Clues to Stone Tool Function Re-examined: Comparing Starch Grain Frequencies on Used and Unused Obsidian Artefacts

The identification of plant residues observed on prehistoric stone artefacts has often been used to inform on tool function without adequate consideration of potential contamination due to post-depositional processes. The paper redresses this balance by proposing a methodology which combines use-wear and residue analyses with systematic testing of depositional context to distinguish residues formed during tool use from accidental contamination. A case study involving obsidian artefacts from an open site in Papua New Guinea is used to illustrate the new approach. Starch grains, a class of residue which has had little attention outside Australia, were chosen as the focus of study because of their abundance at this site. The frequency of starch grains extracted from residues on stone artefacts was compared with those in sediments adhering to and adjacent to the artefact. A use-wear study conducted as a blind test provided an independent measure of whether the artefacts had been used. The frequency of starch grains was shown to be significantly correlated with used artefacts and not correlated with unused artefacts or the sediments. The case study demonstrates the importance of testing for contamination and also illustrates the benefit of studying starch grains as a class of plant residue.     

Obsidian hydration dating by infrared spectroscopy: method and calibration

Low temperature (90–190 °C) hydrothermal experiments have been conducted on seven obsidians where composition of the glass varies significantly in the concentration of structural water within the unhydrated bulk material. Infrared transmission spectroscopy was used to track the diffusion of molecular water into the glass surface as a function of time and temperature. Long-term (60–360 days) hydration sequences at 90 °C show a t^0.6 time dependence for the mass uptake of molecular water that forms the hydration layer. The structural water concentration of the unhydrated bulk obsidian is highly correlated with the pre-exponential and activation energy and may be used to estimate the Arrhenius constants. In addition, secondary ion mass spectrometry (SIMS) hydrogen profiling of Napa Glass Mountain obsidian hydrated at 90 °C reveals that the early stages of diffusion exhibit a dynamic behavior that includes a fluctuating hydrogen concentration and a changing diffusion coefficient that slows with time.     

Obsidian provenance studies in Colombia and Ecuador: obsidian sources revisited

The field occurrences, elemental compositions and formation ages of Colombian and Ecuadorian obsidians are revisited. It is shown that the regional sources of this raw material are linked to two major volcanic structures: the Chacana and the Paletara calderas, localised on the eastern cordillera of Ecuador and on the central Andean cordillera of south Colombia respectively. Seventy-two samples were analysed by inductively coupled plasma-atomic emission spectroscopy (ICP-AES), inductively coupled plasma-mass spectrometry (ICP-MS) and/or particle induced X-ray emission (PIXE). The same 10 types of elemental compositions were identified independently from ICP and PIXE. Four of these types were previously unknown. The formation ages of these obsidians previously determined by fission tracks dating are in the range 0.17–1.58 Ma at Chacana and 3.46–4.27 Ma at Paletara. Most Colombian and Ecuadorian pre-Hispanic artefacts present elemental compositions compatible with a Chacana- or Paletara-derived origin of the raw material. However, some of them present fission track ages discordant with the present-day known obsidian occurrences, which implies that the regional source inventory is not yet exhaustive.     

The Elmenteitan Obsidian Quarry (GsJj50): New Perspectives on Obsidian Access and Exchange During the Pastoral Neolithic in Southern Kenya

Early pastoralists in southern Kenya exploited obsidian sources to supply large regional exchange networks that persisted from c. 3200 to 1400 years ago. Obsidian exchange networks have been a source for speculation on the social and political nature of early pastoralism in eastern Africa. Herders who produced a discrete set of material culture called “Elmenteitan” mainly relied on a particular obsidian quarry site on the upper slopes of Ol Doinyo Opuru (Mt. Eburru), in the Central Rift Valley. These implications of the Elmenteitan pattern for herder social organization have not been systematically investigated. This paper reports on recent surveys and initial excavations at the Elmenteitan Obsidian Quarry (GsJj50) on Mt. Eburru as the central node of a prehistoric herder exchange network. Research revealed a series of stratified extraction and workshopping loci concentrated across a roughly 200-m² extent. Spatial, faunal, ceramic, and lithic datasets support communal resource access by small groups, rather than centralized control. This research has implications for interpreting the role of centralized quarries and resource nodes in the formation of mobile herder exchange and alliance. Networks were an important risk-reduction strategy in unpredictable environments and helped facilitate the spread of African pastoralism.     

A Structural Approach to the Form of the Population Density Function

The central objective of this paper is to explore a comprehensive structural modeling approach that extracts analytical density functions answering questions raised by recent empirical studies.     

