France Natural Resources

Geology: Orogenic mineralization in the axial zone of the Montagne Noire. Gold is associated with arsenopyrite, pyrite and chalcopyrite in quartz veins cutting Cambrian schists. Formation temperatures: 300-400 deg C.

History: Worked since Roman times, with industrial production from 1892 to 2004 and a peak in the 1990s under Mines d'Or de Salsigne.

Production: More than 120 tonnes of gold extracted; maximum annual production around 3.5 t/year in the 1990s.

Status: Closed in 2004. Site undergoing arsenic pollution remediation and classified as polluted by the state.

Reserves: Remaining reserves estimated around 20 t Au at closure.

References: BRGM national mining inventory; Marcoux E. et al. (1993), Mineralium Deposita.

Geology: Free gold in quartz-tourmaline veins cutting Limousin metamorphic formations. Mineralization linked to the Variscan orogeny with gold-antimony-tungsten associations.

History: Operated by Societe des Mines du Bourneix from 1982 to 2002, with many historic gold-panning sites in the region.

Production: Total production estimated at 15-20 tonnes of gold.

Status: Closed. Several exploration permits remain active in the region.

Reserves: Regional potential estimated by BRGM at several tens of tonnes.

References: BRGM RP-52836-FR; Bouchot V. et al. (2005), Ore Geology Reviews.

Geology: Quartz-galena-barite veins in granites and gneiss of the Massif Central. Gold occurs as an accessory metal in lead and zinc sulfides.

History: Worked since the Middle Ages, mainly for lead and silver, with gold as a by-product.

Production: Modest gold production, mainly as a by-product of argentiferous lead.

Status: Closed. Tourist mining museum.

References: BRGM database of former mining sites.

Geology: Gold mineralization in Paleoproterozoic volcanosedimentary formations, 2.1-2.2 Ga, of the Guiana Shield. Gold occurs in quartz veins and alluvium.

History: Gold mining since the nineteenth century. Historic gold routes and persistent illegal mining problems.

Production: Legal production around 1-2 t/year; illegal production estimated at 5-10 t/year.

Status: Active artisanal and industrial operations. The controversial Montagne d'Or project was abandoned in 2019.

Reserves: More than 200 tonnes estimated across French Guiana.

References: BRGM RP-55731-FR; Milesi J.P. et al. (2003), Ore Geology Reviews.

Geology: Quartz-stibnite veins with associated gold in Brioverian schists, linked to the North Armorican shear zone.

History: Operated from 1898 to 1934 mainly for antimony, with gold as an important by-product.

Production: Around 3 tonnes of gold extracted as an antimony by-product.

Status: Closed, with visible mining remains.

References: BRGM mining inventory of the Armorican Massif.

Geology: Ag-Pb-Cu-Co-Ni-Bi-As veins in gneiss and granites of the Vosges basement. Rich mineralogy includes native silver, proustite, pyrargyrite and cobaltite.

History: Worked from the tenth to the eighteenth century, with a Renaissance peak in the sixteenth century and hundreds of galleries.

Production: Historical production estimated at several hundred tonnes of silver over eight centuries.

Status: Closed. Museum, mine tours and a famous mineral fair.

References: Fluck P. (2000), Les mines de Sainte-Marie-aux-Mines; BRGM.

Geology: Argentiferous galena veins in limestones and schists of the Brianconnais, linked to Alpine magmatism.

History: Major medieval working from the tenth to fourteenth century. The Dauphins of Viennois used silver from the district for coinage.

Production: Historical production of several tonnes of silver.

Status: Closed heritage site, with the Fournel mine open to visitors.

References: Bailly-Maitre M.-C. (2002), L'argent, du minerai au pouvoir dans la France medievale.

Geology: Argentiferous galena and sphalerite veins in Chateaulin schists, linked to Variscan granite intrusions.

History: Worked during the nineteenth and twentieth centuries for argentiferous lead.

Production: Modest silver production as a lead by-product.

Status: Closed. Mining remains in the Huelgoat forest.

References: BRGM mining inventory of the Armorican Massif.

Geology: Argentiferous galena veins in Cevennes dolomites and limestones, with Mississippi Valley Type affinities.

History: Gallo-Roman and medieval exploitation; the Gard was an important argentiferous lead producer.

Production: Historically significant but poorly quantified.

Status: Closed archaeological mining sites.

References: BRGM database of former mining sites.

Geology: Alluvial diamonds derived from the Proterozoic Guiana Shield. Primary kimberlite or lamproite source remains unidentified. Diamonds are recovered from river concentrates with gold.

History: Sporadic discoveries since the nineteenth century during gold panning, with no dedicated mining.

Production: A few hundred carats discovered in total as by-products.

Status: No specific exploitation; scientific research continues on origin.

Reserves: Undetermined but probably low.

References: Geological Survey of French Guiana; BRGM Guyane.

Geology: Micro-diamond occurrences in lamproites and Tertiary volcanic breccias. The rift setting differs from classic kimberlites.

History: Recent twenty-first century discoveries during petrographic studies.

Production: No exploitation; scientific-level occurrences only.

Status: Subject of academic research.

Reserves: No economic interest.

References: Tappe S. et al. (2018), Nature Geoscience; BRGM.

Geology: Green beryls in Hercynian granitic pegmatites. Green coloration is due to chromium substitution in beryl.

History: Known to collectors and mineralogists, with no commercial working.

