bluuebunny/crossref_metadata_2025 huggingface dataset:
14C Levels in Tree Rings Located Near Qinshan Nuclear Power Plant, China
Authors: Wang Zhongtang , Xiang Yuanyi , Guo Qiuju
Published: July 2016

Specific activities of radiocarbon in annual tree rings corresponding to 1980-2009 are reported for a pine tree located 2 km from the Qinshan Nuclear Power Plant (Qinshan NPP), China. While a negligible enhanced14C activity due to operation of the Qinshan NPP Plant I is evident, a relative increase (1.8–62.6 Bq/kg C) was observed in the specific activity after operation of the Qinshan NPP Plant II in 2002 and Plant III in 2003. The enhanced values were primarily affected by the14C discharged from Plant III (CANDU-type reactor), and a good correlation was found between the14C discharged from Plant III in the growing season and the14C excess value. The excess14C activities peaked in 2005 (at 302.0 Bq/kg C, which is 62.6 Bq/kg C above the “clean air”14C level), and then declined due to the improvement in14C discharge management of Plant III. In 2009, the14C-specific activity was near the background level.
A Bayesian Re-Assessment of the Earliest Radiocarbon Dates from Tiwanaku, Bolivia
Authors: Marsh Erik J
Published: July 2016

The development of sociopolitical complexity at Tiwanaku around AD 500 was one of the major episodes of social change in the history of the Lake Titicaca Basin. It was the result of poorly understood processes that took place at a series of ceremonial centers in the preceding centuries. The history of Tiwanaku during this time is especially unclear, because the only radiocarbon dates are from excavations whose details were never completely published. Despite this, there is consensus that Tiwanaku was founded around 300 BC. A re-evaluation of the archaeological context of each of these dates shows many of them to be unreliable. Two Bayesian models from independent excavations agree that Tiwanaku was in fact founded centuries later, most likely around AD 110 (50-170, 1σ). This has important implications for widely used monolith and ceramic sequences, as well as understanding the rise of Tiwanaku and other archaic states.
Modeling Regional Radiocarbon Trends: A Case Study from the East Texas Woodland Period
Authors: Selden Robert Z
Published: July 2016

The East Texas Radiocarbon Database contributes to an analysis of tempo and place for Woodland era (∼500 BC–AD 800) archaeological sites within the region. The temporal and spatial distributions of calibrated14C ages (n= 127) with a standard deviation (ΔT) of 61 from archaeological sites with Woodland components (n= 51) are useful in exploring the development and geographical continuity of the peoples in cast Texas, and lead to a refinement of our current chronological understanding of the period. While analysis of summed probability distributions (SPDs) produces less than significant findings due to sample size, they are used here to illustrate the method of date combination prior to the production of site- and period-specific SPDs. Through the incorporation of this method, the number of14C dates is reduced to 85 with a ΔTof 54. The resultant data set is then subjected to statistical analyses that conclude with the separation of the east Texas Woodland period into the Early Woodland (∼500 BC–AD 0), Middle Woodland (∼AD 0–400), and Late Woodland (∼AD 400–800) periods.
AMS 14C Dates and Major Element Composition of Glass Shards of Late Pleistocene Tephras on Tanegashima Island, Southern Japan
Authors: Okuno Mitsuru , Torii Masayuki , Naruo Hideto , Saito-Kokubu Yoko , Kobayashi Tetsuo
Published: July 2016

Four late Pleistocene tephra layers—Tane I (Tn1), II (Tn2), III (Tn3), and IV (Tn4) in ascending order—are intercalated between widespread tephras, Kikai-Tozurahara (K-Tz: 95 ka) and Aira-Tn (AT: 30 cal kBP), on Tanegashima Island, in southern Japan. Paleolithic ruins such as the Yokomine C and Tatikiri archaeological sites were excavated from the loam layer between the Tn4 and Tn3 tephras. To refine the chronological framework on the island, we conducted accelerator mass spectrometry (AMS) radiocarbon dating for 2 paleosol and 6 charcoal samples related with the late Pleistocene tephras and the Yokomine C archaeological site. The obtained 14C dates are consistent with the stratigraphy in calendar years, 33 cal kBP for Tn4, 40 cal kBP for Tn3, and >50 cal kBP for Tn2 and Tn1. The charcoal dates from Yokomine C, 32–38 cal kBP, not only constrain the age of Tn4 and Tn3 ashes, but also serve as a possible date for the site. We also measured the major element compositions of volcanic glass shards with EDS-EPMA to characterize these tephras. Although we could not find a possible correlative for Tn3 and Tn4 ashes using major element oxides of the glass shards, i.e. 75–76 wt% in SiO2, the glass chemistry obtained in this study will be valuable in correlating these tephras with their source volcanoes in the near future.
State Formation in Judah: Biblical Tradition, Modern Historical Theories, and Radiometric Dates at Khirbet Qeiyafa
Authors: Garfinkel Yosef , Streit Katharina , Ganor Saar , Hasel Michael G
Published: July 2016

