The role of structural inheritance on Africa-Eurasia plate boundary evolution and neotectonics in the central Mediterranean sea

Africa-Eurasia plate convergence and the retreat of the subducting slab led to the consumption of the Tethys ocean lithosphere, which has now mostly disappeared below or accreted/exhumed within the Alps/Apennines. Slab tearing plays a major role in plate boundary evolution, asthenospheric upwelling, dynamic topography and magmatism. However, the role played by structural inheritance on the Africa plate is not well constrained. Based on seismological, geodetic and marine geophysical data, we analyse the pattern of crustal deformation in the Calabrian Arc and Sicily Channel, two key regions to unravel the complex Africa/Eurasia plate interaction in the central Mediterranean Sea.The Calabrian Arc subduction-rollback system accommodates Africa/Eurasia plate convergence along thrust faults developing both in the frontal and inner domains of the accretionary wedge. However, the most intriguing and tectonically active features are represented by arc-orthogonal faults deforming the subduction system along a complex strike-slip/transtensional pattern that may have been the source of major earthquakes in the Calabrian Arc. Deformation along the lithospheric transtensional faults is punctuated by buried sub-circular magnetized bodies aligned with Mt. Etna, that were interpreted as serpentinite/mud diapirs intruding the subduction system from the lower plate mantle. These faults are part of the overall dextral shear deformation, resulting from differences in Africa-Eurasia motion between the western and eastern sectors of the Tyrrhenian margin of northern Sicily, and accommodating diverging motions in the adjacent compartments of the Calabrian Arc. To the West, the Sicily Channel is part of the Pelagian block and experienced a lithospheric-scale continental rifting starting from the late Miocene with the development of NW-SE-trending tectonic depressions, bordered by crustal normal faults with variable throws. Our geophysical data, however, show that the most active tectonic feature in the area is a N-S trending and ~220-km-long lithospheric fault system characterized by volcanism, high heat flow and seismic activity. The NW-SE elongated rifting pattern, considered the first order structure in this region, appears currently inactive and sealed by undeformed Pleistocene deposits suggesting a recent change in structural development.Seismological data show that the lithospheric boundaries present in the Calabrian Arc and Sicily Channel correlate well with spatial changes in the depth distribution of earthquakes and separate regions with different Moho depths and thickness of the seismogenic layer. We propose that these boundaries may represent long-lived inherited Mesozoic discontinuities controlling plate boundary evolution and neotectonics.

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The Ionian and Alfeo–Etna fault zones: New segments of an evolving plate boundary in the central Mediterranean Sea?

Tectonophysics ◽

10.1016/j.tecto.2016.03.016 ◽

2016 ◽

Vol 675 ◽

pp. 69-90 ◽

Cited By ~ 45

Author(s):

A. Polonia ◽

L. Torelli ◽

A. Artoni ◽

M. Carlini ◽

C. Faccenna ◽

...

Keyword(s):

Mediterranean Sea ◽

Plate Boundary ◽

Fault Zones ◽

Central Mediterranean ◽

Central Mediterranean Sea

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Crustal deformation, active tectonics and seismic potential in the Sicily Channel (Central Mediterranean), along the Nubia–Eurasia plate boundary

Scientific Reports ◽

10.1038/s41598-020-78063-1 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Mimmo Palano ◽

Andrea Ursino ◽

Salvatore Spampinato ◽

Federica Sparacino ◽

Alina Polonia ◽

...

Keyword(s):

