Assessing XRF for the geochemical characterization of radiolarian chert artifacts from northeastern North America

The purpose of this paper is to emphasize the benefits of adopting non-destructive energy dispersive X-ray fluorescence (ED-XRF) as a first-order technique to determine chert whole-rock geochemistry for archaeological sourcing. Chemical signatures for the Touladi and La Martre prehistoric quarries from the lower St. Lawrence and Gaspé Peninsula region of Quebec, Canada, are determined and serve as references to test the provenance of regional chert artifacts. Chert experimental flakes, created from quarry geological hand samples, are analyzed and used to validate the method. Archaeological flakes and tools recovered from three archaeological sites are analyzed and tested against quarry samples. Geochemical diagrams and Principal Component Analysis are used to establish artifact-quarry relationships. The effects of surface weathering on the geochemical analysis of archaeological chert artifacts are presented. Sample restoration and research avenues are discussed and proposed to further enhance the robustness of future chert geochemical data sets.     

PHOSPHATES IN ARCHAEOLOGICAL FINDS: IMPLICATIONS FOR ENVIRONMENTAL CONDITIONS OF BURIAL*

The occurrence of coarse‐grained vivianite and mitridatite aggregates in a potsherd, a grand ring and a timber imprint from the Second Iron Age site of Adria (Rovigo, northeastern Italy) suggest contrasting environmental conditions of burial. In particular, bone fragments were replaced by vivianite at relatively low pH and Eh, due to the presence of deteriorating organic matter, together with slag and iron flakes. Subsequent interactions with Ca‐rich groundwater characterized by higher pH and Eh determined the growth of mitridatite after vivianite. Although phosphates crystallized after burial, the examined samples were not involved in pervasive chemical contamination.     

Micromorphology of a Late Woodland Cave Site,East-Central Iowa

Abstract

This article discusses a micromorphological investigation conducted at Bogus Cave (13JN23), a Late Woodland occupation in Jones County, Iowa. Micromorphology–the study of undisturbed soil and sediment in thin section–was used to evaluate, and differentiate between, natural and cultural processes evidenced within the cave sediments. Twenty-two thin sections were prepared from samples collected from test units excavated in the front room of the cave, the principal site of human occupation. The cultural material was confined to a 55-cm-thick surface layer that rests on an accumulation of angular to subangular boulder-size dolostone blocks, the result of one or more episodes of pre-Holocene ceiling collapse. The thin sections revealed an accumulation of exogenous mineral grains, chert microdebitage, microvertebrate remains, and charcoal fragments in an organic-rich clay matrix. The absence of microstratification in the samples collected from the artifact-bearing stratum supports previous macroscopic evidence for a thorough mixing of the deposits that precludes an accurate contextual interpretation of the archaeological component.     

Toolstone constraints on knapping skill: Levallois reduction with two different raw materials

Lithic raw material constraints are widely assumed to be a determining factor of flaked stone tool morphology, but this assumption remains largely untested. We conducted a controlled experiment to determine whether a knapper’s growing replication skills would be hindered if the toolstone used was switched from large flakes of an easily worked chert to nodules of less tractable one. Two batches of Preferential Levallois cores were knapped, an earlier series made from standardised large flakes of sediments dominated by chalcedonic quartz followed by a more challenging one using variably-shaped, cortical nodules of microcrystaline quartz that varies in the completeness of quartz replacement of calcite and dolomite. Skill level markers were designed to measure the knapper’s ability to achieve a series of set goals. These were quantified and subjected to statistical testing. In all but one test, significant increases in skill could be detected from the earlier to the later batch of reductions, despite the drop in toolstone quality. Significant improvements in the consistency of the knapper’s output could also be detected. However, the switch to a more challenging, nodular chert did require extra shaping, which resulted in more waste. This masked visible progress towards producing a less costly core. Overall, our results do not support the assumed primacy of toolstone constraints over other factors in influencing the morphology of flaked stone tools.     