During the past 30 yr, the biblical narrative relating to the establishment of a kingdom in Judah has been much debated. Were David and Solomon historical rulers 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, 300 yr later? Recent excavations at Khirbet Qeiyafa, the first early Judean city to be dated by radiocarbon, clearly indicate a well-planned, fortified city in Judah as early as the late 11th to early 10th centuries BC. This new data has far-reaching implications for archaeology, history, and biblical studies.
Considerations of the Scale of Radiocarbon Offsets in the East Mediterranean, and Considering a Case for the Latest (Most Recent) Likely Date for the Santorini Eruption
Authors: Manning Sturt W , Kromer Bernd
Published: July 2016

The debate over the dating of the Santorini (Thera) volcanic eruption has seen sustained efforts to criticize or challenge the radiocarbon dating of this time horizon. We consider some of the relevant areas of possible movement in the14C dating—and, in particular, any plausible mechanisms to support as late (most recent) a date as possible. First, we report and analyze data investigating the scale of apparent possible14C offsets (growing season related) in the Aegean-Anatolia-east Mediterranean region (excluding the southern Levant and especially pre-modern, pre-dam Egypt, which is a distinct case), and find no evidence for more than very small possible offsets from several cases. This topic is thus not an explanation for current differences in dating in the Aegean and at best provides only a few years of latitude. Second, we consider some aspects of the accuracy and precision of14C dating with respect to the Santorini case. While the existing data appear robust, we nonetheless speculate that examination of the frequency distribution of the14C data on short-lived samples from the volcanic destruction level at Akrotiri on Santorini (Thera) may indicate that the average value of the overall data sets is not necessarily the most appropriate14C age to use for dating this time horizon. We note the recent paper of Soter (2011), which suggests that in such a volcanic context some (small) age increment may be possible from diffuse CO2emissions (the effect is hypothetical at this stage and hasnotbeen observed in the field), and that "if short-lived samples from the same stratigraphic horizon yield a wide range of14C ages, the lower values may be the least altered by old CO2." In this context, it might be argued that a substantive “low” grouping of14C ages observable within the overall14C data sets on short-lived samples from the Thera volcanic destruction level centered about 3326–3328 BP is perhaps more representative of the contemporary atmospheric14C age (without any volcanic CO2contamination). This is a subjective argument (since, in statistical terms, the existing studies using the weighted average remain valid) that looks to support as late a date as reasonable from the14C data. The impact of employing this revised14C age is discussed. In general, a late 17th century BC date range is found (to remain) to be most likelyeven ifsuch a late-dating strategy is followed—a late 17th century BC date range is thus a robust finding from the14C evidence even allowing for various possible variation factors. However, the possibility of a mid-16th century BC date (within ∼1593–1530 cal BC) is increased when compared against previous analyses if the Santorini data are considered in isolation.
Erimi-Laonin Tou Porakou (Limassol, Cyprus): Radiocarbon Analyses of the Bronze Age Cemetery and Workshop Complex
Authors: Calabrisotto C Scirè , Fedi M E , Caforio L , Bombardieri L
Published: July 2016

The site area of Erimi-Laonin tou Porakou (Limassol, Cyprus) has been surveyed and systematically excavated since 2007 as a joint research project of the University of Florence and the Department of Antiquities of Cyprus. A focused investigation was dedicated to analyzing funerary evidence from the southern Cemetery (Area E), where 7 single-chamber graves were excavated. The offering goods assemblages from the burials point to a general date ranging from Early to Late Bronze Age I, and draw a sequence of use that is contemporary to the stratigraphic deposits from the top mound Workshop Complex (Area A). During the 2010 field season, charcoal samples from the Workshop Complex and bone samples from the skeleton remains of 2 burials (tombs 228, 230) were opportunely taken for radiocarbon analyses. 14C dating was performed at the AMS-IBA Tandetron accelerator of the INFN-LABEC Laboratory in Florence. This paper will discuss the results of the 14C analyses and compare them with the archaeological evidence in order to outline a chronological sequence for the settlement and cemetery areas at Erimi-Laonin tou Porakou, thus collecting further data on the development and pattern of occupation of the Early to Late Cypriote period in the Kourion area.
14C Dating Human Skeletons from Medieval Archaelogical Sites in Kamakura, Japan: Were they Victims of Nitta Yoshisada's Attack?
Authors: Minami M , Nakamura T , Nagaoka T , Hirata K
Published: July 2016

