Soil geochemistry and detection of early Roman precious metal and copper alloy working at the Roman town of Calleva Atrebatum (Silchester,Hampshire, UK)

A geochemical soil survey was carried out over 500 m² of a first and second century AD house complex in insula IX of the Roman town of Calleva Atrebatum (Silchester, Hampshire, UK) where there was little prima facie evidence for non-ferrous metalworking. Preliminary analyses were made by XRF of lead, zinc and copper. These were followed by analysis for Au, Ag and Sn by ICP-MS of the samples with the highest concentrations of Pb, Zn and Cu. Certain of the Pb, Zn and Cu concentrations suggest the working of copper alloy including brass, and could be associated with archaeological evidence of hearths and burnt areas of second century AD date. Other samples have concentrations of the above metals and of gold and silver which do not appear to be associated with any physical remains of hearths and burnt areas. These concentrations date to the mid-first century AD.     

The application of microfossils in assessing the provenance of chalk used in the manufacture of Roman mosaics at Silchester

Microfossils recovered from chalk tesserae in mosaics from the Roman town of Calleva Atrebatum, modern Silchester, southern England, are used to suggest a provenance for the source-rock. The microfossils include foraminifera characteristic of late Cretaceous (Campanian) foraminiferal biozone BGS20 (quadrata macrofaunal biozone) and foraminiferal subzone BGS21i (basal mucronata macrofaunal biozone). Calcareous nannofossil assemblages from the same tesserae are poorly preserved, preventing precise age determination, but confirm an age of Santonian to Campanian. As indurated chalk beds of this age are not normally present in the stratigraphically higher chalks of southern England, it is probable that calcretised chalk, formed by secondary calcification beneath Palaeogene rock cover, was used to manufacture the tesserae. This suggestion is supported by a comparative analysis of chalk tesserae from the Norden Roman site in Dorset. Although the provenance of the chalk in some of the Silchester tesserae can be placed only within a broad geographical area of downland in southern England, others may have originated in the Dorchester–Swanage area, some 100 km to the southwest of Silchester, or the Portsdown area of southern Hampshire. None of the tesserae have been constructed from chalk found near Silchester.     

Luminescence dating of prehistoric hearths in Northeast Qinghai Lake and its paleoclimatic implication

Archeological research has been trying to provide evidence relevant to understanding both the timing of and processes responsible for human colonization of the Qinghai-Tibetan Plateau (QTP). Hearth is one of the most extensive, important, and typical prehistoric humanity activity evidence on the QTP. However, there are a number of hearths lacking charcoal material because of the wind and water erosion. Fortunately, most of these hearths can be dated by luminescence dating on the remnant sediments around the hearth. In this study, 18 optically stimulated luminescence (OSL) samples from 14 hearths in Yandongtai site (YDT) and Bronze Wire site (BW) in the northeast of Qinghai Lake area were systematically dated. The OSL ages range from 6.8 ± 0.7 to 14.4 ± 1.2 ka. There is a good agreement between OSL dating results and charcoal ages during the last deglaciation period, which indicates that OSL method has great potential in dating hearth on QTP. Combined with the previous dating results from other hearths, the age of hearths concentrates in 11–13 ka BP, i.e., the Younger Dryas (YD) chronozone. The increased number of hearths indicates reinforced colonization in the Qinghai Lake area during YD cold event, implying that the cold climate during YD event was not severe enough to hinder the inhabitation of prehistoric humanity at an elevation of 3.2 km.     

Variability in the Chronology of Late Holocene Aboriginal Occupation on the Arid Margin of Southeastern Australia

Analysis of 28 radiocarbon determinations obtained from the excavation of heat retainer hearths from Sturt National Park in western New South Wales, indicates Aboriginal occupation of the arid margin of Australia during the last 1700 years. The determinations show two phases of hearth construction separated by a period of at least 200 years, and possibly 400 years, when no hearths were constructed. Palaeoenvironmental and archaeological evidence is reviewed in an effort to account for the late Holocene dates from the hearths and the existence of the hiatus in hearth construction. Despite the close match between the hiatus and the so-called Medieval Warm Period, caution is required before extrapolating the results from an archaeological study of a small geographic region to the continent as a whole.     

