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.     

The 13th century polynesian colonization of Hawai’i Island

We assess 926 radiocarbon dates from Hawai’i Island, the largest assemblage of dates compiled from a single island in Oceania. Based on a classificatory approach that arranges the dates based on their reliability, accuracy, and precision, our results indicate that the most reliable estimate for the initial Polynesian colonization of Hawai’i Island is AD 1220–1261, ∼250 to 450 years later than the current consensus. This conclusion is strikingly convergent with recent estimates for the colonization of remote East Polynesia. Our analysis highlights the need for wood charcoal identification to insure selection of short-lived plants/plant parts for radiocarbon dating, and that a reliance on dating unidentified wood charcoal is a waste of resources that only serves to retard progress in refining the settlement chronology of Hawai’i Island and other locations.     

Evaluating the Reliability of Fluoride Dating at Two Prehistoric Mound Sites in Mississippi

Abstract

Ion-selective electrode fluoride dating is used to address chronological problems at two mound sites located in Mississippi. At the Mississippian period (A.D. 900–1520) Lyon's Bluff site, 220K520, the fluoride content of deer and human bone is compared with radiocarbon dates and stratigraphic levels to evaluate the reliability of the fluoride dating method for understanding relative burial chronology. At a second site, Pocahontas Mound A (22HI500), fluoride content of deer bone is used to corroborate radiocarbon dates and to establish the proper chronology of levels associated with two distinct occupations (Archaic and Coles Creek/Plaquemine) identified in a large midden area. Fluoride analysis also is used to date a second midden area at this site. For Lyon's Bluff; fluoride dates did not correspond with accelerator mass spectrometry (AMS)-dated burials and midden strata. In contrast, fluoride dating proved very useful in determining chronological placement of midden levels and dating other areas at Pocahontas Mound A. Sample age, site location, soil, and bone preservation are considered as possible causes for the negative results at Lyon's Bluff.     

Attempts at thermoluminescence dating of fired materials from the Przeworsk Culture settlements

The thermoluminescence (TL) dating method has a significant measurement error margin reaching almost 10%. Due to this fact it could be considered as little effective in case of such sites from the Roman period as burial grounds with many artefacts useful for archaeological dating. However, for many settlements from this period, where pottery is the only kind of artefacts, the TL method can give notable results. The main purpose of the study was to make an attempt at TL dating of pottery and clay daub samples from the Nieszawa Kolonia and Kręcieszki sites and to compare the obtained dates with the results of archaeological dating of selected features from the Przeworsk Culture settlements. In the Kręcieszki site the fragments of burnt clay daub were dated by the TL method for the first time in the Lublin laboratory. It turned out that clay daub is an equally good dating material as pottery. It can be found that the TL dating of pottery from Nieszawa Kolonia confirms two stages of settlement. The first settlement stage is related to the phases B2-B2/C1-C1a of the Roman period, i.e. from the beginning of the 2^nd to the beginning of the 3^rd century. The second group of TL dates corresponds to the phases C2D that is to the second stage of settlement, from the second half of the 3^rd century to the half of the 5^th century AD. The results of TL dating of pottery and clay daub in the Kręcieszki site are rather similar and correspond to the phase B1/B2 of the period of Roman influence, determined from pottery style, but can also indicate the phase B2/C1.     

Potential geoarchaeological sites for luminescence dating in the Ganga Bhagirathi-Hugli delta,west Bengal,India

Archaeological studies in the upper and lower part of the Ganga-Bhaghrathi-Hugli delta were taken up to understand the nature of site formation and human adaptation in a dynamic fluvial zone. This aspect has been neglected in Indian archaeology. However archaeological dating using typological information, has an error margin of a couple of centuries and hence, is of limited use. We suggest that high resolution chronology using Optically Stimulated Luminescence (OSL) and radiocarbon dating can be quite effective in the study of archaeology and human environment relationship in the Ganga-Brahmaputra Delta (GBD).     

