Modelling site formation dynamics: geoarchaeological,chronometric and statistical approaches to a stratified rockshelter sequence,Polynesia

Formation processes and chronology are central to many archaeological endeavours, and accuracy in the latter is dependent on control of the former. Here we consider how to integrate geoarchaeological and chronometric evidence to better understand the formational history, along with the timing and duration of cultural activities, at a regionally significant site in the southern Cook Islands (Polynesia) which dates from ∼12th century AD. Initially we model natural and cultural processes of deposition using geoarchaeological evidence. The results are integrated with 21 radiocarbon dates, including nine new AMS results on identified medium and short-lived materials. Sample outliers are identified manually and statistically and a Bayesian analysis helps to refine age estimates for the site's 12 stratigraphic zones. The timing and rate of sediment accumulation is further considered through an age–depth model. Finally, the chronology developed from these combined approaches is used to address three key processes: 1) initial site use, potentially relevant to human colonisation of this Polynesian island and archipelago; 2) on-site activities and patterns of resource use; and 3) major marine deposition events which disrupted cultural activities and may have palaeoclimatological significance. The approach developed here potentially has utility elsewhere, particularly where human activities are recurrent and of limited duration.     

A simple Bayesian approach to tree‐ring dating

Tree‐ring dating involves matching sequences of ring widths from undated timbers to dated sequences known as ‘master’ chronologies. Conventionally, the undated timbers (from a building or woodland) are sequentially matched against one another, using t‐tests to identify the relative offsets with the ‘best’ match, thus producing a ’site’ chronology. A date estimate is obtained when this is matched to a local master chronology of known calendar age. Many tree‐ring sequences in the UK produce rather low t‐values and are thus declared not to have a ‘best’ match to a master chronology. Motivated by this and the routine use of Bayesian statistical methods to provide a probabilistic approach to radiocarbon dating, this paper investigates the practicality of Bayesian dendrochronology. We explore a previously published model for the relationship between ring widths and the underlying climatic signal, implementing it within the Bayesian framework via a simulation‐based approach. Probabilities for a match at each offset are produced, removing the need to identify a single ‘best’ match. The Bayesian model proves successful at matching in both simulated and real examples.     

宾组卜辞五次月食的先后次序

宾组卜辞中的五次月食是殷商年代学研究极其重要的资料,本文以殷墟甲骨分期研究的最新成果为基础,先对记载五次月食的卜辞材料进行类别的划分,然后再排出五次月食的先后次序,在此基础上,就可根据目前所掌握的历算知识,求出其相应的绝对年代,以作为殷商年代学研究的重要基点。     

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.     

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.     

Towards a Chronology of the Jerzmanowician—a New Series of Radiocarbon Dates from Nietoperzowa Cave (Poland)

The period around 50 000–35 000 years ago constitutes one of the most debated research issues in European archaeology of the Palaeolithic. In this time period, the transition from the Middle to the Upper Palaeolithic took place. Locally, in different areas of Europe, this shift is recorded in so‐called transitional assemblages. The eastern fringe of these transitional assemblages is represented by the Jerzmanowician, the unit described on the basis of a lithic assemblage from Nietoperzowa Cave (Poland). The unit is a part of a European transitional complex called the Lincombian–Ranisian–Jerzmanowician. Up to now, the radiocarbon dates presented in the literature have only allowed us to set the age of the Jerzmanowician at c.40 000–45 000 ka cal bp . In this study, we present 42 new radiocarbon dates. We attempt to set the archaeological record of the Jerzmanowician from Nietoperzowa Cave in an accurate chronological framework, based on Bayesian statistical processing of radiocarbon dates. We conclude that the lower boundary of layer 6 in Nietoperzowa Cave can be statistically located in the range 44 000–42 000 cal bp and the upper limit for the Jerzmanowician is estimated to c.31 000 cal bp . New data raises a question on the correlation with upper layer 4. In the light of the new chronology, the attribution of the archaeological inventory from layer 4 to the Jerzmanowician seems questionable.     

The age of the Dalton culture: a Bayesian analysis of the radiocarbon data

ABSTRACT

Since a radiocarbon chronology of the Dalton culture in the Southeast was first proposed, several new sites have been dated. I propose a new chronology based on radiocarbon dates from sites in the Dalton Heartland and its eastern periphery using Bayesian statistical models in OxCal and an analysis of the associated diagnostic projectile points. The analyses indicate that the Dalton culture probably evolved from the Clovis or Gainey phenomena about 12,680?cal?BP (ca. 10,700?BP) and lasted at least until ca. 10,400?cal?BP (ca. 9,200?BP), if not several centuries later. I propose early and late Dalton phases that follow changes in how Dalton points were made and resharpened. It appears that the people living to the east of the Heartland followed a different trajectory of projectile point evolution. There, notched points appear about 11,500?cal?BP, while in the Heartland, true notched points do not appear in large numbers until the Graham Cave point over 2,000 years later. The chronologies demonstrate that early, coeval, region-wide cultural changes may not have been the norm. They also raise interesting questions about how people in the Heartland and its eastern periphery interacted.     

