Gerardo Pappone

Active fragmentation of Adria, the north African promontory, central Mediterranean orogen

Global Positioning System (GPS) velocities indicate that Adria no longer behaves as a rigid tectonic indenter into southern Europe and is divided into northwestern and southeastern velocity domains. Differential motions are recognized in a velocity field determined from the Peri-Tyrrhenian Geodetic Array (PTGA) and International GPS Service (IGS) sites in the circum-Tyrrhenian region of the central Mediterranean and published GPS velocities from the eastern Adriatic coast. In a fixed Eurasian reference frame, PTGA and IGS site velocities in Sicily and southern Italy are as much as 10 mm/yr in a northward direction, similar to GPS velocities along the eastern coast of the Adriatic Sea. In contrast, velocities in northern Italy are small or statistically insignificant and similar to velocities in Sardinia and Corsica outboard of western Adria. The tectonic boundary dividing Adria is seismically active and passes around the southern and eastern margins of the Tyrrhenian Basin, crosses central Italy, extends into the Adriatic Sea, and follows the western margin of the Dinaride tectonic belt north to the Gulf of Venice. The eastern margin of Adria is approximately located and follows the axis of the central Dinaric Alps southeast to the Hellenic arc. Southeastern Adria has a velocity related to northward motion of Africa, whereas northwestern Adria has negligible differential motion in the Eurasian frame and now is part of the Alpine collage of southern Europe.

Large-scale longitudinal extension in the southern Apennines contractional belt, Italy

During late Cenozoic thrusting, the interior of the peri-Tyrrhenian orogenic belt in the southern Apennines underwent two episodes of nearly orthogonal extension. Early extension was oriented subparallel to the axis of the tectonic belt and formed in response to progressive thrust-belt arcuation. The length of the tectonic belt increased by ∼50%, and the longitudinal strain was accommodated by low-angle normal faults concentrated in tectonic domains recording up to 150%-200% extension. Younger extension, oriented at a high angle to the orogen, was accompanied by Pliocene-Pleistocene uplift and by southeasterly migration of Tyrrhenian Sea rifting.

Extensional detachment faulting on the Tyrrhenian margin of the southern Apennines contractional belt (Italy)

The tectonic evolution of the Campania margin during the late Pliocene–Pleistocene is characterized by extensional deformation coeval with the opening of the Marsili oceanic basin. The initial stages of stretching are represented in the analysed area by the development of low-angle normal faults that extended the belt in the same direction as the direction of spreading recognized for the oceanic basin. Detachment faulting was accompanied by the onset of magmatic activity and by major uplifts that resulted in the accumulation of thick conglomerate successions in the half-grabens that developed in the upper plate of the extensional detachment. Deformation continued during the Mid-Pleistocene with the formation of strike-slip and normal faults trending almost parallel to the spreading direction of the Marsili basin. These faults dissected the extensional detachment and promoted counter-clockwise block rotations about vertical axes, which accommodated the ESE-directed stretching of the Marsili basin and the consequent sinistral shear imposed on the southern Apennine chain. The development of a regional detachment fault along the Tyrrhenian margin of Campania explains the complex patterns of subsidence and uplift that characterize this area during the Pleistocene and fits well within the regional geodynamic framework of the southern Tyrrhenian Sea.

Tectonic history of the Lagonegro Domain and Southern Apennine thrust belt evolution

Abstract The tectonic history of the Lagonegro Domain in Southern Italy is an intriguing topic for the Mesozoic Mediterranean paleogeography and is important for reconstructions of the Tethys. Previous interpretations postulate the paleogeographic position of a deep Lagonegro-Molise-(Sicilide) basinal domain between the external Apulia carbonate platform to the east, and the internal Apenninic carbonate platform (i.e. the Alburno-Cervati-Maddalena Mountains) to the west. A second and separate deep basin more to the west was the home of the Liguride units which cover extensive areas of the Southern Apennines. Following an extensive review of previously published concepts and on the base of the structural interpretation of the Southern Apennines thrust belt using additional subsurface data and extensive field mapping, the authors now suggest that all deep basinal units of the Southern Apennines, i.e. the Ligurides, the Lagonegro units and the Molise-Sicilide units, derive from internal areas located to the west with respect to a coeval wide carbonate platform-slope-shallow-basin complex which, in its pre-Middle Miocene reconstruction, extended from Apulia well beyond the present-day Tyrrhenian coast of Southern Italy. The basinal units were first assembled as an accretionary wedge and overthrusted during the Late Miocene over the carbonate platform-slope-shallow-basin complex. The Liguride-Lagonegro-Molise-(Sicilide) accretionary wedge was later cut by an envelopment thrust which overthrust the previously underlying platform complex over the previously emplaced complex accretionary wedge. Our hypothesis in part revives an old concept proposed by Selli (1962) and requires further testing and research. We conclude that paleogeographic reconstructions of the Southern Apennines and the Mediterranean Tethys are still in a state of flux.