Chemical Alteration of Lithic Artefacts: an Experimental Case Study on the effect of Guano on Stone Flakes and Its Contextualization in the Archaeological Assemblage of Azokh Cave (Southern Caucasus)

Chemical weathering of archaeological material is well known; however, while there have been a number of experimental studies demonstrating different types and degrees of chemical alteration on faunal remains, little attention has been paid to stone tools, and the few studies that exist relate mainly to siliceous materials and water‐induced chemical alteration. Azokh Cave, located in the South Caucasus, contains a Middle Pleistocene to Holocene infill, and detailed macro‐ and microscopic examination of the lithic assemblages recovered there indicates potential chemical weathering of the stone artefacts. The cave is also currently home to one of the largest bat colonies in the region, and their guano forms a significant component of the infill of the inner galleries. Based on these two factors, an experimental pilot study was set up to artificially chemically alter a range of stone flakes produced specifically for the task, in order to determine the nature and likely cause of weathering. The experimental flakes, produced from different raw materials, were buried in fresh bat guano for up to two years. The results reported herein demonstrate that in a relatively short time, the highly acidic composition of bat guano strongly affects calcium‐bearing rocks (e.g., limestone, basalt) altering their entire surface. Similar comparisons may be made with chemical alteration evident on archaeological lithics from Azokh Cave, suggesting that bat guano has played a significant role in diagenetic alteration.     

UNDER THE HAMMER: RESIDUES RESULTING FROM PRODUCTION AND MICROWEAR ON EXPERIMENTAL STONE TOOLS*

This paper presents the results of an experimental programme investigating the effects of production processes on stone tools and their interference with use‐related features. In the first part of the experimental programme, a series of flint flakes was retouched with different kinds of hammers in order to assess the extent and nature of percussion residues. After careful environmental scanning electron microscope (ESEM) observation and energy‐dispersive X‐ray (EDX) analysis, the retouched flakes were thoroughly cleaned and the underlying flint deformation was recorded. The second part of the experimental programme involved selecting several uncleaned retouched pieces for use in short woodworking, hide‐processing and butchery experiments. These pieces were observed and analysed before, during and after use. Some of the percussion features proved to be surprisingly resistant to use, and in some cases turned out to be strikingly similar in appearance to use‐generated features.     

Mixed occupation during the Middle Palaeolithic: Case study of a small pit-cave-site of Les Pêcheurs (Ardèche,south-eastern France)

The Pêcheurs cave is a unique example of a Middle Palaeolithic site with three kinds of accumulations: (1) ibex that died in a natural trap, (2) carnivores that died within the cavity, and, (3) a series of short-term occupations by humans who left a few artifacts and a hearth area. Biological patterns of ibex remains (skeletal parts, age) show a homogeneous structure, related to natural death inside the cave. The Chassezac valley is narrow and sinuous, bordered by steep cliffs occupied by well-adapted hoofed-species (Caprinae). Moreover, Les Pêcheurs is a shallow cave, pit-like, and in its deepest part (Sector 4) provided both man and animals with shelter. The presence of a fire place (in the middle of the sequence of Sector 4) firmly indicates the presence of an in situ occupation by a small group of hominids. According to the stratigraphical patterns and the analysis of the lithic assemblages, artifacts do not seem to have been introduced into sediments. The lithic assemblages (technically homogeneous) indicate that small mobile human groups inhabited a cave that offered, by virtue of its morphology, a natural shelter against the cold winds blowing in the Chassezac valley and the plateaus of the south-eastern borders of the Massif Central Mountains. The exploitation of biotopes such as this rocky area constitutes a specific case of human subsistence behavior and settlement strategy. The deepest layer is characterized by a lithic assemblage mostly made of local raw material (quartz) implying a low investment in lithic production. Few flakes made from non-local flints attest to the mobility of the human occupants who moved across these areas and perhaps found in the valleys, short-term refuge.     