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.     

Soil chemical identification of ten thousand years of prehistoric human activity areas at the Munsungun Lake Thoroughfare,Maine

Soils on a Palaeo-Indian to historic sequence in one Maine locale are analysed for chemical enrichment. To guide excavation of four discrete sites up to 4000 m², samples are collected in grid patterns and analysed for pH, Mg, P and Ca. Concentrations of Mg point to probable hearths to define some centres of human activity on each site. These correlate well with anomalies determined independently by magnetometric survey. Excavation of anomalies provides evidence of hearths, culturally diagnostic artifacts, but also features resulting from tree-throw and drainage variation. The P and Ca results develop definition and delimitation of activity areas thus refining directions for further excavation. Since P and Ca concentrations result from substantial or sustained human occupation, they show promise for preexcavation differentiation of habitation sites from limited and specialized activity sites such as lithic chipping stations. Soil chemical analysis provides both a synchronic and diachronic preview of site perimeters, size and activity areas. The consistent site definition at the Munsungun Lake thoroughfare is useful for explaining patterns as well as locating them.     

Refuse patterning and behavioral analysis in a pinniped hunting camp in the Late Jomon Period: A case study in layer V at the Hamanaka 2 site,Rebun Island,Hokkaido, Japan

During the Dobayashi New Phase (ca. 1450 cal BC–1300 cal BC), the Jomon maritime hunter–gatherers established pinniped hunting camps at the Hamanaka 2 site on Rebun Island, Hokkaido, Japan. They used the camps for animal processing and possibly cooking meat or processing fat using pottery vessels. Concentrations of conjoinable pottery around hearth features reveal that hearths were centers of activity. Analysis of conjoinable pottery within the excavated areas also indicates that artifacts were moved for the purposes of maintenance and cleaning of the hearths and activity areas.     

The telltale potency of a simple milligram of charcoal found in a hearth left by Mesolithic reindeer hunters in the Norwegian mountains

The discovery and excavation of superimposed, information-rich Pre-Boreal hunting sites around the mountain lakes of Myrvatn and Fløyrlivatn in Southwest Norway have been the subject of archaeological debate. A brief review of research is presented here. In contrast to the well-preserved sites, settlement remains of a diametrically different order occur in the strongly water-eroded zone of the lakeshores: small, surface hearths in almost every stage of preservation, from evident hearths to diffuse and irregular scatters of fire-cracked stones. The latter category seems generally underestimated as a source of evidence. However, recent finds at Myrvatn demonstrate how even blurred, heavily eroded and almost intangible hearth remains, by the support of wood anatomical analysis, radiocarbon dating and intra-site comparison, may reveal concise, invaluable information both about the history of local use and regional landscape development.     

MINERALOGICAL AND PETROLOGICAL INVESTIGATIONS OF EARLY BRONZE AGE COPPER‐SMELTING REMAINS FROM THE KIECHLBERG (TYROL,AUSTRIA)

The prehistoric settlement on the Kiechlberg hilltop is located a few kilometres to the north‐east of Innsbruck, in the Tyrolean Inn Valley. Despite its rather isolated location, a multiphase settlement between the fifth and the second millennium bc was confirmed by archaeological investigations in 2007 and 2008. Metallurgical artefacts, such as copper ore fragments, copper slag and raw copper, as well as finished copper and bronze artefacts, are concentrated mainly in Late Copper Age to Middle Bronze Age layers. The chemical compositions of the slag and raw metals confirm Fe—Zn tetrahedrite–tennantite (fahlore) smelting. The ore was most probably imported from the 30–50 km distant copper ore deposits (mainly fahlore) of Schwaz–Brixlegg, in the Lower Inn Valley. The small amount of slag and the presence of slagged and thermally altered ceramic fragments suggest copper production in small‐scale workshops. Most probably, sulphide‐rich ores were smelted in crucibles in a hearth fire. The process was relatively reducing below the 2Sb + 1.5O₂ → Sb₂O₃ reaction (?8.5 log fO₂ at 1100°C), producing Sb‐rich (>10 wt% Sb in metal) raw copper. Inhomogeneous slag remains containing high amounts of sulphide and metal inclusions suggest a poor separation of the metal, matte (copper sulphide) and silicate/oxide melt during the smelting process.     

