New insights on the buckling of the Apulian Foreland from the eastern Salento offshore (Apulian Swell - Italy)

Gianvito Teofilo, Marcello Tropeano, Vincenzo Festa, Luisa Sabato, Carlo Doglioni, Ilaria Antoncecchi, and Luigi Spalluto

The Apulian Swell is a submerged ridge located between the south Adriatic Basin and the Ionian Sea in the central Mediterranean, and represents the southeastern prosecution of the present-day exposed Puglia (southern Italy) in the Salento offshore.

Puglia is a lithospheric anticline that represents the foreland (the Apulian Foreland) of two orogens: the Dinaric- Hellenic, to the east, and the Apennines, to the west. Using a data-set consisting of public seismic reflection profiles and exploration wells (ViDEPI Project and CROP Project), it results that the Apulian Swell spectacularly records the Pleistocene buckling of the Apulian Foreland.

The buckling is testified by three sedimentary/structural stages of evolution of the Apulian Swell.

A first stage is documented by a late Messinian to Pliocene sedimentary wedge (ages are not constrained by well data) lapping toward west onto the eastward flexuring Apulian Swell (becoming the Dinaric-Hellenic foreland-basin). This sedimentary wedge progressively covers the hinge zone of the flexure, and expands onto the top of the Swell, overfilling the foreland basin.

A second stage is documented by the Pleistocene westward flexure of the Swell (becoming the Apennines forelandbasin) that causes the progressive flexure of the tip of the previous sedimentary wedge. Most probably, Dinaric- Hellenic sediments, bypassing the swell, fed the deep Apennines foreland-basin. A Pleistocene sedimentary wedge, unable to fill this foreland basin, onlaps onto the base of the eastern flank of the Swell.

A third stage is documented by the onlap of a new middle-late Pleistocene sedimentary wedge onto the eastern flank of the Swell, namely onto the folded top of the inner part of the first wedge. The unconformable development of a new wedge indicates that sedimentary feeder systems became progressively unable to bypass the Swell.

Since the first flexure didn't avoid sedimentation onto the Swell and the second flexure pulled down the tip of the sedimentary wedge covering the same Swell, a later change in the structural behavior of the area should be taking into account (a folding accompanied by uplift). Likely, as suggested for the existence of the exposed Puglia, this change is induced by a buckling of the Apulian Foreland.

AAPG Search and Discovery Article #90161©2013 AAPG European Regional Conference, Barcelona, Spain, 8-10 April 2013