We investigated the radiocarbon ages and carbon and nitrogen isotope ratios of human skeletal remains from burials at the Yuigahama-minami and Chusei-Shudan-Bochi sites in the Yuigahama area (Kamakura, Japan), which we believe are associated with the great attack on Kamakura by Nitta Yoshisada in AD 1333. The human bones produced enriched δ13C and δ15N values that could be affected by consumption of protein from marine fish and/or mammals with high δ13C and δ15N, and therefore older apparent 14C ages. We thus estimated the marine reservoir effect on human skeletons to determine their true ages. The IsoSource isotope mixing model was employed for reconstructing percentages of marine protein in the human diet, and calibrated calendar dates for the 14C ages were calculated using the marine percentages. At the Yuigahama-minami site, most skeletons from individual burials now date to the last phase of the Kamakura period or the early part of the Muromachi period, while skeletons from mixed human-animal multiple burials date to the latter part of the Kamakura period. The humans from the individual burials, consisting of normal ratios of adult males, could have died a natural death, though the site could also have been used to inter victims of the battle of 1333. The humans from mixed human-animal burials, consisting of a high proportion of infants, were not victims of the 1333 battle, but the site may have been used to inter victims of the Kamakura earthquake in 1293, which resulted in a catastrophic tsunami. On the other hand, the skeletons from multiple burials in the Chusei-Shudan-Bochi site all date to the middle Kamakura period. Coupled with the fact that most humans in the site are male but show no evidence of injuries by sword cuts, it is likely that burials of the Chusei-Shudan-Bochi site could have been a collective interment following the Jinji earthquake in 1241, the Shoka earthquake in 1257, or the Shoka famine in 1258 in the middle Kamakura period. The results of this study indicate that humans from burials in the Yuigahama region were not necessarily victims of the attack by Nitta Yoshisada on Kamakura, but instead were likely victims of natural disasters such as large earthquakes and severe famines, which often occurred in the middle Kamakura period.
Bayesian Spatiotemporal Analysis of Radiocarbon Dates from Eastern Fennoscandia
Authors: Onkamo Päivi , Kammonen Juhana , Pesonen Petro , Sundell Tarja , Moltchanova Elena , Oinonen Markku , Haimila Miikka , Arjas Elja
Published: July 2016

Archaeological phenomena, especially those that have been radiocarbon dated, can be utilized as indications of human activity and occupancy in space and time. 14C dates from archaeological contexts have been used as proxies for population history events in several recent studies (e.g. Gamble et al. 2005; Shennan and Edinborough 2007; Oinonen et al. 2010; Tallavaara et al. 2010; Pesonen et al. 2011). As a step towards a larger spatiotemporal modeling effort, we present examples of spatial distributions obtained using Bayesian methodology, analyzing all available archaeological 14C dates from the Stone Age (9000–1500 cal BC) in eastern Fennoscandia. The resulting maps follow the patterns of pioneer settlement in Finland beginning at ∼9000 cal BC and provide supporting evidence for the postulated population peak around 4000–3500 cal BC in Finland and the subsequent population decline.
Plant Remains and AMS: Dating Climate Change in the Aeolian Islands (Northeastern Sicily) During the 2nd Millennium BC
Authors: Caracuta V , Fiorentino G , Martinelli M C
Published: July 2016

Archaeological plant remains, used to establish a reliable chronology by radiocarbon dating, are used here to investigate trends in past rainfall intensity. The stable carbon isotope ratio in botanic remains depends on environmental conditions during the plant's life. By comparing the δ13C and 14C of selected plant specimens from 3 protohistoric sites in the Aeolian Archipelago, it is possible to identify short-term changes in the rainfall intensity during the 2nd millennium BC. The climate signals inferred from carbon isotope analyses are compared to pollen data for the region and are found to be consistent with changes in vegetal cover. Finally, the climate signals are integrated with the history of the Aeolian communities and the resilience of settlers is evaluated.
Radiocarbon Chronology of the Schurovo Burial Mound Cremation Complex (Viking Times, Middle Oka River, Russia)
Authors: Syrovatko A S , Zaretskaya N E , Troshina A A , Panin A V
Published: July 2016

Excavation of the Schurovo archaeological site, located on a ∼12-m river terrace, has revealed 3 occupation periods: 1) as a dwelling site of the Migration period (4th–5th centuries AD); 2) as local burial mounds (termed “houses of the dead” in Russian); 3) and as a ground burial period, which left a cremation layer directly on the ground and is now covered by the Little Ice Age overbank alluvium. The latter 2 periods contain few artifacts, which makes radiocarbon dating more appropriate for establishing their chronology. The burial mounds were dated to the mid-6th to mid-7th centuries AD. The accumulation of colluvium in mound ditches points to a rather long (at least a century) pause between the construction of burial mounds and the appearance of ground burials. Dates from the cremation layer (ground burials) span a wide range from the 8th to 13th centuries AD. As the younger dates do not correspond to regional historical and archaeological contexts, we believe them to be “rejuvenated” due to their long exposure before burial to the young alluvium. The ground burials are dated to the mid-8th to mid-10th centuries AD, the so-called “dark ages” in the Moscow region characterized by very few archaeological data. An isolated ancient branch of the Oka River near the archaeological site was radiocarbon dated and found to be active until the mid-10th to later-12th centuries AD, meaning that it was likely used as a local harbor on the transit river route throughout the site's occupation.
Characterization of Different Chemical Procedures for14C Dating of Buried, Cremated, and Modern Bone Samples at Circe
Authors: Passariello Isabella , Simone Pasquale , Tandoh Joseph , Marzaioli Fabio , Capano Manuela , De Cesare Nicola , Terrasi Filippo
Published: July 2016

