Histories of deposition: creating chronologies for the Late Bronze Age–Early Iron Age transition in Southern Britain

The Late Bronze Age–Early Iron Age midden sites of Southern Britain are amongst the richest archaeological sites in the country. The organic accumulations contain substantial quantities of animal bone, decorated ceramics, metalwork and other objects; the often deep stratigraphy allows for changes in material culture and depositional practices, food production and consumption, and shifts in social identities, to be traced through time. The well-stratified assemblages also provide useful materials for dating the deposits. This has been problematic, however, as the majority of samples produce unhelpfully broad calibrated radiocarbon dates, due to the effects of the earlier Iron Age plateau in the calibration curve, which spans c. 800–400 BC. Interpretation has relied on current understandings of the associated pottery and metalwork, which placed most midden sites somewhere between the tenth and the seventh/mid-sixth centuries cal BC (c. 1000–600/550 cal BC), but the end-date of these traditions is particularly uncertain. This article addresses this issue by presenting the results of a new dating programme for East Chisenbury in Wiltshire, southern England. Twenty-eight radiocarbon determinations were obtained and combined with the site stratigraphy in a Bayesian chronological model. The results have transformed the chronology of the site, with the end of the occupation sequence being pulled forward some one-hundred years, to the mid-to-late fifth century cal BC. These new chronologies have significant implications for our understanding of the Late Bronze Age–Early Iron Age transition and require a revision of the currently accepted chronology of post-Deverel Rimbury decorated wares in south-central England.     

A REASSESSMENT OF THE CHRONOLOGY OF MOUND A AT TOQUA

Abstract

The Toqua site (40MR6) is one of the most thoroughly excavated Late Mississippian mound sites in East Tennessee. The site has been a focal point of research on late prehistory in southern Appalachia, but there are issues surrounding its chronological placement. The radiometric dates obtained for the site in the 1970s and the archaeomagnetic dates reported in 1999 have large standard deviations. These dates are too imprecise to be useful for a temporal placement of the site that is clear enough for current discussions of the development of Mississippian culture. A newly obtained Accelerator Mass Spectrometry (AMS) date from the large platform mound (Mound A) allows a reevaluation of the occupation sequence of the Toqua site. This date provides an anchor for a refined chronology for Mound A. In addition to the new AMS date, this refined chronology is based on complementary lines of evidence, including architectural evidence, mortuary practices, pottery traditions, and shell gorget styles.     

The earliest evidence of domesticated wheat in the Crimea at Chalcolithic Ardych-Burun

Abstract

This paper reports the discovery of the earliest evidence of domesticated wheat in the Crimean peninsula from the Ardych-Burun shell midden site, Ukraine. The Ardych-Burun site dates to middle of the 4th millennium cal b.c. For the first time, the chronology of a Ukrainian Chalcolithic period site has been established through direct radiocarbon dating of cereal grains retrieved from it. This discovery allows for a wider discussion of the chronology and geographical origins of domesticated plant species in Ukraine and the role the Caucasian corridor may have played in the spread of agriculture into eastern Europe. The presence of cereal crops in the southern Crimea enriches our understanding of the subsistence strategies of the coastal population, which was previously linked only with pastoralism, hunting, and the exploitation of marine resources.     

Timing the Neolithic transition: the application of fluoride dating at Tell Halula,Syria

The study of Near Eastern Neolithic villages provides a unique means of tracing subsistence strategy, population growth, health, and emerging social inequality associated with agricultural origins. However, disentangling these patterns requires a detailed comprehension of the chronological placement of individual households in the site. In this paper, we present a test to determine the reliability and applicability of the fluoride dating method (a relative dating method) on human dentition of 40 samples from 28 Pre-Pottery Neolithic B (or PPNB) burials from the site of Tell Halula, in Syria. This method, applied here for the first time on a Neolithic Near East case study, is an alternative when other dating methods, like radiocarbon dates, do not provide the required temporal resolution to address particular research problems. Nonetheless, the results obtained in the fluoride analysis show how both the age at death of individuals, and the integrity of the burial plug enormously affect the amount of fluoride absorbed by teeth, so that only a small subset of the full dataset was suitable for fluoride dating. Although the distribution of fluoride values of dentine from the small sample of burials from suitable contexts matches the expected chronology, and corroborates the hypothesis that the occupation at Halula extends from the Middle to the Late PPNB, our analysis illustrates the need for a better understanding of the different sources of error in fluoride dating to improve the method itself, and to obtain more reliable fluoride chronologies.     

