Artefact Morphology Research Articles

Mineralogy and chemical composition of lithic artefacts for characterization of raw materials and provenance in archaeological sites of Salobo, Carajás, Pará, Brazil

The Carajás Mineral Province is home to several archaeological sites, each with numerous stone artefacts elaborated in diferente materials. We studied the morphology, mineralogy, and chemistry of lithic artefacts recovered at the archaeological sites in the impacted area of the Solobo copper and gold mine in the Carajás Mineral Province. The results obtained from XRD, XRF and SEM/EDS analyses show that the starting material used was a semi-hard kaolin (semi-flint) that consisted of kaolinite, cryptocrystalline quartz, florencite, sericite, and hematite. This suggests that the same source of raw materials was involved and that this possibly reflected preference for this material. Additionally, the hardness of this raw material probably allowed the artefacts to be elaborated with ease. The mineralogical and chemical results, combined with characteristics of the artefacts' morphology and texture, indicate a relation among the archaeological sites. Similar material to that used in the production of the Solobo artefacts was found in the Alto Bonito amethyst mines that are located 40 km to the north. This site is therefore considered as the source of the raw material used for these artefacts. Finally, this indication is supported by the association of the abundant rock crystal chips and amethyst with the semi-hard kaolin present at the Alto Bonito mine.

Using virtual reality environments to unveil the imageability of the city in homogenous and heterogeneous environments

The presented work explores the way the information conveyed by the morphology of urban artifacts affects the way we perceive the built environment. The above exploration is implemented by means of Virtual Reality Environments we have specifically developed for this purpose. We compare heterogeneous environments characterized by a heavy tailed distribution with homogeneous environments that are characterized by normal distribution and show that the former provide higher level of information and thus better imageability than the latter.

Estudio de la inversión de energía aplicada en la manufactura de instrumentos líticos recuperados en la costa rionegrina del golfo San Matías (Argentina) a lo largo del Holoceno medio y tardío [Study of the energy investment applied in the manufacture...

Estudio de la inversión de energía aplicada en la manufactura de instrumentos líticos recuperados en la costa rionegrina del golfo San Matías (Argentina) a lo largo del Holoceno medio y tardío [Study of the energy investment applied in the manufacture...

Direct dating of resin hafted point technology in Australia

The rare recovery of hafting technology from archaeological deposits around the world prevents a clear picture of Palaeolithic hafting arrangements. Without the recovery of hafted stone tools, our understanding of this technology is limited to extrapolation from artefact morphology and ethnographic analogy, and such is the case in Australia. Here we present a direct date of 3160–2954 cal. BP, obtained from resin on a stone point recovered from Carpenters Gap 1 rockshelter in northern Western Australia. This artefact fits the description of point technology in Australia, being a retouched flake with converging margins, and provides the first direct date of hafting resin in situ on a stone tool from the Australian continent. The hafting arrangement of a stone point during the mid- to late Holocene is archaeologically visible for the first time in Australia. This point was hafted using resin adhesive as well as wound binding material. This rare artefact is used to discuss the current interpretations of technological change in the Holocene record of Australia and the direct dating process.

Geographical variation in Australian backed artefacts: Trialling a new index of symmetry

Geographical variation in backed artefact size and morphology has long been recognised in Australia. This paper evaluates a novel measure of symmetry that can quantify regional and continental-scale geographic patterns in backed artefact forms. The result indicates that we can construct new depictions of regional differences in Australian backed artefacts, and that evolutionary explorations of those differences are worthwhile.

Retouched artifacts production in three hunter–gatherer contexts from Tierra del Fuego (southernmost South America, Argentina): Avilés 1, Avilés 3 and Herradura 1

This paper aims to identify technological decisions involved in the production of retouched lithic artifacts recovered from three Late Holocene archaeological sites located in the northeast of the Isla Grande of Tierra del Fuego (Argentina). More specifically, the main goal is to assess whether there is any relationship among raw material selection, retouching intensity, and the morphology of retouched artifacts. Through the analysis of several correlations between the knapping quality of the different raw materials employed and the index of invasiveness and curvature, it is inferred that raw materials were selected according to their homogeneous texture and convex shape in order to produce long retouched edges. As most of the retouched artifacts have been produced on unifacial blanks, using unipolar debitage techniques which does not require specific knapping skills, it is proposed that similarities found in the three archaeological sites can be explained as a result of oral transmission of basic technological knowledge.

