Showing papers in "Radiocarbon in 2001"
TL;DR: This paper highlights some of the main developments to the radiocarbon calibration program, OxCal, including changes to the sampling algorithms used which improve the convergence of the Bayesian analysis.
Abstract: This paper highlights some of the main developments to the radiocarbon calibration program, OxCal In addition to many cosmetic changes, the latest version of OxCal uses some different algorithms for the treatment of multiple phases The theoretical framework behind these is discussed and some model calculations demonstrated Significant changes have also been made to the sampling algorithms used which improve the convergence of the Bayesian analysis The convergence itself is also reported in a more comprehensive way so that problems can be traced to specific parts of the model The use of convergence data, and other techniques for testing the implications of particular models, are described
1,905 citations
TL;DR: In this paper, three different methods of matching radiocarbon dates to the "wiggles" of the calibration curve in those situations where the age difference between the 14C dates is known are discussed.
Abstract: This paper covers three different methods of matching radiocarbon dates to the ‘wiggles’ of the calibration curve in those situations where the age difference between the 14C dates is known. These methods are most often applied to tree-ring sequences. The simplest approach is to use a classical Chi-squared fit of the 14C data to the 14C curve. This gives the calendar date where the data fit best and allows tests of how good the fit is. The only drawback of this method is that it is difficult to ascertain the uncertainty in the date found in this way. An extension of this technique uses a Monte-Carlo simulation to sample possible 14C concentrations consistent with the measurement made and for each of these possibilities performs a Chi-squared fit. This method yields a distribution of values in the calendrical time-scale, from which the overall dating uncertainty can be derived. A third, rather different approach, based on Bayesian statistics, calculates the relative likelihood of each possible calendar year fit. This can then be used to calculate a range of most likely dates in a similar way to the probability method of 14C calibration. The theories underlying all three methods are discussed in this paper and a comparison made for the fitting of specific model sequences. All three methods are found to give consistent results and the application of any one of them depends on the nature of the scientific question being addressed.
330 citations
TL;DR: In this article, the authors describe an on-line marine reservoir correction database accessed via mapping software, which can be accessed at the website http://www.calib.org/.
Abstract: Calibration is essential for interpretation of radiocarbon dates, especially when the (super 14) C dates are compared to historical or climatic records with a different chronological basis. (super 14) C ages of samples from the marine environment, such as shells or fish bones, or samples with a marine component, such as human bone in coastal regions, require an additional consideration because of the reservoir age of the ocean. While the pre-industrial global mean reservoir correction, R(t), is about 400 years, local variations (Delta R) can be several hundred years or more. Delta R compilations on a global scale have been undertaken previously (Stuiver et al. 1986; Stuiver and Braziunas 1993), but have not been updated recently. Here we describe an on-line reservoir correction database accessed via mapping software. Rather than publishing a static Delta R compilation, new data will be incorporated when it becomes available. The on-line marine reservoir correction database can be accessed at the website http://www.calib.org/.
319 citations
TL;DR: In this article, the authors present routine methods of target preparation for radiocarbon analysis at the ANTARES Accelerator Mass Spectrometry (AMS) Centre, as well as recent developments which have decreased the procedural blank level and improved the ability to process small samples containing less than 200 μg of carbon.
Abstract: We present routine methods of target preparation for radiocarbon analysis at the ANTARES Accelerator Mass Spectrometry (AMS) Centre, as well as recent developments which have decreased our procedural blank level and improved our ability to process small samples containing less than 200 μg of carbon. Routine methods of 14 C sample preparation include sample pretreatment, CO 2 extraction (combustion, hydrolysis and water stripping) and conversion to graphite (graphitization). A new method of cleaning glassware and reagents used in sample processing, by baking them under a stream of oxygen, is described. The results show significant improvements in our procedural blanks. In addition, a new graphitization system dedicated to small samples, using H 2 /Fe reduction of CO 2 , has been commissioned. The technical details of this system, the graphite yield and the level of fractionation of the targets are discussed.
