Zircon Compositions of Lower Mesozoic Redbeds of the Tethyan Margins, West-Central Mediterranean Area

Typologic study and chemistry of zircon populations from Middle Triassic–Lower Liassic areniticcontinental redbeds of the Internal Domains successions of the Mediterranean chains, from theGibraltar Arc to the Calabria–Peloritani Arc, allow assessment of whether this type of study may beused to obtain more comprehensive inferences on the sedimentary evolution of ancient clastic rocks.Calabria-Peloritani Arc zircons are primarily euhedral, with subordinate rounded and subroundedgrains. Rifian Maghrebides samples contain abundant euhedral zircons, with minor rounded andovoid zircons. Betic Cordillera zircons are rounded or subrounded, with minor euhedral elongategrains; rounded zircons of these samples cannot be typologically classified. Electron-microprobeanalyses (Si, Zr, Hf, P, and HREE) indicate homogeneous compositions, suggestive of commonsource areas characterized by granitoid rocks, whereas typology suggests the existence of twodistinct groups. The first group includes arenites from the Calabria-Peloritani Arc and the RifianMaghrebides. The second group includes arenites from the Betic Cordillera. Differences betweenthe two zircon groups may be related to recycling effects, in agreement with a geochemical study ofTriassic to lowermost Jurassic mudrock redbeds. Recycling likely was more significant for the BeticCordillera samples. These results suggest that zircon typology and mudrock geochemistry can beuseful tools for provenance, especially in complex sedimentary contexts where arenite-mudrockcouplets occur.