PLATEFORME DE GEOCHIMIE ISOTOPIQUE ASTER/CEREGE

The ASTER-CEREGE project originates from the CEREGE supervised by five founders: Aix-Marseille University, CNRS, IRD, INRA and Collège de France.

The compact accelerator mass spectrometer (Element 1) has been installed in 2014 in a new building on the Arbois Campus. AixMICADAS has an hybrid ion source working with graphite targets and CO₂ gas, coupled to an interface system that ensures stable gas measurements from different sources. The laboratory is also equipped with an automated graphitization system and other devices for carbon extraction and purification.

The Element 2 includes a mass spectrometer equipped with an inductively-coupled-plasma source, a magnetic mass filter, and multiple collection (MC-ICPMS, Neptune+ type). It is operational since the beginning of 2015. The ultra-clean laboratory for the preparation of samples is also fully operational since 2014.

The new high-intensity ion source for the ASTERisque accelerator (Element 3) was delivered in early 2015 and is operational since late 2015.

In parallel to past and ongoing methodological developments, the three spectrometers already allowed us to contribute to several scientific programs in fundamental and applied geochemistry:

_  Precise and accurate ¹⁴C dating of subfossil wood to expand the tree-ring ¹⁴C calibration,

_ Pollution studies by measuring ¹⁴C and metal isotopes as source tracers,

_ Measurements of ¹⁴C in micro-samples of bone collagen and ¹⁰Be and ²⁶Al of quartz pebbles to date important prehistoric sites,

_ U/Pb geochronology on carbonates applied to secondary cements in petroleum reservoirs,

_ Studies based on ¹⁰Be analyzes of the relief evolution of various regions,

_ Using ³⁶Cl as a tracer of the groundwater of deep aquifers,

_ Surface exposure durations to reconstruct the history of glaciers in several regions,

_ Studies based on ¹⁰Be and ³⁶Cl analyzes in marine sediments or ice cores of the temporal variations in the geomagnetic field intensity.