275 citations
TL;DR: In this article, the (super 14) C dating of soil organic matter (SOM), humin fraction, and charcoal in several soil profiles under natural vegetation from different Brazil locations (north, central, and southeast regions).
Abstract: During the last decade radiocarbon dating has been used extensively in distinct regions of Brazil to provide information about soil chronology in paleoenvironmental studies. This paper presents (super 14) C dating of soil organic matter (SOM), humin fraction, and charcoal in several soil profiles under natural vegetation from different Brazil locations (north, central, and southeast regions). The main objective is to compare the obtained (super 14) C dating of total SOM with humin, the oldest fraction of SOM. In order to validate the humin ages these data are compared with the age of charcoal collected at similar depths. The (super 14) C ages obtained on charcoal were, in most of the cases, in agreement with the humin fraction considering the experimental errors, or 20% older in average. The dates obtained from total SOM showed significantly younger ages than the humin fraction indicating contamination by younger carbon. These results show the humin fraction is considered a reliable material for (super 14) C dating in soils. However, the humin fraction ages could be assumed as the minimum ages for carbon in soils.
225 citations
TL;DR: In this paper, the authors used radiocarbon age determinations of wood charcoal to date past forest fire events, even though such ages should be greater than the fire event due to the age of the wood at the time of burning.
Abstract: Radiocarbon age determinations of wood charcoal are commonly used to date past forest fire events, even though such ages should be greater than the fire event due to the age of the wood at the time of burning. The difference in the (super 14) C-derived age of charcoal and the time-since-fire (the "inbuilt age") may be considerable in some vegetation types and thus must be estimated before interpreting fire dates. Two methods were used to estimate the potential range of inbuilt age of soil charcoal dated to determine ages of forest fires on the west coast of Vancouver Island (Canada). First, 26 (super 14) C ages on charcoal in surficial soil were compared directly with ages of forest fire determined by tree-ring counts, suggesting inbuilt ages of 0-670 years. Second, a simulation model that uses estimated fuel loads, fuel consumption, charcoal production, and the ages of charred wood (time since wood formation), suggests that the combination of slow growth rates and slow decay rates of certain species can account for inbuilt ages of more than 400 years in this forest type. This level of inbuilt age is large enough such that the actual age of a fire may not occur within the 2sigma confidence interval of a calibrated charcoal (super 14) C age determination, and thus significantly affect the interpretation of fire dates. A method is presented to combine the error of a calibrated (super 14) C age determination with the error due to inbuilt age such that the larger adjusted error encompasses the actual age of the fire.
221 citations
TL;DR: The results of stable isotope analyses of the human bone collagen are consistent with a heavy dependence on aquatic protein while radiocarbon dating of the samples reveals an offset of 300-500 years between the two sample types, indicating a freshwater reservoir effect in the human bones samples.
Abstract: Human bones from single inhumation burials and artifacts made from terrestrial mammal (ungulate) bone found in direct association with the skeletons were obtained from the Stone Age site of Schela Cladovei situated just below the Iron Gates Gorge of the River Danube. The results of stable isotope analyses of the human bone collagen are consistent with a heavy dependence on aquatic protein while radiocarbon dating of the samples reveals an offset of 300-500 years between the two sample types, indicating a freshwater reservoir effect in the human bone samples. Since protein consumption is by far the major source of nitrogen in the human diet we have assumed a linear relationship between delta (super 15) N and the level of aquatic protein in each individual's diet and derived a calibration for (super 14) C age offset versus delta (super 15) N which has been applied to a series of results from the site at Lepenski Vir within the gorge. The corrected (super 14) C ages (7310-6720 BP) are now consistent with the previous (super 14) C age measurements made on charcoal from related contexts (7360-6560 BP). In addition, the data indicate a change from a primarily aquatic to a mixed terrestrial/aquatic diet around 7100 BP and this may be argued as supporting a shift from Mesolithic to Neolithic. This study also has wider implications for the accurate dating of human bone samples when the possibility exists of an aquatic component in the dietary protein and strongly implies that delta (super 15) N analysis should be undertaken routinely when dating human bones.