Estimating Coastal Vulnerability in a Meso-Tidal Beach by Means of Quantitative and Semi-Quantitative Methodologies

ABSTRACT DI PAOLA, G., IGLESIAS, J., RODRÍGUEZ, G., BENASSAI, G., AUCELLI, P and PAPPONE, G., 2011. Estimating Coastal Vulnerability in a Meso-Tidal Beach by Means of Quantitative and Semi-Quantitative Methodologies. In: Micallef, A. (ed.), MCRR3-2010 Conference Proceedings, Journal of Coastal Research, Special Issue, No. 61, pp. 303–308. Grosseto, Tuscany, Italy, ISSN 0749-0208. The main goal of this study is to estimate the coastal vulnerability on a stretch of coastline by using two different methodologies and to check if both methodologies give rise to similar results or if notably dissimilar assessments are obtained. To reach the above mentioned objective, a new experimental methodology (Benassai et al, 2009) based on inundation of the inshore land and the well known USGS methodology (Gornitz et al, 1994) are applied and compared. In the first approach, a new parameter, named as impact index, is calculated by using wave climate and geomorphologic data. In general, impact index depends on run-up height, seasonal and long term erosion index and the efficiency of existing structures for coastal defence. The relative value of this parameter is contrasted with that of the often used coastal vulnerability index, CVI, which includes geological and physical variables. The application of these methods gives rise to significantly different levels of vulnerability for the same zone. This situation must be attributed mainly to the distinctive nature of the used methods. Thus, taking into account the results, it is remarked that the procedure to choose a methodology for assessing the vulnerability of a given coastal zone must be based on the available information and on the characteristics of the zone. Furthermore, the use of the same method to do risk and vulnerability comparisons is recommended.

Thrust tectonics in the Picentini Mountains, Southern Apennines, Italy

Abstract Detailed geological mapping carried out in the Picentini Mountains, Southern Apennines, Italy, allowed to reconstruct the geometry of the fold and thrust belt in this region. Contractional structures were formed during multiple episodes of ENE to NNE shortening and were cut during later extension by low- and high-angle normal faults. Based on timing of emplacement and geometrical relationships between thrust units, we worked out a kinematic model of thrust tectonics. Basinal (Sicilid and Lagonegro) units were thrust eastward onto a carbonate-platform-basin system (CPBS) starting in the Serravallian-Tortonian, and were in turn overridden by the CPBS units by means of deeper decollement thrusts. Later contraction, starting from late Tortonian-Messinian times, built up a 15-km-thick antiformal stack during SSW-NNE shortening. We applied the forward kinematic model of thrust imbrication to perform a qualitative palinspastic restoration of a regional cross-section through this area, based on published interpreted seismics and other subsurface data. The thrust tectonics of the Picentini Mountains and more northward regions was controlled in the internal sectors mostly by envelopment thrusting of carbonate platform thrust sheets, which formerly were the floor complex of the Tortonian thrust belt, while multiple progressive decollement of the basinal roof complex occurred in the external part of the belt. Shallow crustal extension on low-angle faults with transport direction oblique to orthogonal to contractional transport was responsible for contemporaneous thinning during the accretion of the antiformal stack at deeper structural levels.

