Mario Bentivenga

Late Pliocene volcaniclastic products from Southern Apennines: distal witness of early explosive volcanism in the central Tyrrhenian Sea

Two volcaniclastic successions intercalated in Pliocene basinal clays from the Southern Apennines have been analysed to determine their provenance and their relationship with the geodynamic evolution of the Western Mediterranean. The studied deposits are exclusively made up of ashy pyroclasts, dominated by fresh acidic to intermediate glass, mostly in the form of shards, pumice fragments and groundmass fragments with vitrophyric texture. Crystals include Pl, Opx, Cpx, Hbl and rare Bt. Sedimentological features suggest that the volcanic material accumulated near the basin margin by primary fallout processes and was later remobilized by density currents. 40 Ar– 39 Ar geochronology allowed dating of one succession at 2.24 ± 0.06 Ma, corresponding to the Late Pliocene. Composition of the volcaniclastic material is typical of a transitional high-K calc-alkaline series. The age and chemical composition constrain the provenance of the volcaniclastic rocks from the Southern Tyrrhenian domain. Here, volcanic centres were active during Pliocene time, approximately at the northern end of a volcanic arc formed before the opening of the southernmost part of the sea. This paper shows that a detailed study of volcaniclastic products from the southern Apennines and Calabria can be very useful in collecting new pieces of information on the eruption history of the southern Tyrrhenian domain, since they record additional data not available from the study of exposed volcanic edifices.

Geomorphological map of the area between Craco and Pisticci (Basilicata, Italy)

This paper presents the results of geomorphological investigations carried out in Basilicata region (southern Italy) from the most external thrust front of the Apennines, where the town of Craco is located, to the adjacent sector of the Apennines foredeep (Fossa Bradanica; Pisticci area). The importance of the chosen area mostly resided in the presence of really diffuse running-waters and gravity-induced landforms which strictly affect urban areas. The geomorphological processes are linked with the Quaternary tectonic uplift affecting the Apennine front-Bradanic foredeep sectors. Series of field surveys, supported by aerial photo-interpretation, have led to the production of a geomorphological map at 1:16,000 scale which outlines the main processes and related landforms recognized in the study area. The latter are the result of the complex interplay of structural, gravitational and fluvial processes. Particular attention was devoted to the recognition, identification and mapping of landslides which affect the slope of the main villages (Craco and Pisticci), locally giving rise to hazardous conditions.

A Geological Itinerary Through the Southern Apennine Thrust-Belt (Basilicata—Southern Italy)

The proposed geological itinerary connects a series of impressive outcrops distributed between the front and the inner portion of the Southern Apennine thrust belt. It offers the opportunity to visit some of the most interesting and best-exposed Southern Apennine geosites, inserted within landscapes typical of the different sectors of the thrust belt, in order to illustrate its geological evolution. The itinerary has been designed in such a way as to intersect different stacked tectonic units and a great variety of sedimentary successions whose age ranges from Triassic to Pleistocene. Each of the chosen geosite contains multidisciplinary geological information that may be of interest for researchers, but may be also appreciated by a general public interested in geology. In particular, the stratigraphy, the structural geology and the geomorphology are the most recurrently treated topics. Most of these outcrops extend for many hundreds or thousands of metres and include villages or mountain reliefs. Therefore, every single site can be considered as an areal geosite containing particular geological features. However, the largest geosite can also be observed in a panoramic view from suitable locations. Thus, each of these sites provides different evidence and when combined together provides an opportunity to understand the complex geological history of the Southern Apennines. The motivation for establishing this itinerary mostly resides in the great scientific interest of the chosen outcrops; this will hopefully facilitate their conservation and the development of geotourism.

VII International Symposium ProGEO on the Conservation of the Geological Heritage ‘Geoheritage: Protecting and Sharing’, Bari (Apulia, Italy), 24th to 28th September 2012

In recent years, many researchers interested in the geological and geomorphological features of the Earth’s surface have also begun to seriously consider the concept of geological heritage. This new interest also often extends to educating local communities and helping transfer this knowledge to the future generations. For this reason and to achieve such goals, two fundamental steps are necessary for the future, firstly, to promote the conservation of geological sites, and secondly, to raise awareness of the resource represented by geodiversity. Within Europe, this process is developing in many countries as a number of regional and national administrations now recognise the importance of geological heritage. The decision to organise the VII International Symposium ProGEO on the Conservation of the Geological Heritage in both the Apulia and Basilicata regions of Italy stems from an aspiration to demonstrate these areas as being of significant geological interest to experts in geoconservation worldwide. The symposiumwas organised by SIGEA (The Italian Society of Environmental Geology) and ProGEO (the European Association for the Conservation of the Geological Heritage). As a title, Protecting and Sharing the Geological Heritage underlines the dualism in the work to protect (define, map, manage) and the general acceptance of this in that the geoheritage is a resource of experiences to share. The meeting aimed to identify the most appropriate strategies for ensuring the conservation of the most important geosites and other features of geodiversity importance, as well as facilitating sharing of up-to-date information on research in geoconservation (e.g., on geosites assessment, classification, mapping, management, and legislation). The symposium was structured with a plenary session and four thematic sessions on the following:

