The radiocarbon reservoir effect: new evidence from the cemeteries of the middle and lower Dnieper basin,Ukraine

This paper presents preliminary results of new radiocarbon dating of human, faunal and fish skeletal remains from a number of the cemeteries from the Middle and Lower Dnieper Basin, Ukraine. The results appear to demonstrate the presence of a radiocarbon reservoir effect during the Neolithic–Eneolithic periods, the first time that this has been identified in this region. The data indicate that the radiocarbon reservoir effect is currently only evident during these periods, and not in the earlier Epipalaeolithic–Mesolithic periods, prompting the suggestion that the radiocarbon reservoir effect is associated with elevated fish consumption from the Neolithic period onwards.     

Stable Isotopes,Chronology, and Bayesian Models for the Viking Archaeology of North-East Iceland

This paper reviews the results of a long-term research project that used stable isotope analyses (δ¹³C, δ¹⁵N, δ³⁴S) and Bayesian mixing models to better model the chronology for a presumed Viking Age cemetery at Hofstaðir, near Lake Mývatn in north-east Iceland. δ¹³C and radiocarbon dating indicated that many of the individuals consumed a large amount of marine protein, which results in a marine reservoir effect (MRE), making ages older than expected. In addition to the MRE, geological activity in the region has the potential to introduce massive quantities of radioactive ‘dead’ carbon into the freshwater system, resulting in a very large freshwater reservoir effect (FRE) that can offset radiocarbon ages on the order of a few thousand years. The radiocarbon dates of organisms that derive an unknown proportion of their carbon from both marine and freshwater reservoirs are extremely difficult to ‘correct’, or, more appropriately, model. The research not only highlights the complexities of dealing with multiple reservoirs, but also how important it is to develop models that are temporally and geographically relevant to the site under study. Finally, it shows how this data can be used to inform the development of chronological models for refining the dating for archaeological activity.     

RESEARCH NOTES AND APPLICATION REPORTS DATING THE AEGEAN LATE BRONZE AGE WITH RADIOCARBON*

The beginning of the Late Bronze Age in the Aegean has usually been thought to coincide with the start of the Eighteenth Dynasty in Egypt, and radiocarbon dates (which consistently suggest an earlier chronology) have been rejected by Aegean specialists because they do not agree with this view. Evidence from pottery is used to re-examine the links between the Aegean and Egypt, with the conclusion that the Aegean Late Bronze Age began during the Hyksos period.     

Understanding the variability in freshwater radiocarbon reservoir offsets: a cautionary tale

Freshwater resources in past diets can lead to inaccuracies when attempts are made to ascertain their radiocarbon ages or those of the consumers. Radiocarbon reservoir effects may lead to significant age offsets when the bones or other tissues of these consumers are radiocarbon dated. A number of recent studies have investigated freshwater reservoir offsets. However no study thus far has satisfactorily obtained a ubiquitous freshwater reservoir correction due to variability in the ecosystems analysed. This study tests the possibility of predicting freshwater reservoir effects from the carbonate alkalinity of the water with measurements on modern fish bone and water samples. A predictive capability would be especially valuable in the absence of well-preserved archaeological fish bone. We surveyed samples from lakes and rivers in varying geological settings in Britain and Ireland. Modern fish bone and water samples were analysed to investigate modern radiocarbon offsets from the atmosphere. Archaeological fish bone was also analysed to examine past reservoir offsets at selected sites. Stable carbon and nitrogen isotope values were measured to aid in interpretation of any variability in the offsets. Large freshwater reservoir offsets were measured in some modern and archaeological samples (maximum offset = 1638 ¹⁴C years). The freshwater reservoir offsets in the fish bone were highly correlated with alkalinity of water in modern lake sites analysed. However, a high amount of variation within and between fish species was also evident in the results, precluding the possibility of providing regional corrections for freshwater reservoir offsets from alkalinity although this still may provide a general guideline. The variability is thought to be due to differences in the diet of individual fish.     

