015-05-282015-05-28575765773Radiocarbon Dating of Atacama (Chile) Snuff Trays: An Update on Stylistic and Chronological Correlations
https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/18318
<p>The Atacama region of Chile has the highest concentration of hallucinogenic paraphernalia from prehistoric cemeteries on the planet. These artifacts have been studied since the late 19th century, primarily from the perspective of stylistic classification, which has been used to infer their temporal assignation. However, direct chronological dating of the snuff trays has not been addressed until now, through an interdisciplinary study conducted in San Pedro de Atacama on the psychotropic paraphernalia collection of the Instituto de Investigaciones Arqueológicas y Museo R.P. Gustavo Le Paige S.J. (IIAM), part of the Universidad Católica del Norte. In this study, samples were taken from eight snuff trays for radiocarbon dating and to develop a suitable procedure and protocol for sample extraction and handling of wooden archaeological pieces. This article provides the results of these activities by establishing the existence of a sequence of styles in the hallucinogenic paraphernalia that goes from the Middle to Late Intermediate period (about AD 300 to 1400), which shows that in this timespan there were two styles (Tiwanaku and local), and then both were replaced by a macroregional style.</p><p>DOI: <a href="/index.php/radiocarbon/article/view/18318">10.2458/azu_rc.57.18318</a></p>Pascale RichardinCatherine LavierHelena HortaValentina FigueroaNicolás Lira
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2015-05-282015-05-2857577578414C and Marine Reservoir Effect in Archaeological Samples from the Northeast Gulf of California
https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/18319
<p>Previous studies of live-collected pre-weapons testing mollusk shells in the northern Gulf of California have demonstrated that the local radiocarbon reservoir effect (ΔR) is large and highly variable. To test the validity of this observation for paired charcoal and shell samples from archaeological contexts, we dated samples from four shell midden locations and six midden layers from the eastern shoreline of the Gulf of California near Puerto Peñasco, Sonora, Mexico. Dated charcoal samples were small twigs or brushy plants used to cook shellfish and the shells dated within each midden showed signs of burning. Ages range from approximately 5700 to 1900 cal BP. The offset between the modeled marine <sup>14</sup>C age for calibrated ages of the middens and measured shell <sup>14</sup>C age (ΔR) averaged 425 yr with a standard deviation of 115 yr.</p><p>DOI: <a href="/index.php/radiocarbon/article/view/18319">10.2458/azu_rc.57.18319</a></p>David L DettmanDouglas R MitchellGary HuckleberryMichael S Foster
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2015-05-282015-05-28575785793Prehistoric Mortuary Practices and the Constitution of Social Relationships: Implications of the First Radiocarbon Dates from Maski on the Occupational History of a South India “Type Site”
https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/18341
<p>In 1954, B K Thapar excavated the multicomponent site of Maski (Raichur District, Karnataka) to establish an archaeological sequence for the southern Deccan region of India. Thapar identified four major periods of occupation, now known as the Neolithic (3000–1200 BC), Iron Age (1200–300 BC), Early Historic (300 BC to AD 500), and the Medieval periods (AD 500–1600). Renewed research at the site by the Maski Archaeological Research Project (F.1/8/2009-EE) has investigated the development of social differences and inequalities in south Indian prehistory. This article reports the first ever radiocarbon assays from habitation and megalithic burial contexts in the vicinity of Maski. Accelerator mass spectrometry (AMS) dates of charcoal sampled from exposed occupational strata on Maski’s Durgada Gudda hill and subsequent Bayesian analyses indicate that the site was extensively occupied during the 14th century AD, corroborating interpretations of numismatic and inscriptional materials. Associated artifacts with these <sup>14</sup>C samples have significant implications for recognizing late Medieval period ceramics and occupation in the region. AMS assays of four charcoal samples from exposed megalithic burials just south of the Durgada Gudda hill, similar to those recognized by Thapar, indicate that burial practices commonly attributed to the Iron Age predate the period, and thus are not precise chronological markers. However, the results also suggest that megalithic burial practices became more labor intensive during the Iron Age, creating a cultural context for the generation of new forms of social affiliations and distinctions through differential participation in the production of commemorative places.</p><p>DOI: <a href="/index.php/radiocarbon/article/view/18341">10.2458/azu_rc.57.18341</a></p>Andrew M BauerPeter G Johansen
