Basin dynamics and sequence stratigraphy in the Calabrian Arc (Central Mediterranean); records and pathways of the Crotone Basin

Abstract

The structural and tectonostratigraphical Late Neogene development of the Crotone Basin is presented, a foreland basin in the accretionary wedge along the external side of the Calabrian Arc (Central Mediterranean). It demonstrates the role of local tectonic activity of the thrust wedge and that of regional relative sea level fluctuations on the formation of unconformity-bound depositional sequences. The tectonostratigraphic development of the basin can be divided in 4 stages: 1. a Serravalian – early Messinian Stage, characterized by a progressive enlargement of the Basin, 2. a middle Messinian – Early Pliocene Stage, characterized by intense and complex fault movements that were overprinted by the Messinian salinity crisis, 3. an Upper Pliocene - Early Pleistocene Stage, characterized by a pulsating onlap, and 4. a Late Pleistocene - Recent Stage, characterized by strong vertical movements in conjunction with the uplift of the Sila basement Massif. At the end of Stage 2 regional compression during the Mid-Pliocene Phase inverted the basin and thrust its cover towards the margins. A kinematic model is proposed whereby the evolution of the Basin was controlled by oblique sinistral movements along two confining NW-SE trending convergent crustal shear zones. Within this concept, the Middle Miocene - Early Pliocene development (Stages 1 and 2) reflects a strike-slip cycle. The sequence boundaries that belong to the Stages 1 and 3 are of remarkably similar tectonostratigraphic significance. They reflect a 'composite tectonic event' comprising an uplift/regression pulse, followed by a rapid subsidence/onlap. Each composite tectonic event is here considered to represent one growth pulse in the progressive evolution of the accretionary wedge system, while the middle Messinian - Early Pliocene phases of basin fill and tectonic inversion (Stage 2), and the Late Pleistocene - Recent uplift phase (Stage 4) reflect the increase of regional stress in the Central Mediterranean.