The western Calabria continental margin forms thetransition between the Late Pliocene to Recent Marsilispreading center and continental Calabria. Integrating highpenetrationand -resolution upper crustal seismic images withseafloor morphology, ODP well data andgeological/geophysical constraints we provide a detailedreconstruction of the architecture of the distal portion of the WCalabria rifted margin and of the adjacent Marsili “oceanic”domain (Fig. 1) and develop a scheme for the Pliocene topresent rifting and drifting of the upper plate of the Ioniansubduction zone. Our seismic data document the presence ofstretched and thinned continental crust, less than 10 Km thickinto the eastern sector of the Marsili abyssal plain previouslyconsidered as floored by a three-layer oceanic crust.Thinning of the crust is associated with a numbers of 2-4km wide tilted blocks composed of an acoustic basement andpre- and syn-rift sediments.Stretching factors between 1.1 and 1.42 (ca. 40% extension)has been obtained assuming a domino-like style ofdeformation. With few exceptions, the infill completelysmoothes out pre-existing topography and explain the flat seafloor in the area surrounding the Marsili volcano. Extensionaltectonics began in the Late (?) Pliocene – Early (?) Pleistocenetimes and ended at ca. 0.5 Ma resulting in the formation of ca.70 km of “oceanic” domain with an average spreading ratebetween ca. 5.1 and 5.9 cm/yr. The appearance of vescicularbasalts in the Marsili basin was not associated with the end ofextension. The post-extensional sedimentary package has fairlyconstant thicknesses of ca. 350 along the entire Marsili abyssalplain. The Marsili volcano grows close to the westerntermination of the stretched and thinned W Calabria continentalcrust, in an asymmetric position with respect to the < 2 MaMarsili Basin itself.
|Numero di pagine||1|
|Stato di pubblicazione||Published - 2012|
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