Luminescence Dating of Monumental Stone Architecture at Chavín De Huántar,Perú

Optically stimulated luminescence (OSL) is applied to quartz extracted from mud mortar collected from Chavín de Huántar, an early Andean monumental center. The samples appear to have been only partially exposed to sunlight during construction, so a minimum age model is applied to equivalent dose distributions. Complications, including complex radioactivity, low sensitivity of the quartz, and limited sample, prevent high precision, but the 14 dates obtained cluster around 1000 BC largely in agreement with radiocarbon assays on charcoal also collected from the mortar. Results suggest a relatively rapid construction for the monument. This work develops OSL as a method for directly dating architectural mortar.     

Gazetteer of small‐scale monuments in prehistoric Hadramawt,Yemen: a radiocarbon chronology from the RASA‐AHSD Project research 1996–2008

This paper provides a new, interpretive gazetteer and chronology of Hadramawt’s highland monuments based on results from archaeological survey and test excavations by the RASA‐AHSD (Roots of Agriculture in southern Arabia‐Arabian Human Social Dynamics) Project. With the exception of a few incidental sightings and an unpublished pipeline survey, the prehistoric record of southern Yemen’s highland plateau has been largely unknown. There are few settlements, so that understanding human landscape history must begin with the numerous small‐scale stone monuments left by mobile people. With examples representing monuments from the fifth, fourth, third and first millennia BC, the corpus of small excavations and radiocarbon dates reported here provides the first guide to the monument types of South Arabian highlands. Monument building began under more moist conditions and appears to have commemorated animal sacrifices long before commemorating mortuary rites and interment. There appears to be a temporal break of 1000 years before the widespread and varied practices of Bronze Age tomb construction, which lasted through the third millennium BC. After another break in monument construction, tombs were reused in the first millennium BC, sometimes with successive ritual visits. The data presented offer new material for the interpretation of the lives and activities of prehistoric pastoralists throughout the Holocene.     

四川广汉三星堆遗址四号祭祀坑的碳十四年代研究

2020年,广汉三星堆遗址新发现祭祀坑的田野考古发掘工作正式启动,为解决祭祀坑的年代问题,四川省文物考古研究院委托国家文物局考古研究中心与北京大学考古文博学院考古年代学联合实验室对四号祭祀坑开展了碳十四年代研究,得到6个碳十四年代数据,经过贝叶斯统计树轮校正计算得到其埋藏年代有95.4%的概率落在距今3148—2966年的时间范围之内,属商代晚期。     

Thermoluminescence dating

Over the last few years the Nordic Laboratory for Thermoluminescence (TL) Dating has obtained TL dates for a considerable number of archaeological samples, ceramics, bricks, burnt clay and burnt stones from the Nordic countries. The majority of TL dates have been consistent and in agreement with other dating evidence. Discrepancies caused primarily by excessive short‐term fading of the latent TL signal were encountered in a few cases. A procedure for eliminating errors caused by short‐term fading is described. A brief discussion of the sources of error in TL dating is given. Finally, results obtained by TL are compared with those obtained by radiocarbon for a number of sites.     

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.     

Evidence for inter-island transport of heirlooms: luminescence dating and petrographic analysis of ceramic inhaling bowls from Carriacou,West Indies

Ceramic snuffing tubes and inhaling bowls used for ingesting hallucinogenic substances are known from several islands in the West Indies, but their chronological distribution is often vague. A partial inhaling bowl found at the site of Grand Bay on Carriacou in deposits dating between ca. A.D. 1000–1200, along with two other unprovenienced specimens from the local museum, were dated using luminescence (TL and OSL) to determine their antiquity. Surprisingly, the dates had a weighted average of 400 ± 189 B.C., making them several hundred years older than all ¹⁴C assays from the island; however, they do overlap in age with similar artifacts found on Puerto Rico and Vieques Island over 750 km away. Additional luminescence dating of two stylistically distinct Suazan ceramic sherds excavated from stratified deposits at Grand Bay fall within the expected ceramic and radiocarbon chronology. These data, coupled with petrographic analysis of the specimens, suggests that they were not made using local materials. Instead, they appear to have been transported to the island, possibly hundreds of years later, as heirlooms. This may be the first evidence for inter-island transport of drug paraphernalia in the Caribbean.     