RADIOCARBON DATING ARCHAEOLOGICAL SAMPLES IN THE EASTERN MEDITERRANEAN, 1730 TO 1480 BC: FURTHER EXPLORING THE ATMOSPHERIC RADIOCARBON CALIBRATION RECORD AND THE ARCHAEOLOGICAL IMPLICATIONS*

The East Mediterranean Radiocarbon (Inter‐)Comparison Project (EMRCP) has measured time series of radiocarbon ages for known age samples of German oak (GeO) and for samples from the near‐absolutely placed Gordion juniper dendrochronology from central Anatolia. In this paper, we review the data for the calendar years from 1730 to 1480 bc , relevant in particular to controversy and debate concerning the absolute date of the Minoan eruption of the Santorini (Thera) volcano. We consider the issue of the radiocarbon (¹⁴C) dating of the Santorini eruption, and the problem of how this relates to the archaeological record and historical chronology of Egypt in light of the ¹⁴C data. We find that these ¹⁴C data, and other recent radiocarbon work, provide good grounds to be confident in the possibility of a robust radiocarbon‐based chronology for the eastern Mediterranean. In contrast, as the radiocarbon case becomes stronger, questions must be asked about some archaeological dating: in particular, at the site of Tell el‐Dab‘a in the Nile Delta of Egypt.     

Implications of a freshwater radiocarbon reservoir correction for the timing of late Holocene settlement of the Elk Hills,Kern County,California

Uncertainties regarding the magnitude of freshwater radiocarbon reservoir effects can introduce random errors into dates on archaeological freshwater carbonates. As a result, many archaeologists avoid dating freshwater shells unless no other datable materials are available. The chronology of prehistoric occupation of the former Naval Petroleum Reserve No. 1 (NPR-1) at Elk Hills, Kern County, has been established with 50 radiocarbon dates on freshwater mussels (Gonidea and Anodonta sp.). Characterization of any freshwater radiocarbon reservoir effect is crucial for the accurate interpretation of inferred settlement and subsistence changes on the Elk Hills. Paired charcoal and freshwater mussels sampled from closely associated contexts were dated to identify a freshwater reservoir effect. Paired Anodonta and Gonidea sp. shells were dated to investigate interspecific differences in fractionation. Results indicate that a 340 ± 20 ¹⁴C yr correction should be applied to conventional ¹⁴C dates on freshwater carbonates in the Buena Vista Basin before calendar calibration. Evidence of interspecific differences is inconclusive. Dates recalibrated with the reservoir correction indicate that widespread occupation of the Elk Hills is correlated with increasing precipitation towards the end of the Medieval Climatic Anomaly and during the Little Ice Age, suggesting that slough resource exploitation may have been driven by regional population pressure rather than drought-related declines in aquatic productivity.     

Two radiocarbon dates for freshwater shells from hierakonpolis: Archaeological and geological interpretations

Shells of two species of freshwater bivalve (Unio willcocksi Bullen Newton and Etheria elliptica Lamarck) from the predynastic Gerzean (Nagada II) Decorated Tomb at Hierakonpolis, Egypt have given dates of 5000±90 bp for the tomb, and 12,900±120 bp for an episode of Nile terrace accumulation (correlated here with the Sahaba-Darau aggradation event). The archaeological and geological significance of these results is discussed, together with an outline of problems associated with radiocarbon dating of shell. Comparisons are made with the few other radiocarbon dates available for the Predynastic period in Egypt and possible reasons for the presence of shells in the tomb are considered.     

The Middle Holocene Shell Mound of El Gouna on the Red Sea (Egypt)

Abstract

In the El Gouna (Hurghada) area on the Red Sea of Egypt, a Middle Holocene shell mound from around 5800 B.P. (uncalibrated radiocarbon years before A.D. 1950) has been tested by a restricted excavation. Collection of shellfish on the Red Sea shore provided subsistence opportunities for Middle Holocene groups coeval with the Early Predynastic Tasian of the Nile Valley. The El Gouna site demonstrates for the first time that prehistoric shell mounds exist near the Egyptian Red Sea shore.     

Investigation of palaeodiet in the North Caucasus (South Russia) Bronze Age using stable isotope analysis and AMS dating of human and animal bones

