Le Grand-Fougeray
Le Grand-Fougeray monazite placer, derived from shales of the Ordovician Traveusot Formation, is the largest and the best documented of the placers in Brittany. Estimated tonnages in alluvium of the Aron and Gras rivers are modest (1900 t of monazite in clayey gravels with a grade of 2 to 2.6 kg of monazite per ton, and a cut-off at 1 kg/t). However, this monazite is exceptionally rich in europium (0.2 to 1 per cent Eu2O3); it also contains neodymium (13 to 14 per cent Nd2O3) and is poor in thorium (<1 per cent ThO2).References
https://en.wikipedia.org
http://www.eurare.eu/countries/france.html
http://www.greenplanet.pro/encyclopedia/geography/korsika/
http://picsfab.com/image/nature-corsica-korsika-priroda-71141
87429a871771208554b30b1914d47561
https://hal-brgm.archives-ouvertes.fr/hal-00942683