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The Boiano Basin is one of the largest Quaternary intermontane basins of the central-southern Apennines within one of the most tectonically active areas of the Mediterranean region. In order to reconstruct its entire Quaternary stratigraphic, tec- tonic, and palaeoenvironment evolution, lithofacies and palaeomagnetic analyses have been performed on a 900 m-deep borehole (CP1) drilled in the southwestern sector of the basin. The Quaternary succession consists of an alternating of alluvial fan and fluvial-marshy deposits for a total thickness of 240 m, unconformably laying on Lower Miocene deposits of the Sannio Unit, thrusted on upper Miocene deposits of the Molise Flysch. In addition, the stratigraphic study and facies distribution of 29 intermediate and shallow wells drilled in the basin, allowing us to define the thick- ness and lithofacies variations of the Quaternary sedimentary units inside the entire Boiano Basin in the sector of Campochiaro alluvial fan. Our results demonstrate that the Boiano Basin infilling started during the late Early Pleistocene (c. 1.1 Ma) and developed with variation in lithofacies distribution and thickness. The first deposi- tional unit (Early Pleistocene-early Middle Pleistocene in age) was palustrine and fluvial-marshy, the second (Middle Pleistocene in age) was characterized by the occurrence of the first cycle of alluvial fan deposition, the third (late Middle Pleisto- cene in age) was newly palustrine and fluvial marshy and, finally, the fourth recorded two cycles of alluvial fan deposition (late Middle Pleistocene and Late Pleistocene in age, respectively), interspersed by short periods of palustrinity, tephra layers deposi- tion, and palaeosols development. The study allows the hypothesizing that the Qua- ternary infilling was accommodated within a graben (or semigraben) structure, affected mainly by extensional fault systems localized in the inner part of the basin and secondly by fault systems bounding the basin.

This paper concerns the reconstruction of the main stages of the long-term landscape evolution of the Molise portion of the central-southern Apennines along a transect divided into three sectors (SW, Central and NE). Analysis mainly focused on geomorphological, stratigraphical and structural data supported by chronological constraints, coming from an overall review of past literature and several studies carried out by the authors of the paper during the last 20 years. The results obtained allowed the elaboration of a conceptual model of the long-term evolution of the Molise sector of the central-southern Apennines. Starting from the Pliocene, the emersion of the Molise area occurred gradually from SW to NE, allowing a polycyclic landscape to evolve under the major controls first of compression then transtensional to extensional tectonics as well as climatic variations. Principal markers of the Quaternary geomorphological evolution of the Molise area are represented by the infill successions of the intermontane tectonic depressions located in its internal, SW sector and by four orders of palaeosurfaces that developed between the Early Pleistocene and the beginning of the Late Pleistocene across the region. These markers testify to the alternation of phases of substantial tectonic stability and uplift whose spatial-temporal distribution could be assessed along the investigated transect. Results highlight that the most important stages of landscape evolution occurred during the Early and Middle Pleistocene. At the beginning of the Late Pleistocene, the Molise sector of the Apennine chain had already reached its present setting and further landscape evolution occurred under the major control of climate and land-use.

An integrated morpho-stratigraphic approach has been used to reconstruct the Quaternary history of the Boiano basin, the largest tectonic depression of the Molise Apennine (Italy). Lacustrine, marshy and fluvial environments alternate all along the investigated infilling succession as a response to tectonic subsidence, volcaniclastic inputs and climate changes, from ca. 500 ka. Two tephra layers 40Ar/39Ar have been dated and referred to the Middle Pleistocene explosive activity of the Roccamonfina volcano, while a younger tephra layer has been related to the Campi Flegrei Neapolitan Yellow Tuff (ca. 15 ka). Pollen analysis has highlighted the vegetation changes related to the 100 ka glacial-interglacial cyclicity, between MIS 13 and 2. From 500 to 350 ka, a strong subsidence led to lacustrine deposition, while between 350 and 250 ka, a decrease in subsidence rates caused the transition to fluvial-marshy conditions and, at a later stage, to floodplain environments. The analysis of palaeosurfaces allowed the geomorphological evolution of the basin to be reconstructed since the Middle Pleistocene and the morpho-sedimentary events to be related to the SW-NE extensional tectonics affecting this sector of the central-southern Apennine. This tectonic behavior is also testified by the differential subsidence rates recorded within the basin through the analysis of two deep cores drilled in the center of the Boiano town.

The Ofanto basin is a Pliocene-Pleistocene thrust-top basin that formed with an unusual east-west orientation along the frontal part of the Southern Apennine Allochthon during the latest stages of tectonic transport. Its tectonic and sedimentary evolution was studied integrating field surveys, biostratigraphic analyses and the interpretation of a large seismic grid. Well data and seismic interpretation indicate that a large east-west-trending normal fault underlies the northern margin of the basin, displacing the Apulian carbonates that form the foreland and the footwall of the Southern Apennine Allochthon. In our reconstruction the Ofanto basin formed at the rear of the bulge caused by buttressing of the Southern Apennine Allochthon against this normal fault. In a second stage of contraction, the footwall of the Southern Apennine Allochthon was involved in deformation with a different trend from the normal faulting and buttressing. This caused eastward tilting of the basin and broad folding around its eastern termination. Good stratigraphic constraints permit the age of buttressing to be defined as Early Pliocene, and that of the shortening in the Apulian carbonates as Early Pleistocene. This study highlights the importance of early orogenic normal faults in conditioning the evolution of the frontal parts of orogenic wedges., This is a contribution of the Group of Dynamics of the Lithosphere (GDL) supported by the projects TopoMed CGL2008e03474-E/BTE, ESF-Eurocores 07-TOPOEuROPE-FP006, and Consolider-Ingenio 2010 Topo-Iberia (CSD2006e00041).