Copying errors of potters from three cultures: Predictable directions for a so-called random phenomenon

The impact of copying error on change in artifact morphology is studied through a field experiment with three groups of potters, each with a distinct potting tradition (one from France and two from India). The nine French potters and the 12 Indian potters had to reproduce – in five specimens – four different model shapes with two different weights of clay (in total, each potter threw 40 pots). Results show that the variability generated while copying depends on both the difficulty of the task and the cultural learning niches of the potters. We conclude that, even though unintended, the copying error is culturally constrained and therefore its amplitude and directions predictable. This is attributed to the cultural selection of motor skills during apprenticeship.

Positron emission tomography (PET) attenuation correction artefacts in PET/CT and PET/MRI

To compare the effect of implanted medical materials on (18)F-fludeoxyglucose ((18)F-FDG) positron emission tomography (PET)/MRI using a Dixon-based segmentation method for MRI-based attenuation correction (MRAC), PET/CT and CT-based attenuation-corrected PET (PETCTAC). 12 patients (8 males and 4 females; age 58±11 years) with implanted medical materials prospectively underwent whole-body (18)F-FDG PET/CT and PET/MRI. CT, MRI and MRAC maps as well as PETCTAC and PETMRAC images were reviewed for the presence of artefacts. Their morphology and effect on the estimation of the (18)F-FDG uptake (no effect, underestimation, overestimation compared with non-corrected images) were compared. In PETMRAC images, a volume of interest was drawn in the area of the artefact and in a reference site (contralateral body part); the mean and maximum standardised uptake values (SUVmean; SUVmax) were measured. Of 27 implanted materials (20 dental fillings, 3 injection ports, 3 hip prostheses and 1 sternal cerclage), 27 (100%) caused artefacts in CT, 19 (70%) in T1 weighted MRI and 17 (63%) in MRAC maps. 20 (74%) caused a visual overestimation of the (18)F-FDG uptake in PETCTAC, 2 (7%) caused an underestimation and 5 (19%) had no effect. In PETMRAC, 19 (70%) caused spherical extinctions and 8 (30%) had no effect. Mean values for SUVmean and SUVmax were significantly decreased in artefact-harbouring sites (p<0.001). Contrary to PET attenuation correction artefacts in PET/CT, which often show an overestimation of the (18)F-FDG uptake, MRAC artefacts owing to implanted medical materials in most cases cause an underestimation. Being aware of the morphology of artefacts owing to implanted medical materials avoids interpretation errors when reading PET/MRI.

The Morphology of Fecal and Regurgitation Artifacts Deposited by the Blow Fly Lucilia cuprina Fed a Diet of Human Blood

Fly feces and regurgitation deposits may be mistaken for bloodstain patterns at a crime scene, potentially compromising event reconstruction and/or misdirecting police resources. In some instances, these artifacts contain sufficient human biological material to generate a full DNA profile, sometimes 2 years after deposition. Clearly, it is important that investigators can make the distinction between artifacts and bloodstains. This study examined 6645 artifacts deposited on a smooth, nonporous surface after Lucilia cuprina were fed human blood. Artifacts were also compared with bloodstains on a variety of other surfaces. Both similarities and differences were found between artifacts and bloodstains, highlighting the need for an identification system to assist personnel with little training in bloodstain pattern analysis. The morphology of the artifacts has been described so that these deposits may be more clearly distinguished from bloodstains, targeted by crime scene personnel as potential sources of human DNA, and/or identified as potential evidence contaminants. Flowcharts have been devised to facilitate the analysis.

