GAUSSIAN CURVES FOR VISUALIZING CHRONOLOGICAL PATTERNS OF CERAMIC FINDS AND RESIDUALITY*

This paper describes a particular statistical approach to chronological data from assemblages of archaeological finds (namely pottery) using Gaussian curves: the method enables us to obtain a graphic representation of chronological patterns that avoids an excessive flattening of data, adding an extra dimension to the usual linear temporal concepts. This enables us to arrive at more likely absolute dating and also visualize residuality. The method has been built during the study of a stratigraphic context from the Site of Ancient Ships of Pisa – San Rossore, Italy, and applied to its pottery. Archaeologists may find in the model a useful tool that is easy to apply.     

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.     

Uniform Probability Density Analysis and Population History in the Northern Rio Grande

One of the basic challenges facing archaeology is translating surface evidence into population estimates with sufficient chronological resolution for demographic analysis. The problem is especially acute when one is working with sites inhabited across multiple chronological periods and the production curves for pottery types are unknown. In this paper, I present a Bayesian statistical method which I call uniform probability density analysis that is tailored to this situation. This method combines uniform distributions derived from the local pottery chronology with pottery assemblage data to reconstruct the population history of individual settlements. I also illustrate applications of this method at the site and regional level using data from Cuyamungue and the surrounding Tewa Basin/VEP II New Mexico project area. The results allow one to identify a period of significant population movement corresponding to the period of Tewa ethnogenesis in the thirteenth century CE.     

STATISTICAL ASPECTS OF POTTERY QUANTIFICATION FOR THE DATING OF SOME ARCHAEOLOGICAL CONTEXTS*

This paper describes some statistical analyses of a particular archaeological material (pottery) originating at some sites in the city of Tours. An important part of the archaeological study of pottery is the comparison of ceramic assemblages to establish the absolute dates of contexts. In this paper, a statistical model is built to assess this comparison. The statistical procedure uses classical tools (correspondence analysis, linear regression and resampling methods) in an iterative scheme. Archaeologists may find in the paper a useful set of known statistical methods, while statisticians can learn a method of ‘arranging’ well‐known techniques. No method is new, but their combination is characteristic of this application.     

A Multi-regional Analysis of AMS and Radiometric Dates from Carbonized Food Residues

Abstract

Accelerator Mass Spectrometry (AMS) is increasingly employed to date encrusted carbonized food residues on prehistoric pottery sherds, particularly in regions where other datable material is absent or scarce, or where such materials lack good association with objects of chronological interest. The accuracy of AMS dating of residues has recently been questioned in Europe and North America, with skepticism directly or indirectly attributed to the presence of carbonate rich bedrock, a freshwater carbonate reservoir resulting from association with such bedrock, or the cooking of aquatic resources such as mollusk or fish engaged in the uptake of older carbonates. It is argued that carbonized food residues from such contexts or resources are expected to display older apparent ages than dates on other materials. We evaluate this proposition through hypotheses assessing the accuracy and internal consistency of a broad range of data from the northeastern and midwestern United States. We statistically assess dates from 25 site components where either both dates on residue and context dates on other materials have been obtained. Of the 70 dates on residue tested, only 5.7 percent are considered inconsistent with their respective context dates. We also test for consistency 46 dates on residues from 14 site components lacking context dates. Of these, only 4.5 percent are considered internally inconsistent with expectations at the site or regional level. At present, we conclude that AMS dating of residues provides results consistent with those of other datable materials.     

The Comings and Goings of Sheep and Pottery in the Coastal Desert of Namaqualand,South Africa

