First U-Pb detrital zircon ages from Numidian sandstones in Southern Apennines (Italy): evidences of African provenance.

Two samples of quartz-rich sandstones collected in theNumidian Flysch of Southern Apennines (Italy) have been studied to highlight the provenance of detritus using radiometric dating by LA-ICP-MS of detrital zircons and to compare the obtained ageswith those of the Betic and Maghrebian Chains. The provenance of quartzose detritus from European or African Plates is still debated in these Chains, accordingly the ages of the detrital zircons can contribute significantly to discriminate the origin of the quartzose supply. The U–Pb zircon ages (n = 47) vary from 3047 ± 13 Ma (Mesoarchean) to 516 ± 19 Ma (Cambrian). The predominance of Paleo-Proteozoic ages (2500–1600Ma) and the lack of Hercynian and Alpine ones suggest a provenance of the Numidian supply from North-African cratonic areas during the early–middle Langhian, when the Numidian successions of Southern Apennines were deposited. In addition, a cluster of ages at 773 ± 24 Ma and 668±12Main one sample and at 664±17Main the other sample, calculated on zircon domainswith magmatic zoning, testify to an important contribution from Neo-proterozoic “granitic” rocks widely outcropping in the North-African Craton. The age data on detrital zircons fromNumidian sandstones in Southern Apennines overlap those found in theNumidian sandstones widespread in the Betic Cordillera and in the Maghrebian Chain from south Spain to Sicily.This suggests that the entire depositional zone in which Numidian Flysch deposited, was fed from a southerly source represented by the African Craton where Archean, Proterozoic and Cambrian rocks widely crop out fromthe Atlantic coast to the Hoggar and Tibesti Massifs. Finally, it must be outlined that aMeso-Archean zircon age (3047 Ma) has been found in the Numidian Flysch of the Southern Apennines whereas in the Numidian Flysch of the Maghrebian Chain, zircons older than Paleo-proterozoic (1840 Ma) have not yet been found.