Bone chemical treatment for radiocarbon dating has drawn the attention of different laboratories because dates of bones and charcoals found in the same layer often disagree. Excluding diet-related reservoir effects, this observation is likely due to a nonoptimized procedure of contaminant removal from the extracted collagen. In this study, systematic work on the bone chemical treatment was performed with the aim to investigate the effect of each known procedure (i.e. AAA, GEL, and ULTR) on the collagen used for14C dating. Isolation and purification of lipids from animal tissues were performed to estimate eventual offsets induced by the applied methods, by comparing the14C ages of lipids with those of collagen. Moreover, cremated bones were treated for the first time at CIRCE. Measured14C isotopic ratios on these samples were used to evaluate the accuracy of the applied procedure by comparing against the results for charcoals found in the same archaeological context as the bones.
Identification, Extraction, and Preparation of Reliable Lime Samples for 14C Dating of Plasters and Mortars with the “Pure Lime Lumps” Technique
Authors: Pesce Giovanni L A , Ball Richard J , Quarta Gianluca , Calcagnile Lucio
Published: July 2016

Radiocarbon dating was first applied to historic lime mortars during the 1960s. However, despite the relative simplicity of the technique in principle, a number of subsequent studies have highlighted important aspects that should be considered. One of the most significant of these challenges arises from sample contamination by carbonaceous substances such as incompletely burnt limestone and aggregates of fossil origin containing “dead” 14C. More recent studies have shown that in the majority of old lime-based mixtures the contamination problem can be avoided through selection of pure lime lumps. These particular types of lumps are believed to originate from areas where the lime is incompletely mixed with the aggregate. It has been demonstrated that even a single lime lump can provide sufficient material for a 14C date of the mortar from which the lump was taken (Pesce et al. 2009). This paper describes the practical challenges associated with location, extraction, and preparation of 4 lime lumps extracted from 2 new sites for 14C dating. These include distinguishing the lime lumps from other lumps present in the matrix and the removal of material surrounding the lime lump. The coherence of 14C dating with other archaeological information on the chronology of historic sites is highlighted through case studies.
Distribution of Sites and Radiocarbon Dates in the Sierra Nevada: Implications for Paleoecological Prospecting
Authors: Anderson R. Scott , Smith Susan J. , Koehler Peter A.
Published: July 2016

The number of paleoecological records for the Sierra Nevada of California has increased substantially since the compilation of Adam (1985). We examine here the geographical and temporal distribution of records within the range in order to identify areas for which “gaps” exist in our paleoecological knowledge. Seventy-two sites with paleoecological information are identified; these sites are dated with 234 radiocarbon dates. Sites occur primarily between ca. 36°N and 38°30'N latitudes, and from ca. 1000 m to over 3000 m elevation on both sides of the Sierran crest, although more sites have been analyzed on the west side of the crest than the east side. In general, packrat (Neotoma) midden series are located at the lowest elevations, meadow and marsh cores originate from mid-elevations, and lake sediments have been analyzed from the highest elevations. Significant gaps in our knowledge occur for much of the east side of the crest, for both sides of the range above modern treeline, and for time periods older than the latest Pleistocene.
A Simple, Extremely Stable Single-Tube Liquid Scintillation System for Radiocarbon Dating
Authors: Theodórsson Pall
Published: July 2016

This paper describes a simple and compact liquid scintillation radiocarbon dating system, ICELS, and demonstrates its long-term stability and reproducibility to a precision level rarely presented before, better than 0.04% (3 14C yr). Inexpensive systems of this kind may, in the future, help to meet increasing demand for high precision (±16 to ±20 14C yr) and strict quality control. ICELS comprises a compact detector unit, where a 3-mL dome-shaped vial, with an optimal light reflector, sits on the top of a vertical 30-mm photomultiplier tube. Sample changing is manual. The high voltage is set at the balance point for each sample, securing maximal counting stability. The quench correction method used (spectrum restoration) corrects with 0.04% precision for all parameters that can normally shift the 14C spectrum. For 3 mL of benzene at 71% 14C counting efficiency (recent carbon 23 cpm), the background is 1.72 cpm behind a 5-cm-thick shield of lead (27 kg) and 1.53 cpm behind 10 cm of lead. The background count rate corrected for atmospheric pressure variations was completely stable over 47- and 57-d testing periods for the 2 systems.
The Contribution of Radiocarbon Dating to New World Archaeology
Authors: Taylor R E
Published: July 2016

When introduced almost five decades ago, radiocarbon (14C) dating provided New World archaeologists with a common chronometric scale that transcended the countless site-specific and regional schemes that had been developed by four generations of field researchers employing a wide array of criteria for distinguishing relative chronological phases. A topic of long standing interest in New World studies where14C values have played an especially critical role is the temporal framework for the initial peopling of the New World. Other important issues where14C results have been of particular importance include the origins and development of New World agriculture and the determination of the relationship between the western and Mayan calendars. It has been suggested that the great success of14C was an important factor in redirecting the focus of American archaeological scholarship in the 1960s from chronology building to theory building, led to a noticeable improvement in US archaeological field methods, and provided a major catalyst that moved American archaeologists increasingly to direct attention to analytical and statistical approaches in the manipulation and evaluation of archaeological data.
Radiocarbon Calibration and Application to Geophysics, Solar Physics, and Astrophysics
Authors: Damon Paul E , Peristykh Alexei N
Published: July 2016

This paper includes a brief history of the calibration of the radiocarbon time scale from the first recognition of the necessity of calibration in 1962 to INTCAL98. Thirty-six years of effort by dendrochronologists and the 14C community have pushed the tree-ring calibration back to 11,854 yr BP. All of this part of the calibration has been done by high-precision beta counting. Uranium-thorium (U-Th) dating of coral samples coupled with accelerator mass spectrometry (AMS) measurement of 14C has extended a fairly detailed calibration back beyond the Bølling warm episode to 15,000 BP. Earlier than 15,000 BP, piecewise linear approximation extends INTCAL98 calibration to 24,200 BP.