This paper evaluates chronological trends in the presence and absence of domestic animal bone (sheep, goat, and cattle) and pottery in Namaqualand, the proposed gateway to the rest of South Africa for early herders or hunter-gatherers with sheep and ceramics. We update date calibrations with local ΔR corrections and mixtures of recent calibration curves and include five previously unpublished dates. We use histograms of calibrated medians, sorted in 100-year bins, to assess sustained regional patterns with dates associated with domestic animal bone and pottery (n = 73). While too small to be useful as a population proxy, the current set of dates does reveal three pulses of occupation separated by two clear gaps, which we evaluate with a Bayesian model of three sequential phases. The model's boundaries are used as estimates of the dates of Early (AD 80–210), Middle (AD 490–790), and Late (AD 1180–1690) occupational phases separated by two substantial lapses of 280 and 380 years, respectively. The alternating phases of presence and absence are suggestively correlated with climate shifts, leading to a discussion of the idea that effective moisture was a crucial factor in choosing whether to occupy Namaqualand. The set of archaeological dates has greater temporal and spatial resolution than many regional climate data, so we suggest that these trends may more accurately reflect the variable conditions specific to Namaqualand, at least until they are refined by future climate research.     

New insights into the neolithisation process in southwest Europe according to spatial density analysis from calibrated radiocarbon dates

The agricultural way of life spreads throughout Europe via two main routes: the Danube corridor and the Mediterranean basin. Current archaeological literature describes the arrival to the Western Mediterranean as a rapid process which involves both demic and cultural models, and in this regard, the dispersal movement has been investigated using mathematical models, where the key factors are time and space. In this work, we have created a compilation of all available radiocarbon dates for the whole of Iberia, in order to draw a chronological series of maps to illustrate temporal and spatial patterns in the neolithisation process. The maps were prepared by calculating the calibrated 14C date probability density curves, as a proxy to show the spatial dynamics of the last hunter-gatherers and first farmers. Several scholars have pointed out problems linked with the variability of samples, such as the overrepresentation of some sites, the degree of regional research, the nature of the dated samples and above all the archaeological context, but we are confident that the selected dates, after applying some filters and statistical protocols, constitute a good way to approach settlement spatial patterns in Iberia at the time of the neolithisation process.     

The Importance of Multiple 14C Dates from Significant Archaeological Contexts

Radiocarbon (¹⁴C) dates are the most important means for determining the age of Holocene archaeological deposits. The theoretical physical basis of this method is by now unassailable, having been consistently tested and refined over two generations. However, the means by which this method has been applied and the interpretation of these results remain as key issues, particularly for complex archaeological discoveries that substantially affect our understanding of world prehistory and social evolution. Many factors can produce uncertainty or variation in the ¹⁴C concentrations of samples, even those that have been selected from the same archaeological context or event. A number of recent studies have also addressed the ways in which ambiguities and irregularities in the ¹⁴C calibration curve can affect the interpretation of archaeological dates and temporal patterns. Of greatest concern, however, is a growing practice of using only one or two samples to date a significant prehistoric context or event. The date of these events, usually relative to other human activities, often holds important theoretical implications for evolutionary anthropology and related disciplines. In this article, we demonstrate that such a practice is rarely adequate or acceptable. Rather, proper procedure requires a suite of dates that permit statistical verification that the deposit or event itself is being correctly dated. We present a detailed case study that highlights the importance of analyzing multiple samples of ¹⁴C from significant archaeological contexts.     

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.     

MEASURING CHRONOLOGICAL UNCERTAINTY IN INTENSIVE SURVEY FINDS: A CASE STUDY FROM ANTIKYTHERA,GREECE*

This paper considers how to make the most out of the rather imprecise chronological knowledge that we often have about the past. We focus here on the relative dating of artefacts during archaeological fieldwork, with particular emphasis on new ways to express and analyse chronological uncertainty. A probabilistic method for assigning artefacts to particular chronological periods is advocated and implemented for a large pottery data set from an intensive survey of the Greek island of Antikythera. We also highlight several statistical methods for exploring how uncertainty is shared amongst different periods in this data set and how these observed associations can prompt more sensitive interpretations of landscape‐scale patterns. The concluding discussion re‐emphasizes why these issues are relevant to wider methodological debates in archaeological field practice.     