Shear Zone ◽

Crustal Deformation ◽

Thermal State ◽

Plate Boundary ◽

Active Tectonics ◽

High Heat ◽

Observation Point ◽

Fault System ◽

Central Mediterranean ◽

Sicily Channel

AbstractBased on multidisciplinary data, including seismological and geodetic observations, as well as seismic reflection profiles and gravity maps, we analysed the pattern of crustal deformation and active tectonics in the Sicily Channel, a key observation point to unravel the complex interaction between two major plates, Nubia and Eurasia, in the Mediterranean Sea. Our data highlight the presence of an active ~ 220-km-long complex lithospheric fault system (here named the Lampedusa-Sciacca Shear Zone), approximately oriented N–S, crossing the study area with left-lateral strike-slip deformations, active volcanism and high heat flow. We suggest that this shear zone represents the most active tectonic domain in the area, while the NW–SE elongated rifting pattern, considered the first order tectonic feature, appears currently inactive and sealed by undeformed recent (Lower Pleistocene?) deposits. Estimates of seismological and geodetic moment-rates, 6.58 × 1015 Nm/year and 7.24 × 1017 Nm/year, respectively, suggests that seismicity accounts only for ~ 0.9% of crustal deformation, while the anomalous thermal state and the low thickness of the crust would significantly inhibit frictional sliding in favour of creeping and aseismic deformation. We therefore conclude that a significant amount of the estimated crustal deformation-rate occurs aseismically, opening new scenarios for seismic risk assessments in the region.

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Pachydema lopadusanorum n. sp. (Coleoptera Melolonthidae) from Lampedusa Island (Sicily Channel, Central Mediterranean Sea, Italy)

10.31396/biodiv.jour.2018.9.3.277.282 ◽

2018 ◽

Vol 9 (3) ◽

pp. 277-282

Author(s):

Ignazio Sparacio ◽

Tommaso La Mantia ◽

Michele Bellavista

Keyword(s):

Mediterranean Sea ◽

Central Mediterranean ◽

Central Mediterranean Sea ◽

Sicily Channel

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Calcareous nannofossil surface sediment assemblages from the Sicily Channel (central Mediterranean Sea): Palaeoceanographic implications

Marine Micropaleontology ◽

10.1016/j.marmicro.2008.03.001 ◽

2008 ◽

Vol 67 (3-4) ◽

pp. 297-309 ◽

Cited By ~ 21

Author(s):

A. Incarbona ◽

S. Bonomo ◽

E. Di Stefano ◽

S. Zgozi ◽

N. Essarbout ◽

...

Keyword(s):

Mediterranean Sea ◽

Surface Sediment ◽

Calcareous Nannofossil ◽

Central Mediterranean ◽

Central Mediterranean Sea ◽

Sicily Channel

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The Graham Bank (Sicily Channel, central Mediterranean Sea): Seafloor signatures of volcanic and tectonic controls

Geomorphology ◽

10.1016/j.geomorph.2018.07.006 ◽

2018 ◽

Vol 318 ◽

pp. 375-389 ◽

Cited By ~ 6

Author(s):

D. Spatola ◽

A. Micallef ◽

A. Sulli ◽

L. Basilone ◽

R. Ferreri ◽

...

Keyword(s):

Mediterranean Sea ◽

Central Mediterranean ◽

Central Mediterranean Sea ◽

Sicily Channel

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Calcareous nannofossil assemblages from the Central Mediterranean Sea over the last four centuries: the impact of the little ice age

Climate of the Past Discussions ◽

10.5194/cpd-6-817-2010 ◽

2010 ◽

Vol 6 (3) ◽

pp. 817-866 ◽

Cited By ~ 5

Author(s):

A. Incarbona ◽

P. Ziveri ◽

E. Di Stefano ◽

F. Lirer ◽

G. Mortyn ◽

...

Keyword(s):