Obsidian hydration dating: accuracy and resolution limitations imposed by intrinsic water variability

Obsidian hydration dating typically yields a range of ages for a single chronometric measurement, even after controlling for source chemistry and effective hydration temperature. Previously published data suggest that this range is due to hydration rate variations caused by variability in the concentration of intrinsic water, and specifically hydroxyl ions, in the obsidian. Such variability exists within any given obsidian source, and even within any particular specimen. This paper analyzes the effect on age estimates of intrinsic water variability and concludes that if a controlled sample of obsidian yields a range of ages, there is no way to tell whether the range is due to long site use or to variations in hydroxyl concentration. At present there is no robust and cost-effective protocol for measuring hydroxyl concentration. Suggested guidelines for obsidian hydration dating are developed using a case study. These findings do not invalidate obsidian hydration as a chronometric technique, but they do suggest limits to the temporal resolution achievable.     

An Experimental Approach to the Disaggregation of Samples from Peat Deposits

Abstract

Excavations carried out at Dudley Castle recovered an assemblage of animal bones dominated by horse from the vaulted cellar beneath the Great Hall. The deposit dates to c. 1710 and appears to have been the result of partial butchery of several aged horses. The possible interpretations are discussed and it seems likely that the deposit represents the leftover waste of a knacker.     

From Ancient to Modern Urbanization: Intermediary Function of an Urban Society

A number of traits identify an urban society from a village. In the 1950s, V.G. Childe identified ten traits for an urban society, including permanent settlement in dense aggregations, centralization of surplus, monumental public buildings, social stratification, a ruling class, systems of recording and administration, exact and predictive sciences regulating the cycle of agriculture operation, conceptualized and sophisticated styles of art, long-distance trade and importing raw materials, and a social organization based upon residence rather than kinship. Although he identified these traits for ancient urban society, these also can be applied in modern times. The most important function of an urban society especially in southeast Iran is its intermediary function. This function can be seen both in ancient and modern times. The present paper aims to identify both urban societies in ancient and modern times, and to explain intermediary function of these societies, including Shahr-i-Sokhta during the third millennium BCE and Zahedan in modern time. In fact, this function may have caused the emergence and development of these urban societies during two different periods. It is also postulated that the decline of this function may have caused the collapse of both societies.     

Obsidian hydration at high elevation: Archaic quarrying at the Chivay source,southern Peru

We examine obsidian hydration as a means to date archaeological sites at high elevation in the central Andes, and in particular quarry sites that are difficult to date by radiocarbon means. The Chivay obsidian source lies in a volcanic depression above the Colca Valley in Arequipa, Peru (71.5355° S, 15.6423° E) at 4950 masl. We compare obsidian hydration readings from one quarry and two workshop locations. Ninety-one flakes from the quarry pit, and 61 and 33 flakes from the workshops were analyzed for hydration bands. Of these, 68 from the quarry, and 54 and 33, respectively from the workshops produced at least one culturally meaningful hydration band. As expected, obsidian appears to hydrate slowly at this high elevation. Yet, variation in hydration readings is low within stratigraphic contexts, suggesting relatively narrow windows of knapping activities in each excavation level. A small number of radiocarbon dates allow us to develop a preliminary hydration rate for Chivay obsidian in this high elevation location. Hydration data indicate that intensive quarrying began by 3800 cal. BC and stopped ca. 2300 cal. BC. By contrast, the two workshops appear to have been deposited 2900 and 1200 cal. BC, and 2700 and 2400 cal. BC. The data are consistent with an uptick in obsidian use by at least the Terminal Archaic period.     

An Approach to Integrated Physical-Geographic Description of an Area

The author proposes an outline for the physical-geographic treatment of an area, emphasizing the integrative aspect of geography instead of the widespread systematic approach. He considers integration a distinctive characteristic of geography and seeks to eliminate the usual enumeration of systematic factual data.     

An Information-Theory Approach to the Partitioning of an Area

The problem of partitioning a territory can be formulated as the problem of constructing a hierarchy out of a set of subsets of a given system of objects. In terms of graph theory, a hierarchy may be defined as a connected directed graph that is both antisymmetric and nonreflexive. The hierarchy represents the result of the partitioning process. The actual process of partitioning can be treated as one in which information is gained about the system as a whole, but is also lost about individual objects as a result of aggregation. This enables us to apply the criteria of information theory to evaluate the quality of various partition schemes and to solve problems of functional and homogeneous regionalization.     

Skill in Stone Knapping: an Ecological Approach

Journal of Archaeological Method and Theory - Skill has allowed lithic analyses to expand their scope beyond the limits set by a representational understanding of practices and sociocultural...     

Building an Experimental Comparative Reference Collection for Lithic Micro-Residue Analysis Based on a Multi-Analytical Approach

Residue analysis applied to stone tools is a useful aid for better understanding their past function and, by extension, reconstructing early human behaviour. However, if the nature of residues found on the lithic tools is misinterpreted, so will be our understanding of their archaeological context. As a consequence, correctly identifying residues in the domain of lithic studies is of paramount importance. With this main goal in mind, we analysed different experimental materials likely to have been involved in daily tasks in the prehistoric context (e.g. bone, wood, meat). Microscopic analyses were then carried out using two (comparable) techniques: Optical Light Microscopy and Scanning Electron Microscopy. Also, energy dispersive X-rays spectroscopy (EDX or EDS) was applied to the experimental samples to determine their elemental composition. Advantages and disadvantages of both microscopic methods and their implications for correct residue identification are discussed. The distribution of residues on lithic surfaces is also considered. This study resulted in the construction of a data-set including both photographic material and EDX spectra for each residue analysed. The main result is that, compared to OLM scanning, SEM analyses highly improves the accuracy of residue identification.     