Calcium oxalate AMS C dating and chronology of post-Palaeolithic rock paintings in the Iberian Peninsula. Two dates from Abrigo de los Oculados (Henarejos,Cuenca, Spain)

Since 2005 we have been utilizing accelerator mass spectrometry (AMS) ¹⁴C dating in research on calcium oxalate crusts associated with open air rock art of the Iberian Peninsula. In this paper we present two dates linked with three eye-idol pictographs at Abrigo de los Oculados (Henarejos, Cuenca, Spain). Radiocarbon ages for these motifs agree with the expected iconography-based archaeological chronology. Such oxalate dates could provide an independent basis for evaluating chronological theories for post-Palaeolithic sites, designated in the UNESCO World Heritage List as Rock Art of the Mediterranean Basin on the Iberian Peninsula.     

ROCK SURFACE HARDNESS AS AN INDICATION OF EXPOSURE AGE: AN ARCHAEOLOGICAL APPLICATION OF THE SCHMIDT HAMMER*

A Schmidt Hammer was employed in evaluating the surface hardness of rocks which line ancient anthropogenic pit features, known as Pukaskwa pits, on the north shore of Lake Superior, Canada. This technique offers a possible new method of producing relative ana absolute dates for such exposed stone features Analysis of the data has provided a relative chronology for the pit features, representing two distinct construction phases. The range of absolute dates generated from the data indicates that the pits were likely constructed by Blackduck peoples c. 900 to 400 years BP.     

A Bayesian AMS C chronology of the Classic Maya Center of Uxbenká, Belize

Archaeologists require precise chronologies of cultural change to understand the nature and timing, and causes and effects, of ecological and social transformations. The Uxbenká Archaeological Project (UAP) has made chronology building a main goal, employing epigraphic data, artifact seriation, and high-precision AMS ¹⁴C dating. With more than 60 ¹⁴C dates with measurement errors below ±25 ¹⁴C yr, primarily on single charcoal specimens, Uxbenká may be the most intensively dated Classic Period site in the tropical Maya Lowlands. Here we take the next step, combining this rich chronometric dataset with associated stratigraphic information in OxCal's Bayesian framework to generate a high-resolution chronology of Uxbenká's early development and expansion in southern Belize. We show how archaeologists may take advantage of complex architectural stratigraphy to constrain broad calibrated ranges during the Classic Period, and to estimate dates for observed construction events that can not be directly dated (e.g., clearing/leveling plazas, laying plaster floors, renovating/rebuilding structural elements). Our analysis confirms the antiquity of the ceremonial Stela Plaza (Group A), where first construction is estimated between 60 cal BC and cal AD 220 and is associated with a Pre-Classic structure obscured by later construction and reorientation of the group to a N-S alignment ca. AD 150–310. The analysis also indicates initial leveling and construction at plaza Group B from cal AD 60–310 and Group D from cal AD 20–240, both earlier than previously assumed. Though Late Classic contexts are not as well represented by direct dates, architectural modifications are documented at all three plaza groups after AD 550, including the extensive plastering, laying paving stones, and construction of facades on existing structures. The resulting chronology revises our previous thinking on the mode of settlement and development of Classic Maya society at Uxbenká and indicates specific areas of investigation to elucidate events in the Late and Terminal Classic at the site, including political and social fragmentation and the abandonment of the urban core late in the Classic Period.     

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.     

觉公簋年代管见

朱凤瀚先生新近撰文介绍并作了详细讨论的觉公簋,由于其铭文关涉到晋国的早期历史,从而又影响到西周王年,故引起了学者的重视。之后,夏商周断代工程办公室的《简报》又登载了李学勤先生的     

Thorium-230 coral chronology of a late prehistoric Hawaiian chiefdom

Documenting the history of settlement in Hawaii during the last few centuries before European contact, is crucial to charting the evolution of the most complex chiefdom in Polynesia. It is precisely this period that Hawaii, and many Polynesian societies, underwent their most rapid changes in political, economic and social organisation. The last ∼500 to 300 years in the ¹⁴C calibration curve is problematic with wide fluctuations often rendering large age spans that do not precisely date single events, especially troubling with a culture-historical record of ∼1000 years duration. Here we present an extremely high precision ²³⁰Th chronology for archaeologically constrained coral samples from a range of occupancy sites. Our high precision dates allow the time of site use to be clearly demonstrated. They also provide the first dates for habitation sites in Hawaii that clearly show contemporaneous occupation—the major problem in settlement pattern archaeology. We demonstrate that two sites were occupied within the same year. Our refined chronology, provides new and exciting opportunities for tracking sociopolitical and economic developments during the last few centuries—the crucial period in the evolution and transformation of Polynesian societies.     

Building a high-resolution chronology at the Maya archaeological site of El Palmar,Mexico

This paper discusses how detailed analyses of archaeological contexts and macrobotanical remains are critical for building a high-resolution chronology in archaeological research. While the application of Bayesian modelling has improved chronology-building significantly, archaeologists have sometimes neglected different dates recovered from the same depositional layer without further scrutiny. Based on 78 radiocarbon samples, this problem is challenged by building a high-resolution chronology of the Guzmán Group, a small plaza compound of the ancient Maya city of El Palmar, Mexico. The results permit a deeper understanding of relationships between dynastic interactions and the emergence of non-royal elites in Classic Maya society.     