Problems in the interpretation of radiocarbon dates: the Pastoral Neolithic of East Africa

For the Pastoral Neolithic of East Africa radiocarbon dates suggest two apparent anomalies in the archaeological record: pastoralism in the Central Rift at perhaps 7000 bp, and the very long duration of particular pottery traditions. This paper examines the dating evidence closely, in particular the assertion that apatite gives more reliable dates than collagen. Both the assertion and the anomalies appear to be false. It is shown that there is no firm evidence for pastoralism in East Africa before about 4000 bp. Similarly, the Narosura tradition is of shorter duration and more recent than previously supposed. The meagre dating evidence for the Namoratunga sites and its implications are also assessed. Examination of the dates for the Pastoral Iron Age shows that the Turkwel tradition is dated only by a single date and that the appearance of twisted cord rouletted pottery in the present millennium post-dates the end of stone tool manufacture by several centuries. The paper concludes with a plea for more critical assessment of radiocarbon dates and for greater rigour in their presentation.     

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.     

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.     

Agricultural slope management and soil erosion at La Laguna,Tlaxcala, Mexico

Several superimposed systems of agricultural terracing are preserved at the archaeological site of La Laguna in central Mexico. Excavations uncovered complex stratigraphic sequences of terrace fills and colluvial deposits. Their chronology was established by radiocarbon, optically stimulated luminescence (OSL), and the presence of diagnostic features and artifacts. The Formative occupations of the site (ca. 600–400 BC and 100 BC–AD 100) resulted in severe erosion and exposure of indurated subsoil horizons. In the Middle to Late Postclassic (AD 1150–1520) stone-walled terraces were built to recover the degraded slopes for cultivation. Renewed reclamation works have been undertaken since the Colonial period, eventually taking the form of sloping-field terraces with berms planted in maguey. The reconstructed sequence of local land use underscores the risks of dating agricultural features by association with sherd scatters, as well as the complexity of the relationships between demographic variables, agricultural intensity and terracing.     

Age determination of Petra's engineered landscape – optically stimulated luminescence (OSL) and radiocarbon ages of runoff terrace systems in the Eastern Highlands of Jordan

The unfavourable mountainous environment of the Petra region in southern Jordan was modified by ancient engineers to supply the Nabataean/Roman city of Petra with food and water. The area was reclaimed by installing extended runoff terrace systems and hydraulic structures. The agricultural terrace systems have so far been dated based on surface pottery, and the chronology of the systems is under debate. In this study, optically stimulated luminescence (OSL) and radiocarbon dating techniques were successfully applied to date these terrace systems. Samples were taken from the fills of agricultural terraces and underneath their walls to determine the chronology of the construction, use and abandonment of the agricultural terraces. The results suggest that runoff farming in the Petra region started around the beginning of the Common Era, and construction, use and maintenance lasted at least until 800 AD.     

Archaeomagnetic dating of archaeological sites from Switzerland and Bulgaria

Baked materials from three archaeological sites in Switzerland and one in Bulgaria have been examined and dated archaeomagnetically. The detailed rock-magnetic properties of the burnt clay collected have already been studied therefore and have been published elsewhere (Geophysical Journal International 153 (2003) 146). The main aim of this paper is to determine the terminus ante quem for the last firing of the clay collected from pottery kilns or burnt layers. The directional and intensity results of the ancient geomagnetic field corresponding to the time of the structure's last firing are given for each site. These geomagnetic parameters are then compared with reference curves to provide archaeomagnetic dates for the last use of the kilns. Application of archaeomagnetism as a dating tool is only possible for those regions that already have reference curves. Bulgaria is fortunate in having established reference curves covering almost the last 8000 years. Two Swiss sites were dated using only directional results on the basis of existing palaeodirectional results for Switzerland as well as the French directional reference curves. The archaeomagnetic dates of three of the sites were then compared to archaeological evidence and available radiocarbon dates. The palaeointensity data obtained from this study will enrich the existing archaeomagnetic database for western Europe.     

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.