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Simple Summary: There is increasing interest in the study of how the ongoing climate change is affecting insect populations. However, most research has been focused on a limited number of groups that are particularly charismatic or expected to respond more clearly to climate change. Moreover, most research has been developed in a few areas (especially northern and central European countries), while others (such as the Mediterranean basin) have been largely overlooked. Therefore, more empirical research is needed, particularly on less charismatic species, groups that are expected to react less dramatically to climatic change, and key areas that are still poorly investigated. This study investigates changes in distributional and activity patterns in a common, ecologically tolerant, forest tenebrionid beetle in a region (central Italy) within the Mediterranean biodiversity hotspot, an area strongly subjected to the ongoing climate change, but for which research is still limited. By analyzing changes in elevation, latitude, longitude, and seasonal activity between 1900–1980 and 1981–2022, the results provided insights into the potential effects of climate change on this species. The beetle's average values of elevation and latitude were found to have been increased in the second period. In response to rising temperatures, the species became more frequent at higher elevation and in northern places. No strong evidence was found for an earlier species seasonal activity, but this could be due to the inclusion in the analysis of likely overwintering individuals. The findings suggest that even thermally tolerant species can undergo distributional shifts in elevation and latitude, even at a relatively small scale. There is an increasing volume of literature on the impact of climate change on insects. However, there is an urgent need for more empirical research on underrepresented groups in key areas, including species for which the effects of climatic change may seem less evident. The present paper illustrates the results of a study on a common forest tenebrionid beetle, Accanthopus velikensis (Piller and Mitterpacher, 1783), at a regional scale within the Mediterranean basin. Using a large set of records from Latium (central Italy), changes in the median values of elevation, latitude, longitude, and phenology between two periods (1900–1980 vs. 1981–2022) were tested. Records of A. velikensis in the period 1981–2022 showed median values of elevation and latitude higher than those recorded in the first period. Thus, in response to rising temperatures, the species became more frequent at higher elevation and in northern places. By contrast, A. velikensis does not seem to have changed its activity pattern in response to increased temperatures, but this might be an artifact due to the inclusion of likely overwintering individuals. The results obtained for A. velikensis indicate that even thermally euryoecious species can show changes in their elevational and latitudinal distribution, and that poleward shifts can be apparent even within a small latitudinal gradient. [ABSTRACT FROM AUTHOR]

In the Northern Apennines, the Internal Ligurian Units are considered deformed and metamorphosed fragments of the Ligure-Piemontese oceanic basin. In this paper, we report on the temperature and pressure conditions of the metamorphic peak for four Internal Ligurian Units, estimated using different geothermometers and geobarometers based on the white mica and chlorite compositions. These minerals were formed during the D1 deformation phase in the pre-Oligocene. The results indicate that the Portello and Gottero units are both characterized by metamorphic conditions pertaining to low blueschists facies, while the Colli-Tavarone and Bracco-Val Graveglia Units show a lower metamorphic imprint that produces assemblages of prehnite-pumpellyite facies. The estimated geothermal gradient for the metamorphic peak achieved by the analyzed Internal Ligurian Units during the D1 phase is 7–15 °C/Km, which is indicative of deformation in a subduction setting. Under these conditions, the D1 phase developed in these units as a result of underplating at the base of the accretionary wedge during the closure of the Ligure-Piemontese basin. These data indicate a close geodynamic correlation among the Internal Ligurian Units and the ophiolite-bearing units of the Alps. [ABSTRACT FROM AUTHOR]

Carbonate deposits related to active seeps are documented along most continental margins and are characterized by peculiar seep-related facies and by chemical (isotope signature), paleontological and mineralogical markers. Their fossil analogues are recognized all over the world by the same features and occurred since the beginning of Phanerozoic. In this paper, we present a new seep outcrop (Castagneto village, Reggio Emilia, northern Italy) belonging to the late Eocene Loiano Formation which, to our knowledge, is in Italy the most ancient seep deposit with not-reworked chemosymbiotic fauna The outcrop can be roughly divided into two portions, a northern part showing abundant presence of macrofossils in silty carbonate matrix and subhorizontal subdivisions, and a southern part, where macrofossils are almost absent, characterized by sub-vertical internal subdivisions and a clear vertical structure consisting of the rhythmic alternation of light and dark mineralization. Detailed analysis of samples from the southern portion showed the occurrence of authigenic calcite and pyrite, the latter with a peculiar framboidal texture. This feature, together with the occurrence of chemosymbiotic species and 13C isotope depletion, suggests possible hydrocarbon-rich fluid-related genesis and provides useful criteria for identifying hydrocarbon-rich fluid-related deposits in geologic units. [ABSTRACT FROM AUTHOR]