An Experimental Test of the Accumulated Copying Error Model of Cultural Mutation for Acheulean Handaxe Size

Archaeologists interested in explaining changes in artifact morphology over long time periods have found it useful to create models in which the only source of change is random and unintentional copying error, or ‘cultural mutation’. These models can be used as null hypotheses against which to detect non-random processes such as cultural selection or biased transmission. One proposed cultural mutation model is the accumulated copying error model, where individuals attempt to copy the size of another individual's artifact exactly but make small random errors due to physiological limits on the accuracy of their perception. Here, we first derive the model within an explicit mathematical framework, generating the predictions that multiple independently-evolving artifact chains should diverge over time such that their between-chain variance increases while the mean artifact size remains constant. We then present the first experimental test of this model in which 200 participants, split into 20 transmission chains, were asked to faithfully copy the size of the previous participant's handaxe image on an iPad. The experimental findings supported the model's prediction that between-chain variance should increase over time and did so in a manner quantitatively in line with the model. However, when the initial size of the image that the participants resized was larger than the size of the image they were copying, subjects tended to increase the size of the image, resulting in the mean size increasing rather than staying constant. This suggests that items of material culture formed by reductive vs. additive processes may mutate differently when individuals attempt to replicate faithfully the size of previously-produced artifacts. Finally, we show that a dataset of 2601 Acheulean handaxes shows less variation than predicted given our empirically measured copying error variance, suggesting that other processes counteracted the variation in handaxe size generated by perceptual cultural mutation.

Comparison of centrifuged liquid based cytology method with conventional brush cytology in oral lesions

Abstract Background: Exfoliative cytology is the study of cells that are shed or scrapped off from mucosal surfaces. Centrifuged Liquid based cytology is a modified technique employed in the present study. Aims: To compare the utility of centrifuged liquid based cytology with conventional cytology in oral lesions after staining with Papanicolaou (PAP) stain. Materials and Methods: 50 cases of oral lesions comprising of normal mucosa (n=14), hyperkeratotic lesions (n=17), ulcerated lesions (n=7) and atrophic lesions (n=12) were selected. Two smears were obtained from the lesion using a cytological brush. One was spread on the slide using conventional technique, fixed immediately in 95% ethyl alcohol. Second sample was suspended in suspending solution for 10 minutes then spun in centrifuge for 10 minutes. The supernatant was poured off and the obtained cell pellet was used to prepare a smear by sedimentation and left to dry overnight. Both the smears were stained by PAP. The stained smears were compared for seven morphological parameters such as adequacy of smear, clear background, cell distribution, smear thickness, cell morphology, and presence of blood, inflammatory cells, microbial colonies and artifacts. Wilcoxon Signed rank test was used and P≤0.05 was considered statistically significant. Results: There was a statistically significant difference (P&lt;0.001) between centrifuged liquid based cytology and conventional cytology when clear background was evaluated while in all other parameters the difference was not significant. Conclusion: Centrifuged Liquid based cytology showed clearer background than conventional brush cytology in oral lesions.

Spatial and chronological patterns of the lithics of hearth 1 at the Gravettian site Krems-Wachtberg

A spatial and micro-stratigraphic interpretation of the Gravettian open-air site Krems-Wachtberg in Lower Austria uses analysis of the lithic artefacts of an area of the excavations. The results are based on conclusive aspects of the artefact morphology and raw material attribution. Investigations focus on the acquisition of the spatial structure of living floor AH (archaeological horizon) 4.4 with a well-preserved hearth. Different utilization phases of hearth 1 with their relationships to the surrounding areas are discussed and a comparison of the in situ AH 4.4 and the post-occupational deposition of AH 4.11 presented. The examination of the artefact typology supports an attribution to the Early Gravettian of Central Europe (Pavlovian, 30–24 ka BP).

Assessing the macrofracture method for identifying Stone Age hunting weaponry

Macrofracture analysis is an experimentally derived method used as an initial step in investigating the hunting function of stone artefacts. Diagnostic impact fractures, which can only develop as a result of longitudinal impact, underpin this method. Macrofracture analysis recently gained favour in Middle Stone Age studies, supporting hypotheses for effective hunting during the late Pleistocene in southern Africa. However, the factors affecting diagnostic impact fracture formation and the interpretation of these fracture frequencies are not yet fully understood. This paper outlines a set of experiments designed to test macrofracture formation under human and cattle trampling and knapping conditions. The results show that: (a) macrofractures occur frequently when stone artefacts are trampled by cattle and humans and in knapping debris; (b) diagnostic impact fractures occur on some of the trampled flakes and knapping debris (≤3%), but significantly less often than in previous hunting experiments; (c) when they do occur, they are likely produced by longitudinal forces similar to those experienced during hunting; (d) considering artefact morphology is important during macrofracture analysis; and (e) macrofracture analysis is not a standalone method, but is most useful as part of a multi-analytical approach to functional analysis. These experiments help to establish a significant baseline diagnostic impact fracture frequency for the interpretation of archaeological macrofracture frequencies.

