Active tectonics of the Calabrian subduction revealed by new multi-beam bathymetric data and high-resolution seismic profiles in the Ionian Sea (Central Mediterranean)
|Author(s)||Gutscher Marc-Andre1, Kopp Heidrun2, Krastel Sebastian3, Bohrmann Gerhard4, Garlan Thierry5, Zaragosi Sebastien6, Klaucke Ingo2, Wintersteller Paul4, Loubrieu Benoit7, Le Faou Yann5, San Pedro Laurine1, Dominguez Stephane8, Rovere Marzia9, De Lepinay Bernard Mercier10, Ranero Cesar11, Sallares Valenti12|
|Affiliation(s)||1 : Univ Brest, Lab Geosci Ocean, CNRS, F-29280 Plouzane, France.
2 : GEOMAR Helmholtz Ctr Ocean Res, D-24148 Kiel, Germany.
3 : Christian Albrechts Univ Kiel, D-24118 Kiel, Germany.
4 : MARUM Univ Bremen, D-28334 Bremen, Germany.
5 : SHOM, F-29228 Brest, France.
6 : EPOC Univ Bordeaux, F-33405 Talence, France.
7 : IFREMER, Geosci Marines EDROME, F-29280 Plouzane, France.
8 : Univ Montpellier, Geosci Montpellier, F-34095 Montpellier, France.
9 : ISMAR CNR, Inst Marine Sci, I-40129 Bologna, Italy.
10 : Univ Nice, CNRS, GeoAzur, F-06560 Valbonne, France.
11 : CSIC, ICREA, ICM, E-08003 Barcelona, Spain.
12 : CSIC, ICM, E-08003 Barcelona, Spain.
|Source||Earth And Planetary Science Letters (0012-821X) (Elsevier Science Bv), 2017-03 , Vol. 461 , P. 61-72|
|WOS© Times Cited||32|
|Keyword(s)||subduction, active faults, Eurasia-Africa plate boundary, bathymetry, seismic profiles, accretionary wedge|
|Abstract||The detailed morphology and internal structure of the Calabrian accretionary wedge and adjacent Eastern Sicily margin are imaged in unprecedented detail by a combined dataset of multi-beam bathymetry and high-resolution seismic profiles. The bathymetric data represent the results of 6 recent marine geophysical surveys since 2010 as well as a compilation of earlier surveys presented as a 2 arc-sec (60 m) grid. Several distinct morpho-tectonic provinces are identified including: the deeply incised Malta–Hyblean Escarpment, numerous submarine canyons, broad regions of relatively flat seafloor dominated by fields of sediment waves, the gently undulating anticlinal fold-and-thrust belts of the external Calabrian accretionary wedge and the adjacent portion of the Western Mediterranean Ridge. The Calabrian arc can be divided into 4 domains (from SE to NW): 1) the undeformed Ionian abyssal plain, 2) the external evaporitic wedge, 3) the internal clastic wedge, 4) the Calabrian backstop (Variscan crystalline basement). The Calabrian accretionary wedge can also be divided laterally into two major lobes, the NE- and the SW lobes, and two minor lobes. The kinematics of the limit between the two major lobes is investigated and shown to be sinistral in the external (evaporitic) wedge. A network of radial slip lines within the southernmost external wedge unequivocally demonstrate ongoing dextral displacement of a rigid indenter (representing the corner of the clastic wedge) into the evaporitic wedge thereby confirming the geodynamic model of an active lateral slab tear fault here off eastern Sicily. The slab tear produces a series of major sub-parallel dextral strike-slip faults offshore Mt. Etna and south of the Straits of Messina consistent with the relative motions between Calabria and the Peloritan domain (NE Sicily). Abundant strike-slip faulting, and wide-spread folding and thrusting observed throughout the entire accretionary wedge, indicate regional shortening between the Ionian abyssal plain (foreland) and the Calabrian–Peloritan backstop caused by active subduction.|