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2015-05-282015-05-28575795806Radiocarbon Dating of Aghios Antonios, Potos, and Intersite Chronological Variability in South Thasos, Greece
https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/17778
<p>Radiocarbon dates obtained for the coastal hilltop settlement of Aghios Antonios Potos in south Thasos are statistically treated to define the absolute chronology for the start and the end of the various habitation and cultural phases at the site. The location was first occupied during the Final Neolithic (FN) between 3800 and 3600 BC, extending this much contested phase to the lowest up to now record for Thasos and the northern Greece. The site is continuously inhabited from Early Bronze Age I until the early Late Bronze Age (LBA; 1363 BC) when it was abandoned. Comparison with other sites in Thasos and particularly with the inland site of Kastri Theologos showed that the first occupation at Aghios Antonios came soon after the abandonment of Kastri in the beginning of the 4th millennium. In fact, after the decline and abandonment of Aghios Antonios in the LBA, the site of Kastri was reinhabited, leading to the hypothesis that part of the coastal population moved inland. The presumed chronological sequence of alternate habitation between the two settlements may evoke explanations for sociocultural and/or environmental dynamics behind population movements in prehistoric Thasos. A major conclusion of the project is that the 4th millennium occupation gap attested in many sites of Greece, especially in the north, is probably bridged in south Thasos, when the data from all sites are taken together. The mobility of people in Final Neolithic south Thasos may explain the general phenomenon of limited occupational sequences in the FN of north Greece.</p><p>DOI: <a href="/index.php/radiocarbon/article/view/17778">10.2458/azu_rc.57.17778</a></p>Yannis ManiatisNerantzis NerantzisStratis Papadopoulos
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2015-05-282015-05-28575807823Radiocarbon Dating Shows an Early Appearance of Philistine Material Culture in Tell es-Safi/Gath, Philistia
https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/18391
<p>The Late Bronze Age to Iron Age transition in the coastal southern Levant involves a major cultural change, which is characterized, among other things, by the appearance of Philistine pottery locally produced in styles derived from outside the Levant. This transition in the coastal southern Levant is conventionally dated to the 12th century BC, based on historical and archaeological artifacts associated with the Philistine pottery. Radiocarbon dating can provide a more precise independent absolute chronology for this transition, but dating for the period under discussion is complicated by the wiggles and relatively flat slope in the calibration curve, which significantly reduce precision. An additional complication is that the stratigraphic record below and above the transition at this site, as well as at most other sites in the region, is far from complete. We thus used a variety of microarchaeological techniques to improve our understanding of the stratigraphy, and to ensure that the locations with datable short-lived materials were only derived from primary contexts, which could be related directly to the associated material culture. The <sup>14</sup>C dates were modeled using Bayesian statistics that incorporate the stratigraphic information. Using this integrative approach, we date the appearance of the Philistine pottery in Tell es-Safi/Gath in the 13th century BC.</p><p>DOI: <a href="/index.php/radiocarbon/article/view/18391">10.2458/azu_rc.57.18391</a></p>Yotam AsscherDan CabanesLouise A HitchcockAren M MaeirSteve WeinerElisabetta Boaretto
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2015-05-282015-05-28575825850Radiocarbon Age Determinations of Mosaic Mortar Layers of Churches from North Jordan
https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/18197