Mass transport deposits overprinted by contractional tectonics: a case study from the southern Apennines of Italy

Mass transport deposits (MTDs), created by gravity-driven deformation of unlithified sediments, and tectonic melanges produced by contractional deformation are characterized by a similar chaotic appearance. It follows that distinguishing structures formed by soft-sediment deformation during mass transport from those produced by contractional tectonics can be problematic. In fact, deformation occurring along detachment levels may completely obliterate the original sedimentary fabric. Although a number of advances have been made during recent decades, field criteria for discriminating structures within MTDs that are overprinted by later regional contraction are not readily applicable to all the exposed examples. We address some of these general issues through a detailed case study of the Monte Facito Formation in Italy. This Triassic unit was formed during the Africa–Europe continental separation and, since the Miocene, has been involved in contractional deformation during the construction of the Apennines. The Monte Facito Formation consists of a series of stratigraphically coherent units, separated by chaotic and often deformed intervals, whose origin has been previously attributed to either tectonic or sedimentary processes. An example is provided by a characteristic pebbly mudstone (or ‘paraconglomerate’) which has been interpreted as either a Triassic gravity-flow deposit, or alternatively, as a product of shearing along regional contractional detachments during the Miocene. This detailed field-based study allows us to recognize structures related to the depositional processes that created these chaotic intervals, and which can therefore be interpreted as MTDs. We also discriminate structures connected to later contractional tectonics that locally produced intense reworking of the MTDs.

Deep-Seated Gravitational Slope Deformation in Urban Areas Matching Field and in-SAR Interferometry Surveys: The Case Study of the Episcopia Village, Southern Italy

A limited sector of the left side Sinni River, including Episcopia village, has been investigated matching geological and geomorphological data to In-SAR Interferometry analysis. A large Deep-Seated Gravitational Slopes (DSGSD), affecting the Episcopia slope, has been documented for the first time. The DSGSD largely develops within phyllites belonging to the Liguride Units and, in the upper portion of the slope, within the sandy and conglomerate deposits of the Sant’Arcangelo Basin. Field survey has shown typical DSGSD features as well as trenches at the top and an evident bulge at the base corresponding to the Sinni River. These data allow us to hypothesize a listric geometry of the DSGSD plane reaching a depth of about 700 m.

Geomorphology of Pisticci area (Basilicata, Southern Italy)

ABSTRACT This paper presents the results of geomorphological investigations carried out in Basilicata region (Southern Italy) in the sector of the youngest foredeep (Bradano trough) relative to most of the communal territory of Pisticci. The importance of the chosen area mostly lies in the presence of diffuse running-water landforms and landslides affecting urban areas. The geomorphological processes are linked with Quaternary tectonic uplift affecting the Apennine front-Bradanic foredeep sectors. A series of field surveys, supported by aerial photo interpretation, have led to the production of a geomorphological map at 1:35,000 scale which outlines the main processes and related landforms recognised in the study area. The latter are the result of the complex interplay of structural, gravitational and fluvial processes. Particular attention has been devoted to the recognition, identification and mapping of landslides which affect the slope, locally giving rise to hazardous conditions.

Caratteri geomorfologici della instabilità del versante sinistro del Fiume Basento interessato dalla grande frana di Brindisi di Montagna Scalo (Potenza, Basilicata).

The left slope of the river Basento valley near Brindisi di Montagna (PZ) railway station is characterized by the presence of diffuse geomorphological instability. There is a large complex landslide that from Tempa Pizzuta hill develops down to the base of the slope where river Basento flows and the Potenza-Metaponto railway and an important motorway occur. In the upper part the landslide has the form of a deep slide, that in the lower part of the hill becomes a large earthflow with retrogressive evolution. A detailed study of the stability condition of the whole left hand slope of river Basento valley has been carried out after the last reactivation of the earth-flow. On the base of a detailed geological and geomorphological survey it has been possible to define the relationships between the different geological formations outcropping in the area and to define the geomorphological evolution. In the area a complex superposition of tectonic units have, characterized by an eastward vergence, can be observed. The study, starting from the analysis of the geomorphological characters of the studied area, tried to explain the complex interaction between the slide in the upper part of the slope and the earth-flow at the bottom. Key terms: Complex landslide; Basilicata Appenine; Brindisi di Montagna (Potenza, Basilicata) Landslide Termini chiave: Frana complessa, Appennino lucano, Frana Brindisi di Montagna (Potenza, Basilicata)