3D Analysis in Archaeology

This study explores the effects of the copying error process on material culture. The goal is to assess whether the morphometric variability of standardized vessels, generated by copying errors, can reveal both collective and individual signatures. In this perspective, we collected a corpus of 320 present-day standardized water jars, made by 23 Indian expert potters belonging to two endogamous communities distributed between eight villages. The vessels are analyzed through advanced shape analysis of ceramic vessels. The issue is to assess whether mor-phometric variability is observable at the 'community,' the 'village,' and the 'individual' scales. The results show a clear separation between the two endogamous communities, even when barely visible by the naked eye. Furthermore, village-level trends can be obtained, especially when village productions are associated with distinct learning networks. Identifying individual signatures within standardized production made by multiple potters belonging to the same learning network remains challenging.

Le renouvellement des méthodes d’analyse des décors par imagerie 3D s’est appuyé sur les séries céramiques Impressa et Cardial de l’abri Pendimoun. Par la variété des outils, des techniques, des gestes et des architectures, ces céramiques ont constitué un ensemble adéquat pour aborder la globalité de la chaîne opératoire décorative et explorer l’apport des méthodes virtuelles pour l’étude des décors.
Dans une démarche technologique, l’analyse des décors archéologiques s’appuie sur un vaste référentiel expérimental d’impressions afin de préciser, d’une part, la nature des outils et, d’autre part, leurs modalités d’utilisation.
La numérisation à haute résolution des vases archéologiques et de plaquettes expérimentales, ainsi que le recours à des logiciels spécifiques, ont ainsi permis une approche comparative fondée sur des données qualitatives et quantitatives à différentes échelles.
L’usage de plusieurs types outils utilisés pour le décor a été ainsi identifié (e.g. Patella caerulea) ou précisé (front denté de bivalves, canal siphonal de gastéropodes…).
L’analyse de l’agencement des empreintes (observation des recoupements, mise en évidence des rythmes d’impression) a permis de mettre en évidence les gestuelles et schémas opératoires des décors Impressa et Cardial de Pendimoun. In fine, l’analyse des modes de composition (i.e. architecture) permet de proposer une nouvelle grille de lecture efficace pour articuler les différents assemblages de ce complexe culturel.

A methodology for identifying prehistoric local learning communities is proposed.
We wish to test possible relationships among communities based on continuity and
variability in lithic reduction sequence technological traits with different visibility and
malleability. Quantitative features reflecting different technological traits are measured
on 3-D models of flint cores in different scales: the ratio between core thickness and
reduction surface width, the angle between subsequent bands of production blank
scars to the relative striking platform, and the average curvature of the ridge between
each blank scar striking platform pair. Continuity and variability in these features are
used to establish the relations among lithic assemblages on different hierarchical
levels: local learning communities and geographically widespread cultural lineages.
The Late Upper Palaeolithic and the Epipalaeolithic of the Southern Levant (ca. 27,000–
15,000 cal BP) provide an opportunity to test our method. A progressive increase in
territoriality is hypothesized throughout this timespan, yet the precise timing and
modes of this phenomenon need to be defined. The present study analyzes six core
assemblages attributed to different cultural entities, representing chronologically
separated occupations of the Ein Gev area and the coastal Sharon Plain. Continuity in
technological traits between the Atlitian (ca. 27,000–26,000 cal BP) and Nizzanan (ca.
20,000–18,500 cal BP) occupations of the Ein Gev area suggests that the same learning
community repeatedly settled there during a long time span. Two geographically
separate learning communities were defined in the study areas within the Kebaran
cultural entity (ca. 24,000–18,000 cal BP); the group occupying the Ein Gev area
possibly continued to settle there during the Geometric Kebaran (ca. 18,000–15,000
cal BP). Continuity in more conservative traits of the reduction sequence allows to tie
these two communities to the same cultural lineage. The ability to track prehistoric
learning communities based on quantitative features helps increase the objectivity
and the resolution in the reconstruction of past cultural dynamics.

Neandertal manual activities, as previously reconstructed from their robust hand skeletons, are thought to involve systematic power grasping rather than precise hand movements. However, this interpretation is at odds with increasing archeological evidence for sophisticated cultural behavior. We reevaluate the manipulative behaviors of Neandertals and early modern humans using a historical reference sample with extensive genealogical and lifelong occupational documentation, in combination with a new and precise three-dimensional multivariate analysis of hand muscle attachments. Results show that Neandertal muscle marking patterns overlap exclusively with documented lifelong precision workers, reflecting systematic precision grasping consistent with the use of their associated cultural remains. Our findings challenge the established interpretation of Neandertal behavior and establish a solid link between biological and cultural remains in the fossil record.

The production of three-dimensional (3D) digital meshes of surface and computed tomographic (CT) data has become widespread in morphometric analyses of anthropological and archaeological data. Given that processing methods are not standardized, this leaves questions regarding the comparability of processed and digitally curated 3D datasets. The goal of this study was to identify those processing parameters that result in the most consistent fit between CT-derived meshes and a 3D surface model of the same human mandible. Eight meshes, each using unique thresholding and smoothing parameters, were compared to assess whole-object deviations, deviations along curves, and deviations between specific anatomical features on the surface model when compared with the CT scans using a suite of comparison points. Based on calculated gap distances, the mesh that thresholded at "0" with an applied smoothing technique was found to deviate least from the surface model, although it is not the most biologically accurate. Results have implications for aggregated studies that employ multimodal 3D datasets, and caution is recommended for studies that enlist 3D data from websites and digital repositories, particularly if processing parameters are unknown or derived for studies with different research foci.

Con questo contributo si intendono mostrare alcune delle applicazioni della grafica voxel al campo dell'archeologia. Nella prima sezione verrà fatta una breve introduzione sulla disciplina archeologica e sulle sue modalità di indagine e di documentazione, per spiegare quali siano i reali vantaggi dell'utilizzo dei voxel in fase di rielaborazione dei dati. La seconda parte dell'articolo è invece dedicata all'esposizione di un caso di studio concreto, i cui dati sono stati però modificati (trattandosi di materiale non ancora pubblicato). Gran parte del progetto è stato elaborato all'interno di GRASS, anche se ci si è avvalsi del contributo di altri software (FS/OS) per la ricostruzione in tre dimensioni di alcuni oggetti (Blender) e per la visualizzazione finale dei dati (Paraview). Il principale obbiettivo dell'esperimento era la ricostruzione dei volumi dei vari strati, ecofatti e manufatti che componevano un deposito archeologico, ormai distrutto dallo scavo.