Simple Summary: Italy plays a central role in the research on Europe's biogeography because of its position in the middle of the Mediterranean, which is a global hotspot of diversity. This study investigated how present patterns of earwig species richness and composition in Italy are affected by climatic, geographical, and historical factors. Earwig richness does not decrease from the base to the tip of the Italian peninsula, which contrasts with the so-called 'peninsula effect'. However, richness does not increase southward either, suggesting that southern regions did not play a crucial role as a refuge during Pleistocene glaciations. Inter-regional similarities in species composition between regions is more influenced by their geographical proximity than climatic similarity, although richness is positively correlated with precipitation, in accordance with earwig preferences for humid conditions. The similarity in species composition with central European fauna decreases southward, indicating possible exchanges between central Europe and Italy. The majority of the earwigs of the Italian fauna are either widespread across Europe and the Palearctic, or confined to the main Italian mountain ranges, that is, the Alps and the Apennines. The isolation of ancient earwig populations on mountains resulted in the development of a high proportion of endemics, making the Italian earwig fauna one of the richest in Europe. Placed in the center of the Mediterranean biodiversity hotspot, Italy plays a central role for the study of Europe's biogeography. In this paper, the influence of climatic, spatial, and historical factors on current patterns of variation in earwig species richness and composition is investigated. The Italian earwig fauna is mainly composed of species which are either widely distributed in Europe and the Palearctic region or that are endemic to the Alps and the Apennines. Variation in species richness does not follow any obvious geographical patterns, but a positive influence of precipitation on richness is consistent with earwig preferences for humid climates. European mainland territories did not contribute substantially to the current biodiversity of Italian earwigs, which explains the lack of a distinct peninsula effect, although a southward decrease in similarity with the central European fauna was observed. However, southern areas did not exert a pivotal role during Pleistocene glaciations in determining current patterns of species richness. Variation in species composition among Italian regions can be mostly explained by geographical proximity, while climatic differences and historical (paleogeographical and paleoecological) events seem to have played a minor role. However, the isolation of ancient earwig stocks on Italian mountains led to the origin of a relatively large number of endemics, which makes the Italian earwig fauna one of the richest in Europe. [ABSTRACT FROM AUTHOR]

Simple Summary: Plant species of a regional flora have different ecological preferences, leading to the presence of different assemblages along environmental gradients. Botanists elaborated score systems to express species preferences for environmental factors, such as temperature, light, soil moisture, etc. The most popular system is that of the 'Ellenberg indicator values' (EIVs). EIVs have been largely applied to use plant species as indicators of environmental characteristics. In this research, we adopted a different perspective, and used EIVs to study how species are filtered by variations in ecological conditions along an elevational gradient. We used the flora of a small mountain in Central Italy as our case study. We found that heat-loving species are progressively replaced by cold-adapted ones at increasing elevations. Sunlight-adapted species prevail at low and high elevations (where open habitats occur), whereas in the middle of the gradient (occupied by the beech forest) shade-loving species predominate. Variation for moisture and soil nutrient preferences followed a similar pattern since humus abundance makes forest soils moister and richer in nutrients. Preferences for pH and continentality did not follow any clear pattern, since these factors are subject to more local variations. These results highlight the possible use of EIVs to study how plant communities respond to environmental gradients. Ellenberg indicator values (EIVs) express plant preferences for temperature, light, continentality, soil moisture, pH, and soil nutrients, and have been largely used to deduce environmental characteristics from plant communities. However, EIVs might also be used to investigate the importance of filtering mechanisms in shaping plant communities according to species ecological preferences, a so far overlooked use of EIVs. In this paper, we investigated how community-weighted means (CWM), calculated with EIVs, varied along an elevational gradient in a small mountain in Central Italy. We also tested if species abundances varied according to their ecological preferences. We found that the prevalence of thermophilous species declines with elevation, being progressively replaced by cold-adapted species. Heliophilous species prevail at low and high elevations (characterized by the presence of open habitats), whereas in the middle of the gradient (occupied by the beech forest), sciophilous species predominate. Variations for moisture and soil nutrient preferences followed a similar pattern, probably because of the high moisture and nutrient levels of forest soils with a lot of humus. No distinct pattern was detected for EIVs for pH and continentality since these factors are subject to more local variations. These results highlight the possible role of EIVs to investigate how environmental gradients shape plant communities. [ABSTRACT FROM AUTHOR]