Obsidian sources in highland Yemen and their relevance to archaeological research in the Red Sea region

The Red Sea and surrounding area formed through dynamic uplift and rifting of Afro-Arabia, and associated volcanism (both oceanic and continental in character). As a result, volcanic landforms and products are widespread and play a vital role in the natural and cultural landscapes of humans occupying the highlands and lowlands on both sides of the Red Sea. Archaeologists have suggested for some time that Afro-Arabian trade in obsidian had its roots in the prehistoric period and that the region was very likely the source of an abundance of obsidian artefacts found as far afield as Egypt, the Persian Gulf and Mesopotamia, and which do not match the well-known Anatolian, Transcaucasian or Mediterranean sources. Nonetheless, the southern Red Sea is one of the few obsidian-rich regions exploited in antiquity that has been barely investigated. In this paper, we highlight new geochemical analyses (carried out by LA-ICP-MS) of obsidian sources in Southern Arabia and beyond, that enhance our knowledge of obsidian exploitation from as early as the Neolithic period, and which enable us to evaluate the role that highland Yemen obsidian sources played in prehistoric long-distance trade. In addition, we present new evidence for explosive volcanic eruptions that likely affected the highland populations of Yemen in the 4th millennium BC.     

Obsidian sources and distribution systems in Island Southeast Asia: a review of previous research

This paper summarises research on obsidian findings across the region of Island Southeast Asia (ISEA), from the first reporting of obsidian on Sumatra as a result of cave excavations in the early 1900s through to the latest published discoveries in 2009. These results are the background for the first region-wide research project focussing on obsidian characterisation and its role in prehistoric inter-island exchange. It is commonly held that distribution of obsidian in ISEA was only localised and inter-island transportation limited. The review, however, suggests that this hypothesis derives from an incomplete knowledge of obsidian distribution in the region rather than typifying prehistoric social patterns. Obsidian sourcing has been carried out only intermittently in ISEA since the 1970s and has generally been focussed only at the single site level, thus explaining this very partial understanding.     

(Sea)ways of Perception: an Integrated Maritime-Terrestrial Approach to Modelling Prehistoric Seafaring

Journal of Archaeological Method and Theory - The seaways have played a significant role in the movement of people, goods and ideologies since prehistory; yet, the ephemerality of movement combined...     

Through the Glass Darkly: Prehispanic Obsidian Procurement and Exchange in Southern Peru and Northern Bolivia

Recent discovery of the major geological sources of Central Andean obsidian permits a new understanding of the patterns of obsidian procurement and exchange by the Prehispanic societies of southern Peru and northern Bolivia. Based on the trace element analysis of obsidian artifacts from 160 archaeological sites, it can be established that the two major deposits of obsidian were being exploited by 9400 BP, and that volcanic glass was being transported over long distances throughout Andean prehistory. Inhabitants of the Cuzco region acquired most obsidian from the Alca source in central Arequipa, while those in the high plateau surrounding Lake Titicaca obtained most obsidian from the Chivay source in southern Arequipa. Obsidian evidence suggests close ties between the Cuzco and Circum-Titicaca regions throughout prehistory, except during the Middle Horizon (ca. 1400–1050 BP), when the expansion of the Huari and Tiahuanaco states disrupted this pattern.     

English Regionalization and Sustainability: Towards the Development of an Integrated Approach to Strategic Environmental Assessment

Central to this article is the suggestion that modern planning and development frameworks in England are currently at a potentially productive, although problematic turning point. Whilst on the one hand the UK is attempting to make the legislative and institutional changes necessary to facilitate the process of regionalization and devolution, it is at the same time facing the challenge of ensuring the necessary levels of inter-agency cohesion and integration required for the delivery of the meta-objectives at the heart of sustainable development. Of particular concern for the English regions is the increasing complexity of organizational relations, the fragmentary nature of provisions, the potential mismatch between the need to preserve environmental welfare and at the same time ensure regional economic competitiveness, and more fundamentally, the failure to provide an appropriate mechanism for the evaluation of sustainable development goals. In the light of these challenges, the authors highlight the value of Strategic Environmental Assessment (SEA) as a mechanism for improving the environmental quality of decision-making and make recommendations as to how the regional level of decision-making can provide an effective platform for the development of an SEA system which is capable of reconciling the sustainability conflicts derived from different tiers of decision-making. Within this discussion, suggestions are made as to the manner in which current ideas for introducing sustainability appraisal for Regional Planning Guidance should be amended.