Directional analysis of surface artefact distributions: a case study from the Murghab Delta, Turkmenistan

This paper investigates directional influences in the distribution of Bronze Age surface pottery in the northern Murghab Delta, Turkmenistan. Drawing upon a continuous dataset of pottery sherd counts obtained by intensive field survey, it examines the degree to which we can make sense of the archaeological processes at work in a heavily obstructed and dynamic landscape. In so doing, it makes use of two analytical methods that have rarely been used in archaeology: a) geostatistical analysis using variograms to investigate directional spatial autocorrelation in recorded sherd counts; and b) angular wavelet analysis in evaluating directional influences in the sherd distributions for particular chronological periods. While some kinds of directional influence can be identified visually, a quantitative approach is particularly useful in deconstructing such patterns. In this particular dataset, distinct but related directional processes can be identified and measured: a) the impact of the complex system of watercourses in the delta on both settlement and post-depositional processes; and b) recovery bias in the observations made during survey.     

Evidence of Iberian Bronze Age ‘Boquique’ Pottery in the Balearic Islands: Trade,Marriage or Culture?

Summary.   This paper deals with the recent discovery of Iberian 'Boquique' Bronze Age pottery on the Balearic Island of Mallorca. It marks the 'maritime' spread of this distinctive pottery into a geographic area not previously recorded. It should therefore be of particular interest to mainland investigators and others concerned with its geographical distribution as well as those dealing with long-distance trade and possible kinship links during the period. The find is further supported by the 'micaceous' and 'quartz' composition of the pottery clay fabric, since mica is not known on the island as a component of local clays. The presence of Boquique pottery with 'micaceous' clay properties is demonstrated by microphotographic slab and thin sections as well as chemical clay analysis. This suggests that the pottery was imported, either as a trade item or as personal possessions.
Along with recent evidence of earlier trade in exotic 'elephant' ivory and other items during Bell Beaker times, where the Boquique pottery appears to be a late intrusive element into local Beaker contexts ( Waldren 1998 ), this new evidence represents the first material sign of cultural maritime interaction (Boquique in the present case), either as demographic extension or commercial exchange of these cultural items into the area.
Furthermore, contextual radiocarbon dating surveys strongly indicate a date of 1700–1400 BC for the pottery, in accord both with recent Iberian mainland dates as well as the local archaeological sequence in which it was found.     

Asimah: Neue 14C-Datierungen zum späten 3. vorchristlichen Jahrtausend auf der Halbinsel Oman

The third millennium BC domestic sites of Asimah (Emirate of Ras al-Khaimah, U. A. E.), excavated in 1988 and published in 1994, produced a common Umm an-Nar inventory, but with a high percentage of imported Indus Valley pottery. A comparison of finds with the well-stratified Hili-8 sequence is contrasted with five new radiocarbon dates which, together with the artefacts recovered, place Asimah in the late third millennium BC chronological and cultural context of Tell Abraq.     

Woodland Pottery Function,Cooking, and Diet in the Upper Great Lakes of North America

A multidimensional approach to functional analysis was employed to examine pottery use, cooking, and subsistence in pre-European North American contexts. A variety of analytic techniques were applied to ceramic assemblages from two sites on the south shore of Lake Superior: the Middle Woodland Naomikong Point site and the Late Woodland Sand Point site. The analyses of both technical attributes and use-alteration traces suggest that a majority of pottery vessels from these sites were used for cooking throughout the Woodland period. Lipid residue analysis corroborates traditional subsistence information but specifies which foods were cooked in pottery vessels. Vessel size varies according to context rather than by time or by function, with larger vessels associated with ritual areas and smaller vessels originating from domestic spheres, a trend potentially related to feasting behavior. Interior carbonization patterns change in frequency between the Middle and Late Woodland periods, suggesting a shift in cooking and possibly subsistence practices.     

PETROGRAPHIC MODAL ANALYSIS - A NECESSARY COMPLEMENT TO CHEMICAL ANALYSIS OF CERAMIC COARSE WARE

Bulk chemical analysis is shown to be insufficient for the archaeometric interpretation of coarse ware pottery. Accompanied by quantitative petrographic analysis of the temper much more conclusive information can be obtained at little more expense. Three small groups of prehistoric pottery from Switzerland have been examined with both techniques, showing that expensive chemical bulk analyses may be obsolete or even misleading, and in any case need further confirmation and interpretation by petrographical means. Assuming a rigorous sampling strategy, the number of analyses necessary for valid statements can be substantially reduced relative to those necessary for the statistical interpretation of bulk analyses only.     

