EGU2020-18473
https://doi.org/10.5194/egusphere-egu2020-18473
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Extensional tectonics during the Tyrrhenian back-arc basin formation synthetized in a new morpho-tectonic map

Maria Filomena Loreto1, Nevio Zitellini1, César Rodriguez Ranero2, Camilla Palmiotto1, and Manel Prada3
Maria Filomena Loreto et al.
  • 1National Research Council (CNR), Institute of Marine Sciences (ISMAR), Bologna, Italy (filomena.loreto@bo.ismar.cnr.it, nevio.zitellini@bo.ismar.cnr.it, camilla.palmiotto@bo.ismar.cnr.it)
  • 2Institució Catalana de Recerca i Estudis Avançats, ICREA, Barcelona, Spain (cranero@cmima.csic.es)
  • 3Barcelona Center for Subsurface Imaging, ICM, CSIC, Barcelona, Spain (manelprada@gmail.com)

A new tectonic map is presented focused upon the extensional style accompanying the formation of the Tyrrhenian back-arc basin. Our basin-wide analysis synthetizes the interpretation of vintage multichannel and single channel seismic profiles integrated with modern seismic images and P-wave velocity models, and with a new morpho-tectonic map of the Tyrrhenian (Palmiotto & Loreto, 2019). Four distinct evolutionary opening stages have been constrained: 1) the initial Langhian(?)/Serravallian opening phase actives offshore central/southern Sardinia and offshore western Calabria; 2) the Tortonian/Messinian phase dominated by extension offshore North Sardinia-Corsica, and by oceanic accretion in the Cornaglia and Campania Terraces; 3) the Pliocene phase, dominated by mantle exhumation which was active mainly in the central Tyrrhenian and led to the full opening of Vavilov Basin; and 4) the Quaternary phase characterized by the opening of the Marsili back-arc basin. Listric and planar normal faults and their conjugates bound a series of horst and graben, half-graben and triangular basins. Distribution of extensional faults, active since Middle Miocene, throughout the basin allowed us to define a faults arrangement in the northern / central Tyrrhenian mainly related to in a pure shear which evolved a simple shear opening of continental margins. At depth, faults accommodate over a Ductile-Brittle Transitional zone cut by a low-angle detachment fault possibly responsible for mantle exhumation in the Vavilov and Magnaghi abyssal plains. In the southern Tyrrhenian, normal, inverse and transcurrent faults appear to be related to a large shear zone located along the continental margin of the northern Sicily. Extensional style variationthroughout the back-arc basin combined with wide-angle seismic velocity models, from Prada et al. (2014; 2015), allow to explore the relationship between shallow deformation, represented by faults distribution throughout the basin, and crustal-scale processes, subduction of Ionian slab and exhumation.

 

REFERENCES

Palmiotto, C., & Loreto, M. F., (2019). Regional scale morphological pattern of the Tyrrhenian Sea: New insights from EMODnet bathymetry. Geomorphology, 332, 88-99.

Prada, M., Sallarès, V., Ranero, C.R., Vendrell, M.G., Grevemeyer, I., Zitellini, N. & De Franco, R., 2014. Seismic structure of the Central Tyrrhenian basin: Geophysical constraints on the nature of the main crustal domains. J. Geophys. Res.: Solid Earth, 119(1), 52-70.

Prada, M., Sallarès, V., Ranero, C.R., Vendrell, M.G., Grevemeyer, I., Zitellini, N. & De Franco, R., 2015. The complex 3-D transition from continental crust to backarc magmatism and exhumed mantle in the Central Tyrrhenian basin. Geophys. J. Int., 203(1), 63-78.

How to cite: Loreto, M. F., Zitellini, N., Ranero, C. R., Palmiotto, C., and Prada, M.: Extensional tectonics during the Tyrrhenian back-arc basin formation synthetized in a new morpho-tectonic map, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-18473, https://doi.org/10.5194/egusphere-egu2020-18473, 2020

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