An integrated geomorphological, geological-structural and stratigraphic approach was applied to the Sessano intra-montane basin (Molise, Central-Southern Apennines) to understand the Quaternary environmental and sedimentary evolution of the basin and the surrounding areas. The morpho-evolutionary and sedimentary changes were mainly controlled by tectonics and strongly influenced by the huge amount of volcaniclastic input from the Roccamonfina volcano (located ca. 50km to the south-west) as well as by climatic changes. Chronological constraints, supported by Ar/Ar ages of tephra layers, archaeo-tephro-stratigraphy and pollen analysis, permit identification of the main phases of the geological-geomorphologic evolution of the Sessano basin from the Middle Pleistocene onwards. The sedimentation within the basin was controlled by NE-SW extensional tectonics and occurred from the end of Oxygen Isotope Stage (OIS) 15 to the beginning of OIS 11 allowing the deposition of ca. 85m of fluvial to lacustrine sediments, mainly made up of reworked volcaniclastic material. The first phase of sedimentation was lacustrine, while an important sedimentary change from lacustrine to fluvial-marshy environment occurred during OIS 14. After this phase, the variable input of volcaniclastic material from the Roccamonfina volcano together with climatic influences caused repeated changes from palustrine to fluvial sedimentation, and the formation of various palaeosols present mainly in the upper portion of the infill. Towards the end of OIS 11, NNW-SSE extensional tectonics caused the tilting of the fill succession and the drying up of the basin. The fill succession was then affected by fluvial erosion and denudation that generated an erosion surface nowadays hanging at 700-720m asl. This surface can be related to the limbs of a palaeo-surface at about 600m asl present in the adjacent Carpino-Le Piane intra-montane basin and referred to a fourth order, Tyrrhenian-ward oriented palaeo-landscape. This palaeo-landscape can be dated to ca. 350-300ky and, therefore, represents an important morpho-chronological stage. It provides a robust maximum and minimum age framework for reconstructing the geological and geomorphological evolution of the study area and, in general, of the Molise Apennines including the Boiano, Carpino-Le Piane and Sessano intra-montane basins. In particular, the morpho-chronological data from the Sessano basin allow us to date more precisely the main tectonic phases that occurred during the Middle Pleistocene in this sector of the Apennine chain. Finally, the multi-proxy data derived from the Sessano basin can be compared and integrated with those referring to other proximal intra-montane basins in order to improve our knowledge on the relationships between tectonics, volcanism and climate and the stratigraphic-sedimentary features, geomorphologic evolution and palaeoenvironmental changes that characterized the Central-Southern Apennines during Middle Pleistocene. © 2010 Elsevier B.V.

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. The40Ar/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 firstante quemandpost quemdate that allows the chronological position of the other orders of paleosurfaces to be better constrained.

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.

Since the early 70’s the majority of tectonic reconstructions of the western Mediterranean employ the Alboran domain notion as a migrating microcontinent or landmass mainly composed of Paleozoic-Triassic rocks affected by ‘Alpine’ HP-LT metamorphism. For nearly three decades, since the mid-80’s, the Alboran domain was considered as a fragment of the Alpine chain that moved westward, colliding into Iberia and North Africa to produce the Gibraltar arc and Betic-Rif chain. In 2012, a new hypothesis for the evolution of the western Mediterranean was presented in which the Betic-Rif orogenic chain originates from rollback of an initially SE-dipping subduction of the westernmost segments of the Ligurian-Tethys under the Africa margin. This interpretation considers the metamorphic ‘Alboran domain’ rocks as crustal successions of the hyper-extended African and Iberian continental margins, which have undergone a complete subduction-exhumation cycle above a NW- to W-retreating subduction. A key outcome of this hypothesis is that the Alboran domain is not a fragment of the Alpine chain but a consequence of rollback dynamics. In this contribution we try to elucidate the historical reasons behind the classical ‘Alpine’ interpretation of the Betic-Rif, by briefly describing key contributions, which appear linked in a logical sequence that traces the evolution of the Alboran domain concept since its original formulation by Andrieux and coauthors in 1971., This study was developed during a JAEDOC project (E.C.) in the frame of the FSE 2007-2013 Program, and benefitted from the constructive environment and discussions generated around the TopoMed CGL2008e03474-E/BTE, ESFEurocores 07-TOPOEUROPE-FP006, and Consolider-Ingenio 2010 Topo-Iberia (CSD2006e00041) projects.