<p>This research is aimed at radiocarbon dating organic inclusions and lime-binder powders of mortar layers of mosaic pavements in four churches of arguable archaeological date located in northern Jordan. One mortar sample from each mosaic pavement of each church was collected, examined by thin section microscopy, and then physically pretreated by gentle crushing and dry sieving to collect lime-binder powders of different grain sizes. Charcoal samples uncovered from three samples and the CO<sub>2</sub> gases, collected by hydrochloric acid (HCl) hydrolysis of the powders, were <sup>14</sup>C dated using accelerator mass spectrometry (AMS). Four powders of 63–45 μm from the four samples and two powders of 45–38 μm from two samples were analyzed in order to get more precise dates and examine previous proposed models for the interpretation of the results. <sup>14</sup>C determinations showed agreement between charcoal ages and archaeological data, while the fine lime-binder’s powders, especially from the mosaic’s bedding layer, produced more precise dates. Results suggest that <sup>14</sup>C date profiles produced by HCl hydrolysis of the lime-binder powders can be clearly interpreted by the existing models.</p><p>DOI: <a href="/index.php/radiocarbon/article/view/18197">10.2458/azu_rc.57.18197</a></p>Khaled Al-Bashaireh
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2015-05-282015-05-28575851863Tel Tsaf and the Impact of the Ubaid Culture on the Southern Levant: Interpreting the Radiocarbon Evidence
https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/18200
<p>A data set of 18 radiocarbon dates from the domestic quarter and the well at Tel Tsaf provide conclusive evidence for the absolute dating of this Middle Chalcolithic site. Bayesian modeling suggests that the site was occupied in the last quarter of the 6th millennium BC and abandoned in the first quarter of the 5th millennium. The absolute dating of Tel Tsaf has further implications for the synchronization of the protohistory of the Levant. The ceramic assemblage of Tel Tsaf included delicately painted ceramic sherds (so-called Tel Tsaf ware), which are distinct from the common plain ware. Comparable motifs have been identified in ceramic assemblages of contemporary Ubaid sites such as Tell Mashnaqa, Tell Zeidan, Tell el-Abr, and Hammam et-Turkan IV in northern Mesopotamia. Tel Tsaf is a rare example of a little researched connection between the Ubaid culture and the Middle Chalcolithic of the southern Levant. The findings of Tel Tsaf expand the southwestern border of the Ubaid sphere of influence and shed new light on long-distance interaction in protohistory.</p><p>DOI: <a href="/index.php/radiocarbon/article/view/18200">10.2458/azu_rc.57.18200</a></p>Katharina StreitYosef Garfinkel
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2015-05-282015-05-28575865880King David’s City at Khirbet Qeiyafa: Results of the Second Radiocarbon Dating Project
https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/17961
<p>Seventeen samples of burnt olive pits discovered inside a jar in the destruction layer of the Iron Age city of Khirbet Qeiyafa were analyzed by accelerator mass spectrometry (AMS) radiocarbon dating. Of these, four were halved and sent to two different laboratories to minimize laboratory bias. The dating of these samples is ~1000 BC. Khirbet Qeiyafa is currently the earliest known example of a fortified city in the Kingdom of Judah and contributes direct evidence to the heated debate on the biblical narrative relating to King David. Was he the real historical ruler of an urbanized state-level society in the early 10th century BC or was this level of social development reached only at the end of the 8th century BC? We can conclude that there were indeed fortified centers in the Davidic kingdom from the studies presented. In addition, the dating of Khirbet Qeiyafa has far-reaching implications for the entire Levant. The discovery of Cypriot pottery at the site connects the <sup>14</sup>C datings to Cyprus and the renewal of maritime trade between the island and the mainland in the Iron Age. A stone temple model from Khirbet Qeiyafa, decorated with triglyphs and a recessed doorframe, points to an early date for the development of this typical royal architecture of the Iron Age Levant.</p><p>DOI: <a href="/index.php/radiocarbon/article/view/17961">10.2458/azu_rc.57.17961</a></p>Yosef GarfinkelKatharina StreitSaar GanorPaula J Reimer
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2015-05-282015-05-28575881890Radiocarbon Dating Khirbet Qeiyafa and the Iron I–IIA Phases in the Shephelah: Methodological Comments and a Bayesian Model
https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/18336