Radiocarbon Dating of Architectural Mortar: A Case Study in the Maya Region,Quintana Roo,Mexico

Abstract

The use of radiocarbon dating to analyze mortar and charcoal inclusions within mortar or plaster is a useful way to date the construction of architecture, particularly when options for other chronometric methods are limited. In the Yalahau region of northern Quintana Roo, Mexico, members of the Yalahau Regional Human Ecology Project have faced challenges in dating buildings made of large blocks of stone in the Megalithic architectural style. The Megalithic style poses serious problems for any analysis, as excavating into structures with stones weighing several tons can be dangerous, expensive, and time consuming. Additionally, there are no associated sculptures, texts with dates, or other traditionally accessible chronological markers. These factors have resulted in a reliance on a ceramic chronology despite the uncertainty of the dating of many ceramic types in this region, as well as the questionable contextual associations between recovered ceramics and architectural construction phases. Megalithic-style structures at the ancient Maya site of El Naranjal have residual mortar with charcoal inclusions left behind during the mortar-making processes that can be extracted and dated with AMS ¹⁴C methods. Several samples of mortar and charcoal were obtained from structures 1 and 10 from exposed exterior walls and an interior vault. The resulting dates confirm the date for the construction based on ceramics excavated from the same site.     

Comparison of fluoride and direct AMS radiocarbon dating of black bear bone from Lawson Cave,Missouri

Abstract

After a 20-year hiatus (1955–1975) during which few archaeologists discussed fluoride dating, the method again received attention in the 1980s and 1990s when some argued for its validity. As a dating method, fluoride dating depends on the rate at which fluorine ions replace hydroxyl ions in osseous tissue. The rate of replacement is influenced by the properties of the skeletal part (SP), sediment chemistry (K), and sediment hydrology (H), and the replacement rate influences estimates of time. Calibrated AMS radiocarbon assays of 10 black bear (Ursus americanus) femora from a natural-trap cave in central Missouri are weakly correlated with fluorine concentrations, determined by neutron activation analysis in the 10 femora. Despite minimal variation in SP, K, and H, results indicate fluoride dating can be considered a valid dating method only in cases when the chronological validity of its results are confirmed with independent chronometric data. As similarities in fluorine amounts across specimens increase, provenience information and bone orientation data as well as fine resolution data on K and H become critical to the application of fluoride dating.     

Radiocarbon Dates on Textile and Bark Samples from the Central Grave of the Adena Mound (33RO1), Chillicothe,Ohio

The Adena Mound (33RO1) is the type site of the Adena culture, yet there have been no radiocarbon dates to place it reliably within a temporal framework. Fortunately, the artifact collection, curated by the Ohio Historical Society, includes objects that are highly suitable for radiocarbon dating, including fragments of textiles and tree bark associated with the central burial. We selected a textile fragment and two bark fragments for radiocarbon dating. The textile exhibits alternate pair twine with very fine yarns probably composed of cellulose bast fibers. The bark is from a black locust (Robinia pseudoacacia) tree. The results of the radiocarbon dating indicate that the Adena Mound was constructed between the end of the second century B.C. and the beginning of the first century A.D., placing it near the midpoint in the sequence of radiocarbon-dated Adena culture sites. This study demonstrates the value of museum collections for gleaning new data from curated materials.     

A radiocarbon chronology for Sāmoan prehistory

The corpus of radiocarbon dates for Sāmoan archaeology has grown exponentially since the pioneering work of Green and Davidson in the 1960s, enabling us to re-analyze the archipelago's cultural chronology. A reliable and valid radiocarbon chronology forms the basis for describing and explaining cultural variability and change in the central Pacific. Towards that end, in this paper we compile the available radiocarbon dates from published and unpublished (“grey literature”) sources. We critically evaluate 236 radiocarbon dates following a chronometric hygiene protocol to identify the most secure and reliable age estimates. We accept 147 dates (62.3%) as a means of addressing two significant issues for Sāmoan prehistory: (1) the chronology of settlement and human expansion across the archipelago pre-2000 cal BP, which relates to issues of Lapita colonization, and the effect of island geomorphology on settlement; and (2) analysis of the so-called “Dark Ages” (ca. 1500–1000 cal BP), a period relevant to issues of social complexity and East Polynesian settlement. Our research highlights the need for a rigorous sampling protocol for radiocarbon dating.     