New morphostratigraphic and chronological constraints for the Quaternary paleosurfaces of the Molise Apennine (southern Italy)

New morphostratigraphic and chronological constraints for the Quaternary paleosurfaces of the Molise Apennine (southern Italy) The Molise Apennines feature numerous relicts of paleosurfaces, mostly of erosional origin, which represent the remnants of gently-rolling ancient landscapes now hanging at different altitudes above the local base-levels of erosion. Their genesis can be related to prolonged periods of relative tectonic stability alternating with periods of uplift, or to the interplay between steady tectonic uplift and climatic fluctuations. Four orders of paleosurfaces were recognized: I (> 1,100 m a.s.l.), II (900-1,000 m a.s.l.), III (750-850 m a.s.l.), IV (600-720 m a.s.l.). The most ancient orders (I and II) are cut into the bedrock and are located at the top of the Matese and Montagnola di Frosolone massifs. The youngest paleosurfaces (III—IV), partially cut into Quaternary deposits, are found along the valley flanks of the main river systems and within the Boiano, Carpino, Isernia and Sessano intramontane basins. The present study deals with the dating of the Sessano Basin Paleosurface (SBP) which is related to the IV order and is cut into the basin infill. The 40Ar/39Ar age of a tephra layer (437 ± 1.9 ka), intercalated at the top of the succession, supported by archaeo-stratigraphic, palynological and paleopedological data, allowed the SBP surface to be constrained to 350-300 ka. The SBP chronological position represents an important morphostratigraphic marker: it is the first ante quem and post quem date that allows the chronological position of the other orders of paleosurfaces to be better constrained.

Recent evolution and the present-day conditions of the Campanian Coastal plains (South Italy): the case history of the Sele River Coastal plain

The low coasts of the Campania are generally located in the main alluvial coastal plains of the region. These coasts have been affected, during late Quaternary, by strong progradation and more recently by erosion and episodic flooding particularly during storm events. The causes are essentially to be sought in the decrease in sedimentary discharge due to forest hydraulic engineering works but especially to the construction of many artificial dams along the main rivers, coupled whit subsidence and or increases in sea levels. Such events generally occur in coastal plains where the sectors close to the present-day dune ridge are morphologically lower (in general no more than 1–3 m a.s.l.). The main goal of this study was to provide a synopsis of the coastal vulnerability and present a new semi-quantitative method to assess coastal erosion. Eight factors describing the current system state of the beaches and the effects of the wave climate and human activity were combined to assess the potential erosion of the Sele River coastal plain. The method shows the high erosion potential at the mouths of the Sele, Picentino and Tusciano Rivers, while the areas south of the Sele river mouth and the zone stretching from Lido Lago to the Asa channel showed low hazard levels.

The 2002 Molise, Italy, Earthquake: Geological and Geomorphological Data on the San Giuliano di Puglia Area

The small village of San Giuliano di Puglia sustained the most severe damage from the Molise earthquake sequence of 2002. This study involved detailed geological and geomorphological mapping and is supported by a large set of geotechnical, geophysical and drill-hole data available from existing studies. These data were used to compile a seismic microzonation map of the San Giuliano di Puglia area as part of a study officially commissioned by the Department of Civil Protection. The map provides seismic hazard information that will be useful in the repair and reconstruction of the town.

INTEGRATED STRATIGRAPHY OF MIDDLE-LATE MIOCENE SYNOROGENIC DEPOSITS OF THE EASTERN SOUTHERN APENNINE CHAIN: THE SAN BARTOLOMEO FLYSCH

The present paper deals with the stratigraphic and biostratigraphic study of the middle-late Miocene thrust-top basin deposits of the San Bartolomeo Flysch, exposed north of Matese mountains and analysed during the geological survey of the sheet N° 405 Campobasso of the new Geological Map of Italy, 1:50.000 scale. The integrated study of calcareous nannofossils and planktonic foraminifera, based on the semi-quantitative distribution range of index species, revealed the presence of age-diagnostic assemblages which are comparable with those of different middle-late Miocene deep-marine sedimentary settings of the Mediterranean Basin. The biostratigraphic dataset suggests an early Serravallian – early middle Tortonian age. In terms of calcareous nannofossil biostratigraphy, the studied succession falls between the Last Occurrences of Sphenolithus heteromorphus and the First Occurrence of Discoaster bellus gr., corresponding to the MNN6 – MNN8 zone interval. In terms of planktonic foraminiferal biostratigraphy the studied sediments fall between the Last Occurrence of Globorotalia peripheroronda and the First Regular Occurrence of Neogloboquadrina acostaensis , corresponding to the MM6 p.p. - MMi10 p.p. zone interval. This study documents the applicability of the recent Mediterranean middle –late Miocene biozonations for the biostratigraphic study of siliciclastic synorogenic sediments, and challenges the most recent studies that dated the San Bartolomeo Flysch to the late Tortonian- early Messinian.