The Nirano Salse in Italy is a well-studied site where natural gas seepage (NGS) and other hydrocarbon fluids and gases are emitted at the earth's surface. A novel integrated approach is applied to define a comprehensive structural interpretation of the gas seepage and flow dynamic in the mud volcano system of the Nirano Salse Regional Nature Reserve (Modena, Northern Apennines). The paper investigates the relationship between gas emissions and local structures, particularly faults and fractures, in the shallow subsurface (down to 500–600 m depth) to understand the control that structures have on fluid ascent from deep leaky hydrocarbon traps. We performed continuous monitoring of mud levels within vents; carried out geological surveys to characterize the main stratigraphic and structural discontinuities; measured the carbon emissions (CH 4 and CO 2) seepage both from volcanoes and the surrounding soil by a portable gas fluxmeter; and integrated the results with available geophysical surveys. The authors argue that the transgressive Pleistocene-Pliocene Argille Azzurre Formation hides the complex and highly structured pre-Pliocene geology of the area, in which faults and fractures act as pathways for deep fluid ascent. The emissions are aligned along a NE-SW trend at the intersection of a NE-SW fracture system and NW-SE-oriented normal faults, which are both associated to the local tensional stress field of a likely left-lateral strike-slip transfer structure or in the extrados of a fold. By examining both natural gas macroseepage and diffuse flux, it is shown that local structures control the fluid ascent and contribute to the emission of hydrocarbon gases and fluids at the Earth's surface. Understanding the structural control of carbon emissions at the Nirano Salse is also important for evaluating the carbon budget at the site, particularly in areas where there are detectable surface emissions. The study has implications for geologic, environmental, and economic issues, including hydrocarbon exploration, hazard assessment, and impact on the atmospheric carbon budget. Furthermore, the outcomes have an important implication to evaluate the potential for dangerous abrupt mud eruptions, and the site safety in proximity to the mud volcanoes. [Display omitted] • Alignment of surface mud vents with a NE-SW to ENE-WSW direction relate to a transfer strike-slip structural element in the Apennines thrust fault belt. • Green house emissions from mud volcanoes at Nirano are small compared to the anthropogenic sources of the area. • Stress concentration in the extensional quadrants of NE-SW to ENE-WSW-oriented strike-slip fault segments promotes NW-SE normal faults formation with associated fracturing and rise of CH4 and water that forms mud volcanoes. • Fluid ascent and methane emissions are related to the complex Miocene fault structures that are hidden below the Pliocene-Pleistocene marine clays. [ABSTRACT FROM AUTHOR]

This paper presents an overview on the response of the healthcare system in the area mostly affected by the 2016 Central Italy earthquake based on specific surveys and information from local health authorities. The authors collected in the field information on the seismic response capacity of the healthcare system. They surveyed five hospital complexes from medium to small dimension whose maximum capacity was up to 50 beds. This type of hospitals are representative of those ones present in the small towns located along the Apennines mountain range, usually including few buildings (i.e. 3–5) constructed in different periods and with different structural types. In all the surveyed hospitals there were partially or totally unusable buildings causing severe limitations to the functionality of the healthcare services, forcing to move many patients to other hospitals and to stop outpatient treatment. This was due mainly to severe damage to non-structural components and, in some cases, to moderate damage to structural components. In the present paper, two hospital case studies, namely "Tolentino" and "San Severino" hospitals, both located in Marche region, are analysed and discussed in detail in order to better understand their performance to the earthquakes, by also estimating their seismic risk via simplified methods, including the WHO Safety Index and the Cosenza and Manfredi (in: Fajfar and Krawinkler (eds) Seismic design methodologies for the next generation of codes, Balkema, Rotterdam, 1997) damage index. [ABSTRACT FROM AUTHOR]

Rift-basins are the shallow effects of lithosphere-scale extensional processes often producing polyphase faulting. Their sedimentary evolution depends on the mutual interplay between tectonics, climate, and eustasy. Estimating the role of each factor is generally a challenging issue. This paper is focused on the tectono-sedimentary evolution of the Neogene Siena-Radicofani Basin, a polyphase structural depression located in the inner Northern Apennines. Since Miocene, this basin developed after prolonged extensional tectonics, first as a bowl-shaped structural depression, later reorganized into a half-graben structure due to the activation of high-angle normal faults in the Zanclean. At that time the basin contained coeval continental and marine settings controlled by the normal faulting that caused the development of local coarse-grained depositional systems. These were investigated to: (i) discriminate between the influences of tectonics and climate on sedimentation patterns, and (ii) provide detailed time constraints on fault activity. The analysed successions were deposited in an interval between 5.08 and 4.52 Ma, when a climate-induced highstand phase occurred throughout the Mediterranean. However, evidence of local relative sea-level drops is registered in the sedimentary record, often associated with increased accommodation space and sediment supply. Such base-level fluctuations are not connected to climate changes, suggesting that the faults generally control sedimentation along the basin margins. [ABSTRACT FROM AUTHOR]

