DYNAMICS and ACTIVE PROCESSES - International Lithosphere ...

ILP TASK FORCE on SEDIMENTARY BASINS
2010 International Workshop
November 7-12, 2010, Tirana (Albania)
CONTRACTION and VERTICAL MOVEMENTS in the GARGANO PROMONTORY
and ADJACENT OFFSHORE: IMPLICATION for the TECTONICS of the SOUTH
ADRIATIC DOMAIN
Nicolaas J. HARDEBOL and Giovanni BERTOTTI
Delft Univ. of Techn., Stevinweg 1, 2628 CN Delft, the Netherlands; VU University, De
Boelelaan 1085, 1081 HV Amsterdam, The Netherlands; T +31 15 27 81352; E
N.J.Hardebol@tudelft.nl
Introduction
The Adriatic plate has been described as a double-verging plate that is bordered to the west by
the Apenninic and to the east by the Dinaric-Helvetic fold-and-thrust belts (Figure 1a). The
interior of the plate supposedly hosts a north-south trending flexural bulge from Istria to the
Gargano promontory (and the Apulian Ridge), which divides the Adriatic basins in respect to
their relative foreland position to either the Apenninic or Dinaride orogenic systems. The
Neogene deformation history and vertical motions in the interior of the Adriatic plate is
subject to flexural forcing or compressional effects transmitted from the plate margins. This
study present new field and offshore seismic data from the Gargano Promontory and adjacent
Southern Adriatic Basin to examine their deformation history.
The Southern Adriatic Basin (SAB) stretches southeast-ward offshore of the Gargano and
Puglia coastlines (Figure 1a) and is underlain by a basement of Triassic-Lias salts to platform
carbonates and a Lias-Cretaceous succession of mostly pelagic carbonates and marls that
show an eastward, Dinaric-Hellenic facing dip. The SAB contains an Oligocene to Quaternary
succession of mainly siliciclastics and calcarenites and subject to tilting and faulting of strata
that are commonly regarded as transtensional and transpressional expressions linked to
basement lineaments.
The Gargano Promontory (GP) to the north forms up to 1000m relief and comprises mostly
Jurassic-Cretaceous carbonates. The GP exhibits a peculiar morphological shape with four
prominent peneplains that are divided by high and steep slopes (Figure 1d). Miocene shallowwater
limestones cover the eroded substratum unconformably and are found over most of the
Gargano Promotory. Post-Lower Messinian deposits however are scarce and especially
developed onto the two lowermost peneplains at 80m and 200m along the southern border of
the GP (Figure 1b). These Mio-Pliocene deposits cover erosional surfaces and contain
diagnostic coastal cliff facies linked to abrasive marine terrace that help deciphering the
Tertiary deformation and relief development (Casolari et al., 2000; Bertotti et al., 2001).
This study presents new data from the GP and from offshore seismic profiles of the SAB. We
examine their contrasting physiographic expression in effect to a Miocene-Pliocene
contractional and uplift-subsidence history. We especially focus on the marine terrace
sediments in association to their tilted substratum for the GP and on the coeval depositional
and deformation history in the adjacent SAB. The onshore field data and offshore seismic
interpretations are combined aiming at a more univocal picture of the kinematics and vertical
motions for Tertiary times.
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