GIS and paleoanthropology: Incorporating new approaches from the geospatial sciences in the analysis of primate and human evolution

The incorporation of research tools and analytical approaches from the geospatial sciences is a welcome trend for the study of primate and human evolution. The use of remote sensing (RS) imagery and geographic information systems (GIS) allows vertebrate paleontologists, paleoanthropologists, and functional morphologists to study fossil localities, landscapes, and individual specimens in new and innovative ways that recognize and analyze the spatial nature of much paleoanthropological data. Whether one is interested in locating and mapping fossiliferous rock units in the field, creating a searchable and georeferenced database to catalog fossil localities and specimens, or studying the functional morphology of fossil teeth, bones, or artifacts, the new geospatial sciences provide an essential element in modern paleoanthropological inquiry. In this article we review recent successful applications of RS and GIS within paleoanthropology and related fields and argue for the importance of these methods for the study of human evolution in the twenty first century. We argue that the time has come for inclusion of geospatial specialists in all interdisciplinary field research in paleoanthropology, and suggest some promising areas of development and application of the methods of geospatial science to the science of human evolution.

Reducing the gradient artefact in simultaneous EEG-fMRI by adjusting the subject's axial position

Large artefacts that compromise EEG data quality are generated when electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) are carried out concurrently. The gradient artefact produced by the time-varying magnetic field gradients is the largest of these artefacts. Although average artefact correction (AAS) and related techniques can remove the majority of this artefact, the need to avoid amplifier saturation necessitates the use of a large dynamic range and strong low-pass filtering in EEG recording. Any intrinsic reduction in the gradient artefact amplitude would allow data with a higher bandwidth to be acquired without amplifier saturation, thus increasing the frequency range of neuronal activity that can be investigated using combined EEG-fMRI. Furthermore, gradient artefact correction methods assume a constant artefact morphology over time, so their performance is compromised by subject movement. Since the resulting, residual gradient artefacts can easily swamp signals from brain activity, any reduction in their amplitude would be highly advantageous for simultaneous EEG-fMRI studies. The aim of this work was to investigate whether adjustment of the subject's axial position in the MRI scanner can reduce the amplitude of the induced gradient artefact, before and after artefact correction using AAS. The variation in gradient artefact amplitude as a function of the subject's axial position was first investigated in six subjects by applying gradient pulses along the three Cartesian axes. The results of this study showed that a significant reduction in the gradient artefact magnitude can be achieved by shifting the subject axially by 4cm towards the feet relative to the standard subject position (nasion at iso-centre). In a further study, the 4-cm shift was shown to produce a 40% reduction in the RMS amplitude (and a 31% reduction in the range) of the gradient artefact generated during the execution of a standard multi-slice, EPI sequence. By picking out signals occurring at harmonics of the slice acquisition frequency, it was also shown that the 4-cm shift led to a 36% reduction in the residual gradient artefact after AAS. Functional and anatomical MR data quality is not affected by the 4-cm shift, as the head remains in the homogeneous region of the static magnet field and gradients.

A new approach to recording and monitoring wet-preserved archaeological wood using three-dimensional laser scanning

The analysis and preservation of organic materials preserved within wetland environments represents one of the most costly parts of any post-excavation strategy. This paper outlines the application of high-resolution terrestrial laser scanning to one class of preserved material, worked archaeological wood. Scanning allowed the recording of the artefacts in three dimensions and the identification of features such as toolmarks. Features can be measured and volumetrically modelled within the digital environment, which may not always be possible for these often fragile materials using conventional techniques. Repeat scanning of the artefacts provided an opportunity to use comparative analysis software to investigate changes in the morphology of artefacts under contrasting conditions of short-term storage. The results suggest that immersion in water results in the least deterioration, whereas both freezing and air-drying caused distortion and degradation. This paper demonstrates that laser scanning provides a viable alternative post-excavation method for the recording, analysis and long-term ‘virtual archiving’ of organic archaeological materials, which may be more cost-effective in some instances than other methods of preservation.