Blending 1-, 2-, 3-, 10-, and 20-yr tree-ring samples containing regional and data offsets into a decadal time scale does not make an ideal error and bias free δ14C record. Nevertheless, spectral analysis reveals some statistically significant fundamental frequencies as well as interesting “beat” frequencies and the second harmonic of the around 208-yr cycle that is considered to be solar in origin. Although, some very prominent peaks such as the 88-yr (Gleissberg) are clearly solar in origin, some of the lower frequencies such as of the 512-yr period may have an origin in thermohaline circulation. Thus, INTCAL98 provides useful data for geophysical and solar physics research. Lastly, single year δ14C analysis would be useful for revealing invaluable information for solar physics, astrophysics and geophysics not accessible by decadal data. We provide several examples.
Radiocarbon Beyond this World
Authors: Jull J A Timothy , Lal Devendra , Burr George S , Bland Philip A , Bevan Alexander W R , Beck J Warren
Published: July 2016

In this paper, we review the production of radiocarbon and other radionuclides in extraterrestrial materials. This radioactivity can be produced by the effects of solar and galactic cosmic rays on solid material in space. In addition, direct implantation at the lunar surface of 14C and other radionuclides can occur. The level of 14C and other radionuclides in a meteorite can be used to determine its residence time on the Earth's surface, or “terrestrial age”. 14C provides the best tool for estimating terrestrial ages of meteorites collected in desert environments. Age control allows us to understand the time constraints on processes by which meteorites are weathered, as well as mean storage times. Third, we discuss the use of the difference in 14C/12C ratio of organic material and carbonates produced on other planetary objects and terrestrial material. These differences can be used to assess the importance of distinguishing primary material formed on the parent body from secondary alteration of meteoritic material after it lands on the earth.
Burnt and Unburnt Carbon: Dating Charcoal and Burnt Bone from the Willandra Lakes, Australia
Authors: Gillespie Richard
Published: July 2016

A new analysis of previous results on conflicts between shell and charcoal dates and on burnt human bones, with new data presented here, suggests that alternative interpretations are possible for the archaeology and environmental history of the Willandra Lakes region. Black sediment samples from archaeological sites at Lake Outer Arumpo exhibit wide variation in burnt and unburnt carbon content; high humic acid concentrations in midden layers and in one group of hearth/ovens are absent in another, older, group of hearth/ovens. There are no acceptable results on charcoal from hearth/ovens older than ca. 31 ka bp, and no evidence that these samples are associated with numerous midden shell dates at 34–37 ka bp. Similar logic applied to humic-free residue dates on burnt human bones places five gracile skeletons (including Mungo 1) as post–Last Glacial Maximum.
University of Granada Radiocarbon Dates VIII
Authors: González-Gómez Cecilio , Villafranca-Sánchez Elena
Published: July 2016

This paper includes determinations of archaeological, geological and paleobotanical samples from Spain and Brazil, measured at the University of Granada Radiocarbon Dating Laboratory, mainly from 1991 to 1992. As previously reported (González-Gómez 1992), pretreatment of charcoal and wood samples is a standard acid-basic procedure using 8% HCl and 2% NaOH at boiling temperature. The collagen of bone samples was extracted by the Longin (1971) method. The method of dating is liquid scintillation counting of synthesized benzene.
Analytical Protocol and Quality Assurance for 14C Analyses: Proposal for A Further Intercomparison
Authors: Scott E. M. , Harkness D. D. , Cook G. T.
Published: July 2016

We present a proposal for a further intercomparison exercise following discussions at the 16th International Radiocarbon Conference in Groningen in 1997. This new intercomparison will build on previous exercises by making use of both reference materials already characterized and additional known-age material. For this comparison, we describe two separate but essentially related protocols that are meant to satisfy the different priorities of radiometric and AMS laboratories. The new intercomparison is planned to begin in mid-1998.
Atmospheric 14C Variability Recorded in Tree Rings from Peninsular India: Implications for Fossil Fuel CO2 Emission and Atmospheric Transport
Authors: Chakraborty Supriyo , Dutta Koushik , Bhattacharyya Amalava , Nigam Mohit , Schuur Edward A G , Shah Santosh K
Published: July 2016