186 citations
TL;DR: In this article, a method of dating unburnt bone by accelerator mass spectrometry (AMS) using structural carbonate in the mineral fraction of the bone has been proposed.
Abstract: When dating unburnt bone, bone collagen, the organic fraction of the bone, is used. Collagen does not survive the heat of the cremation pyre, so dating of cremated bone has been considered impossible. Structural carbonate in the mineral fraction of the bone, however, survives the cremation process. We developed a method of dating cremated bone by accelerator mass spectrometry (AMS), using this carbonate fraction. Here we present results for a variety of prehistoric sites and ages, showing a remarkable success rate for this method.
169 citations
TL;DR: In this paper, the authors reported an apparent marine radiocarbon ages for the northern Indian Ocean region for the pre-nuclear period, based on measurements made in seven mollusk shells collected between 1930 and 1954.
Abstract: Apparent marine radiocarbon ages are reported for the northern Indian Ocean region for the pre-nuclear period, based on measurements made in seven mollusk shells collected between 1930 and 1954. The conventional (super 14) C ages of these shells range from 693+ or -44 to 434+ or -51 BP in the Arabian Sea and 511+ or -34 to 408+ or -51 BP in the Bay of Bengal. These ages correspond to mean Delta R correction values of 163+ or -30 yr for the northern Arabian Sea, 11+ or -35 yr for the eastern Bay of Bengal (Andaman Sea) and 32+ or -20 yr for the southern Bay of Bengal. Contrasting reservoir ages for these two basins are most likely due to differences in their thermocline ventilation rates.
140 citations
TL;DR: In this paper, the authors used radiocarbon dating of bulk sediment for last resort when reliable wood, charcoal, or plant macrofossils are not available for analysis, and found that the presence of carbon bound by clay minerals can significantly reduce the accuracy of a sediment age determination, with the oldest 14 C ages seen in samples with the highest clay content.
Abstract: Radiocarbon dating of bulk sediment has long been used as a method of last resort when reliable wood, charcoal, or plant macrofossils are not available for analysis. Accurate dating of sediment is complicated by the presence of multiple organic carbon fractions, each with a potentially different 14 C activity. Additionally, the presence of carbon bound by clay minerals can significantly reduce the accuracy of a sediment age determination, with the oldest 14 C ages seen in samples with the highest clay content (Scharpenseel and Becker-Heidmann 1992).
113 citations
TL;DR: In this article, the gas chromatographic column, part of the Elemental Analyzer system, was modified such that the trapped CO 2 no longer passed the GC column, which reduced the memory effect significantly, as shown by lower radiocarbon concentration values for anthracite backgrounds, and a smaller spread in these values.
Abstract: In Groningen, all organic samples for accelerator mass spectrometry (AMS) are combusted in an automatic Elemental Analyzer, coupled to an Isotope Ratio Mass Spectrometer and Cryogenic Trapping System. The Gas Chromatographic (GC) column, part of the Elemental Analyzer system, appeared to be the main cause for memory effects. Therefore we modified the Elemental Analyzer, such that the trapped CO 2 no longer passed the GC column. Our system modification reduced the memory effect significantly, as shown by lower radiocarbon concentration values for anthracite backgrounds, and a much smaller spread in these values. Our modified system can perform up to 40 combustions unattended in about 6 hr.
TL;DR: In this paper, a general-purpose curve derived from annually averaged atmospheric (super 14) CO (sub 2) values in the northernmost northern hemisphere (NNH, 30 degrees -90 degrees N).
Abstract: Peat deposits in Greenland and Denmark were investigated to show that high-resolution dating of these archives of atmospheric deposition can be provided for the last 50 years by radiocarbon dating using the atmospheric bomb pulse. (super 14) C was determined in macrofossils from sequential one cm slices using accelerator mass spectrometry (AMS). Values were calibrated with a general-purpose curve derived from annually averaged atmospheric (super 14) CO (sub 2) values in the northernmost northern hemisphere (NNH, 30 degrees -90 degrees N). We present a through review of (super 14) C bomb-pulse data from the NNH including our own measurements made in tree rings and seeds from Arizona as well as other previously published data. We show that our general-purpose calibration curve is valid for the whole NNH producing accurate dates within 1-2 years. In consequence, (super 14) C AMS can precisely date individual points in recent peat deposits within the range of the bomb-pulse (from the mid-1950s on). Comparing the (super 14) C AMS results with the customary dating method for recent peat profiles by (super 210) Pb, we show that the use of (super 137) Cs to validate and correct (super 210) Pb dates proves to be more problematic than previously supposed. As a unique example of our technique, we show how this chronometer can be applied to identify temporal changes in Hg concentrations from Danish and Greenland peat cores.