Economic and environmental changes during the 4th and 3rd millennia BC: the 25th Jubilee Symposium of the AEA in Bad Buchau,southern Germany

Abstract

This study represents the first detailed published analysis of a relatively large archaeologically derived faunal assemblage in eastern Beringia for the Late Pleistocene/Early Holocene. The faunal remains, dated to 10,100 cal. BP, are well preserved and have highly resolved spatial association with lithics and hearth features. Factors in the formation of the assemblage are assessed through analyses of weathering, presence/absence of carnivore damage, fragmentation patterns, bone density, and economic utility. Taphonomic analyses indicate that human transport and processing decisions were the major agents responsible for assemblage formation. A spatial model of wapiti and bison carcass processing at this site is proposed detailing faunal trajectories from the kill sites, introduction on site in a central staging area to peripheral marrow extraction areas associated with hearths and lithic items. Data from mortality profiles, spatial analysis, and economic analysis are used to interpret general economy and site function within this period in Interior Alaska. These data and intersite comparisons demonstrate that considerable economic variability existed during the Early Holocene, from broad spectrum foraging to efficient, specialized terrestrial large mammal hunting.     

Charcoal scarcity in Epigravettian settlements with mammoth bone dwellings: the taphonomic evidence from Mezhyrich (Ukraine)

Fuel management during the Paleolithic periods is an important issue to understand past human subsistence. Numerous Palaeolithic sites relate an abundance of burnt bones in hearths and an absence or scarcity of wood charcoals, which leads studies to focus on burnt bone remains and the use of bones in hearths. Few works take into account the micro-residues of wood charcoals which can still be present in hearth areas and excavated sediments. We studied the Epigravettian site with mammoth bone dwellings of Mezhyrich (Ukraine) previously characterized by its high content of burnt bones and an “absence” of wood charcoal during the so-called mammoth steppe. The presence or absence and proportions of both wood charcoals and burnt bones were quantified in macro-, meso- and microscale sediment size fractions by an image analysis method. Our results show that excavations during field-works at Mezhyrich give only a partial image of the original anthracological record and that most charcoal materials are lost with standard archaeological and anthracological approaches. The scarcity of charcoals in this site was possibly due to an important mass reduction accentuated by the addition of bones in hearths. By applying our protocol we recovered a significant amount of wood charcoals which provides the first ¹⁴C dates from charcoals at Mezhyrich. Numerous charcoals are identified contributing subsequent information about vegetation, environment and burning practices. They indicate, by comparison with pollen data already collected, the presence of forest patches in a mammoth steppe landscape, which might have influenced the collecting behavior of Epigravettian populations.     

A new approach to study the fuel used in hearths by hunter-gatherers at the Upper Palaeolithic site of Abri Pataud (Dordogne,France)

The fuel used in hearths in the Upper Palaeolithic period and the management of this fuel have long given rise to questions on intentional or opportunistic human comportment. To understand how fuel was managed during the Aurignacian and Gravettian cultures, hearth samples from the French site of Abri Pataud (ca. 34–20 kyr BP) were collected. An image analysis method for the automated quantification of burnt particles from macroscopic-to-microscopic sediment fractions was developed, and the results obtained using this method were compared with the palaeoenvironmental data available close to the site. At Abri Pataud, the use of bones was dominant during the Pleniglacial, suggesting an intentional practice. However, environmental pressures could have influenced the fuel management practices of the hunter-gatherers, even if the dualistic relationship between the availability of firewood and the use of bone in hearths must be considered. Thus, burnt particle quantification provides more than just an observation of burnt macroremains in hearths: it relates to fundamental information on human behavior.     

Cemented ash as a receptacle or work surface for ochre powder production at Sibudu,South Africa, 58,000 years ago

The white ash of Sibudu hearths sometimes became cemented and, when this was the case, some of these crusts were used as work surfaces or receptacles, particularly in occupations dating about 58,000 years ago. Substantial deposits of red and yellow ochre powder have been found on these crusts. This suggests that the ochre was not associated with hearths for heat treatment because yellow ochre readily transforms to red even at low temperatures. XRF readings suggest that the ochre used at the site derives from different geological sources. Micromorphological studies imply that phosphatization caused the cementation of the ashes in some hearths, while gypsum growth hardened one of the hearths described here.     