The chronology of the Neolithic sequence at Dikili Tash,Macedonia, Greece: TL dating of domestic ovens*

The chronological sequence of a major reference site for Neolithic periods in southeastern Europe and the Aegean, Dikili Tash (Macedonia, Greece), has been reassessed by TL. Baked adobe material samples extracted from domestic ovens, directly associated with specific occupational levels, have been studied. The fine‐grain technique has been used for equivalent dose determination. K, U and Th contents and the equilibrium state of U‐series have been measured by low‐background gamma spectroscopy. Since the archaeological levels were already partly excavated, the environmental dose‐rate was evaluated by a reconstruction technique combining laboratory analysis and on‐site measurements. The TL results (weighted average of multiple age determination, oven 400, middle of the Dikili Tash I (DT‐I) phase, 5500 ± 320 bc ; oven 600, end of DT‐I, 4920 ± 310 bc ; house 3, DT‐II, 4260 ± 280 bc ; house 4, DT‐II, 4510 ± 410 bc ) are in general agreement with the timeframe deduced from previous radiocarbon dates. This convergence strengthens the settlement's chronology, established now by independent dating methods.     

Late Holocene Historical Ecology: The Timing of Vertebrate Extirpation on Crooked Island,Commonwealth of The Bahamas

We report eight new accelerator-mass spectrometer (AMS) radiocarbon (¹⁴C) dates performed directly on individual bones of extirpated species from Crooked Island, The Bahamas. Three dates from the hutia (Geocapromys ingrahami), recovered from a culturally derived bone assemblage in McKay's Bluff Cave (site CR-5), all broadly overlap from AD 1450 to 1620, which encompasses the time of first European contact with the Lucayan on Crooked Island (AD 1492). Marine fish and hutia dominate the bone assemblage at McKay's Bluff Cave, shedding light on vertebrate consumption by the Lucayans just before their demise. A fourth AMS ¹⁴C date on a hutia bone, from a non-cultural surface context in Crossbed Cave (site CR-25), is similar (AD 1465 to 1645) to those from McKay's Bluff Cave. From Pittstown Landing (site CR-14), an open coastal archaeological site, a femur of the Cuban crocodile (Crocodylus rhombifer) yielded an AMS ¹⁴C date of AD ～1050–1250, which is early in the Lucayan cultural sequence. From a humerus in a non-cultural surface context in 1702 Cave (site CR-26), we document survival of the Cuban crocodile on Crooked Island until AD ～1300–1400, which is several hundred years later than the well-documented extinction of Cuban crocodiles on Abaco in the northern Bahamas. We lack a clear explanation of why Cuban crocodiles likely survived longer on Crooked Island than on a larger Bahamian island such as Abaco. One AMS ¹⁴C date on Crooked Island's extinct, undescribed species of tortoise (Chelonoidis sp.) from 1702 Cave is BC 790 to 540 (2740 to 2490 cal BP), which is ～1500–1700 years prior to human arrival. A second AMS ¹⁴C date, on a fibula of this tortoise from McKay's Bluff Cave, is AD 1025 to 1165, thereby demonstrating survival of this extinct species into the period of human occupation.     

The integration of chronological and archaeological information to date building construction: an example from Shetland,Scotland, UK

This paper presents new chronological data applied to the problem of providing a date for the construction of a prehistoric building, with a case study from the Old Scatness Broch, Shetland. The innovative methodology employed utilises the combination of radiocarbon and optically stimulated luminescence (OSL) dates with the archaeological information, which includes the stratigraphic relationships of sampled deposits, context information, and evidence relating to the formation of the deposit. This paper discusses the scientific validity of the dates produced, and the advantages that the methodology employed at this site offers for archaeological interpretation. The combined dating evidence suggests that the broch at Old Scatness is earlier than the conventionally accepted dates for broch construction. More broadly it shows the value of integration of the specialists at the planning stages of the excavation. The application of a Bayesian statistical model to the sequences of dates allowed investigation of the robustness of the dates within the stratigraphic sequences, as well as increasing the resolution of the resulting chronology. In addition, the value of utilising multiple dating techniques on the same deposit was demonstrated, as this allowed different dated events to be directly compared as well as issues relating to the formation of the sampled deposit. This in turn impacted on the chronological significance of the resulting dating evidence, and therefore the confidence that could be placed in the results.     