<p>This article discusses methodological issues related to the radiocarbon dating of Khirbet Qeiyafa, mainly the question of whether the site should be dated solely according to samples retrieved there or dated as part of a regional sequence of stratigraphically based ceramic typology phases. For the latter, we deploy the large number of <sup>14</sup>C determinations now available for several sites in the Shephelah, which are located in close proximity to each other, in order to establish a Bayesian model for the absolute chronology of the Iron I–IIA phases in the region. We argue that the information assembled from six neighboring sites in the Shephelah pushes forward the date of Qeiyafa to the 10th century, a date later than the one the excavators estimated based on the more limited <sup>14</sup>C information from the site alone.</p><p>DOI: <a href="/index.php/radiocarbon/article/view/18336">10.2458/azu_rc.57.18336</a></p>Israel FinkelsteinEli Piasetzky
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2015-05-282015-05-28575891907Identifying Specialized 19th Century Fishing Camps on California’s Northern Channel Islands: Applying AMS Radiocarbon Dating to Historical Sites
https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/18397
<p>California’s Northern Channel Islands have long been an epicenter of specialized fishing economies dating from 13,000 yr ago to the mid-19th century. With thousands of well-preserved shell middens, some dominated by single shellfish species and little to no material culture, it can be difficult to distinguish between specialized prehistoric and historical deposits at some site types. Beginning at least in the Early Holocene and continuing into the Historic period, California mussels, turban snails, and abalone were targeted for specialized collection and processing by Native Americans and later Chinese and Euro-American fishers. Here, we demonstrate how selective accelerator mass spectrometry (AMS) radiocarbon dating of specialized abalone processing camps can help distinguish between prehistoric and historical sites. While unconventional, our case study demonstrates the utility of <sup>14</sup>C dating at sites less than 300 yr old.</p><p>DOI: <a href="/index.php/radiocarbon/article/view/18397">10.2458/azu_rc.57.18397</a></p>Todd J BrajeTorben C Rick
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2015-05-282015-05-28575909916Geoarchaeological Perspectives on the “Millennial Series” of Earthquakes in the Southern Puget Lowland, Washington, USA
https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/18201
<p>Surface-breaking ruptures on shallow crustal faults in the southern Puget Lowland in western Washington State about a millennium ago prompted abrupt changes in land level and triggered tsunamis in Puget Sound. The displacement on the Seattle fault most likely occurred in the 1050–1020 cal BP interval. Structures further south (the Tacoma and Olympia faults, and one or more faults in the southern Hood Canal zone) ruptured at about the same time, or slightly earlier. The low frequency of radiocarbon ages from archaeological sites in the region in the aftermath of the “millennial series” of earthquakes, when compared to bootstrapped samples from a database of 1255 ages from the Pacific Northwest as a whole, suggests that these very large earthquakes had significant socioeconomic consequences. The cultural record from coastal archaeological sites shows that although survivors camped on the shore in the aftermath, many coastal villages appear to have been abandoned, and were not reoccupied for several centuries. There is little evidence, however, to suggest that people migrated from southern Puget Sound to neighboring areas, and no evidence of social conflict in the adjacent areas that might have served as havens.</p><p>DOI: <a href="/index.php/radiocarbon/article/view/18201">10.2458/azu_rc.57.18201</a></p>Ian Hutchinson
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2015-05-282015-05-28575917941AMS Dating of the Late Pleistocene Mammals at the Colorado Creek Site, Interior Western Alaska
https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/18436
<p>The Colorado Creek section of Alaska is an important paleontological site first excavated and reported on in the early 1980s and 1990s. The remains of two individual mammoths (the “Upper” and “Lower”), and elements of horse, bison, and caribou make this a unique faunal assemblage for a region in interior western Alaska, and the western edge of eastern Beringia. The mammoth remains were the only portions of the faunal assemblage radiocarbon dated in the 1980s. The Upper mammoth ages were widespread between 13,000 and 16,200 BP with the older dates being more accepted for the death of the individual. A single age on the Lower mammoth was produced at 22,880 <sup>14</sup>C yr BP. New accelerator mass spectrometry (AMS) dates generally