Deciphering bone depositional sequences in caves through the study of manganese coatings

The presence of black-coloured bones in caves has been sometimes associated to the use of fire by humans, but more frequently the agent responsible for black colour is the natural deposition of manganese oxides. Manganese coatings were not usually studied once human action was discarded. However, they can provide valuable information about the origin and the sequence of formation of a palaeontological or archaeological deposit. In this paper, we present a quantitative and qualitative study of the manganese coatings that affect most of the bones recovered in the palaeontological site of Liñares cave (NW of Iberian Peninsula) together with other taphonomic marks. The manganese coatings are superimposed on other features previously existing on the surface of the bones. In turn, the coatings can be affected by other agents that modified them totally or partially. The combined interpretation of the different taphonomic marks provides us with valuable information on the sequence where the different taphonomic processes were produced, as for example the intervention of carnivores in the disarticulation of some elements before the burial, the preservation of anatomic connections until after the burial of the carcasses, and the existence of reworking processes in some parts of the infill.     

Non-destructive provenance study of chert using infrared reflectance microspectroscopy

In this paper we explore the potential of non-destructive Infrared reflectance microspectroscopy (IRRMS) for the characterization of chert samples from 10 different geological outcrops in North America with emphasis on the Midcontinent. A principle objective of the project is to determine whether IRRMS analysis can provide a mineral-based signature for bedrock sources of chert artifacts. The technique utilizes a Bio-Rad Digilab FTS-40 Infrared spectroscope and microscope attachment that reflects an infrared beam off a chert specimen. Our findings indicate that spectral features from the molecules constituting minor and trace minerals in chert may provide sufficient characterization for chert sourcing.     

THE TECHNOLOGICAL AND TYPOLOGICAL BEHAVIOUR OF A NEANDERTHAL GROUP FROM EL SIDRÓN CAVE (ASTURIAS,SPAIN)

This paper presents the first detailed analysis of the lithic industry from El Sidrón Cave. Previously we have published other works concerning Anthropology and Palaeogenetics. The lithic assemblage contains 415 artefacts coming from both unofficial and official excavations and is largely flake‐based. The raw material derives from the immediate cave environment, and is mostly chert, with quartzite in a lesser proportion. To date, 67 artefacts have been refitted, including some tools and cores. The spatial distribution of the refitted lithic artefacts confirms, on the one hand, the unity of the assemblage and, on the other, its secondary context.     

Systematic Reworking of Lithics from Earlier Cultures in the Early Holocene of Dakhleh Oasis,Egypt

Abstract

A raw material form scarcely mentioned in the literature on lithic production—chipped stone artifacts manufactured by members of still earlier cultures—is used for a substantial portion of the toolkits in certain industries of Dakhleh Oasis, south-central Egypt. In one group of early Holocene (Masara) sites, the majority of double patinated tools are chunky burins, systematically manufactured from Levallois flakes and similar thick-sectioned older artifacts. Since fresh chert and other workable stone is available in the area, it appears that old, recycled lithics constitute the preferred raw material for these tool classes. The sites in question seem to be field camps where the burins were both made and used.     

Assessing bone transformation in late Miocene and Plio‐Pleistocene deposits of Kenya and South Africa

Bone reactivity offers a potential way to record local physical–chemical conditions prevailing in fossilization environments and archaeological sites. In the present study, a series of fossil bone samples from the karstic environments of the Bolt's Farm cave system (Cradle of Humankind, South Africa) and from fluvio‐lacustrine environments of the Tugen Hills (Gregory Rift, Kenya) is analysed. The chemical composition and infrared and nuclear magnetic resonance (NMR) spectroscopic properties of fossil samples point to a transformation of the biogenic apatite and formation of secondary apatite. Depending on the sample, the secondary apatite corresponds to a carbonate‐bearing hydroxy‐ or fluor‐apatite. The maximum fraction of secondary apatite is close to 60%, coinciding with previous observations in experimental alteration of bone in aqueous solutions and suggesting that a fraction of pristine biological apatite is likely to be preserved. The present results also suggest that the acetic acid treatment of fossil samples moderately increases their average crystallinity but may dissolve carbonate‐rich domains of secondary apatite.     