Chronostratigraphy of an Eroding Complex Atlantic Round House,Baile Sear,Scotland

A high-resolution chronostratigraphy has been established for an eroding Atlantic round house at Sloc Sàbhaidh (North Uist, Scotland), combining detailed OSL profiling and dating of sediments encompassing the main bracketing events associated with the monument, radiocarbon AMS dates on bone recovered from excavated features and fills within it, and TL dates on pottery and burnt clay. Concordant OSL and radiocarbon evidence place construction of the wheelhouse in the first to second centuries AD, contemporary with dates from the primary occupation. Beneath the wheelhouse, clay deposits containing burnt material, attest to cultural activity in vicinity to the monument in the preceding second to first centuries BC. At a later date, the southern wall collapsed, was rebuilt, and the interior spaces to the monument re-structured. The chronology for the later horizons identified from the sediment luminescence dates extends to the second half of the first millennium AD, which goes beyond the range of the radiocarbon dates obtained. The data from ceramics encompass both periods. The juxtaposition of the dating evidence is discussed relative to short and longer chronologies for this Iron Age monument. Corollaries of this research are the implications that based on the long chronology, some of the ecofacts (bone) appear to be residual, and that the temporal duration of Hebridean Coarse Ware may extend into the second half of the first millennium AD.     

Stone Age midden deposition assessed by bivalve sclerochronology and radiocarbon wiggle-matching of Arctica islandica shell increments

Sclerochronology, the study of the skeletal diaries of mollusks and corals, is a high-resolution geochronological tool of versatile usage in archaeology and paleontology with increasingly growing opportunities. Much of the recent efforts have concentrated on building multi-centennial bivalve growth records using annually deposited increments in the Holocene shells, comparable to tree-ring chronologies. In the context of geoarchaeology, the hitherto unachieved potential includes the application of sclerochronology to reconstruct long-term settlement histories. Here we contribute to both of these critical issues by presenting the first multi-shell sclerochronology constrained by methods originally developed in tree-ring research, using anthropogenically deposited bivalve shells of Arctica islandica excavated from a Stone Age midden in North Norway. Our systematic chronological approach to shell growth histories lays the foundation for a multi-dimensional dating framework that interacts between the incremental, radioisotopic and stratigraphic evidence. We show how the crossdating within and between the single-shell records yields a 155-year multi-shell sclerochronology, supported by the ¹⁴C AMS dates, that demonstrates minimum midden accumulation of 82 years and a depositional rate of 0.3 cm/yr. Sclerochronology paves the way for radiocarbon wiggle-matching, which narrows the probabilistic 2-σ uncertainty range for the oldest and youngest ¹⁴C AMS dates to 3150–2980 and 3060–2890 BC, respectively. We attribute the spectral characteristics of the chronology primarily to the North Atlantic Oscillation, suggesting essentially similar influences of climate variability on the Stone Age culture and our own society.     

Chronological Reconstruction of Natfieh Tombs,Northern Jordan

Abstract

This research radiocarbon dates human teeth and bones sampled from seven tombs from the archaeological site of Natfieh, Northern Jordan. The small number of artifact fragments uncovered, looting and disruption of the tombs in antiquity and/or recent times, and the continuity between the Greek and Roman burial traditions and similarity in tomb architecture impede determining accurate dates and chronology of the tombs. This research aims to ascertain the archaeological dates and the chronological sequence of the tombs and the artifacts uncovered. Results show that the probable earliest use of these tombs was between 90 BC and AD 20, and their probable latest use was from AD 126–236. Most probably, at Natfieh new tombs spread northward and carving the tombs started in the lower rock layers and later in the upper layers.     

Bayesian modelling of an absolute chronology for Egypt's 18th Dynasty by astrophysical and radiocarbon methods

Only a few astrophysical points and synchronisms listed in texts provide anchor points for the absolute chronology of Ancient Egypt. At first we will show how we can re-calculate some of these anchor points by using Sothic dating based on the arcus visionis method, and modelling lunar dates using a Bayesian approach. Then, we will discuss two radiocarbon studies carried out on short-lived Egyptian materials held at the Louvre Museum that could be attributed to particular reigns or other precise periods. Using a Bayesian approach, these dates were combined with the known order of succession and the lengths of reigns. Sothic and lunar dates were integrated as priors in the model. This approach has led to a new proposal for the absolute chronology of Egypt's 18th Dynasty.     