confirm the accepted ages for the two mammoths and provide more precise ages of 16,200 ± 50 and 22,710 ± 90 <sup>14</sup>C yr BP for the Upper and Lower mammoths, respectively. AMS dates on caribou and horse are similar to ages on the Upper mammoth and show an overlap in their ecological ranges in interior western Alaska between 16,000 and 17,000 <sup>14</sup>C yr BP during the Late Glacial, similar to other areas of the state. The sole AMS date on bison produced an infinite <sup>14</sup>C age (>43,500 <sup>14</sup>C yr BP), considerably older than the Upper and Lower mammoths’ remains, and indicates that older deposits are present at the site. A dearth of dated Quaternary paleontological specimens from western Alaska hinders our understanding of this region’s paleoecology. This study enhances our conception of the geographic and chronological spread of late Pleistocene large terrestrial mammals in Alaska and Beringia.</p><p>DOI: <a href="/index.php/radiocarbon/article/view/18436">10.2458/azu_rc.57.18436</a></p>Joshua D ReutherJason S RogersJulie RousseauPatrick S Druckenmiller
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2015-05-282015-05-28575943954The Marine Radiocarbon Reservoir Effect on Adak Island (Central Aleutian Islands), Alaska
https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/18329
<p>Radiocarbon dates (<em>n</em> = 18) from three archaeological sites on Adak Island, Alaska, were analyzed to understand the marine reservoir offset. Samples of marine and terrestrial origins recovered from the same archaeological context were compiled in nine pairs. The mean ΔR value calculated for them totaled 545 ± 10 yr. This value can be regarded as a sound estimate of the marine reservoir offset in the central Aleutians.</p><p>DOI: <a href="/index.php/radiocarbon/article/view/18329">10.2458/azu_rc.57.18329</a></p>Bulat F KhasanovToshio NakamuraMitsuru OkunoEkaterina N GorlovaOlga A KrylovichDixie L WestVirginia HatfieldArkady B Savinetsky
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2015-05-282015-05-28575955964Bayesian Chronological Modeling of SunWatch, a Fort Ancient Village in Dayton, Ohio
https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/18179
<p>Radiocarbon results from houses, pits, and burials at the SunWatch site, Dayton, Ohio, are presented within an interpretative Bayesian statistical framework. The primary model incorporates dates from archaeological features in an unordered phase and uses charcoal outlier modeling (Bronk Ramsey 2009b) to account for issues of wood charcoal <sup>14</sup>C dates predating their context. The results of the primary model estimate occupation lasted for <em>1–245 yr </em>(<em>95% probability</em>), starting in <em>cal AD 1175–1385</em> (<em>95% probability</em>) and ending in <em>cal AD 1330–1470 </em>(<em>95% probability</em>). An alternative model was created by placing the <sup>14</sup>C dates into two unordered phases corresponding with horizontal stratigraphic relationships or distinct groups of artifacts thought to be temporally diagnostic. The results of the alternative model further suggest that there is some temporal separation between Group 1 and Group 2, which seems more likely in the event of a multicomponent occupation. Overall, the modeling results provide chronology estimates for SunWatch that are more accurate and precise than that provided in earlier studies. While it is difficult to determine with certainty if SunWatch had a single-component or multicomponent occupation, it is clear that SunWatch’s occupation lasted until the second half of the AD 1300s.</p><p>DOI: <a href="/index.php/radiocarbon/article/view/18179">10.2458/azu_rc.57.18179</a></p>Anthony M KrusRobert CookDerek Hamilton
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2015-05-282015-05-28575965977Flame-Sealed Tube Graphitization Using Zinc as the Sole Reduction Agent: Precision Improvement of EnvironMICADAS 14C Measurements on Graphite Targets
https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/18193