‘The debatable territory where geology and archaeology meet’: reassessing the early archaeobotanical work of Clement Reid and Arthur Lyell at Roman Silchester

The first large-scale archaeobotanical study in Britain, conducted from 1899 to 1909 by Clement Reid and Arthur Lyell at Silchester, provided the first evidence for the introduction of Roman plant foods to Britain, yet the findings have thus far remained unverified. This paper presents a reassessment of these archaeobotanical remains, now stored as part of the Silchester Collection in Reading Museum. The documentary evidence for the Silchester study is summarised, before the results are presented for over a 1000 plant remains including an assessment of preservation, identification and modern contamination. The dataset includes both evidence for the presence of nationally rare plant foods, such as medlar, and several archaeophytes. The methodologies and original interpretations of Reid and Lyell's study are reassessed in light of current archaeobotanical knowledge. Spatial and contextual patterns in the distribution of plant foods and ornamental taxa are also explored. Finally, the legacy of the study for the development of archaeobotany in the 20th century is evaluated.     

New dates from Ushki-1, Kamchatka,confirm 13,000 cal BP age for earliest Paleolithic occupation

For many years cultural layer 7 at the Ushki sites, Kamchatka was considered to represent the earliest human occupation of Beringia, because four radiocarbon dates indicated an age of 16,000–17,000 calendar years ago (cal BP). In 2003, however, Goebel et al. reported that layer 7 more likely formed only 13,000 cal BP, nearly 4000 years later than N.N. Dikov, the site’s primary excavator, originally reported. Some researchers have downplayed the significance of the new dates, continuing to regard Dikov’s early dates as evidence that at least some of the hearth and dwelling features previously excavated at Ushki-1 date to as early as 17,000 cal BP. Here we present four new radiocarbon dates (and two previously unpublished dates) on curated charcoal from hearth features excavated at Ushki-1 more than 20 years ago. They indicate that these hearths and associated dwelling features date to about 13,000 cal BP. We now know 15 radiocarbon dates on charcoal from a variety of features and profiles across Ushki-1 and Ushki-5 that indicate the age of layer 7 is about 13,000 cal BP. We discount the four 16,000–17,000 cal BP dates, first, because two of them came from a deeply dug human burial pit and were likely secondarily introduced into the burial; second, because provenience data for the other two dated samples were never reported and do not exist in the records of the radiocarbon laboratories that produced them; and, third, because sediments immediately underlying layer 7 at Ushki-1 are only a few centuries earlier than 13,000 cal BP, providing an important lower-limiting age for the layer-7 occupation. We conclude that the age of all of the layer-7 features at Ushki-1 and Ushki-5 should be considered to be about 13,000 cal BP, at least until the earlier obtained old dates of 16,000–17,000 cal BP can be replicated.     

Fuelling the Fires: The Contribution of Wood Charcoal Analysis to a Landscape Scale Project at and Around Pre-Conquest Iron Age Silchester and a Reflection on Its Wider Implications

ABSTRACT

The contribution of targeted wood charcoal analysis (anthracology) to understanding of the 1st millennium BC Pre-Conquest Late Iron Age oppidum and transition to Early Roman town life at Silchester and nearby late prehistoric hinterland sites investigated by the Silchester Environs project is considered. Attention is given to whether substantive differences in charcoal assemblages of varying size and origin are discernible through time and space, and to their value in elucidating landscape, environment, woodland structure, taphonomy, site function and lifestyles. This paper aims to take stock of the work so far and reflect on what lessons can be learned within and beyond the project. Site-level data are summarised and contrasted for the reader, while full context-level interpretation is published elsewhere [Barnett Forthcoming a. “The Early Roman Wood Charcoal and Waterlogged Wood at Silchester.” In Silchester Insula IX: The Claudio-Neronian occupation of the Iron Age Oppidum. Britannia Monograph Series, edited by M. G. Fulford, A. Clarke, E. Durham, and N. Pankhurst. London: The Society for the Promotion of Roman Studies; and Barnett Forthcoming c Barnett, C. Forthcoming c. “Overview of the Archaeobotanical Evidence.” In Silchester Environs: the Landscape Context of Iron Age Calleva, edited by C. Barnett and M. G. Fulford. Oxford: Oxbow Books monograph due 2020. [Google Scholar]. “Overview of the Archaeobotanical Evidence.” In Silchester Environs: The Landscape Context of Iron Age Calleva, edited by C. Barnett, and M. G. Fulford. Oxford: Oxbow Books monograph].     