Radiocarbon analysis in annual rings of a teak tree (Tectona grandis) is reported in comparison with previously published results. Samples (disks) were collected from Hoshangabad (22°30′N, 78°E), Madhya Pradesh, in central India. The previously published sample was collected from Thane (19°12′N, 73°E), Maharashtra, near the west coast of India (Chakraborty et al. 1994). Two short Δ14C time series were reconstructed with these tree samples to capture the bomb peak of atmospheric 14C and the spatial variability in this record. These time series represent the periods 1954–1977 and 1959–1980 for Hoshangabad and Thane, respectively. The 14C peaks in these places appear around 1964–1965. The Hoshangabad tree records a peak Δ14C value of 708 ± 8%, which conforms to the peak value of Northern Hemisphere Zone 3 as described in Hua and Barbetti (2004). But the peak Δ14C at Thane is somewhat less (630 ± 8%) probably due to the dilution by fossil fuel CO2 free of 14C emanating from the neighboring industrial areas. This depletion of peak values has been used to estimate the local emission of fossil fuel CO2, which is approximately 2.3% of the background atmospheric CO2 concentration.
Age Discrepancies with the Radiocarbon Dating of Sagebrush (Artemisia Tridentata Nutt.)
Authors: Geib Phil R
Published: July 2016

When ancient hearths at open archaeological sites do not yield carbonized annual plant remains or other high-quality samples, wood charcoal is commonly used for radiocarbon dating. Sagebrush (Artemisia tridentata Nutt.), a shrub frequently used for fuel across much of the western United States, seems a potentially better candidate for 14C dating than tree wood since the possibility for significant age discrepancy might be less. A comparison of multiple assays from single features reveals that sagebrush can overestimate age more than even tree wood charcoal. A plausible cause of this appears to be persistence of the shrub on the ground surface for an extended interval after death, such that use as fuel almost invariably occurs hundreds of years after fixation of carbon. The potential for age discrepancy may decrease as population density increases because the demand for fuel wood would have resulted in a more rapid turnover of the fuel biomass. This is not true for Archaic period foragers of western North America when population levels were likely quite low and residential mobility quite high.
Wiggle-Matching Using Known-Age Pine from Jermyn Street, London
Authors: Tyers Cathy , Sidell Jane , Van der Plicht Johannes , Marshall Peter , Cook Gordon , Bronk Ramsey Christopher , Bayliss Alex
Published: July 2016

A slice of pine from the period covered by single-year calibration data (Stuiver 1993) was selected to serve as part of the quality assurance procedures of the English Heritage radiocarbon dating program, following successful wiggle-matching of 14C measurements from structural 15th century English oak timbers (Hamilton et al. 2007). The timber selected was a roofing element from a house on Jermyn Street, central London, demonstrated by dendrochronology to have been felled in AD 1670. Eighteen single-ring samples were dated by the 14C laboratories at Groningen, Oxford, and SUERC: each laboratory was sent a random selection of 6 samples. This approach was intended to mimic the mix of samples and relative ages incorporated into Bayesian chronological models during routine project research. This paper presents the results of this study.
Absolute Dating of Monoxylous Boats from Northern Italy
Authors: Martinelli Nicoletta , Cherkinsky Alexander
Published: July 2016

Twelve monoxylous boats were analyzed from different provinces of northern Italy by radiocarbon and dendrodating. Most of them were dated in the range 6th–12th centuries cal AD. All boats were made from single tree trunks containing ~50 to ~250 tree rings. The results from archaeometric dating in logboats confirm that these kinds of vessels remained practically unchanged for centuries and were in use until recently. The technical features are more strictly related to local traditions than to chronology.
Dating of the Cultural Layers from Vilnius Lower Castle, East Lithuania: Implications for Chronological Attribution and Environmental History
Authors: Mažeika J , Blaževičius P , Stančikaitė M , Kisielienė D
Published: July 2016

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. The14C 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-correlated14C 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.
Radiocarbon and Dendrochronological Dates of the Corded Ware Culture
Authors: Włodarczak Piotr
Published: July 2016

This paper presents and discusses radiocarbon dates of the Corded Ware culture (CWC) from different regions of Europe (mainly from southern and central Germany and southern and central Poland). The main questions addressed are the controversial significance of particular results, the incompatibility of the obtained date sequences, and the “imprecision of the method.” There is clearly the problem of hundreds of dates from different laboratories and performed in different years. A slight difference in the results leads to an “elongated” chronology and acceptance of a model with synchronicity of many cultural groups. The proposed verification of the14C chronology is connected with both the dendrochronological method and the comparison of dating sequences obtained from particular regions. At present, the most reliable dating scheme for the Corded Ware culture is the one based on the dendrochronological dates of settlements on Swiss lakes; therefore, the scheme must constitute a reference point for14C analyses conducted for other regions. Due to the typological diversity of materials, however, not every situation allows for this approach. Thus, many14C grave dates, particularly the results referring to the late CWC phase (after ~2400 BC), remain controversial.
Radiocarbon Dating of Lumps from Aerial Lime Mortars and Plasters: Methodological Issues and Results from San Nicolò of Capodimonte Church (Camogli, Genoa, Italy)
Authors: Pesce G , Quarta G , Calcagnile L , D'Elia M , Cavaciocchi P , Lastrico C , Guastella R
Published: July 2016

