To browse Academia. The French Massif Central represents one of the rare occurrences in Europe where lower Pleistocene fossil deposits are associated to a substantial volcanic activity. Zircon, a weathering-proof heavy mineral, was dispersed over the landscape through Plinian eruptions, and quickly reworked in fossil-bearing sedimentary deposits. These new chronological data constrain the duration of the MNQ18 in central France to about ka.
The confirmation of an old age for the Blassac-La Girondie deposit indicates that the MNQ19 biozone started significantly earlier than previously thought. Zircon is a highly resistant, high-temperature mineral widely used to date magmatic and metamorphic formations, including silicic volcanic deposits.
Compared to other minerals used by absolute geochronology techniques feldspars, amphiboles, micas , zircon is preserved during weathering of volcanic deposits and subsequent transport and is reworked within secondary sedimentary deposits. Dating of volcanic zircons provide a minimum age for clastic sedimentary deposits, however, if transport processes are fast cf. Pastre, , the age of the sedimentary deposit will be within error of the age of the volcanic zircons.
All the investigated Middle to Late Villafranchian faunae belong to the Gelasian age 2. The existing ages are however imprecise, with uncertainties of at least a few hundred thousand years.
The Mont-Dore massif is a composite edifice formed by two stratovolcanoes Baubron and Cantagrel, ; Nehlig et al. To improve our knowledge of the oldest explosive stages of the Mont-Dore.