This paper addresses the question of human palaeodietary adaptation in the Eneolithic and Early Bronze Age periods of the North Caucasus (South Russia) using stable isotope analysis. One of the key questions is the presence of fish in the diet. AMS radiocarbon dating of archaeological bone collagen has also been carried out to investigate potential radiocarbon reservoir effects in human skeletal material as a result of an aquatic diet. A fish component has previously been suggested in the diet of Iron Age and Bronze Age humans across Eurasia by isotopic research and radiocarbon dating of contemporaneous human and animal bones. In the North Caucasus however, isotopic data is scant. This study presents a new set of stable isotopic data from several Early Bronze Age sites, mainly belonging to the Maikop culture of the North Caucasus. The results show that the diversity in climate and environment across the northern Caucasus may be a causal factor for the patterns observed in the stable isotope values of terrestrial herbivores. This affects the isotopic values of the humans consuming them. The differences in δ¹⁵N and δ¹³C ranges of both humans and fauna were found to correlate strongly with geography and climate; the most enriched isotopic values are found in the dry steppe areas to the north. Overall, a relatively high enrichment in δ¹⁵N values of humans compared to local terrestrial herbivores and carnivores was observed. This indicates that aquatic resources were probably part of the Bronze Age diet in the region although the extent of this needs further investigation. The dramatic effect of environmental factors on isotopic values in the Early Bronze Age of the North Caucasus illustrates how confident conclusions cannot be drawn on the basis of a small number of samples from widely differing regions and time periods. Radiocarbon dating can provide a useful tool for identifying dietary derived reservoir ages in humans, potentially caused by a fish diet. With two possible exceptions, the nine human–animal bone pair dated as part of this study showed no consistent indication for a consistent reservoir effect.     

Radiocarbon dating of marine shell samples. The marine radiocarbon reservoir effect of coastal waters off Atlantic Iberia during Late Neolithic and Chalcolithic Periods

Radiocarbon dates on marine shells have not been used as extensively as charcoal or bone dates for the setting up of absolute chronologies because interpreting these dates is complicated by the marine radiocarbon reservoir effect. Nevertheless marine shellfish were used widely at least during the Holocene and their shells are abundant and usually well preserved in archaeological deposits located near shorelines. Consequently prior research concerning the oceanographic conditions and the marine radiocarbon reservoir effect of a particular coastal area is needed in order to set up reliable chronologies for that region. Values of regional marine radiocarbon reservoir effect – ΔR – of coastal waters off Atlantic Iberia, some of its variability along the Holocene and its correlation with the upwelling phenomenon were determined during previous research. More data related to the ΔR values for western Portuguese coastal waters during the Late Neolithic and the Chalcolithic, a time interval badly sampled in previous research, were recently obtained. These values can be compared with ΔR values already determined for the Gulf of Cadiz. Besides the importance of these values for a better knowledge of the palaeoceanography and palaeoclimatology of Atlantic Iberia, from now on archaeologists can set up reliable chronologies for Late Neolithic and Chalcolithic contexts using marine shell samples of that origin for radiocarbon dating.     

Cretaceous aggregate and reservoir effect in dating of binding materials

Lime mortars may contain carbon from different origins. If the mortars are made of totally burnt lime, radiocarbon dating yields the true age of building construction. The presence of carbonaceous aggregates gives the so-called dead carbon effect, which may generate older ages. Another source of carbon is charcoal present in mortars. An attempt has been made to apply the radiocarbon method to mortars of archaeologically estimated age from the Dead Sea region. Petrographical analyses of these samples show the carbonaceous character of the binder and large amounts of limestone aggregate. Determination of the mineral composition of the mortars and comparison with the geology of the surrounding, allows the provenance of the raw materials to be identified. They probably represent the Cretaceous rocks of the Judea Group. Separate radiocarbon dates were made on bulk mortar samples, binder, charcoal fragments and separated fractions from mortars. In the case of binder-aggregate mixture the reservoir effect correction has been applied.     

Archaeopedological analyses around a Neolithic hearth and the beginning of Sabaean irrigation in the oasis of Ma'rib (Ramlat as-Sab'atayn,Yemen)

Archaeopedological analyses in the oasis of Ma'rib (Yemen) yield new information of Neolithic land use, Bronze Age soil formation, and Sabaean irrigation. The AMS radiocarbon age of a Neolithic fireplace buried under Sabaean irrigation sediments in the Southern oasis indicates Pre-Sabaean human activities in Wadi Dhana about 5600 years ago. The associated Mid-Holocene palaeosol, developed in fluvial sediments of Wadi Dhana and also in the filling of the hearth, marks the Bronze Age-land surface before it was covered with irrigation sediments. Based on AMS radiocarbon data from charcoal in reservoir sediments of the “Great Dam” and an estimated time span of pedogenesis of the Mid-Holocene palaeosol in this region, we propose the beginning of the irrigation in Ma'rib in the period of 2500–1000 cal yr BC.     