This paper deals with the potentialities and technical and methodological issues associated with the use of lumps of not completely melted lime as material suitable for the radiocarbon dating of aerial lime mortars and plasters. In fact, the identification and selection of single aggregates of unmelted lumps allows one to reduce the possible contamination resulting from external sources of carbon such as “14C-dead” limestone in sand added to the mixture during preparation. This procedure results in the possibility for accurate 14C determinations from single pieces of masonry, supplying important information about the construction phases of historical buildings. The potential of this approach is shown by presenting the results of the archaeological study on the walls of San Nicolò of Capodimonte church (Camogli, Genoa, Italy), where this technique has been successfully applied to obtain absolute ages of different parts of the building. The obtained results were then compared with the information gathered from historical sources and with stratigraphic and other archaeological studies.
Development of Radiocarbon Dating Methods for Modern Bone Collagenization
Authors: Kim K J , Hong W , Park J H , Woo H J , Hodgins G , Jull A J T
Published: July 2016

The relationship between temperature and time required for collagenization using modern bone samples was investigated. Gelatinized samples of bone collagen were filtered to selectively collect different molecular weight fractions. The results of this study suggest that heating to 70 ° for a duration of 12 hr provides the optimal conditions for gelatinization.
Tell Sabi Abyad, Syria: Radiocarbon Chronology, Cultural Change, and the 8.2 ka Event
Authors: van der Plicht J , Akkermans P M M G , Nieuwenhuyse O , Kaneda A , Russell A
Published: July 2016

At Tell Sabi Abyad, Syria, we obtained a robust chronology for the 7th to early 6th millennium BC, the Late Neolithic. The chronology was obtained using a large set of radiocarbon dates, analyzed by Bayesian statistics. Cultural changes observed at ~6200 BC are coeval with the 8.2 ka climate event. The inhabitation remained continuous.
Bayesian Analysis of High-Precision AMS14C Dates from a Prehistoric Mexican Shellmound
Authors: Kennett Douglas J , Culleton Brendan J , Voorhies Barbara , Southon John R
Published: July 2016

We establish a precision accelerator mass spectrometry (AMS) radiocarbon chronology for the Archaic period Tlacuachero shellmound (Chiapas, Mexico) within a Bayesian statistical framework. Carbonized twig samples were sequentially selected from well-defined stratigraphic contexts based on iterative improvements to a probabilistic chronological model. Analytical error for these measurements is ±15 to 2014C yr. This greater precision and the absence of stratigraphic reversals eclipses previous14C work at the site. Based on this, we establish a chronological framework for a sequence of 3 clay floors dating to between 4930 and 4270 cal BP and determine that the bedded shell deposits that formed the mound accumulated rapidly during 2 episodes: a lower 2-m section below the floors that accumulated over a 0–150 cal yr period at 5050–4875 cal BP and, an upper 3.5-m section above the floors that accumulated over a 0–80 cal yr period at 4380–4230 cal BP.
The Canadian Archaeological Radiocarbon Database (Card): Archaeological 14C Dates in North America and Their Paleoenvironmental Context
Authors: Gajewski K , Munoz S , Peros M , Viau A , Morlan R , Betts M
Published: July 2016

Databases of accumulated paleoecological and archaeological records provide a means for large-scale syntheses of environmental and cultural histories. We describe the current status of the Canadian Archaeological Radiocarbon Database (CARD), a searchable collection of more than 36,000 14C dates from archaeological and paleontological sites from across North America. CARD, built by the late Dr Richard Morlan of the Canadian Museum of Civilization, consists of uncalibrated 14C data as well as information about the material dated, the cultural association of the date (e.g. Paleoindian, Archaic, Woodland), and its geographic location. The database can be used to study questions relating to prehistoric demography, migrations, human vulnerability to environmental change, and human impact on the landscape, but biases relating to sampling intensity and taphonomy must first be accounted for. Currently, Canada and the northern United States are well represented in the database, while the southern United States is underrepresented. The frequency of 14C dates associated with archaeological sites increases through time from 15,000 cal yr BP until European contact, which likely reflects, among other factors, both the destruction of older cultural carbon due to erosion and dissolution and increasing population numbers through time. An exploratory analysis of the dates reveals their distribution in both time and space, and suggests that the database is sufficiently complete to enable quantitative analysis of general demographic trends.
Rudjer Bošković Institute Radiocarbon Measurements XVI
Authors: Obelić Bogomil , Krajcar Bronić Ines , Horvatinčić Nada , Barešić Jadranka , Rajtarić Anita
Published: July 2016

In this paper, we present dating of archaeological samples performed since our last report (Obelić et al. 2002). Included are results of samples measured by the gas proportional counting (GPC) method until the abandonment of this technique in 2007, as well as results of several series measured by both GPC and liquid scintillation counting (LSC) methods.
The Impact of Bioturbation on Ams 14C Dates On Handpicked Foraminifera: A Statistical Model
Authors: Andree Michael
Published: July 2016

When single species of foraminifera picked from marine sediments are 14C dated with Accelerator Mass Spectrometry (AMS), bioturbation puts limits on the minimal sample size to be used, as uncertainty is added to the result by statistics of the picking process. The model presented here simulates the additional statistical uncertainty introduced into the measurement by the coupling of bioturbation and small sample amounts. As there is no general solution for this problem, we present two simple cases only. The model can also be used to simulate more complicated situations occurring in sediments.
British Museum Natural Radiocarbon Measurements XX
Authors: Ambers Janet , Matthews Keith , Bowman Sheridan
Published: July 2016