LA–ICP–MS,SEM–EDS AND EPMA ANALYSIS OF EASTERN NORTH AMERICAN COPPER‐BASED ARTEFACTS: IMPACT OF CORROSION AND HETEROGENEITY ON THE RELIABILITY OF THE LA–ICP–MS COMPOSITIONAL RESULTS*

This study discusses the relevance of compositions obtained using laser ablation – inductively coupled plasma – mass spectrometry (LA–ICP–MS) for the purpose of identifying the provenance of copper‐based artefacts found in Virginia at Native American sites dated from the 16th to the 18th centuries. Ten artefacts were investigated by scanning electron microscopy – energy dispersive spectrometry (SEM–EDS) to visualize the corrosion and characterize the heterogeneities in the metal and electron probe micro‐analysis (EPMA) to determine separately the compositions of the intact metal and of the corrosion product. It is shown that the corroded surfaces are highly depleted in zinc but that representative concentrations can be determined by sampling the deeper, uncorroded metal. In contrast, lead values are highly variable because of the heterogeneous distribution of this metal within the bulk copper. Despite these problems, brass is easily identifiable and American native copper and European smelted copper can be unambiguously distinguished with LA–ICP–MS on unprepared artefacts using As, Ag, Ni and Sb trace elements.     

Cesium magnetometer surveys at a Pithouse Site near Silver City,New Mexico

The La Gila Encantada Site is located on an isolated ridge top north of Silver City, New Mexico in an area defined culturally as the Mimbres Mogollon region. The 180 m × 80 m (14400 m²) sized site was originally recorded as a dense scatter of ceramics, lithics, and ground stone along with a number of surface depressions that appear to represent pithouses. Cesium magnetometer surveys were conducted to identify hearths, pithouse boundaries, and activity areas outside of pithouses in support of archaeological investigations, and to test this instrument's ability to image these features. This paper presents a characterization of the magnetic signature of a pithouse as a magnetic high in the center caused by the central hearth, low magnetic variability along the floor of the house, and then increased magnetic variability at the pithouse boundary. This characterization was successfully confirmed for three pithouses using cesium magnetometery and archaeological excavation.     

Andean Ores,Bronze Artifacts,and Lead Isotopes: Constraints on Metal Sources in Their Geological Context

With a focus on bronze production in the south-central Andes during the Middle Horizon, this study reports the first archaeological use of lead isotope analysis to investigate metallic ores and metal artifacts in the Andean zone of South America. Because the vast majority of metal deposits in the Andean cordillera formed in a convergent plate boundary setting, lead isotope compositions of most Andean ore sources are not unique. Lead isotope ratios of central and south-central Andean ores define four geographically distinct ore lead isotope provinces, oriented and elongated parallel or sub-parallel to the trend of the Andean cordilleras. Consequently, ore lead isotope ratios vary strongly from west to east along transects through the coast, highlands, and altiplano, but they exhibit much less variation from north to south. The strong west-to-east variation in ore lead isotope signatures allows discrimination between ore bodies, and ultimately between metal artifacts, as a function of macro-ecozone location: coast, junga-qiswa, puna, and altiplano. We present the most up-to-date database of ore lead isotope signatures for the south-central Andes including those determined for ores we sampled over an approximate 250,000-km² region within Bolivia, northern Chile, and northwest Argentina. Lead isotope signatures of Cu-As-Ni bronze artifacts from Tiwanaku (altiplano capital) and San Pedro de Atacama (desert oasis entrepôt) establish that altiplano and high sierra ore bodies provided the metal for both assemblages. Conchopata (Wari) arsenic bronze artifacts exhibit lead isotope ratios compatible with the Julcani (Huancavelica) copper sulfarsenide deposit.