Example from the Atlas of Mineral Deposits of National Interest (GIN - Gisements d'Intérêt National): sheet no. 8 of the Regional Quarry Plan (SRC) for the Bourgogne Franche-Comté region.
© BRGM
The need
The DREAL Bourgogne-Franche-Comté commissioned BRGM to manage and produce an innovative and sensitive component of the new Regional Quarry Plans (SRC - Schéma Régional des Carrières): the inventory and mapping of mineral Deposits of Regional and National Interest (GIR and GIN – Gisements d'Intérêt Régional/National). Following on from the previous work on the inventory of primary resources carried out jointly by the DREAL and BRGM between 2018 and 2020, the methodology for identifying and, above all, mapping these types of deposits needed a thorough review and update in the light of previous feedback. Consequently, a complete overhaul of the approach was implemented in the Bourgogne-Franche-Comté region, at the same time as the work being carried out in the Grand-Est region.
The results
The participatory methodology developed by BRGM is based on the principle that mining operators are best placed to appreciate the quality of the resources they exploit. Following more than 130 consultations, around a hundred deposits were classified as GIR or GIN, with a ratio of 1/3 (GIN) and 2/3 (GIR). In terms of types of use, the field of Ornamental and Construction Rocks (ROC) represented the greatest number of deposits of interest, followed by Industrial Construction Materials (MIC) and Construction Materials, i.e. aggregates (MC), and finally Minerals for Industry (MI). By the end of this work, only 18 different resources out of a total of 46 in the Bourgogne-Franche-Comté region were classified as GIR or GIN. Gypsum, which is not currently exploited in the region, remains a strategic substance on a national scale and could be added to this list of 18 resources.
The cartographic contributions were integrated and combined using GIS processing, applying a buffer zone of 2 or 5km (depending on the case) around the active quarries, serving as qualitative focus points on the map for the wider geological resource. The work produced two atlases (GIR and GIN), each comprising a breakdown of the territory into 9 sheets at 1:100,000 scale. Each sheet includes the map itself, showing the GIR or GIN on a greyed-out IGN background, the superficial geological formations, which can mask the resources sought, and a breakdown by municipality, enabling users to quickly identify the presence of a GIR or GIN in a given municipality. Finally, each sheet is accompanied by a text explaining how the GIR/GIN contours were drawn and how to read the map.
Regional map of GINs and GIRs according to the lithostratigraphic resource concerned.
© BRGM
Using the results
This cartographic GIRN inventory aims to provide local authorities with information about the potential existence of a strategic resource in their area. The breakdown by municipality displayed on the maps makes it easier to understand the impact and extent of the zones mapped. These maps, which are included in the documents produced as part of the SRC, have a direct impact on other planning documents, such as the SCoTs (regional coherence plan) and PLUi (Inter-Municipal Local Urban Planning Scheme), which must be compatible with the SRC.
The partner
- DREAL Bourgogne-Franche-Comté