TL;DR: The radiocarbon reservoir age correction values (R) for the Russian Far East are estimated as 370 ± 26 yr for the northwestern Sea of Japan, and 711 ± 46 year for the southern Kurile Islands as mentioned in this paper.
Abstract: The radiocarbon reservoir age correction values (R) for the Russian Far East are estimated as 370 ± 26 yr for the northwestern Sea of Japan, and 711 ± 46 yr for the southern Kurile Islands.
TL;DR: Despite an incomplete understanding of the process of incorporation of 14C into human bones, the present dating technique is still more precise than most estimates by geriatric experts, for conventional 14C dating follows that 14C dates of bone collagen represent the years of the termination of puberty rather than those of death.
Abstract: Initially, radiocarbon dating by bomb 14 C was used to check vintages of wine and whisky and to estimate the turnover times of carbon in various biological tissues. However, this technique has never been widely used for routine dating, although it has a wide field of application in geriatric medicine and forensic investigations. Fifteen years' experience in this field has shown the potential and limits of this technique. Taking into account the decisive biological factors, such as growth and aging, a complicated picture is obtained. Recent human bones cannot be dated with a constant precision. Despite an incomplete understanding of the process of incorporation of 14 C into human bones, the present dating technique is still more precise than most estimates by geriatric experts, for conventional 14 C dating follows that 14 C dates of bone collagen represent the years of the termination of puberty rather than those of death. Another application is the identification of furs of illegally hunted animals on the Red List of threatened species of the World Conservation Union (IUCN). For court cases, the year the animals were killed must be precisely determined. Due to the long and variable turnover time of more than one year of leather hair is the best dating material for animals.
TL;DR: A line for graphite targets for accelerator mass spectrometry (AMS) radiocarbon dating has been built in the Gliwice (super 14) C Laboratory as discussed by the authors.
Abstract: A line for preparation of graphite targets for accelerator mass spectrometry (AMS) radiocarbon dating has been built in the Gliwice (super 14) C Laboratory. The AMS (super 14) C measurements of our targets are performed in the Leibniz-Labor fur Altersbestimmung, Kiel, Germany. The quality of our line has been tested in two series of AMS (super 14) C measurements of background and Ox-II standard samples and by measurements of the amount of CO (sub 2) released during combustion of sample-free quartz tubes. Most background contamination in the first series was introduced during combustion, which has been greatly reduced by baking quartz tubes vacuum-sealed with CuO and Ag. The residual contamination (ca. 1.5 mu g C) seems to come mostly from the quartz tubes themselves. At present, most of the contamination of the background is introduced during graphitization. The reproducibility of background preparations is satisfactory, especially for samples larger than 1.5 mg, when it is better than + or -0.09 pMC. Despite still significant contamination with low- (super 14) C carbon during the graphitization process (corresponding to 1.2+ or -0.2% of (super 14) C-free carbon), the good reproducibility of the results allows us to use our line in routine (super 14) C dating.
TL;DR: In this article, the authors used radiocarbon dating to date cave paintings from southern France and northern Spain using pigment samples collected from several paintings, and in some instances the sample size allowed for multiple independent measurements on the same figure, so that the coherence of the calculated dates could be tested.