The territory extending between the Venetian Alps and the Emilian Apennines is formed by a mosaic of environments which span from high mountains to hilly and plain areas. These present rather varied features from one extreme (Alpine watershed) to the other (Emilian Apennines watershed). In the early Holocene, the plain area included between the two mountain chains – the Venetian-Po plain – was extended some tens km to the south with respect to the present day coast. This vast territory has been the object of research since the 1970s and 1980s. Field activities have allowed identifying a rich set of sites that occupy different topographic and geographic locations, thus composing an articulated mosaic characterised by a much wider variability with respect to the well-known case of the Adige basin, located at the western limit of the examined area, which is exclusively included within a mountain territory. In this paper, we analyse for the first time the rich record from this area in its whole with the aim of investigating the territorial organisation of hunter–gatherer groups on a wide scale. This research has allowed us to set hypotheses on the mobility and occupation strategies of human groups and on the key-aspects that may have favoured the extensive and intensive occupation of this area. Besides the supposed presence of a biomass compatible with the demographic increase that has characterised this period, we also suggest that the “pragmatic” Sauveterrian technological systems played an important role in the adaptation of early Mesolithic hunter–gatherers to the varied ecosystems offered by this area. [ABSTRACT FROM AUTHOR]

Scientists who travelled often developed specific practices, which in many cases, were influenced by the use of measuring instruments. This is particularly noticeable when considering the history of Earth sciences. While geologists used certain commonly known tools and instruments during their travels and fieldwork, at the turn of the 19th century other instruments began to appear which were designed and made for specific purposes. Some of them were successfully tested and later adopted in the field, while others remained projects or their use proved to be awkward, especially in mountainous areas. The records of these attempts may be found in unpublished primary sources or in technical papers related to geological surveying and mapping. However, the references to the instruments used in the field (and sometimes later in the laboratory on the collected specimens) are also frequently found in major printed works on scientific travels. The aim of this paper is to provide an overview and discussion of the role of instruments in some significant cases related to geological travels undertaken by Italian scientists during the second half of the 18th century and the early decades of the 19th century. [ABSTRACT FROM AUTHOR]

Abstract: The Apennine mountains of the Parma Province (Italy) are characterized by a young geological structure subjected to continuous morphological modification in many areas. As a consequence, several active landslides can be identified in this region. Among others, slow movements occurring over large areas are the typical type of instability in this zone. The slow but constant deformation process can induce major damage when interacting with major civil infrastructures such as bridges, roads and railways, but has a less severe effect on agricultural practice and smaller structures. Four different slope instability phenomena are analyzed in this paper. All the slopes are characterized by similar geological and hydrogeological features and by similar deformation rates. All slopes have been studied by means of experimental tests and numerical modelling in order to understand the failure mechanism and the evolution of slope movement. The deformation of each slope was monitored using superficial topographic control points and inclinometers, while its water level regime is controlled by means of discontinuous piezometric readings. The monitoring results, together with in-situ and laboratory testing, allowed a more detailed understanding of processes such as deformation under a constant active stress. The development of a numerical model was necessary to predict creep rates. Special attention has been given to the mineralogical components of the material involved in the unstable areas, in order to identify the material structure characterizing these types of landslides. This work is aimed to be a methodological study of a type of complex phenomena that are recurrent in a zone of the Apennines. These phenomena can be partly considered as mudslides acting in undrained loading condition along localized shear zones but creep gives a fundamental contribution to mass deformation that must also be considered in the phenomenon modelling to be able to obtain measured displacement rates. For this purpose creep tests have been performed in undrained conditions and modeled by a finite difference code for the calibration of relevant material mechanical parameters. The paper reports the description of the problems encountered to sample and to make experimentation on this kind of complex materials along with the obtained results and, at the end, gives some operative suggestions on how to overcome such difficulties. [Copyright &y& Elsevier]

Abstract: This paper deals with the structural evolution along a transect across the inner Northern Apennines (Monte Amiata volcano-geothermal area–Monte Cetona), mainly focussing on the post-orogenic Middle Miocene–Quaternary structures. The tectonic setting of the study area derives from the superimposition of three main faulting events: the first and second events developed during the Middle–Late Miocene and Early–Middle Pliocene, respectively, and took place in response to extensional tectonics. The third faulting event developed in a transcurrent/transtensional setting during the Quaternary. Quaternary faults mainly strike NE–SW and show left-lateral kinematics with a minor dip–slip normal component. They caused the Monte Amiata volcanic eruptions (300–190 ka) and controlled the widespread Pleistocene and present hydrothermal fluids circulation. Quaternary strike-slip faults have been documented in the Monte Amiata–Monte Cetona area for the first time in this paper. Correlation with the adjoining areas (e.g. Vulsini region) identifies the Quaternary strike-slip faulting recognised in the study area as a feasible source for the seismic activity in the Monte Amiata region, where the origin of diffuse low-magnitude seismicity is still under debate and poorly understood. [Copyright &y& Elsevier]

