Sequence stratigraphy of a Mesozoic carbonate platform-to-basin system in western Sicily

Abstract

Sequence stratigraphic studies of the Triassic through Paleogene carbonate successions of platform, slope and basin in western Sicily (Palermo and Termini Imerese Mountains) have identified a sedimentary cyclicity mostly caused by relative oscillations of sea level. The stratigraphic successions of the Imerese and Panormide palaeogeographic domains of the southern Tethyan continental margin were studied with physical-stratigraphy and facies analysis to reconstruct the sedimentary evolution of this platform-to-basin system. The Imerese Basin is characterized by a carbonate and siliceous-calcareous succession, 1200-1400 m thick, Late Triassic to Eocene in age. The strata display a typical example of a carbonate platform margin, characterized by resedimented facies with progradational stacking patterns. The Panormide Carbonate Platform is characterized by a carbonate succession, 1000-1200 m thick, Late Triassic to Late Eocene, mostly consisting of shallow-water facies with periodic subaerial exposure. The cyclic arrangement has been obtained by the study of the stratigraphic signatures (unconformities, facies sequences, erosional surfaces and stratal geometries) found in the slope successions. The recognized pattern has been compared with coeval facies of the shelf. This correlation provided evidence of sedimentary evolution, influenced by progradation and backstepping of the shelf deposits. The stratigraphic architecture of the platform-to-basin system is characterized by four major transgressive/regressive cycles during the late Triassic to late Eocene. These cycles, framed in a chronostratigraphic chart, allows the correlation of the investigated shelf-to-basin system with the geological evolution of the African continental margin during the Mesozoic, showing tectono-eustatic cycles. The first cycle, encompassing the late Triassic to early Jurassic, appears to be related to the late syn-rift stage of the continental margin evolution. The following three cycles, spanning from the Jurassic to Eocene, can be related to the post-rift evolution and to thermal subsidence changes.

Geology of Monte Gallo (Palermo Mts, NW Sicily)

“…A major downlap surface with AFU and mz, associated with submarine erosion and hiatus, characterizes the lower boundary of the unit (Basilone, 2009(Basilone, , 2015 as observable at Piano dello Stinco (Figure 4 and Stop 7, yellow itinerary),…”

Structural and tectono-stratigraphic review of the Sicilian orogen and new insights from analogue modeling

“…Setting aside the Permian-Lower Triassic formations, which are poorly or not outcropping in Sicily, the lowermost formation characterizing the base of the Meso-Cenozoic cover of the African margin is represented by the Triassic flysch-like marly limestones of the Mufara Fm. (Basilone, 2009(Basilone, , 2018. Above it, a major Upper Triassic carbonate sequence deposited on the northwestward (Panormide, column C from Figure 4 and Appendix A) and southeastward (Trapanese-Saccense and Hyblea, column F and G from Figure 4 and Appendix A) platforms of the African paleomargin (Basilone, 2009(Basilone, , 2018, whereas deepwater carbonates and siliceous deposits sedimented in intermediate basins (Imerese and Sicanian, column D and E from Figure 4 and Appendix A).…”

“…(Basilone, 2009(Basilone, , 2018. Above it, a major Upper Triassic carbonate sequence deposited on the northwestward (Panormide, column C from Figure 4 and Appendix A) and southeastward (Trapanese-Saccense and Hyblea, column F and G from Figure 4 and Appendix A) platforms of the African paleomargin (Basilone, 2009(Basilone, , 2018, whereas deepwater carbonates and siliceous deposits sedimented in intermediate basins (Imerese and Sicanian, column D and E from Figure 4 and Appendix A). The Imerese and Sicanian domains are believed to belong to the Ionian Tethydes (the so-called "Ionides", Finetti, (2005), including also the Lagonegrese units of southern Apennines) in a stretched continental to oceanic crust setting (OCT) deriving from the Late Paleozoic to early Mesozoic eastern Gondwana break-up.…”

“…The SFTB appears as a central piece of the Mediterranean orogenic subduction systems and its understanding is essential to constrain paleogeographic models of the Mediterranean and, more generally, the dynamics and mechanics of subduction related orogens. Many studies focused on the stratigraphy of Sicilian units (e.g., Patacca et al, 1979;Avellone et al, 2010;Guerrera et al, 2012;Pinter et al, 2016;Basilone, 2009Basilone, , 2018, local (e.g., Oldow et al, 1990;Catalano et al, 1995Zarcone et al, 2010;Vitale et al, 2018), regional paleogeographic settings (e.g., Dewey et al, 1989;Stampfli and Borel, 2002;Handy et al, 2010;Frizon de Lamotte et al, 2011;Van Hinsbergen et al, 2020), internal structure of the SFTB (e.g., Roure et al, 1990;Avellone et al, 2010;Guarnieri et al, 2002;Catalano et al, 1995Catalano et al, and 2013a and tectono-stratigraphic reconstructions (e.g., Roure et al, 1990;Corrado et al, 2009;Guerrera et al, 2012;Napoli et al, 2012;Gugliotta et al, 2011Gugliotta et al, , 2014Butler et al, 2019;Basilone et al, 2016;Basilone, 2020). However, only a few studies were dedicated to the Sicilian orogen dynamics and, in particular, to constrain the small and large scale deformation mechanisms controlling its structural evolution (e.g., Balestra et al, 2019;Ben-Avraham et al, 1995;Barreca and Monaco, 2013).…”

Quaternary marine and continental unconformity-bounded stratigraphic units of the NW Sicily coastal belt

“…In these areas, affected by depositional and erosional events, UBSUs provide easy stratigraphic synthesis. They are rarely used as more attention is given to sequence stratigraphy, but synthem stratigraphy has been effectively applied to Mesozoic and Cenozoic successions around the world (Basilone, 2009;Benvenuti & Degli Innocenti, 2001;Benvenuti, Papini, & Rook, 2001;Ruban, Zerfass, & Pugatchev, 2009;Sacchi, Horvath, & Magyari, 1999;Vezina, Jones, & Ford, 1999;Zavala, 2000).…”