Abstract: Advances in radiocarbon dating by accelerator mass spectrometry (AMS) have made it possible to date prehistoric cave paintings by sampling the pigment itself instead of relying on dates derived from miscellaneous prehistoric remains recovered in the vicinity of the paintings. The work at the Laboratoire des Sciences du Climat et de l'Environnement (LSCE) concentrated on prehistoric charcoal cave paintings from southern France and northern Spain. In most caves, pigment samples were collected from several paintings, and in some instances the sample size allowed for multiple independent measurements on the same figure, so that the coherence of the calculated dates could be tested. Before being dated, each specimen was subjected to a thermal treatment preceded by an acid and basic treatment of intensity commensurate with the sample size. Nine bison drawings from three caves in the Cantabrian region of Spain-two from Covaciella, three from Altamira, and four from El Castillo-were sampled and dated. The 27 dates fell between 13,000 and 14,500 BP, allowing us to attribute the drawings to the Magdalenian period. The 24 dates for 13 drawings in the Cosquer cave indicated two distinct periods of painting activity-one around 28,000 BP and the other around 19,000 BP. The Chauvet cave paintings turned out to be the oldest recorded to date, as five dates fell between 32,000 and 31,000 BP. After discussing the sample preparation protocol in more detail, we will discuss the ages obtained and compare them with other chronological data.
TL;DR: In this article, high-precision radiocarbon (∆14C) measurements from annual bands of a Hawaiian surface coral decreased by 7 ǫ from AD 1893 to 1952.
Abstract: We show that high-precision radiocarbon (∆14C) measurements from annual bands of a Hawaiian surface coral decreased by 7‰ from AD 1893 to 1952 This decrease is coincident with the Suess Effect, which is mostly due to the dilution of natural levels of 14C by 14C-free fossil fuel CO2 This decrease is equal to that expected in surface waters of the subtropical gyres, and indicates that the surface waters of the North Pacific were in steady state with respect to long term mixing of CO2 during the past century Correlation between ∆ 14 C and North Pacific gyre sea surface temperatures indicates that vertical mix- ing local to Hawaii and the North Pacific gyre as a whole is the likely physical mechanism to result in variable ∆14C Prior to 1920, this correlation starts to break down; this may be related to the non-correlation between biennial ∆14C values in corals from the southwest Pacific and El Nino events observed during this period as well
TL;DR: In this paper, an elutrope sequence of five solvents that dissolve most customary conservation chemicals was selected and applied to reference wood samples with subsequent accelerator mass spectrometry (AMS) measurements.
Abstract: At the Leibniz radiocarbon lab, art and archaeological objects, often chemically conserved and thus potentially contaminated with respect to their 14 C content, are treated using a computer-controlled Soxhlet-type series extractor. This device uses a continuous procedure of boiling and condensation of different solvents for extraction and vacuum filtration under constant process conditions. An elutrope sequence of five solvents that dissolve most customary conservation chemicals was selected. A study of these different contaminants applied to reference wood samples with subsequent accelerator mass spectrometry (AMS) measurements demonstrates that their effective removal is dependent on the use of adequate solvents. For many contaminants (e.g. wood glue, methyl cellulose, Klucel®, sugar, and polyethylene glycol), routine acid-alkali-acid (AAA) treatment already yields satisfactory results, whereas for Caparol® and beeswax a relatively mild treatment with acetone, methanol, water, and subsequent standard AAA extraction is sufficient. Complete removal of rubber glue, epoxy resin, and paraffin can only be accomplished with our full set of solvents. The latter procedure is also appropriate when no or only incomplete information about the type of conservation material is available. For epoxy resin the contamination appears to be enriched in the alkali residue, and the easily soluble humic acid fraction, even after standard AAA treatment, gives satisfactory results. Two case studies on the application of the extraction procedures are presented.
TL;DR: This paper reported (super 14) C ages of charred adhesions on five potsherds and three charred wood fragments that were collected with the archeological artifacts (stone tools from the Chojakubo Culture) in the loam layers at the Odai Yamamoto I site (41 degrees 03'44"N, 140 degrees 033'20"E) in Aomori prefecture, at the northern end of the Japanese main island.
