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.
Biomineralization is a generic term used to indicate biological-mediated mineral formation. In carbonate mineralization, nucleation of crystals can be: (1) controlled directly by the organisms, like in the skeletal formation of most metazoans; (2) induced by microbial communities, by indirect precipitation mediated by their metabolic activities; or (3) influenced by organic matter decay, with mineral precipitation on specific non-living organic cell surfaces. Recognition of these products is a direct marker of biological activity in time and space and is a key element in the study of the biological evolution and of its interactions with the geological processes. In this paper, primary carbonate cements from the Anisian microbial build-up of the ‘Monte Facito’ Formation (Basilicata region, Southern Italy) have been studied from a geobiological point of view. Optical microscopy, UV-epifluorescence and micro-Raman spectroscopy have been applied to investigate the organic mediation on their precipitation. The cements formed in microcavities or on grain substrates, and often show a microstromatolite-like pattern of growth. They are composed of alternations of cloudy organic and whitish inorganic bands that point to a double phase of mineralization. In the first phase, a biologically induced/influenced biomineralization is confirmed by the presence of organic matter strictly connected with the cloudy bands. This phase is followed by a pure abiotic mineralization that leads to the formation of whitish bands. This process repeated cyclically, ending at the complete filling of the microcavities or because of changes in the chemical conditions of the microsystem, for example, due to burial processes. This model of mineralization is similar to that proposed for primary cements forming in recent beach rocks. The Monte Facito Formation cements could be considered as the product of unconventional biomineralization, and the understanding of their growth process could provide an innovative tool in the research of biological signatures in the fossil record. The term unconventional is here utilized to discriminate this type of biomineralizations from those related to well-known biotic mineralization processes, like those involved in skeletons and microbialites growth, which can be considered as conventional biomineralizations.
This paper shows the main results of a multidisciplinary study performed along the southeastern sector of the Agri Valley in Basilicata (Southern Italy), where Cenozoic units, crucial for constraining the progressive evolution of the Southern Apennine thrust and fold belt and, more in general, the geodynamic evolution of the Mediterranean area are widely exposed. In particular, we aimed at understanding the stratigraphic and tectonic setting of deep-sea, thrust-top Cenozoic units exposed immediately to north of Montemurro, between Costa Molina and Monte dell’Agresto. In the previous works different units, showing similar sedimentological characteristics but uncertain age attribution, have been reported in the study area. In our study, we focussed on the Albidona Formation, pertaining to the Liguride realm, which shows most significant uncertainties regarding the age and the stratigraphic setting. The study was based on a detailed field survey which led to a new geological map of the area. This was supported by new stratigraphic, biostratigraphic and structural analyses. Biostratigraphic analysis provided an age not older than the upper Ypresian and not younger than the early Priabonian. Recognition of marker stratigraphic horizons strongly helped in the understanding of the stratigraphy of the area. The study allowed a complete revision of the stratigraphy of the outcropping Cenozoic units, the recognition of until now unknown tectonic structures and the correlation between surface and subsurface geology.
Mudstone samples from the Moreno (Upper Cretaceous-Paleocene) and Kreyenhagen (Eocene) formations are analysed using X-ray diffraction (XRD) and X-ray fluorescence (XRF) to determine their mineralogy. Smectite (Reichweite R0) is the predominant phyllosilicate present, 48% to 71.7% bulk rock mineralogy (excluding carbonate cemented and highly bio siliceous samples) and 70% to 98% of the <2 μm clay fraction. Opal CT and less so cristobalite concentrations cause the main deviations from smectite dominance. Opal A is common only in the Upper Kreyenhagen. In the <2 μm fraction, the Moreno Fm is significantly more smectite-rich than the Kreyenhagen Fm. Smectite in the Moreno Fm was derived from the alteration of volcaniclastic debris from contemporaneous rhyolitic-dacitic magmatic arc volcanism. No tuff is preserved. Smectite in the Kreyenhagen Fm was derived from intense sub-tropical weathering of granitoid-dioritic terrane during the hypothermal period in the early to mid-Eocene; the derivation from local volcanism is unlikely. All samples had chemical indices of alteration (CIA) indicative of intense weathering of source terrane. Ferriferous enrichment and the occurrence of locally common kaolinite are contributory evidence for the intensity of weathering. Low concentration (max. 7.5%) of clinoptilolite in the Lower Kreyenhagen is possibly indicative of more open marine conditions than in the Upper Kreyenhagen. There is no evidence of volumetrically significant silicate diagenesis. The main diagenetic mineralisation is restricted to low-temperature silica phase transitions.
The Brindisi di Montagna Scalo Landslide in Southern Italy is an active complex mass movement, which affects the left slope of the Basento River. In the last few decades, this landslide has been continuously monitored, as it directly threatened some of the most important communication routes in the Basilicata Region. Nevertheless, little progresses have been made to prevent further landslide advancement, and continuous maintenance is required. With the aims of better understanding, the main factors controlling the evolution of this landslide, and suggesting the most appropriate countermeasures, a multidisciplinary study, based on the integration of direct and indirect techniques, was carried out. Direct techniques included multi-temporal geomorphological analysis of the slope, alongside geological and structural field observations. Indirect techniques consisted of electrical resistivity tomography acquisition. The combined analyses of the geological and geophysical data showed that Quaternary tectonic processes played a fundamental role as a predisposing factor, whereas seasonal rainfall, and the perpetual undercutting by erosional processes caused by the Basento River at the toe of the landslide are the main triggering mechanisms. The Brindisi di Montagna Scalo Landslide represents an outstanding case-study, concerning the interaction between a flow-like complex landslide and essential linear infrastructure, such as motorways and railways.