THE RELATIONSHIP BETWEEN LITHOLOGY, FLAKING PROPERTIES AND ARTEFACT MANUFACTURE FOR AUSTRALIAN SILCRETES*

Mechanical properties of Australian silcrete strongly influenced raw material selection and artefact manufacture. Microcrystalline silcrete, with high compressive and tensile strength, is suitable for blade tools requiring fine retouch. Fine‐grained silcrete (high compressive strength but lower tensile strength) was often used for blade‐based implements, but is more susceptible to edge fracturing. Medium‐grained silcrete has poor flaking properties (low compressive and tensile strength) and was often used for flake manufacture. Thus material determinism can explain much of the variability in silcrete artefact morphology and assemblage composition. Silcrete compressive strength is positively correlated with percentage of microcrystalline matrix and negatively correlated with average grain size, so hand lens examination of a silcrete sample can give a good indication of its likely flaking quality.

Quantifying flake scar patterning on cores using 3D recording techniques

A key feature of stone artefact morphology is the arrangement and patterning of negative flake scars left on flakes and cores. Scar patterning is often treated as a rough guide to identifying methods of core preparation and reduction and usually forms a key component of lithic typologies and other systems of analysis. However, scar patterns are often complex and difficult to capture using traditional measurement or classificatory techniques, particularly where flakes are thick and irregular, or where cores are flaked on many sides from a number of platforms. Three-dimensional analysis of flake scars is now more feasible using digital 3D surface scanning technologies, or using three-dimensional measurement tools such as the Microscribe-3DX which is now widely used in biological geometric morphometric studies more generally [D.C. Adams, F.J. Rohlf, D.E. Slice, Ital. J. Zool., 71 (2004) 5–16; F.J. Rohlf, L.F. Marcus, Trends Ecol. Evol. 8 (1993) 129–132. [ 1,34]]. This paper develops a mathematical formula for describing scar patterning using vectors calculated from the start and end points of flake scars recorded in three dimensions.

Dynamic landscapes, artifact taphonomy, and landuse modeling in the western Mediterranean

AbstractThe Polop Alto valley, in eastern Spain, is characteristic of many Mediterranean landscapes. It has been sporadically reoccupied over the course of at least 80 kyr. Its landforms have undergone various geomorphic processes resulting from late Quaternary environmental fluctuations. During the Holocene, the valley has been modified by millennia of extensive land clearance, cultivation, and terracing. As a result, the evidence for human activity and landuse is a cumulative, but discontiguous palimpsest of the most durable behavioral residues—primarily stone and ceramic artifacts—whose distributions have been affected by diverse natural and cultural formation processes. Human occupation of the Polop Alto spans the evolution of morphologically modern humans and the replacement of foraging economies by farming, arguably the two most significant biobehavioral transitions for human life today. To better understand the changes in human landuse that accompanied these important transitions, we have employed an integrated suite of techniques aimed at unmixing the diverse formation processes that have affected Polop Alto landscapes and material culture. These include patch‐based survey methods, photogrammetry, GIS‐based spatial analysis, and using artifact morphology and distribution to assess artifact taphonomy. This has permitted us to develop a diachronic settlement model for the 80 kyr of human occupation in the Polop Alto. © 2002 John Wiley &amp; Sons, Inc.

‘Nowadays with glass’: regional variation in Aboriginal bottle glass artefacts from Western Australia

AbstractThis paper builds on the few well known analyses of glass artefacts by recognising that bottle shape strongly influences glass artefact morphology in glass tool manufacture. Analysis of Aboriginally worked glass artefacts, using similar bottles, from two regions in Western Australia show differences that cannot be attributed to regional variation in raw materials. These differences may relate to long term approaches to artefact manufacture.