Abstract: Recently, primitive-type pottery was discovered in the Russian Far East, China, and Japan. Radiocarbon ages of far earlier than 10,000 BP have been obtained, relating directly or indirectly to the pottery. As an example of these very old (super 14) C ages for incipient pottery, we report here (super 14) C ages of charred adhesions on five potsherds and three charred wood fragments that were collected with the archeological artifacts (stone tools from the Chojakubo Culture) in the loam layers at the Odai Yamamoto I site (41 degrees 03'44"N, 140 degrees 033'20"E) in Aomori prefecture, at the northern end of the Japanese main island. The carbonaceous remains on the surface of the potsherds could be ancient food residues or soot from fuel for cooking. These small carbon samples were dated at the Tandetron accelerator mass spectrometry (AMS) (super 14) C dating facility at Nagoya University, as well as by Beta Analytic Co. Ltd. Except for two charred wood (super 14) C dates, 7070+ or -40 and 7710+ or -40 BP, all five charred-residue samples and one wood charcoal sample gave older (super 14) C ages of 12,680-13,780 BP, corresponding to the period of the Chojakubo Culture in Japan. This culture marks the beginning of the Jomon Culture, which is characterized by pottery usage and bow-and-arrow hunting.
TL;DR: In this paper, the authors present preliminary results for two common 14C cases: rejuvenation of a 0.4 pMC wood and of an Oxygen Isotope Stage 3 (OIS3) paleosol.
Abstract: It is well known that, during the widely used AAA pretreatment (de Vries and Barendsen 1954), alkali treatment is responsible for the incorporation of modern carbon due to the precipitation of atmospheric CO2 as carbonate. Until now, the last step of the experiment, consisting in acid treatment (most of the time with hydrochloric acid) was considered to be sufficient to eliminate all of lab contamination. But wood, peat and sediment present a complex molecular structure. During radiocarbon chemical treatments, functional groups still present in the molecules are likely to form ionic bonds with “modern” carbonates. These new chemical bonds resist a “classical” acid treatment and are responsible for rejuvenation. This short paper presents preliminary results for two common 14C cases: rejuvenation of a 0.4 pMC wood and of an Oxygen Isotope Stage 3 (OIS3) paleosol. For both cases, contamination due to incorporation of modern carbon during chemical treatment is evaluated and an alternative protocol is proposed.
TL;DR: In this paper, the authors assessed marine reservoir age R(t) for the costal area of the northwest Pacific using radiocarbon measurements of the annually banded coral core (Porites sp) collected on Ishigaki Island in southern Japan.
Abstract: We assessed marine reservoir age R(t) for the costal area of the northwest Pacific using radiocarbon measurements of the annually banded coral core (Porites sp) collected on Ishigaki Island in southern Japan. Reservoir age R(t) during the early 1900s at the Pacific coast of Ishigaki Island ranged between 290 and 455 14 C yr, with a weighted mean of 355 ± 25 14 C yr (n=5, ±1 σ). The regional-specific ΔR, defined as 14 C age difference of regional and world ocean surface layer, was 35 ± 25 14 C yr (n=5, ±1 σ) on average and increased between 1900 and 1950.
TL;DR: In this paper, a chemical protocol is reported to extract the organic matter of loess (organic carbon content lower than 0.1% by weight) for accelerator mass spectrometry (AMS) (super 14) C dating.
Abstract: Due to very high accumulation rates, loess sequences are best suited archives for the continental paleoclimate of glacial periods. Accurate chronologies cannot be easily established by radiocarbon-dating, because of the lack of organic macrorests, the only material for reliable (super 14) C dating so far. A chemical protocol is reported to extract the organic matter of loess (organic carbon content lower than 0.1% by weight) for accelerator mass spectrometry (AMS) (super 14) C dating. Sediments were taken from the loess sequence of Nussloch, for which a large dataset of luminescence ages (TL, IRSL/OSL) is available. The (super 14) C chronology of the organic matter extracted from loess is in good agreement with the corresponding luminescence ages. It allows high resolution correlations with climatic proxy signals (magnetic susceptibility, malacological assemblages, delta (super 13) C on organic matter, etc.) derived from the loess sequence and global environmental proxy records.