Settlement Reorganisation and the Rebirth of the Ottoman Empire: Bayesian Modelling Narrows Dates for Post-Medieval Occupation at Kaman-Kalehöyük,Kırşehir Province,Turkey

The Ottoman reoccupation of the site of Kaman-Kalehöyük (K?r?ehir Province, Turkey) apparently occurred sometime during the fifteenth century CE, a time of massive territorial and administrative transformation in the Empire. A rich suite of archaeobotanical material recovered from the site offers a potentially invaluable source of information on Ottoman-era Anatolian agroeconomy, especially since historiographic research on the topic has uniformly ignored archaeological perspectives. Here we present results of a multi-proxy analysis aimed at establishing an absolute multiphasic chronology for Kaman-Kalehöyük’s Ottoman occupation, founded upon Bayesian statistical modelling of high-precision radiocarbon dates from cereal remains. We use the new chronology to position Kaman-Kalehöyük’s resettlement within a historical context, allowing a new perspective on settlement responses to large-scale Ottoman sociopolitical change in Anatolia.     

TWENTY YEARS AFTER “ABSOLUTE CHRONOLOGY: ARCHAEOLOGICAL EUROPE 2500‐500 BC” NEW DATA ON ITALIAN PROTOHISTORY

The article is a tribute to the pioneering role of Klavs Randsborg in the early Nineties in search for a new comprehensive chronology for Italian and European prehistory based on a combination of dendrodates with C14 dates. The debate of the last 25 years on this matter is presented, demonstrating a scholarly split, in particular in Italy. At the same time, an Italian peculiarity, the presence of layers of volcanic eruptions mixed with archaeological deposits is proposed as a sort of meeting ground for opponents and proponents of absolute chronology and a way to pair it with known cultural phenomena.     

A comprehensive numerical chronology for the pre-Columbian cultures of the Palpa valleys,south coast of Peru

Before the arrival of the Spaniards in Peru in 1532, many different societies flourished in the coastal desert of southern Peru. Of these, one of the best known is the Nasca culture (living in the area between about 260 cal BC and 640 cal BC.), which created the famous geoglyphs on the desert floor. In this paper we present a numerical chronology for the cultural development in the valleys of Palpa, in the northern part of the Nazca region, which spans the time from the Archaic Period (starting there around 3760 cal BC) to the Late Intermediate Period (terminating with the arrival of the Spaniards in 1532 AD). The chronology is based on more than 150 ¹⁴C samples collected by our project from well-documented archaeological excavations of 17 different sites in and around Palpa. Thanks to the advanced AMS-¹⁴C dating technique, demanding only few milligrams of organic material, we could focus on samples of plants, like beans, corn, or reed, representing single years of growth or use, and also on delicate materials like straw from clay bricks (adobe) and textiles. All single ¹⁴C dates were combined to cultural phases using a Bayesian statistical model, implementing the a priori information of the archaeological contexts, and adopting the relative ceramic chronologies available for this area.     

Thermoluminescent dating of the Late Bronze and Early Iron Age pottery on sites in Kłyżów and Jarosław (SE Poland)

The absolute chronology of Late Bronze and Early Iron Ages in Polish territories is a result of long-term and complex research. Here, we have investigated the absolute dating of two sites, namely K?y?ów, a cemetery of the Tarnobrzeg Lusatian culture, and Jaros?aw, a settlement spanning from the late phase of the former to Pomeranian culture, possibly with Jastorf elements. Having been spurred by promising results of thermoluminescence (TL) dating of medieval and Przeworsk materials, we have employed it in those situations, where no other chronometric methods seem to be efficient. TL dating has been combined with typological analysis of the dated pottery and, partially, with radiocarbon method. Albeit the produced TL dates do not represent the level of sought-for fine chronological resolution, they indicate the temporal trends and corroborate the typological research. Our study has shown the potential of TL dating for periods with plateaus on ¹⁴C calibration curve. We also have dealt with unexpected TL ages and suggested some solutions of the problem. Finally, we have demonstrated that the condition sine qua non for archaeological interpretation of TL dates is a thorough stylistic-chronological analysis of dated pottery and clear understanding of relations between chronometric dates and the archaeological event to be dated.     

The Unitary Association Method of Relative Dating and Its Application to Archaeological Data

The primary objective of relative dating techniques is to determine a reliable sequence of archaeological deposits. This task becomes more difficult whenever our research steps beyond individual sites to the study of intercommunity relationships because we need to develop some means of associating unconnected deposits in time. Radiocarbon dating, as a stand-alone method, cannot always be used to draw reliable correlations between sites. The relevance of archaeological dates, including absolute dates, relies ultimately on the determination of artifact or sample associations and their respective superpositional relationships. The Unitary Association Method of Relative Dating is an alternative to seriation methods that is less susceptible to spatial variation and offers analytical strengths needed for regional chronological analyses.