Notwithstanding the winter break we finally submitted to the AGU journal Tectonics a paper describing the results of a scientific cruise aboard of the research vessel Urania that was held in January 2011 in the offshore of the Jonian coast of Calabria, southern Italy.
This paper describes geological and geophysical evidence of the activity of a transpressional fault zone connected with the submerged Amendolara Ridge.
This is the abstract of the paper:
"High-resolution, single-channel seismic (sparker) profiles and multibeam bathymetry data collected in the Amendolara Ridge, the submarine extension of the Apennines thrust belt underneath the Ionian Sea, provide evidence of recent deformation in a supposedly stable crustal sector. New data show that Middle-Late Pleistocene sediments are involved in growth folds related to blind or near surface transpressional faults (Amendolara Fault System, AFS) located on the southwest flank of the ridge. Results from the new acquisition are consistent with analysis of existing multichannel seismic profiles calibrated with oil-exploratory wells. Morpho-bathymetry and seismic data indicate that distinct, ~10 to 20 km long banks which top the ~80 km long ridge are structural culminations above en-echelon fault segments. Numeric modeling of the bathymetry and of stratigraphic markers suggests that two steep (45° dip) upper crustal (2-10 km) blind fault segments underlie the ridge. The AFS spatially coincides with a belt of Mw<4.7 strike-slip and thrust earthquakes, which indicate left-oblique reverse motion. Elastic modeling of fault segments indicates they may be capable of moderate (M~6.1-6.4) earthquakes, although un unknown part of aseismic slip likely contributes to deformation. Late Pliocene-Quaternary growth of the Amendolara Ridge temporally coincides with cessation of thin-skinned Apennines thrust belt motion, when oblique collision between the Calabrian Arc and the Apulian continental crust overwhelmed subduction retreat of the Adriatic slab. Localization of the transpressional belt was controlled by an inherited mechanical interface between the thick Apulian crust and the attenuated Ionian basin."
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| Morphobathymetric map of the northern Jonian coast of Calabria, from Rebesco et al. (2009), Int. J. Earth Sci. (Geol. Rundsch.), 98, 791–805, doi:10.1007/s00531-009-0429-1. |
The study area of the Teatioca 2011 Cruise
Here are some pictures from my Panoramio space:
The R/V Urania
Chirp bathymetry of the Amendolara Ridge
Aeolian Islands