TL;DR: A semi-automated system to transform carbonate samples to CO2, as a means to increase sample-processing capacity, and measurements of 14C concentrations were made on samples of IAEA C-1 Carrara marble to test the reliability of the system.
Abstract: We constructed a semi-automated system to transform carbonate samples to CO 2 , as a means to increase sample-processing capacity. The physico-chemical process includes hydrolysis of carbonate, quantification of the mass of carbon and CO 2 collection in a glass ampoule. The system is computer-controlled and monitored, and all the data are stored. A single run of five consecutive samples requires about 3.5 hours. Measurements of 14 C concentrations were made on samples of IAEA C-1 Carrara marble to test the reliability of this semi-automated system. These measurements have allowed the determination of the total system background and the memory effect of our system.
TL;DR: In this article, a radiocarbon-based chronology of the early Iron Age at Tel Dor is presented, where the authors explore the possible implications of a sequence of 22 radiometric dates obtained from a detailed Iron I-IIa stratigraphic/ceramic sequence.
Abstract: The absolute date of the Iron Age I and IIa periods in Israel, and by inference in the Southern Levant at large, are to date among the hottest debated issues in Syro-Palestinian archaeology. As there are no pegs of absolute chronology throughout this range, conventional chronology had been established on proposed correlations of the material record with events and social phenomena as portrayed in historical and literary sources, chiefly the Hebrew Bible. With the growing impact of so-called revisionist notions in Biblical studies, which to various extents question the historicity of the Bible, it is imperative to try to establish a chronological framework for the Iron I-IIa range that is independent of historical and so forth considerations, inter alia in order to be able to offer an independent archaeological perspective of the biblical debate. The most obvious solution is to attempt a radiocarbon-based chronology. This paper explores the possible implications of a sequence of 22 radiometric dates obtained from a detailed Iron I-IIa stratigraphic/ceramic sequence at Tel Dor, on Israel's Mediterranean coast. To date, this is the largest such sequence from any single early Iron Age site in Israel. Having been part of the Phoenician commercial sphere in the early Iron Age, Dor offers a variegated sequence of ceramics that have a significant spatial distribution beyond Phoenicia, and thus transcend regional differences and enable correlation with the surrounding regions. By and large, the absolute dates of these ceramics by the Dor radiometric chronology are up to a century lower than those established by conventional Palestinian ceramic chronology. The ramifications of the lower Dor dates for some Phoenician, Israelite, and Cypriot early Iron Age archaeological issues are explored.
TL;DR: In this paper, two new radiocarbon determinations of material associated with Lapita pottery found at Mulifanua are presented, and the accuracy of this data is evaluated according to the results of recent re-assessment of pottery from the site, and current theories regarding the age of Lapita settlement in the eastern Pacific.
Abstract: The Mulifanua ferry berth has the distinction of being the only site in Samoa with dentate-stamped Lapita wares, and is the most easterly Lapita site in the Pacific. Two new radiocarbon determinations of material associated with Lapita pottery found at Mulifanua are presented. The accuracy of this data is evaluated according to the results of recent re-assessment of pottery from the site, and current theories regarding the age of Lapita settlement in the eastern Pacific. The resulting calibrated radiocarbon ages put occupation of the Mulifanua Lapita site at around 2880-2750 cal BP (930-800 BC). This conclusion is in agreement with the pottery chronology and supports recent hypotheses of rapid Lapita settlement in the Fiji/Tonga region around 2850-2700 cal BP (900-750 BC).
TL;DR: In this article, the ages of terrestrial and marine mammals belonging to the same archaeological deposits were compared to evaluate the marine radiocarbon reservoir ages around the Hokkaido island, Japan.
Abstract: Faunal remains originating from terrestrial and marine mammals, and belonging to the same archaeological deposits were compared to evaluate the marine radiocarbon reservoir ages around the Hokkaido island, Japan. From five shell middens of different ages from the Jomon period (4900 BP) to the Ainu cultural period (800 BP), 107 animal bone samples were selected for radiocarbon measurements. The apparent age differences between Japanese deer and northern fur seal showed the clear effect of deep-water upwelling in this region. Our data showed relatively stable age differences from 4500 BP to 800 BP, with an estimated Delta R values around 380 (super 14) C yr. Results are consistent with previous estimation based on simulation models and oceanographic properties.