Geophysical investigations in the service of Mount Carmel (Israel) prehistoric research

Geophysical investigations in el-Wad Cave, Mount Carmel, Israel, enabled the mapping of the surface of the bedrock and a reconstruction of the depth of the archeological deposits. Seismic refraction and Ground Penetrating Radar (GPR) provided similar results, indicating the potential value of geophysical studies when one seeks to reconstruct site features and establish future excavation strategies. Results of a GPR survey later conducted in the adjacent Jamal Cave were supported, to a high degree, by subsequent archeological excavations in the course of which Lower and Middle Paleolithic layers were unearthed.A Continuous Vertical Electrical Sounding (CVES) geoelectric survey in the (collapsed) Misliya Cave indicates a low resistivity layer at the upper, central part of the cave, suggesting that lithified archeological deposits, of ca. 4 m, are preserved at the site. This has been supported by a test excavation recently conducted at the site.More intriguing is the case of what, on the basis of the outer morphology of the cliff, seemed to be another collapsed cave just to the north of el-Wad. The CVES survey, at the bottom of the cliff and across the hypothesized cave (or chamber), shows a two-layer model, with a low resistivity (100–200 ohm-m) layer, overlying a layer of high resistivity (8000–10,000 ohm-m). A trial trench indicates that here the bedrock is covered by shallow, recent, surface material, with no archeological value.All three methods of geophysical investigation proved applicable and resulted in the successful evaluation of sites' location, depth and spatial extension, thus forming essential tools in future prehistoric research.     

Vein quartz in lithic traditions: an analysis based on experimental archaeology

Worldwide, vein quartz was a commonly used raw material for stone tools but this material has proved difficult for archaeologists to analyse because many quartz assemblages appear to be comprised of amorphous pieces, not easily recognised as humanly modified or forming ‘tools’. This paper discusses the analysis of the debitage – focusing on the debitage fragmentation rate, the debitage, break, and fragment types, and the quantitative analysis of the complete flakes – resulting from experimental knapping of quartz, which formed part of a project which investigated the use of quartz in Irish prehistoric lithic traditions. The results have highlighted the complexity involved in analysing quartz assemblages, and the significant differences between the debitage products of quartz and chert knapping assemblages. While bipolar knapping is generally easy to differentiate from direct percussion, it is harder to differentiate between soft and hard hammer percussion.     

Sentinel Butte: neutron activation analysis of White River Group chert from a primary source and artifacts from a Clovis cache in North Dakota,USA

Instrumental neutron activation analysis (INAA) was used to characterize the chemical composition of chert from a primary source in western North Dakota. Known as Sentinel Butte, this source is part of the Eocene-age White River Group (WRG), a widespread geological formation on the central and northern Plains. INAA results demonstrate that it is chemically distinct from other known chert-bearing WRG. Further, analysis of three bifaces from the nearby Beach Clovis cache site demonstrates that they are made of chert from Sentinel Butte, and most likely the other 55 White River Group Silicate (WRGS) bifaces in the cache are as well. Although Clovis caches typically are dominated by materials transported hundreds of kilometers, it is argued that the advance manufacture and caching of bifaces even a short distance from a source may be a highly effective tactic to reduce gearing up time and hence search costs associated with the pursuit of mobile game at the close of the Pleistocene.     

