Acquisition and commissioning of an Isoprime Precision Isotope Mass Spectrometer.
dendroisotopie group and partners (Daux V., Pierre M., Stievenard M.)
The aim of the RIOCAS project is to increase the capacity and analytical performance of dendro-isotopy in the Île-de-France region. It involves the acquisition of an isotope ratio mass spectrometer (IRMS) coupled to a high-temperature elemental analyser (TC/EA) to analyse the isotopic composition of oxygen, carbon, nitrogen and sulphur (δ18O, δ13C, δ15N and δ34S) in cellulose, wood and other plant organic matter.
The project partners, from 7 research laboratories in the Paris region and a consultancy firm, plan to use the TC/EA – IRMS in a number of large-scale projects. Among other projects, they plan to carry out a dendro-isotopic reconstruction of the medieval climate in the Ile-de-France region and to assess the potential of dendro-anthracology in palaeoclimatology, using the charred wood of Notre-Dame de Paris. They will also take advantage of the gains in productivity and reliability offered by this new equipment to explore the potential of the isotopic approach in palaeobotany and palynology. The resulting databases will be made available to the scientific community for multidisciplinary applications. Finally, this new equipment will enable innovative developments that will open up new themes in the environmental field.
The RIOCAS spectrometer was 66% funded by the DIM-PAMIR (2021 call for tenders), with the remaining 34% coming from the various partners’ own funds (ArchAm and ArScAn laboratories at U. Panthéon Sorbonne/CNRS; AASPE, CR2P and HNHP laboratories at MNHN/CNRS/Sorbonne University or U. Perpignan via Domitia; METIS Laboratory of Sorbonne University/CNRS and Dendrotech).
Initial applications: One of the medium-term objectives of the acquisition project is to create dendro- and anthraco-isotopic reference systems that will be made available to the scientific community on an open platform. Work has begun on a dendro-isotopic database (δ18O, δ13C and δ15N), based in particular on the Dendrotech collection (several thousand wood cores, dense and continuous coverage from 888 to 1942). This unique database can be used for climatic and environmental studies and will serve as a reference for dendro-isotopic dating of wood that cannot be dated using conventional dendrochronology, an approach that has never been used before in France.
The rubble from the framework of Notre-Dame de Paris yielded a large quantity of coals formed over a wide temperature range, up to 1300°C. The potential of the anthraco-isotopic approach for reconstructing climatic and environmental conditions will be assessed using this unique collection of coals (ANR-CASIMODO). A reference system, which compares changes in isotopic composition with the rate of combustion (deduced from the analysis of charcoal by Raman spectrometry), is currently being set up. As charcoal is an ecofact commonly encountered in archaeological contexts, the field of application of this reference system will be very broad. The study of charcoal of older ages, in palaeobotany, will also benefit from conceptual advances linked to the interpretation of the repository.