TL;DR: In this paper, the authors presented a fully calibrated radiocarbon chronology of Proto-Neolithic and Neolithic cultures in the Middle East covering the time range from 12,500 to 5500 cal BC.
Abstract: We present for the first time a fully calibrated radiocarbon chronology of Proto-Neolithic and Neolithic cultures in the Middle East covering the time range from 12,500 to 5500 cal BC. A total of 1300 14 C dates were evaluated, leading to the selection of 731 reliable dates. These were calibrated in a special collective approach presented in a series of graphs. The 14 C dates are derived from 160 sites across the Middle East. The period with Proto-Neolithic cultures began around 12500 cal BC and lasted for more than 4000 years. The true Neolithic, with agriculture and livestock breeding, appeared just before 8000 cal BC, subsequently spreading across a wide area within just a few hundred years. Ceramics first occurred around 7000 cal BC. The Mesopotamian cultures that emerged around 6000 cal BC started the urban revolution.
TL;DR: The cave of Theopetra as discussed by the authors is a unique prehistoric site for Greece, as the Middle and Upper Paleolithic, Mesolithic, and Neolithic periods are present here, bridging the Pleistocene with the Holocene.
Abstract: The cave of Theopetra is located on the northeast side of a limestone rock formation, 3 km south of Kalambaka (21 degrees 40'46"E, 39 degrees 40'51"N), in Thessaly, central Greece. It is a unique prehistoric site for Greece, as the Middle and Upper Paleolithic, Mesolithic, and Neolithic periods are present here, bridging the Pleistocene with the Holocene. Several alternations of the climate during the Pleistocene are recognized in its stratigraphy. Among the most striking finds, two human skeletons, one from the Upper Paleolithic period after the Last Glacial Maximum and one from the Mesolithic period, should be emphasized, while in a deep Middle Paleolithic layer, the oldest human footprints, with remains of fire, were uncovered. During the 13 years of excavation, evidence of human activity suitable for radiocarbon dating was collected, such as charcoal samples from hearths and bones from the two human skeletons. The use of proportional counters for the measurement of (super 14) C in combination with the recent improvement of the calibration curve has enabled the production of high-precision reliable ages Sixty (super 14) C-dated samples, originating from 19 pits and from depths ranging from 0.10 m to 4.20 m, have already provided an absolute time framework for the use of the cave. The earliest limit of human presence probably exceeds 48,000 BP and the latest reaches World War II. Within these limits the (super 14) C dating of samples from consecutive layers, in combination with the archaeological data, permits the resolution of successive anthropogenic and environmental events.
TL;DR: In this paper, a dating program was designed to test the reproducibility of radiocarbon dates on different materials of Late-Glacial age (plant macrofossils, fossil beetle remains, and the "humic" and "humin" chemical fractions of limnic sediments) using a combination of radiometric (beta counting) and accelerator mass spectrometry (AMS) techniques.
Abstract: This paper outlines a dating program designed to test the reproducibility of radiocarbon dates on different materials of Late-Glacial age (plant macrofossils, fossil beetle remains, and the "humic" and "humin" chemical fractions of limnic sediments) using a combination of radiometric (beta counting) and accelerator mass spectrometry (AMS) techniques. The results have implications for the design of sampling strategies and for the development of improved dating protocols, both of which are important if a high-precision (super 14) C chronology for the Late-Glacial is to be achieved.
TL;DR: Ostrich eggshell from archaeological sites remains largely free of more recent carbon contamination and as such is suitable material for radiocarbon dating as discussed by the authors, however, the carbonate fraction of the shell does, however, display an initial deficit in 14C, which causes the ages to appear 180 ± 120 yr too old.
Abstract: Ostrich eggshell from archaeological sites remains largely free of more recent carbon contamination and as such is suitable material for radiocarbon dating. The carbonate fraction of the shell does, however, display an initial deficit in 14C, which causes the ages to appear 180 ± 120 yr too old.