Two small outcrops of wollastonite- and melilite-bearing paralavas, with a pyrometamorphic genesis, have been found along the Apennine chain, in Central Italy, at the localities of Colle Fabbri and Ricetto. Recent papers added new data strengthening the hypothesis that the Ricetto wollastonite- and melilite-bearing rocks were produced by pyrometamorphism of carbonate-rich siliciclastic sedimentary rocks. In addition, these new papers depicted the Ricetto paralavas as having wide mineralogical and compositional variations due to liquid immiscibility and/or carbonate devolatilization, paralleling the trend observed for other paralavas (e.g., Colle Fabbri, Italy: British Columbia, Canada; Wyoming, U.S.A.; etc.). The source of heat for inducing pyrometamorphism was not investigated in the original paper, which was the subject of the comment. Capitanio et al. (2004), on the basis of 14C age determination and of a mineralogical study, argued convincingly that heat was supplied to the Ricetto rocks by wood-combustion for charcoal production. [ABSTRACT FROM AUTHOR]

Landslide dams are a particular kind of natural dam which forms when an earth or rock mass reaches a river channel causing its complete or partial blockage. Since 1995, the Earth Sciences Department of the University of Firenze has been running a project involving the inventory of landslide dams in the Northern Apennines, which currently contains more than 60 case studies. It is known that the geotechnical characterisation of landslide dams is closely related to the grain size distribution of the materials composing the dams. In particular, grain size exerts a control on dam stability, influencing the strength and the permeability of the dam material. The main purpose of this work is to contribute to grain size characterisation of landslide dams by giving an outline of the possible methods that can be used for grain size assessment and showing the results obtained from the case studies selected in the Northern Apennines. Indeed, despite its importance, there are few quantitative studies directed at determining grain size distribution of debris dams, mainly because customary bulk sieve analyses are impractical when dealing with materials often ranging in size from blocks tens of cubic metres in size, to microscopic particles. This paper presents results derived from the application of two main sampling methods on 42 landslide dams, (a) volumetric analysis and (b) grid by number analysis (here presented in two variants). These techniques allow us to obtain very similar grain size distributions for the coarser part of the debris material, while some differences persist for the finer fraction. The paper would also like to highlight the importance of getting accurate grain size data, with particular reference to the determination of the hydrograph derived from a landslide dam failure. Many deterministic models attempt to approach this problem, by taking into account only the median percentile (D50) of the cumulate grain size distribution. However, in most of the selected cases, a marked bimodal distribution was found in the frequency diagrams, so the fiftieth percentile (D50) is often one of the less representative grain size classes. It should thus be taken carefully into account that this choice could be misleading, as it is not necessarily justified by the physical evidence. [Copyright &y& Elsevier]

In the middle of the Mediterranean, the partly still active Apennines subduction system has been usually defined using tomographic images and available shear wave splitting measurements. In this paper we describe the new seismic anisotropy dataset for Central Italy, the region where the transition between Northern and Southern Apennines occurs. The new measurements show NW-SE fast polarisation directions beneath the belt, due to the retreat of the slab, NN E -SSW orientations from proper Adriatic mantle sources, and E-W directed anisotropy, attributed to mantle convection flow at the Thyrranian side. Additionally, the new data suggest the presence of a toroidal mantle flow through a tear in the Apenninic slab, from the Adria to the Tyrrhenian side. However, mantle circulation and flows, identified by the pattern of shear wave splitting results, seem different from what was proposed in previous geodynamic models. Indeed, our results support the presence of a vertical slab tear with limited dimension. In the geodynamic model we propose, the tear acts to accommodate a differential slab retreat. The slab partitioning results in a different pattern and strength of seismic anisotropy traced from the Central Apennines with respect to the adjacent Northern and Southern Apennines. • New SKS data consistent with previously defined mantle deformation patterns • Geodynamic model for Central Mediterranean from new seismic anisotropy data • NW-SE Apenninic mantle anisotropy interrupted by a narrow well developed mantle flow • Seismic anisotropy consistent with shallow horizontal slab tear beneath central Italy [ABSTRACT FROM AUTHOR]

This study reviews the thickness statistics of non-channelized turbidites from four tertiary basins of Central-Northern Apennines (Italy), where bed geometry and sedimentary character have been previously assessed. Though very different in terms of size and, arguably, character of feeder system, these basins share a common stratigraphic evolution consisting in transition from an early ponded to a late unconfined setting of deposition. Based on comparison of thickness subsets from diverse locations and stratigraphic heights within the studied turbidite fills, this paper seeks to answer the following questions: i) how data collection procedures and field operational constraints (e.g. measure location, outcrop quality, use of thicknesses data from single vs. multiple correlative sections, stratigraphic thickness of the study interval) can affect statistics of sample data? ii) how depositional controls of confined vs. unconfined turbidite basins can result in different thickness-frequency distributions?; and iii) is there in thickness statistics a ‘flow confinement’ signature which can be used to distinguish between confined and unconfined turbidites? Results suggest that: i) best practices of data collection are crucial to a meaningful interpretation of sample data statistics, especially in presence of stratigraphic and spatial trends of turbidite bed thickness; ii) a systematic bias against cm-thick Tcd Bouma sequence turbidites exists in sample data, which can result in the low-end tail of empirical thickness-frequency distributions to depart significantly from the actual distribution of turbidite thickness; and iii) thickness statistics of beds starting with a basal Ta/Tb Bouma division bear a coherent relationship to the transition from ponded to unconfined depositional settings, consisting in reduction of variance and mean and, consequently, parameters, or even type, of best fit model distribution. This research highlights the role of flow stripping, sediment by-pass and bed geometry in altering the initial thickness distribution of ponded turbidites and suggests how fully ponded mini-basins represent the ideal setting for further research linking turbidite thickness statistics and frequency distribution of parent flow volumes. [ABSTRACT FROM AUTHOR]