Prehistoric demography of North America inferred from radiocarbon data

Large radiocarbon datasets are increasingly used as a paleodemographic proxy, although potential sources of bias in such records are poorly understood. In this paper, we use more than 25,000 radiocarbon dates extracted from the Canadian Archaeological Radiocarbon Database (CARD) to estimate long-term population trends in North America, while critically examining biases in such records. The frequency distribution of CARD dates shows a positive curvilinear pattern, such that older dates exist in lower numbers than more recent dates, which in part reflects the removal of cultural carbon from the archaeological record through processes such as erosion and dissolution. The average annual growth rate of radiocarbon dates in CARD was calculated and used to derive estimates of the population of North America from the Paleo-Indian to the Contact Periods. While taphonomic bias has likely affected the CARD data, other factors, such as the overrepresentation of Paleo-Indian and Archaic radiocarbon dates, may have offset any bias due to taphonomy. A quantitative reconstruction of Native American population shows that population increased rapidly around 2000 cal yr BP, reaching a maximum of 2,500,000 people by ～AD 1150. From this time until European contact, the population declined, possibly due to the effects of increased sedentism and population density.     

Radiocarbon Chronometry of Site QJ-280, Quebrada Jaguay,a Terminal Pleistocene to Early Holocene Fishing Site in Southern Peru

Excavations in 1970, 1996, and 1999 at Site QJ-280, Quebrada Jaguay, in southern Peru, yielded enough dateable terrestrial plant material to establish an extensive radiocarbon chronology for the site. QJ-280 is one of oldest well-dated fishing sites in the Americas: it was occupied from the terminal Pleistocene to the mid-Holocene (about 13,000–8,300 calibrated years BP) based on 42 terrestrial radiocarbon dates, encompassing the Jaguay and Machas Phases of the local archaeological sequence. In addition to the terrestrial dates, radiocarbon measurements on valves of two marine surf clam (Mesodesma donacium) individuals from a single, well-dated mid-Holocene Manos Phase archaeological context have provided insight into marine upwelling conditions during the occupation of Quebrada Jaguay. The marine reservoir age varied between 130 and 730 ¹⁴C years during the brief lives of the two clams (up to 5 years each), and varied by up to 530 ¹⁴C years within an individual valve, suggesting strong and variable deep marine upwelling; conditions broadly similar to those that exist in coastal Peru today. These rapid variations in marine radiocarbon age suggest that marine radiocarbon dates from environments with variable upwelling could be skewed by up to hundreds of years.     

Reconstructing the holocene depositional environments in the western part of Ancient Karnak temples complex (Egypt): a geoarchaeological approach

This paper presents the results of a geoarchaeological study undertaken in Upper Egypt, in the western part of the Karnak Temples complex. The geoarchaeological approach helps to better understand the fluvial dynamics of the Nile in the proximity of the Pharaonic site during the late Holocene. Until recently, most researchers assumed that Karnak was built on a fluvial island and that a large basin connected to the Nile was built in front of the first pylon during the dynastic period. However, recent excavations conducted by the archaeologists of the Supreme Council of Egyptian Antiquities revealed a jetty or quay with probable direct access to the Nile. Therefore in order to reveal in more detail the landscape and waterscape changes in the most western part of Ancient Karnak, a palaeoenvironmental study was conducted. We studied several stratigraphic profiles, manual boreholes (maximum depth of 5.50 m) and percussion drillings (maximum depth of 25 m). Sedimentological and magnetic susceptibility analyses helped to characterize Nile River deposits and to identify the presence of aeolian deposits (associated with wadi fan deposits) in the lower part of the drillings. Fluvial dynamics characterized by flood events, sandy accretions and thick Nile silts/clay deposits are presented and discussed here for later palaeoenvironmental reconstruction. Accurate leveling of the different profiles and boreholes, together with a topographic survey, allow us to recover long sedimentological sequences and to correlate the different sedimentary units. Finally, in order to obtain a chronostratigraphic sequence, radiocarbon dates were obtained from wood, charcoal and ash samples (analyses undertaken at the laboratory of radiocarbon dating of Ifao, Cairo, Egypt). The presence of the Nile River in front of the first pylon in Karnak is attested from the end of the Second Intermediate Period (SIP, ca 1600 BC) until the end of Roman Times (ca. 350 AD), which both correspond to two main phases of Nile River floods.     

Stable isotope data from the early Christian catacombs of ancient Rome: new insights into the dietary habits of Rome's early Christians

This study reports on the first attempt that determines the diet of a small but conceivably representative section of Rome's early Christian community by means of δ¹³C and δ¹⁵N measurements on collagen extracted from twenty-two samples of human bone. Samples derive from the Liberian Region in the catacombs of St. Callixtus on the Appian Way—an area that has been radiocarbon dated to the period from the mid-3rd through early 5th century AD. Comparing our results to those produced for several other sites, we argue that this population's typical diet included freshwater fish. We also briefly discuss breastfeeding and the freshwater reservoir effect, to then explore the dietary, art historical, and possible sociological ramifications of our results.     