Mediterranean Sea ◽

Little Ice Age ◽

Ice Age ◽

Tyrrhenian Sea ◽

Calcareous Nannofossil ◽

Central Mediterranean ◽

Decadal Scale ◽

Central Mediterranean Sea ◽

Sicily Channel ◽

The Impact

Abstract. We present decadal-scale calcareous nannofossil data from four short cores (Station 272, 37° 17' N, 12° 48' E, 226 m depth; St 342, 36° 42' N, 13° 55' E, 858.2 m depth; St 407, 36° 23' N, 14° 27' E, 345.4 m depth; C90-1M, 40° 36' N, 14° 42' E, 103.4 m depth) recovered in the central Mediterranean Sea (northern Sicily Channel and Tyrrhenian Sea), which, on the basis of 210Pb activity span the last 200–350 years. Assemblages are dominated by placoliths, mostly Emiliania huxleyi, while, at least in the Sicily Channel sediments, Florisphaera profunda was an important part of the coccolithophore community. The paleoenvironmental reconstruction, based on ecological preference of species and groups, suggests that the Tyrrhenian core C90-1M maintained higher productivity levels over recent centuries, with respect to the Sicily Channel sites, possibly because of more pronounced winter phytoplankton blooms, in agreement with modern primary productivity variations over the last ten years. The lowermost part of the record of one of the cores from the Sicily Channel, Station 407, which extends down to 1650 AD, is characterized by drastic changes in productivity. Specifically, below 1850 AD, the decrease in abundance of F. profunda and the increase of placoliths, suggest increased productivity. The chronology of this change is related to the main phase of the Little Ice Age, which might have impacted the hydrography of the southern coast of Sicily and promoted vertical mixing in the water column. The comparison with climatic forcings points out the importance of stronger and prolonged northerlies, together with decreased solar irradiance. The identification of the LIA in the northern Sicily Channel cover the Bond cycle BO that was missing in a previous study of Holocene climatic anomalies in the Sicily Channel. Finally, we suggest that major abundance changes in reworked nannofossil specimens, recorded in the Tyrrhenian core C90-1M, might be linked to variations in terrigenous supply from land. Paradoxically, higher amounts of reworking correspond to dry periods. We argue that soil and rock vulnerability is enhanced during times of prolonged drought and vegetation cover loss.

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New insights on bottom water flows crossing a marine sill under periodic or impulsive perturbations: an application to the Sicily Channel sill (Central Mediterranean Sea)

10.5194/egusphere-egu2020-6046 ◽

2020 ◽

Author(s):

Federico Falcini ◽

Marco Di Paolantonio ◽

Ettore Salusti

Keyword(s):

Mediterranean Sea ◽

Red Sea ◽

Deep Sea ◽

Large Scale ◽

Water Dynamics ◽

Intermediate Water ◽

Central Mediterranean ◽

Geophysical Research ◽

Central Mediterranean Sea ◽

Sicily Channel

We here discuss the remarkable uplift of the Eastern Mediterranean bottom waters that flow westward, over the Malta Escarpment, and cross the sill of the Channel of Sicily (Astarldi et al., 2001; Iudicone et al., 2003; Falcini & Salusti 2015); a dynamics that is rather similar to the one occurring at the Strait of Gibraltar (Mediterranean Sea) and Bab el Mandab (Red Sea) (Siddall et al., 2002). This classical uplift, which usually occurs under a three layer system dynamics, is mostly explained by the Bernoulli suction effect (Lane-Serff et al., 2000). However, the real filed analyses suggest that this dynamics are significantly perturbed by tidal effects and or large scale storms (Smeed et al., 2004). Here consider a novel, theoretical approach to obtain a rather realistic view of natural perturbations that affect these deep flow dynamics. Our insights on uplift processes, in addition, give a contribution to the general understanding of the Mediterranean Sea deep water circulation and, on climatological grounds, heat storage dynamics. We finally remark that similar phenomena happens in several marine straits and/or in semi-enclosed, peripheral basins of particular importance for local and large-scale processes.&#160;ReferencesAstraldi, M., Gasparini, G. P., Gervasio, L., & Salusti, E. (2001). Dense water dynamics along the Strait of Sicily (Mediterranean Sea). Journal of Physical Oceanography, 31(12), 3457-3475.Falcini, F., & Salusti, E. (2015). Friction and mixing effects on potential vorticity for bottom current crossing a marine strait: an application to the Sicily Channel (central Mediterranean Sea). Ocean Science, 11(3), 391-403.Iudicone, D., Buongiorno Nardelli, B., Santoleri, R., & Marullo, S. (2003). Distribution and mixing of intermediate water masses in the Channel of Sicily (Mediterranean Sea). Journal of Geophysical Research: Oceans, 108(C9).Lane-Serff, G. F., Smeed, D. A., & Postlethwaite, C. R. (2000). Multi-layer hydraulic exchange flows. Journal of Fluid Mechanics, 416, 269-296.Siddall, M., Smeed, D. A., Matthiesen, S., & Rohling, E. J. (2002). Modelling the seasonal cycle of the exchange flow in Bab el Mandab (Red Sea). Deep Sea Research Part I: Oceanographic Research Papers, 49(9), 1551-1569.Smeed, D. A. (2004). Exchange through the Bab el Mandab. Deep Sea Research Part II: Topical Studies in Oceanography, 51(4-5), 455-474.

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