Analysis of high-resolution seismic profiles integrated with archaeological data along the coast has allowed quantifying the last ∼10 ka BP displacements in the offshore part of the Campi Flegrei resurgent caldera, one of the world's highest-risk volcanic areas. Previous onland studies revealed that, following the Neapolitan Yellow Tuff (NYT) eruption at 15 ka, post-caldera evolution was associated with rapid ground uplift and subsidence cycles. In this paper, we use the stacking pattern of Prograding Wedges (PWs) and Aggrading Fills (AF) to reconstruct relative sea-level changes and estimate the amount of vertical deformation in the Pozzuoli Bay, the submerged part of the caldera. We document five generations of prograding wedges (PW1 to PW5), associated with as many periods of relative ground stability between uplift and subsidence. Instead, deposition of aggrading fills above prograding wedges underpins the subsidence that typically follows volcanic unrest and uplift. The older wedges PW1 and PW2 are larger and likely indicate whole-caldera uplift events. In particular, the development of PW2 starting from ∼5.2 ka is related to the rapid growth of a resurgent dome in the central part of the caldera. After ∼3.7 ka, subsidence prevailed in the caldera leading to deposition of an aggrading fill (AF2). However, subsidence was interrupted by short-term uplift episodes in historical times at (100 BCE-100 CE, 600–700 CE, 1430–1538 CE) that led to the growth of comparatively minor-sized wedges PW1 to PW3, respectively. Displacement of coastal infrastructures of the Roman age (∼2 ka BP) is consistent with the vertical motion retrieved by the seismostratigraphic analysis, and further indicates the existence of two deformation signals. A short-wavelength signal confined to the Pozzuoli Bay reflects the contribution of an intra-caldera source. This signal is superposed to a long-wavelength regional subsidence increasing between Naples and Procida Island from 1.5 to 2 mm/a, respectively. The east-to-west enhancing subsidence likely reflects the transition between the uplifting Apennines and the foundered Tyrrhenian back-arc basin. • High-resolution seismic profiles analysis in the offshore Campi Flegrei caldera • Seismostratigraphic bodies document relative sea-level changes • Quantitative reconstruction of vertical ground displacements in the Holocene • Roman-age coastal remains constrain ground deformation in the last 2 ka. • We disentangle the contribution of intra-caldera dynamics and regional tectonics. [ABSTRACT FROM AUTHOR]

The microscale mechanisms of hydrocarbons movement along faults and fault zones, the potential carriers of hydrocarbons toward the productive geological traps, remain largely unknown. The majority of previous studies inferred the hydraulic behavior of faults with respect to hydrocarbon movements without providing meso and microstructural observations from faults permeated by hydrocarbons. To fill this gap, we document meso-structures together with the first fossil microstructural portraits of hydrocarbon flow and pathways along two hydrocarbon-bearing carbonate-hosted normal faults exposed in the central Apennines, Italy. In particular, we show that hydrocarbons cyclically move within tectonically active carbonate normal faults possibly during interseismic and coseismic phases of the seismic cycle. Channelized structures, injection features, and clast-cortex grains suggest the occurrence of transient and localized pulses of pressurized hydrocarbons during coseismic slip. In particular, clast-cortex grains are very similar to microstructures that develop along fault planes for slip velocities between 0.0001 and 1 m/s. Patches of hydrocarbon-bearing breccias/cataclasites with lobate and irregular boundaries, crackle breccias filled by hydrocarbons, and hydrocarbons arrested against hydrocarbon-free discrete fault planes suggest hydrocarbon flow during the interseismic phases with hydrocarbon (over)pressure dissipation after coseismic phases. Fault permeability is created during the coseismic phase and hydrocarbons penetrate the most permeable and uncemented uncohesive fault rocks within the damage zone and arrest against and/or within low-permeability and cemented fault cores. Results are consistent with previous numerical simulations on hydrocarbon movements along faults and time-lapse seismic-reflection imaging, suggesting that the movement of hydrocarbon occurs during interseismic periods within tectonically active faults and along permeable zones cyclically created by seismic activity. Results from this paper are crucial for modelling the hydraulic behavior of carbonate fault damage zone, which have progressively gained popularity as targets of hydrocarbon exploration and production and for CO 2 or H storage. • Hydrocarbon movement along carbonate normal fault is strongly heterogeneous. • Hydrocarbons permeate fault rocks based on local permeability. • Hydrocarbons move during coseismic and interseismic phases. • Transient and local pressurized hydrocarbons can occur during the coseismic phase. [ABSTRACT FROM AUTHOR]

