Sequence stratigraphy and architectural variability in growth fault-bounded basin fills: a review of Plio-Pleistocene stratal units of the Crotone Basin, southern Italy

Field examples from the Pliocene to Pleistocene succession of the Crotone Basin document the variability of stratal architecture in syntectonic units deposited in normal fault-bounded basins. Relatively thick trangressive intervals are common within these successions, as shown in the Zinga 2, Zinga 3 and Strongoli stratal units. Transgressive packages are formed by lagoonal mudstones that are abruptly overlain by shoreface sandstones. Aggradational highstand shallow-marine packages are typical of the lower Pliocene succession in half-graben basins. These deposits resulted from balanced conditions between the rate of sediment supply and the rate of creation of accommodation. Relatively thick forced regressive deposits are common within basins during phases where the accommodation-supply ratio is low (e.g. the middle Pleistocene San Mauro Sandstone). These deposits, influenced by growth faulting and folding, recorded base-level lowering linked to glacio-eustasy. A complex stratal architecture may be the consequence of the alternation between tectonic subsidence and uplift (e.g. the Serra Piani stratal unit). Such variations are thought to be related to the onset of an earliest mid-Pliocene transpressional tectonic phase. The studied deposits, therefore, show a marked tectonic control that strongly influenced their stratal architecture. These examples represent interesting cases of sequence-stratigraphic analysis in growth-faulted contexts.