Quaternary deformation in SE Sicily: insights into the life and cycles of forebulge fault systems
Diego Di Martire1, Alessandra Ascione1, Domenico Calcaterra1, Giovanna Pappalardo2, Stefano Mazzoli1
1 Dipartimento di Scienze della Terra, dell’Ambiente e delle Risorse, Università degli Studi di Napoli Federico II, Largo San Marcellino 10, 80138 Napoli, Italy
2 Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Università di Catania, Italy3
LITHOSPHERE; v. 7; no. 5; p. 519–534, 2015
Integrated geological, geomorphological, and differential interferometry synthetic aperture radar (DInSAR) data are used to constrain the timing and modes of activity of Quaternary fault systems in the Hyblean Plateau. This area, which represents a unique natural laboratory for studying surface deformation in relation to deep slab dynamics, has grown since middle Miocene times as a doubly plunging forebulge associated with slab rollback during NW-directed subduction. Bimodal extension has produced two mutually orthogonal normal fault systems. The detailed stratigraphic record provided by synrift sediments and postrift marine terraces allowed us to define the timing of activity of an early Pleistocene, flexure-related fault system, thus constraining the duration of a typical foreland extensional tectonic event to ~1.5 m.y. Subsequent late Quaternary to present deformation was dominated by strike-slip faulting associated with NW-oriented horizontal
compression. During this latest stage, regional uplift progressively increased toward the thrust front to the NW and was accompanied by differential uplift accommodated by dip-slip components of motion along active NNW-trending faults. The general active tectonic setting of the study area, characterized by NW-oriented horizontal compression consistent with major plate convergence, and the regional uplift pattern can both be explained within the framework of intraplate shortening and foreland rebound following complete slab detachment, a major geodynamic event interpreted to have taken place at ca. 0.7 Ma in southern Italy.