Contemporary newspapers and seismological literature describe in detail an earthquake occurred on December 31, 1948 in the Monti Reatini area (central Apennines, Italy). The seismic sequence that had this event as its main shock started in December 1948, went on for most of 1949 and was recorded in full by an unpublished regional earthquake catalogue compiled in 1980. However, none of the Italian parametric earthquake catalogues printed from the 1980s onwards records either the December 31, 1948 earthquake or the earliest part of the 1948 - 1949 sequence. This paper describes how the "forgotten" event of December 31, 1948 was rediscovered and reinstated as one of the main quakes on record in the Monti Reatini area. [ABSTRACT FROM AUTHOR]

Archaeological areas in the mountain region of central Italy can be seriously threatened by geological hazards, and efforts are required to preserve cultural heritage. The Lucus Angitiae is a pre-Roman site located along the western edge of the Fucino Basin, the largest continental depression of central Apennines. The carbonate slope overhanging the area is affected by active rockfall processes from two main rock escarpments. In this paper, rockfall assessment was pursued through a 3D kinematic modelling, performed by adopting a probabilistic approach. Specific attention was dedicated to the choice and calibration of the input data, based on field evidence and a literature review. Two different sizes of wedge-shaped rock blocks were identified on rock escarpments, and specific stability analyses were performed. Sensitivity analyses accounting for possible triggering factors, such as water pressure increase and seismic action, were also carried out, together with an investigation of the seismological characteristics of the area. The results of the numerical simulations were used to design effective countermeasures in the framework of a mitigation plan for protection of the archaeological site. Finally, clues of gravity-driven slope deformations at the slope scale were documented, framing the rockfall process in a wider geological scenario. [ABSTRACT FROM AUTHOR]

The Apennines belt of Italy undergoes a northeast-trending extension at a rate of a few millimeters per year that generates moderate to large normal-faulting earthquakes. In this paper, we show that seismicity, large earthquakes, strong gas emission, and belt topography all correlate with a broad, low Vp anomaly in the uppermost mantle. We propose that a thermal/fluid anomaly in the mantle, associated with sub-lithospheric mantle replacement after delamination of the Adria lithosphere, supports the topography of the belt and drives the extensional tectonics. The mantle anomaly is likely caused by deep fluids coming from the dehydration of the material subducted during the Europe-Adria collision and the delamination of Adria. Beneath the belt, CO2-rich fluids are accumulated and occasionally discharged during large normal faulting earthquakes. After the replacement of sub-lithospheric mantle, the temperature at the base of the crust increases causing crustal stretching, anatexis, and strong degassing. [ABSTRACT FROM AUTHOR]

Abstract: Landscape evolution in active mountain chains can be dominated by gravitational slope movements. This is observed in a large portion of the Reno river catchment, Apennines, Italy, where weak rocks, such as clayshales, are subject to earthflows that control hillslope morphology and supply sediments to the channel network. In this paper, we evaluate the sediment flux generated by earthflows and compare it with Holocene-averaged deposition rates to assess the contribution of mass movements to landscape evolution. Present-day hillslope sediment flux is estimated by combining measured displacement rates (72 inclinometers) and spatial attributes of earthflows and historical frequency of reactivations. Averaged sediment yield (~1.6x103 t/km2/yr) compares well with similar studies on earthflow-dominated landscapes, despite notable differences in methodology. In the study area, the connectivity between hillslopes and the stream network is well developed and no significant sediment sinks influence the sediment transport processes. We document best estimates of regional sediment fluxes and related uncertainties, based on available data. Coarse limestone fragments, present in the clayshales, are used as a natural sediment tracer to allow a comparison with sedimentation rates taking place at the mouth of the intramontane catchment. Here, available borehole logs, 14C datings and stratigraphic correlations of the alluvial fan are used to obtain an estimate of the deposition that took place during Holocene times. Taking also into account the role of solute transport, sedimentation rates are compared to earthflow sediment production rates. Results show a good agreement and demonstrate that earthflows are the primary mass wasting process in these weak rock lithologies. We document best estimates of regional sediment fluxes and related uncertainties. Present earthflow sediment production outpaces Holocene-averaged sedimentation rates by a factor of two. The gap between sediment production and deposition can be partly justified by uncertainties associated with our estimates and by time-scale differences. With this respect, the dynamic equilibrium between erosion and deposition, is likely affected by intra-Holocene oscillations at a short time scale (10 to 1ky) attributable to climate variability. Terraced deposits documenting sedimentary episodes would also support such interpretation. [Copyright &y& Elsevier]