The use of summed radiocarbon probability distributions in archaeology: a review of methods

Using a database of Australian archaeological radiocarbon dates (n = 2996), this paper explores three key methodological issues associated with the use of summed probability plots of radiocarbon data: 1) the minimum sample size needed for a statistically reliable plot; 2) the effect of radiocarbon calibration on the structure of these plots; and 3) the application of a taphonomic correction to such time-series data. The results identify several protocols, recommended as best-practice when using summed probability plots: 1) a minimum sample size of 500 radiocarbon dates should be used, and the sample size and the mean of the standard deviations of the radiocarbon dates (ΔT) in the sample should both be reported; 2) a moving average trendline of 500-800 years should be used to offset the effects of the calibration process; and 3) Surovell et al. “Correcting temporal frequency distributions for taphonomic bias” [Journal of Archaeological Science 36 (2009) 1715-1724] is explored, with modifications and temporal limits (<25,000 cal years BP) proposed. Correction of time-series data using theoretical taphonomic correction curves is useful as a heuristic tool but can obscure real trends if applied routinely. Comparison between summed probability plots and other occupation data is presented and shows good correlation. However it is recommended that plots are supplemented by other archaeological indices and the cross-comparison of such multiple proxies will strengthen identification of occupation trends.     

Radiocarbon Dating and the Historical Archaeology of Korea: An Alternative Interpretation of Hongryeonbong Fortress II in the Three Kingdoms Period,Central Korea

Relying heavily upon historical records to build archaeological chronologies, many Korean historical archaeologists question the utility of radiocarbon dating. To challenge this tendency, we test a model based on historical records by analyzing radiocarbon dates. We dated two bulk samples from Hongryeonbong Fortress II, Seoul, South Korea, which is known historically to have been occupied between a.d. 500 and 551. By dividing bulk samples into smaller aliquots, we dated 40 subsamples and statistically estimated consensus dates. The consensus dates do not support expectations of the historical model, as they do not lie within the temporal range provided by historical records. We propose an alternative model that explains both the radiocarbon dates and the historical records. It is suggested that radiocarbon dating can be successfully applied to the reconstruction of historical periods and is a way of mitigating possible biases of models based solely on historical records.     

Ancient Egyptian Pottery from the Subsurface Floodplain of the Saqqara–Memphis Area: Its Mineralogical and Geochemical Implications*

Potsherds recovered from the Saqqara–Memphis floodplain in Egypt, dated according to their typology and radiocarbon dating of the included sediments, are analysed geochemically and mineralogically to identify source materials and fabrication characteristics. Pottery layers were identified and potsherds were recovered from several settlement levels. Sherd typology was used to identify sherds from four periods (the Old and New Kingdoms, and from the Late Period to the Ptolemaic). The Pharaonic pieces were found at depths of between 8 and 12 m and the later material was between 6 and 3 m. Chemical analyses of the potsherds revealed three main source materials: local Nile silt, marl clay and mixed Nile silt–marl. Two marl clay types were recognized: marl clay from Upper Cretaceous marine sediment and another one from Late Pliocene deltaic sediments. The mineralogical composition of the pottery samples shows that the estimated firing temperature was about 850–900°C. No consistent differences in sherd mineralogy and geochemistry were found according to pottery types, so that the ancient Egyptian potters used essentially the same materials throughout the Pharaonic period. However, this initial study has revealed the existence of extensive pottery‐rich occupation sites buried within the Nile floodplain deposits between Memphis and Saqqara.     

Radiocarbon Marine Reservoir Effect in Human Remains from the Kitakogane Site,Hokkaido, Japan

Accelerator mass spectrometry (AMS) was used to measure radiocarbon (¹⁴C) in bones excavated from the Late Jomon shell midden at the Kitakogane site, Hokkaido, Japan. Comparison between ¹⁴C ages of terrestrial and marine mammals from the same site showed systematic age differences which could be attributed to the ¹⁴C marine reservoir effect in the western North Pacific Ocean. Furthermore, this effect was clearly observed in human remains from this site, indicating a heavy dependence on seafood. Dietary habit was estimated from δ¹³C and δ¹⁵N measured in the same human remains. Apparent ¹⁴C ages indicated 79% of protein originated from marine sources.