The chert from the Castelltallat Formation (south-central Pyrenees): archaeometric characterisation and archaeological implications

Chert from the limestones and marly limestones of Castelltallat Formation (Ebro Basin) was widely used throughout prehistoric times in north-eastern Iberia to produce stone tools due to its properties and accessibility. A rough estimate indicates that this rock—either as raw material or as lithic products—was distributed mainly to the north of the outcrops, over an area of 6000–8000 km². However, other rocks in the area have similar characteristics which can lead to confusion in the interpretation of its prehistoric use and distribution. In order to establish useful archaeometric criteria for differentiating this chert from other similar, the Castelltallat chert is characterised in petrographic, mineralogical and geochemical terms. The chert nodules are found to be homogenous at the macroscopic and microscopic level, with a significant presence of bioclasts, thus indicating they might be formed in a freshwater lake environment by the early diagenetic replacement of carbonates in shallow waters. The mineralogical composition is homogeneously uniform and of a flint type, characterised by an almost exclusive predominance of quartz, without any opaline phases, and a variable proportion of moganite. The iron oxide content is very low, whereas its chemical composition is unusually high in uranium which correlates positively with carbonate content and negatively with silica. Archaeometrical parameters are provided to reach a proper identification of tools knapped with this chert. This way, chert from Castelltallat Formation turns out to be a valuable lithological marker to evaluate the range of mobility of the human groups who lived in the north-eastern Iberia and their contacts with neighbouring areas.     

The Bearded Vulture (Gypaetus barbatus ) as an Accumulator of Archaeological Bones. Late Glacial Assemblages and Present-day Reference Data in Corsica (Western Mediterranean)

Assemblages of 751 bone remains of an endemic Corsican deer (Megaloceros cazioti) from Late Glacial layers at Luri- Grı̀tulu cave (Northern Corsica) show an uncommon taphonomic pattern, mainly characterized by high dominance of third phalanxes and high rate of digestion marks. The authors demonstrate that this pattern cannot result from accumulation by human beings or by large mammal carnivores. The bearded vulture, which is able to accumulate large mammal bones in its nest and the presence of which is attested in the faunal remains at Grı́tulu, is the principal putative accumulator. In order to test this hypothesis, bone contents from 11 nests of modern Corsican bearded vultures (871 bone remains, i.e., more than 105 individual carcasses) are analysed from a taphonomic point of view. They are mainly characterized by overwhelming quantities of third phalanxes from middle-size ruminants, abundance and location of digestion marks around proximal articulations, and few bone flakes. A comparison of the Grı́tulu cave assemblages with these new present-day reference data leads to the conclusion that they have actually been accumulated by Late Glacial bearded vultures. Small discrepancies can, however, be explained by differences in food availability between the Late Glacial and modern times.     

Archaeological implications of human-derived manganese coatings: a study of blackened bones in El Mirón Cave,Cantabrian Spain

The main interest in the study of taphonomic processes lies, from the archaeological point of view, in being able to draw conclusions about human behaviour from them. This paper analyzes the causes of a specific taphonomic alteration: the differential appearance across levels and among site areas of a black stain on bones from the Magdalenian levels in El Mirón Cave. From an understanding of these taphonomic agents, we aim to achieve a better comprehension of aspects of human use of the cave toward the end of the Late Glacial period. By determining the processes that stained many of the bones with manganese in the rear part of the cave vestibule, we are able to suggest some characteristics of the human occupation of the cave and its possible seasonal use.     

A Taphonomic Perspective on Neolithic Beginnings: Theory,Interpretation, and Empirical Data in the Western Mediterranean

The fills of caves and rockshelters generally comprise complex depositional palimpsests, making fine scale chronological resolution extremely difficult. Nevertheless, these settings remain very important in archaeology because they often preserve long records of cultural change. This is true for the initial appearance of food producing economies in the western Mediterranean. The chronologically ambiguous nature of cave and shelter deposits is one of the reasons for the continued debate over the processes responsible for the beginning of the Neolithic in this region. We employ taphonomic studies of the archeofaunal record from Mesolithic and early Neolithic cave and shelter sites in Mediterranean Spain to disentangle some of the formation processes affecting relevant deposits in order to better understand the processes of cultural change that led to the spread of agricultural communities.