Beneath our feet lies a veritable mosaic of rocks, which may themselves contain various minerals and metals, some of which are of economic or even strategic interest to our industry and our daily lives.
To learn more about the mineral resources in France’s subsurface, BRGM scientists employ various methods, especially for the Inventory of Mineral Resources, undertaken in February 2025.
Supporting a secure and responsible supply of mineral resources
The supply of mineral resources to French and European industry is coming under increasing pressure, due to sovereignty issues and growing demand for raw materials, particularly as part of the energy transition.
This is why France launched an update of its mineral resources inventory in 2025. Spearheaded by BRGM, the French geological survey, the aim of this work is to update and extend the data in the reference inventory carried out between 1970 and 1995 by BRGM in mainland France and French Guiana.
Geochemical campaigns to determine the mineral resource potential of regions
Geochemistry is used to detect traces of minerals in the sediments of streams in a catchment area. These minerals, produced by erosion and carried by watercourses before being deposited in calm waters, are precious clues for determining the nature of the subsurface geological formations and their mineral resource potential.
Geochemical analyses now enable us to detect much lower concentrations of metals than during the first mining inventory, and to analyse more substances, including in particular a number of critical metals (lithium, rare earths, tungsten, antimony, etc.) which were not detected at the time, or which could only be detected at much higher detection limits.
Improving geological knowledge of France
This non-invasive method complements other techniques, such as airborne geophysics, implemented in various regions of mainland and overseas France. They are used to produce reference data to improve geological knowledge of the territory.
Geochemistry analysis of stream sediments is a historical method that has been used for decades, but advances in analytical methods now enable a much more diverse and detailed characterisation of the nature of the subsurface.
It has many applications, particularly for identifying mineral concentrations on a regional scale, but can also be used for environmental applications. It can, for example, help define the regional geochemical background, i.e. to provide us with information about the natural chemical composition of the soil and subsurface, particularly in terms of certain trace metal elements.