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.     

Radiocarbon dating of prehistoric hearths in alpine northern Sweden: problems and possibilities

The chronology of prehistoric Sami settlement sites has previously been established by conventional radiocarbon dating of bulk charcoal samples associated with hearths from sunken hut floors (stállo-foundations). Here we present results of a comprehensive dating exercise of stállo-foundations in the alpine area of northern Scandinavia using Accelerator Mass Spectrometry (AMS) radiocarbon dating of charcoal. Over a 3 km² study area, AMS calibrated ages of hearth charcoal from 22 stállo-foundations across 12 sites securely date these features to between cal. AD 640 and AD 1180. Only small variations in age were found between charcoal samples from different areas of a given hearth. Statistical analysis of all the charcoal AMS radiocarbon dates obtained reveals that 12 stállo-foundations across nine sites are contemporaneous and date to the Viking Period (AD 800–AD 1050). The tightly constrained AMS-based chronology of stállo-foundations contrasts with the existing chronology based on conventional radiocarbon analysis, which places these features within a significantly greater time-frame of between AD 600 and AD 1900, with most dates ranging between AD 800 and AD 1350.This discrepancy is likely to result from the necessity of collecting composite hearth charcoal particles, which may originate from different phases of occupation, in order to achieve the required final carbon content for conventional radiocarbon analysis. We argue that the new AMS-based radiocarbon chronology of stállo-foundations presented here supersedes the existing chronology based on conventional (Gas Proportional counting) radiocarbon analysis and we advocate the use of AMS radiocarbon dating in future hearth investigations.     

OYSTER DEMOGRAPHICS AND THE CREATION OF COASTAL MONUMENTS AT ROBERTS ISLAND MOUND COMPLEX,FLORIDA

Abstract

Anthropogenic coastal landscapes often incorporate shell, a durable remnant of subsistence activity. Collection, consumption, and even feasting can thus contribute to histories of site formation and mound construction. This research assesses how oyster consumption related to the creation of Mound A, a shell mound at the Roberts Island Shell Mound Complex in Citrus County, Florida, is differentiated from the instances of oyster consumption that resulted in the midden constituting the rest of the island. I compare the size of shell remains from mound and off-mound midden contexts to assess variation in the sizes represented across the samples, stratigraphic variation within each context, and evidence for directional change indicative of over-exploitation. I identify a relationship of dependence between shell size and stratigraphic depth in off-mound samples that does not appear in mound samples, suggesting a relatively short period of time for the accumulation of mound deposit oyster shells. The findings of this study point to mound construction at Roberts Island Shell Mound Complex as a distinct and deliberate activity, with the construction event likely sharing importance with the community aggregation and consumption that facilitated it.     

Faunal remains from radiocarbon-dated soils within landslip debris from The Undercliff,Isle of Wight,Southern England

An examination of coastal sections of landslip material forming The Undercliff of the Isle of Wight has revealed the presence of buried soils, in places, within the debris. Critical sections at Binnel Point and St. Catherine's Point have been logged and the contained vertebrate and molluscan faunas analysed. The Mollusca from both sites are very similar and indicate a shaded environment, contrasting sharply with the immediate local environments today. The vertebrates, present only at Binnel Point, again suggest woodland. The presence of red squirrel (Sciurus vulgaris) and dormouse (Muscardinus avellanarius) is especially noteworthy constituting their earliest and only secure British fossil records respectively. Some marine shells (Patella, Gibbula) and remains of larger vertebrates (including red deer) possibly represent midden debris. Charcoal from the lower soil at Binnel Point yielded a radiocarbon date of 4480 ± 100 bp (BM-1737) indicating that at least some of the middens at Binnel date from the Neolithic, much earlier than previously demonstrated. The sections at St. Catherine's Point provided no evidence of human occupation but yielded two further radiocarbon dates of 4490 ± 40 bp (SRR-1813) and 3960 ± 50 bp (SRR-1947) from wood incorporated within the landslips. The significance of these dates in relation to the history of landslipping is discussed.