<p>The flame-sealed tube zinc reduction graphitization method has been successfully adapted and optimized for radiocarbon measurements on EnvironMICADAS in the Institute for Nuclear Research of the Hungarian Academy of Sciences, Hertelendi Laboratory of Environmental Studies (ATOMKI HLES). To reduce the cost and treatment time of producing graphite targets from samples of about 1 mg carbon content, we have omitted the titanium hydride (TiH<sub>2</sub>) reagent and used a decreased amount of zinc as the sole reductant in our new method. These changes have also helped to eliminate methane formation during the graphitization processes as well as to recover higher ion current at the same background level. These conditions have led to improved efficiency in the <sup>14</sup>C measurements; furthermore, the instrument background level remained sufficiently low (<49,000 yr BP). After determining the optimum parameters of the new Zn graphitization method (2.5 mg Fe powder, 15.0 mg Zn powder, 10 hr graphitization at 550°C in heating block, reaction cells with reagent pretreated at 300°C for 1 hr), verification of the accuracy was carried out by the preparation and measurement of IAEA standard samples (C2, C6, C7, C8) with known <sup>14</sup>C activity. The sensitivity of the method for gas contamination was tested and determined by comparing the results to measurements of reserved portions of previously processed real samples.</p><p>DOI: <a href="/index.php/radiocarbon/article/view/18193">10.2458/azu_rc.57.18193</a></p>Gergely OrsovszkiLaszlo Rinyu
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2015-05-282015-05-28575979990One-Year-Long Continuous and Synchronous Data Set of Fossil Carbon in Atmospheric PM2.5 and Carbon Dioxide in Debrecen, Hungary
https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/18191
<p>Radiocarbon investigation of atmospheric PM<sub>2.5</sub> aerosol synchronized with <sup>14</sup>CO<sub>2</sub> observations began in Debrecen in the winter of 2010. The aim of the study was to determine the contemporary and fossil carbon fractions<sub> </sub>in the aerosol<sub> </sub>and to set them against the fossil CO<sub>2</sub> excess data referring to the same period. The mass of the collected PM<sub>2.5</sub> mode on prebaked quartz filters was determined gravimetrically, while its total carbon mass was calculated from the pressure of CO<sub>2</sub> gas produced after the combustion of the filters. As a result of the applied sampling and preparation method, the stable, nonvolatile carbon forms were principally studied. <sup>14</sup>C measurements of the tiny aerosol bulk samples were performed using the EnvironMICADAS accelerator mass spectrometer at ATOMKI. The sample preparation method was tested using several blanks, standards, and real samples. Test results showed good reproducibility for the applied aerosol sample preparation and accelerator mass spectrometry (AMS) <sup>14</sup>C analyses. Atmospheric fossil CO<sub>2</sub> excess data were calculated according Levin et al. (2003), using the <sup>14</sup>C results of collected CO<sub>2</sub> samples measured by the gas proportional counting system at ATOMKI. Mass concentration of PM<sub>10</sub> involving the PM<sub>2.5</sub> mode in the city air exceeded the daily average of 50 µg/m<sup>3</sup> (24-hr limit value in the EU) several times in 2011, mainly during the winter. The results showed that recently derived carbon most likely from domestic wood burning was causing the elevated carbon mass concentration of PM<sub>2.5</sub> in Debrecen at the time. In the course of the 1-yr-long continuous and systematic comparison of fossil carbon mass concentration of PM<sub>2.5 </sub>mode and mole fraction of fossil excess of atmospheric CO<sub>2</sub>, similar and synchronous trends were observed during the studied period in Debrecen.</p><p>DOI: <a href="/index.php/radiocarbon/article/view/18191">10.2458/azu_rc.57.18191</a></p>István MajorEnikő FuruLászló HaszpraZsófia KertészMihály Molnár
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2015-05-282015-05-285759911002A Process- and Provenance-Based Attempt to Unravel Inconsistent Radiocarbon Chronologies in Lake Sediments: An Example from Lake Heihai, North Tibetan Plateau (China)
https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/18221
<p>Aquatic macrophytes from a lacustrine environment are highly prone to a reservoir effect, resulting in an overestimation of age. This is often caused by the incorporation of dissolved carbon (CO<sub>2</sub> and HCO<sub>3</sub><sup>–</sup>) through photosynthesis from lake waters that have a different <sup>14</sup>C activity than the atmosphere. The atmosphere-water disparity is often produced by a mixing of carbon between the water body and its terrestrial surroundings, a process highly prone to temporal variations. Thus, only a comprehensive understanding of the <sup>14</sup>C budget over time enables a reliable chronology of lacustrine records. We studied lacustrine sediments from Lake Heihai on the northern Tibetan Plateau with a recent reservoir effect of 6465 ± 75 <sup>14</sup>C yr as estimated from accelerator mass spectrometry (AMS) dating of three living aquatic plants. Age inversions in a well-laminated composite core from the lake suggest that the reservoir effect