Reference : UPR2940-ELOBER-054
Workplace : GRENOBLE
Date of publication : Wednesday, April 13, 2022
Scientific Responsible name : Pauline Martinetto (Institut Néel, UGA-CNRS) / Claudia Defrasne (EDYTEM, USMB-CNRS)
Type of Contract : PhD Student contract / Thesis offer
Contract Period : 36 months
Start date of the thesis : 1 September 2022
Proportion of work : Full time
Remuneration : 2 135,00 € gross monthly
Description of the thesis topic
This PhD project proposes a physico-chemical analysis of the pictoral matter used to produce Neolithic cave paintings at several sites of Mediterranean France with the aim of revealing traces of both ancient know-how (preparation of the matter) and the origin of the coloring materials used. This project will initially focus on the study of two major sites: Otello (Saint-Rémy-de-Provence, Bouches-du-Rhône) and les Eissartènes (Le Val, Var), chosen for the abundance of their iconography, their polychromy and the chronological succession of different graphic phases and the presence of coloring geological materials around.
The methodology used to carry out this project will incorporate both a non-invasive (non-contact analysis, directly on the rock) and a non-destructive (a micro-sample is taken and kept after analysis) approach. X-ray diffraction and fluorescence measurements will be carried out with a mobile instrument developed as part of an interdisciplinary project (CDP PATRIMALP, IDEX UGA) and other non-invasive analysis techniques (diffuse reflectance spectroscopy and hyperspectral imaging) will also be used, in particular to allow a global reading of the pictorial materials at the rock scale.
The mobile instruments will also help in the selection of representative micro-fragments, when the sampling of material is possible. In the case of micro-fragments, one difficulty lies in the fact that the physico-chemical analyses implemented have to be both sensitive and spatially selective. X-ray diffraction and fluorescence tomography experiments will therefore be carried out at synchrotron in order to obtain elementary and structural images that finely reconstruct the stratigraphy of the micro-samples.
These micro-samples can then be prepared in cross-sections for observation under an optical/electronic microscope. A comparison with geological references will also be essential to specify possible sources of supply.
With the help of these analytical tools, the doctoral student will be able to identify/quantify/locate materials in the mixtures and stratigraphies and thus:
- characterise the diversity of colouring materials used on the Otello and les Eissartènes sites and their evolution over time;
- reference the potential sources of supply and decide on the origin of the materials (local supply or exchanges/circulation of materials);
- understand the operating chain of the pictorial materials (manufacturing process, addition of possible fillers) and identify a possible cultural diversity.
These results will thus contribute to a better understanding of the social practices associated with the graphic act and its inclusion in the territories of prehistoric societies.
The PhD student will be co-supervised by two researchers from different disciplines: C. Defrasne (archaeologist, EDYTEM), a specialist in the rock graphic productions of prehistoric societies and P. Martinetto (physicist, Institut Néel) who develops instruments and methods for the characterisation of ancient materials.
He/she will be a student of UGA (Doctoral School of Physics) and will be hosted at the Institut Néel : this CNRS unit (UPR 2940), under agreement with the University Grenoble Alpes, is one of the largest French national research institutes for fundamental research in condensed matter physics enriched by interdisciplinary activities at the interfaces with chemistry, engineering and biology. It consists of 450 employees, including 175 researchers.
It is located in Grenoble, in the heart of a unique scientific, industrial and cultural environment, right next to the French Alpes.
In the PLUM department, and in the MRS team (Materials, Radiations, Structure), the PhD student will therefore be able to benefit from the environment offered to the Institute's research teams.
He/she will spend approximately half of his/her time in the EDYTEM laboratory (CNRS, Bourget-du-Lac) where he/she will join the "Sociétés" team. Other structures will also support the supervision of this thesis: IPAG (B. Schmitt, diffuse reflectance spectroscopy) and LAPCOS (Ph. Hameau, schematic expression).
Constraints and risks
This PhD work requires several field missions for the implementation of physico-chemical analysis methods in situ on each of the sites studied.
Access to these sub-rock shelters requires approach walks on sometimes steep paths as well as the carrying of analytical instruments. The doctoral student must therefore be able to carry out such missions.
Applicants must hold a Master's degree (or be about to earn one) or have a university degree equivalent to a European Master's (5-year duration) in either physics, materials science, chemistry, geosciences or closely related science.
A background in physicochemical analysis techniques is desirable.
A motivation for prehistory, archaeology or more generally in heritage sciences is obviously expected.
Application deadline: May 18, 2022 at 18:00 (CET)
Applications will be evaluated through a three-step process:
1. 1st round of selection: the applications will be evaluated by a Review Board in May 2022. Results will be given by May 23, 2022.
2. 2nd round of selection: shortlisted candidates will be invited for an interview session on June 9, 2022.
3. Final results will be given in June 2022, after study of the selected applications by the doctoral school.
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