Provenance changes for arenaceous formations of the northern Apennines, Italy

Abstract

A complex pattern of provenances is displayed by 15 formations in the northern Apennines composed chiefly of turbidites that were deposited during the Alpine orogenesis. Q-F-L and Qp-Lv-Ls values can be used to characterize specific source areas that existed in the Apennine region from Cretaceous through Miocene time. Whereas sandstone mineralogy can be used to infer plate-tectonic setting, such an approach must make allowances for both the size of the area studied and the tectonic framework that existed prior to sandstone deposition. In an early stage of the compressive phase of the Tethys (Late Cretaceous), both arkose and litharenite were derived from cratonic blocks, whereas volcanic sandstone was derived from uplifted oceanic sediments and lavas. Sediments recording the main Oligo-Miocene collisional tectonic phases accumulated in two principal tectonic settings: (1) intermontane (successor) basins, and (2) foreland basins. In the first case, individual formations exhibit a wide provenance variability. Arkosic-lithic sandstone (recycled orogen), volcanic sandstone (magmatic arc), and arkose were deposited simultaneously. In the second case, basins filled with thick turbidite sequences composed of arkose and lithic arkose, which were supplied by basement rocks uplifted along the edge of the European craton and/or by the nascent orogenic belt.