Sm?Nd dating of fluorite from the worldclass Montroc fluorite deposit, southern Massif Central, France

A three-point Sm–Nd isotope isochron on fluorite from the very large Montroc fluorite vein deposit (southern Massif Central, France) defines an age of 111±13 Ma. Initial eNd of −8.6 and initial 87Sr/86Sr of ~0.71245 suggest an upper crustal source of the hydrothermal system, in agreement with earlier work on fluid inclusions which indicated a basinal brine origin. The mid-Cretaceous age of ~111 Ma suggests the Albian/Aptian transition as the...