Production: No commercial production; collector specimens only.

Status: Known mineralogical sites.

Reserves: No economic interest.

References: Mindat.org; BRGM departmental mineralogical inventory.

Geology: Beryls in pegmatites associated with Hercynian granites of the Pyrenees. Mineralogy includes beryl, tourmaline and muscovite.

History: Mineralogical discoveries without mining.

Production: None.

Status: Mineral collecting sites.

Reserves: No economic interest.

References: Mineralogy of the Pyrenees, BRGM.

Geology: Ruby or sapphire corundum in xenoliths of metamorphic rocks transported by Tertiary basalts of the Massif Central. Crystals form at high pressure and temperature in the lower crust.

History: Known to mineralogists since the nineteenth century.

Production: No mining; collector specimens only.

Status: Mineralogical collecting sites.

Reserves: No economic interest.

References: Pin C. and Vielzeuf D. (1983), Bulletin de Mineralogie; Mindat.org.

Geology: Red corundum in spinel lherzolites, the type locality of the mantle rock lherzolite. Formation at pressure above 1 GPa and temperature above 1000 deg C.

History: World-renowned geological site discovered by naturalists in the eighteenth century.

Production: None; scientific reference site.

Status: Protected geological reference locality.

Reserves: No economic interest.

References: Fabries J. et al. (1991), Journal of Petrology; BRGM.

Geology: H2 generated by serpentinization of deep ultramafic basement rocks and trapped below Triassic salt layers at 600-3000 m depth. Concentrations measured up to 98 percent H2.

History: Discovered in 2023 by the University of Lorraine and CNRS during study drilling.

Production: Not yet producing; exploration phase.

Status: Active exploration. Exclusive research permit awarded to Francaise de l'Energie.

Reserves: Preliminary estimates of 46 to 260 million tonnes of H2. If confirmed, one of the largest deposits in the world.

References: Lefeuvre N. et al. (2024), Science; University of Lorraine/CNRS.

Geology: H2 produced by serpentinization of exhumed mantle rocks in the North Pyrenean zone. The Mauleon Basin exposes mantle rocks at shallow depth.

History: Recent detections during soil-gas measurement campaigns in the 2020s.

Production: Not in production.

Status: Exploration by 45-8 Energy and TBH2.

Reserves: Under evaluation.

References: Grellet-Tinner G. et al., BRGM; 45-8 Energy reports.

Geology: H2 may be generated by radiolysis of water in contact with uranium-rich basement granites or by water-iron reactions in Paleozoic basement rocks.

History: Detected by geochemical measurements in the 2010s.

Production: Not in production.

Status: Exploration permit awarded to TBH2, an academic-industrial consortium.

Reserves: Under evaluation.

References: Prinzhofer A. et al. (2018), International Journal of Hydrogen Energy; BRGM.

Geology: Active serpentinization of obducted oceanic rocks in the Alps. Reaction of olivine with water produces H2, magnetite and serpentine.

History: Recent detections during geochemical studies.

Production: Not in production.

Status: Academic research.

Reserves: Under evaluation.

References: Vacquand C. et al. (2018), Geochemistry, Geophysics, Geosystems.

Geology: Oil trapped in Dogger limestones and Triassic sandstones. Source rocks are Lias clays, with anticlinal structure.

History: Discoveries in the 1950s and 1960s, with production peak in the 1980s.

Production: Current output around 300,000-400,000 t/year for the basin.

Status: Active but declining. More than 3,000 wells drilled. The 2017 Hulot law prohibits new permits.

Reserves: Remaining reserves estimated at a few tens of million tonnes.

References: BRGM; IFP Energies nouvelles; DGEC 2023 report.

Geology: Oil in Upper Cretaceous reef limestones. Structural anticline trap. Source rock: marly limestones of the Upper Jurassic.

History: Discovered in 1954 by Societe Nationale des Petroles d'Aquitaine.

Production: Cumulative production above 20 million tonnes of oil; current production declining.

Status: Active, operated by Vermilion Energy, with pumping below the lake.

Reserves: Initial reserves around 40 million tonnes; recovery rate around 50 percent.

References: BRGM; Vermilion Energy annual report.

Geology: Gas and oil in Upper Cretaceous reef limestones at 3500-5000 m depth. Gas rich in H2S, around 15 percent, within a closed anticline.

History: Discovered in 1951 and supplied up to 30 percent of French gas needs in the 1960s and 1970s.

Production: Cumulative production around 250 billion cubic meters of gas. Gas production ended in 2013.

Status: Gas production stopped in 2013. Site converted into the Induslacq industrial platform.

Reserves: Depleted.

References: Total/SNPA historical reports; BRGM.

Geology: Oil in Oligocene sandstones and marls of the Rhine Graben. Stratigraphic trap with heavy bituminous oil.

History: First mentioned in 1498, with industrial exploitation from 1735 to 1970. Birthplace of the French oil industry.

Production: Cumulative production around 3.5 million tonnes of oil.

Status: Closed in 1970. Oil museum at Merkwiller-Pechelbronn.

Reserves: Depleted.

References: BRGM; French Petroleum Museum of Merkwiller-Pechelbronn.

Geology: Oil in Jurassic limestones, structural trap, modest deposit in the Languedoc foreland.

History: Discovered in the 1920s and worked at small scale.

Production: Very modest production.

Status: Closed.

References: BRGM inventory.