The following list consists of dates, obtained by liquid scintillation counting of benzene, for archaeologic samples mostly measured from June 1985 to June 1986.
Institut Royal Du Patrimoine Artistique Radiocarbon Dates XII
Authors: Dauchot-Dehon Michele , Strydonck Mark Van
Published: July 2016

This list contains the results of 14C determinations obtained at the laboratory in 1985. ∗δ13C values are estimated (Stuiver & Polach, 1977).
Calculation of Past Dead Carbon Proportion and Variability by the Comparison of AMS 14C and Tims U/TH Ages on Two Holocene Stalagmites
Authors: Genty Dominique , Massault Marc , Gilmour Mabs , Baker Andy , Verheyden Sophie , Kepens Eddy
Published: July 2016

Twenty-two radiocarbon activity measurements were made by accelerator mass spectrometry (AMS) on 2 Holocene stalagmites from Belgium (Han-stm1b) and from southwest France (Vil-stm1b). Sixteen thermal ionization mass spectrometric (TIMS) U/Th measurements were performed parallel to AMS analyses. The past dead carbon proportion (dcp) due to limestone dissolution and old soil organic matter (SOM) degradation is calculated with U/Th ages, measured calcite 14C activity and atmospheric 14C activity from the dendrochronological calibration curves. Results show that the dcp is different for the 2 stalagmites: between 10,800 and 4780 yr from present dcp=17.5% (σ=2.4; n=10) for Han-stm1b and dcp=9.4% (σ=1.6; n=6) between 3070 and 520 yr for Vil-stm1b. Despite a broad stability of the dcp during the time ranges covered by each sample, a slight dcp increase of about 5.0% is observed in the Han-stm1b sample between 8500 and 5200 yr. This change is synchronous with a calcite δ13C increase, which could be due to variation in limestone dissolution processes possibly linked with a vegetation change. The dcp and δ13C of the 2 studied samples are compared with 5 other modern stalagmites from Europe. Results show that several factors intervene, among them: the vegetation type, and the soil saturation leading to variable dissolution process systems (open/closed). The good correlation (R2=0.98) between the U/Th ages and the calibrated 14C ages corrected with a constant dcp validates the 14C method. However, the dcp error leads to large 14C age errors (i.e. 250–500 yr for the period studied), which is an obstacle for both a high-resolution chronology and the improvement of the 14C calibration curves, at least for the Holocene.
14C Age of Glaciation in Estrecho De Magallanes–Bahía Inútil, Chile
Authors: Heusser C J
Published: July 2016

Basal 14C dates from a core of the mire at Puerto del Hambre (53°36'21″S, 70°55'53″W), located within the area of glaciation in Estrecho de Magallanes–Bahía Inútil, Chile, are no older than 14,455 ± 115 yr BP. The 14C dates are on samples from which screening isolated autochthonous plant remains. Previous 14C dates of 15,800 ± 200, 16,590 ± 320, and 16,290 ± 140 yr BP are from bulk samples collected from similar basal increments at the site during 3 separate, independent coring operations. The previous suite of 14C dates was suspected to be contaminated by older carbon in the light of chronological evidence, which indicates a 14C age of approximately 14,850 yr BP for glaciation elsewhere in southern Chile. Contamination by “infinitely old” carbon reworked from nearby Tertiary beds and redeposited at Puerto del Hambre is evidently the cause for the older 14C dates.
Effects of 14C Sample Selection in Archaeology: An Example from Hawai'i
Authors: Dye Tom
Published: July 2016

A comparison of radiocarbon histograms of samples controlled and uncontrolled for sample provenance and composition factors indicates that differences are sufficiently large to influence the discrimination of alternative hypotheses on the age of the important, early Bellows Dune site in Hawai'i.
Performance of Models for Radiocarbon Dating of Groundwater: An Appraisal using Selected Irish Aquifers
Authors: Gallagher D , McGee E J , Kalin R M , Mitchell P I
Published: July 2016

Appropriate management strategies are essential for the protection and maintenance of groundwater resources. It is therefore important that aquifers are understood in terms of hydraulics, recharge, and yield potential, and that the vulnerability of aquifers to surface pollution is evaluated. A range of aquifer types were examined in this study, and water samples were analyzed for the radiocarbon content of the total dissolved inorganic carbon (TDIC), stable isotopes, and a suite of chemical and physical parameters. The data were input to a selection of models for the estimation of the initial activity of the TDIC, and groundwater ages were calculated. Eight commonly used models were comparatively assessed in the study. The Tamers, Mook, and IAEA models gave anomalous ages, probably because of their inability to correct for solid phase isotopic exchange in aquifers. The Pearson, F&G, Evans, Eichinger, and Mass Balance models produced results in broad agreement.

The study shows that contrary to popular belief, there are sources of ancient groundwater in Ireland. Of the 19 sampling stations, two boreholes yielded waters with age estimates of greater than 10,000 BP. Water samples from a further six sites returned ages of between around 800 and 4000 BP. In contrast to borehole samples, spring wells yielded water of consistently young ages, demonstrating rapid recharge and flow mechanisms. Samples from several spring wells produced negative ages, indicating the presence of anthropogenic 14C. The findings demonstrate the potential for contamination of springs by surface runoff, while sources of greater age generally offer a greater degree of protection from surface pollution.