markedly changed over the depositional period. In the lower part of the core, an excellent correlation was observed between the allochthonous input of dolomite and the inverse <sup>14</sup>C ages, indicating the incorporation of dissolved <sup>14</sup>C-dead carbon from a limestone catchment in the plant material. For the upper part of the core, sediment recycling of Holocene high-stand deposits may have further contributed to the reservoir effect. These findings give rise to a reliable process- and provenance-based chronology within a confidence interval supported by <sup>137</sup>Cs measurements and magnetostratigraphic investigations. Our results highlight the need to identify the interactions of lakes with their surroundings to estimate reservoir-corrected ages in lacustrine settings.</p><p>DOI: <a href="/index.php/radiocarbon/article/view/18221">10.2458/azu_rc.57.18221</a></p>Gregori LockotArne RamischBernd WünnemannKai HartmannTorsten HaberzettlHao ChenBernhard Diekmann
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2015-05-282015-05-285751003101914C Ages of the Last Eruptive Stage of Faial Island Caldeira Volcano
https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/17957
<p>Faial is one of the nine islands that form the Azores archipelago in the North Atlantic, characterized by a complex geodynamic setting dominated by the triple point where the North American, Eurasian, and African lithospheric plates meet. Faial Island comprises two central volcanoes and two basaltic fissure systems. The oldest central volcano is the Ribeirinha Volcano, on the northeast sector of the island. It is an extinct volcano, extensively dissected by the regional distensive faults of the Pedro Miguel Graben. The volcano has an age spanning from more than 850 ka BP to about 340 ka BP. The central portion of the island is formed by the Caldeira Volcano, a central volcano that has been active since before 440 ka BP. The ages of the basaltic fissure systems are less well constrained. The Horta Platform Fissure System, on the southeast sector of the island, has been active since more then 11 ka BP and its most recent activity is older than 6 ka BP. The Capelo Peninsula Fissure System, forming the west portion of the island, is a geomorphologically young region. This system has been active until the present and produced two historical eruptions, one in AD 1672–1673 and another in AD 1957–1958.</p><p>DOI: <a href="/index.php/radiocarbon/article/view/17957">10.2458/azu_rc.57.17957</a></p>J M Pacheco
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2015-05-282015-05-2857510211027When 14C Dates Fall Beyond the Limits of Uncertainty: An Assessment of Anomalies in Western Mediterranean Bronze Age 14C Series
https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/18180
<p>The aim of this article is to bring to light a serious problem affecting radiocarbon dates produced at least from 2009 onwards by the AMS Leibniz laboratory at the Christian-Albrechts-Universität (Kiel, Germany). Archaeological observations and cross-checkings between several laboratories confirm that in a significant number of dates, clear deviations of the results from chronological schemes based on stratigraphical sequences and hundreds of measurements have occurred, which usually implies an aging of the <sup>14</sup>C values.</p><p>DOI: <a href="/index.php/radiocarbon/article/view/18180">10.2458/azu_rc.57.18180</a></p>Vicente LullRafael MicóCristina Rihuete-HerradaRoberto Risch
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2015-05-282015-05-2857510291040Accuracy and Reproducibility of 14C Measurements at the Leibniz-Labor, Kiel: A First Response to Lull et al., “When 14C Dates Fall Beyond the Limits of Uncertainty: An Assessment of Anomalies in Western Mediterranean Bronze Age 14C Series”
https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/18569
<p>In this issue, Lull et al. (2015) have compiled a list of anomalous radiocarbon dates on samples of archaeological material from La Bastida and other sites in Spain, reported by our laboratory in 2009–2013. On this basis, they suggest that “at least from 2009 onwards” all Kiel’s dates on organic samples are potentially inaccurate, and often too old. We would like to briefly respond to these claims, and to reassure readers that the quality of accelerator mass spectrometry (AMS) <sup>14</sup>C measurements at Kiel is comparable again to that in other research laboratories.</p><p>DOI: <a href="/index.php/radiocarbon/article/view/18569">10.2458/azu_rc.57.18569</a></p>John MeadowsMatthias HülsRalph Schneider
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2015-05-282015-05-2857510411047