M/F Post-doctorat en archéométrie appliqué à l'étude de l'art pariétal

Job Description

Missions

This postdoctoral contract in archaeometry focuses on the study of coloring matter used in Neolithic schematic rock paintings in southern France. The position is part of the ANR SCHEMA project (https://schema.hypotheses.org/a-propos). ANR SCHEMA is an interdisciplinary project aiming to develop a methodological framework for the study of open-air rock art, combining archaeology, geomorphology, materials science, planetary science, cognitive sciences, and social anthropology.
The postdoctoral researcher will be supervised by Claudia Defrasne (CNRS Researcher, EDYTEM), Pauline Martinetto (Associate Professor, UGA / Institut Néel), and Emilie Chalmin (Associate Professor, EDYTEM / USMB). The successful candidate will join the Sociétés et Matières and Architectures Moléculaires teams within the EDYTEM laboratory.

Activity

The objective of this postdoctoral research is to continue the characterization of pictorial matter from the Otello rock shelter (Saint-Rémy-de-Provence, Bouches-du-Rhône) and to investigate the provenance of geomaterials used for graphic purposes. The Otello rock shelter is the most important schematic rock art site in southern France (over 300 figures) and is characterized by the presence of an in situ geological source of coloring matter.
This work follows on from a PhD research whose methodology is based on the combined use of in situ pXRF (portable X-ray fluorescence spectroscopy using a mobile instrument with a millimetric beam size) and the study of micro-samples using XRF and XRD (X-ray diffraction) on a large-scale instrument (ESRF).
Observation of the main decorated wall (north wall) reveals numerous superimpositions, reflecting a variety of intertwined natural and anthropogenic processes. The characterization of the pictorial matter at the Otello rock shelter highlights a typical composition including iron oxides (goethite (FeOOH) and hematite (α-Fe₂O₃)), kaolinite (Al₂Si₂O₅(OH)₄), titanium oxides (rutile (TiO₂) and anatase (TiO₂)). This composition, along with specific features such as variations in the crystalline lattice parameters of goethite (FeOOH) or the diffraction peak profiles of kaolinite (Al₂Si₂O₅(OH)₄), supports the hypothesis of a local origin of the coloring matter used to produce the paintings (Théron 2026).
Within the framework of this postdoctoral research, the representativeness of these indicators will be examined: are they specific to a deposit, to a facies, linked to formation conditions, or are they the result of alteration processes? More specifically, for the Otello rock shelter, the aim will be to assess the variability of these features within the shelter itself, as well as across the Alpilles massif. This will involve acquiring high angular resolution synchrotron XRD patterns of geomaterial samples and quantifying mineral phases.
In situ XRF spectroscopy makes it possible to characterize superimpositions non-invasively and to propose a multilayer model (Théron 2026). The construction of this model allows estimation of the thickness of the pictorial layer and the composition of the layers forming the stratigraphy at each measurement point. The model also enables investigation of variability in the iron (Fe) / titanium (Ti) ratio between different figures, providing insight into graphic structures. This ratio appears to be homogeneous within a single figure but heterogeneous when comparing different figures. The aim of this postdoctoral research will therefore be to validate this model and test its relevance for describing wall micro-stratigraphies through the processing of measurements acquired at the decorated site of Les Eissartènes (Le Val, Var).
Building on the stratigraphy published in 1995 by P. Hameau et al. (Hameau et al. 1995), established from a paint micro-sample (based on observation of a transverse section by electron microscopy), as well as on combined archaeological and geomorphological analyses, a multilayer model will be developed and applied to XRF measurements already acquired at this site within the ANR SCHEMA project. The objective will be to assess the robustness of this innovative method for investigating superimpositions and compositional variations in figures.
Finally, the robustness of the multilayer model will be tested on experimental rock paintings produced by Ph. Hameau in the late 1990s (Hameau et al. 2009). This approach will make it possible to know the originally applied material while avoiding constraints related to the protection of archaeological sites. The aim will be to validate the multilayer model derived from in situ XRF measurements, coupled with SEM-EDS observations of the micro-stratigraphy of micro-samples.

Your Profil

Skills

The postdoctoral researcher must demonstrate excellent proficiency in structural data processing techniques (Rietveld refinement of powder X-ray diffraction data) and in XRF data analysis, as well as the ability to use tools for processing cartographic (chemical and structural) data.
The candidate must also have a solid understanding of the scientific and methodological issues related to the study of rock art sites and show openness to interdisciplinary approaches. As this research involves extensive fieldwork in sometimes steep and rugged environments, the postdoctoral researcher must have very good physical fitness.
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Your Work Environment

The research will be carried out at the EDYTEM laboratory, an interdisciplinary Joint Research Unit (UMR) of the CNRS and Université Savoie Mont Blanc, bringing together expertise in geomorphology, geology, geography, archaeology, and sedimentology, with a shared focus on mountain environments.
The postdoctoral researcher will be integrated into the ANR SCHEMA project team, which includes researchers, research engineers, and PhD students from various laboratories and disciplinary backgrounds (LPG, IPAG, LaMPEA, LAPCOS, MONARIS). This postdoctoral research will directly contribute to the project by advancing understanding of rock wall materials and the processes responsible for their formation. The postdoctoral researcher will therefore interact closely with all disciplines involved in the study of painted rock surfaces.
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Compensation and benefits

Compensation

3 131.32 - 3 569.85

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

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