Pottery and the Visual World at Early Iron Age Hascherkeller,Germany

Abstract

On most late prehistoric and early historic settlement sites all over the world, pottery is the most abundant material recovered by archaeologists. Analysis of pottery provides information about the chronological position and cultural affiliation of a site, as well as about techniques of manufacture, organization of production, trade relations, and patterns in the social structure of the community. Here, a new approach is presented that focuses on pottery as a principal factor in the visual world of the people who made and used it. Pottery from the Early Iron Age settlement of Hascherkeller in southern Germany is examined in the context of the physical and social world of which the community was a part. It is argued that the shapes, textures, and decoration of the pottery refer to other elements of the physical world. This approach offers a new way to understand how prehistoric people responded to economic and political changes through the purposeful fashioning of their material culture.     

A method for chronological apportioning of ceramic assemblages

Artifact assemblages from long-inhabited sites may include ceramic types and wares from multiple time periods, making temporal comparisons between sites difficult. This is especially problematic in macro-regional data sets compiled from multiple sources with varying degrees of chronological control. We present a method for chronological apportioning of ceramic assemblages that considers site occupation dates, ceramic production dates, and popularity distribution curves. The chronological apportioning can also be adjusted to take into account different population sizes during the site occupation span. Our method is illustrated with ceramic data from late prehispanic sites in the San Pedro Valley and Tonto Basin, Arizona, U.S.A., compiled as part of the Southwest Social Networks Project. The accuracy of the apportioning method is evaluated by comparing apportioned assemblages with those from nearby contemporaneous single component sites.     

Imperial Expansion, Ethnic Change, and Ceramic Traditions in The Southern Chad Basin: A Terminal Nineteenth-Century Pottery Assemblage from Dikwa, Borno State, Nigeria

In the course of an archaeological project in the southern Chad Basin of Nigeria, excavations were conducted at several deeply stratified mound sites that date from the Late Neolithic to the Late Iron Age. As a way to complement the ceramic sequence obtained so far and to link it with today's pottery tradition, a small excavation was conducted at a site that dates to the turn of the nineteenth to the twentieth century A.D. A pottery assemblage was discovered that shows obvious links to today's tradition but notable breaks with those of the nineteenth century and earlier. This break in decoration style and technique is interpreted as an archaeologically visible expression of changing ethnic identity. This ethnic change and the associated spread of the ceramic tradition can be linked with the expansion of the sphere of power of the Kanem-Borno Empire into the area south of Lake Chad after the sixteenth century A.D.     

A probabilistic framework for assessing spatio-temporal point patterns in the archaeological record

The assessment of spatial patterns in archaeology is hampered by a number of constraints, one of the most serious of which is the intrinsic temporal uncertainty associated with most of the archaeological record. Different types of chronological definition or different degrees of temporal knowledge will suggest different kinds of spatial pattern, ultimately obscuring and restricting our interpretation of the background process, especially in cases where we are seeking a diachronic perspective. This paper addresses these problems by adopting both a probabilistic approach and a more standardised framework for diachronic analysis. First, we define the notion of temporal uncertainty and explore its analytical consequences. Second, we consider two methods by which it might be formally quantified, emphasising (a) the advantages of probability-weighted spatial analysis and (b) the comparison of alternative spatio-temporal patterns via Monte-Carlo simulation. Finally, we apply these methods to a case study that considers the distribution of Middle to Late Jomon (ca.5000–3000 BP) pithouses recorded in the Chiba New Town area of Japan.     

The goodness of fit and statistical significance of seriation solutions

This paper presents a method for determining the statistical significance and goodness of fit of seriation solutions based on correspondence analysis. The basic assumption is that seriation solutions corresponding to relative chronological sequences should have unimodal distributions of types across assemblages in a sequence. In order to evaluate significance of chronological signal in data, the observed number of modes of a seriation solution based on correspondence analysis is compared to a distribution of number of modes generated by randomization of the original data table. A quantitative measure of the goodness of fit is presented. The method is tested on two data sets: 1) archaeological data with a known chronological ordering 2) non-archaeological data without a chronological patterning. The method successfully detected a significant chronological signal in the former, and failed to detect it in the latter.