Abstract: Most of the oil and gas resources located within the Adriatic domain are genetically linked to the flexure of the Adria continental margin and to the evolution of the Apennines fold and thrust belt. The source rocks contained in the pre-flexure epi-continental successions reached the maturity window during the flexural subsidence or, alternatively, the flexural accommodating siliciclastic flysch themselves generated and stored hydrocarbons. The petroleum exploration plays of the Adriatic domain are tentatively classified in this paper, according to their geological evolution with respect to the Apennines fold and thrust belt. The description of the geological evolution of these structures and related petroleum plays are described, including plays set in undeformed or poorly deformed foreland areas. A new isochrones map showing the structural setting of the substratum at the level of the Fucoidi Fm. is presented. Several different groups of structures can be recognized in the Adriatic domain, that can be connected to the final phases of deformation of the Apennines, or to the interaction with the Dinarides fold and thrust belt front to the east. [Copyright &y& Elsevier]

Abstract: 3D geological models from multi-source data (cross-sections, geological maps, borehole logs and outcrops) are a critical tool to improve the interpretation of the spatial organization of subsurface structures that are not directly accessible. In this paper, we reconstruct the main geological structures and surfaces in three dimensions through the interpolation of closely and regularly spaced 2D seismic sections, constrained by wells data and surface geology. The methodology was applied in the Marche–Abruzzi sector of the Periadriatic basin, where the more external part of the Apennines fold-and-thrust belt is mostly buried under a syn- and post-orogenic, Plio–Pleistocene, siliciclastic sequence. The 3D model allowed us to correlate the main thrust fronts and related anticlines along strike, revealing a general ramp – flat – ramp trajectory characterizing the main structural trends. This geometric organization influences the sequence of thrust-system propagation and characterizes the evolution of syntectonic basins. The obtained 3D model points out several variation occurring along strike: i) main trends geometric relationships; ii) deformation chronology and iii) displacement distribution. In the northern sector, higher displacement and structural elevation are reached out by the Nereto–Bellante structure, whereas in the southern sector the Villadegna–Costiera Structure is the prevalent. All structures show a diachronic thrusts activity along strike, younger toward the north. [Copyright &y& Elsevier]

Abstract: The Paganica normal fault, that caused the April 9, 2009, L''Aquila earthquake (Central Apennines), is part of the Paganica-San Demetrio fault system (PSDFS). All available data useful to constrain the Quaternary activity of the PSDFS were reviewed, with the aim to point out its role in the landscape evolution of the L''Aquila region and particularly of the Middle Aterno Valley basin. Uplifted remnants of a low relief landscape (Summit Paleosurface, SP) constrain to about 800 m the total offset of the PSDFS since the late Lower Pleistocene. Also, a sedimentary cycle ended at the beginning of Middle Pleistocene is now displaced about 550 m along the PSDFS, whereas alluvial deposits containing tephra layers (560–360 ka) have been displaced more than 150 m by the Paganica fault segment. The long term slip rate values based on this evidence (ranging between 0.4 and 0.9 mm/y), together with the short term slip rate values based on displacements along Late Pleistocene geomorphic features and deposits, have shown that the PSDFS i) has played a primary role in the landscape evolution of the area, despite its minor geomorphic appearance, ii) is linked at depth with other important listric faults located in the PSDFS footwall (Assergi and Campo Imperatore faults) that in this paper are interpreted as secondary faults. This result has relevant seismotectonic implications for the Middle Aterno Valley basin. The PSDFS is the main seismic source of the basin and controls also the seismic potential of other linked structures, including the Assergi and Campo Imperatore faults. [Copyright &y& Elsevier]

Abstract: The so-called Umbria–Marche Domain of Northern Apennines represents a vast depositional system, also stretching across the Adriatic Sea subsurface, that was characterized by dominantly pelagic sedimentation through most of its Jurassic to Oligocene/Early Miocene history. The pelagic succession is underlain by Hettangian shallow-water carbonates (Calcare Massiccio Fm.), constituting a regional carbonate platform that was subjected to tectonic extension due to rifting of the Adria/African Plate in the earliest Jurassic. While tectonic subsidence of the hangingwalls drove the drowning of the platform around the Hettangian/Sinemurian boundary, the production of benthic carbonate on footwall blocks continued parallel to faulting, through a sequence of facies that was abruptly terminated by drowning and development of condensed pelagites in the early Pliensbachian. By then rifting had ceased, so that the Pliensbachian to Early Cretaceous hangingwall deposits represent a post-rift basin–fill succession onlapping the tectonically-generated escarpment margins of the highs. During the early phases of syndepositional faulting, the carbonate factories of footwall blocks were still temporarily able to fill part of the accommodation space produced by the normal faults by prograding into the incipient basins. In this paper we describe for the first time a relatively low-angle (<10°) clinoform bed package documenting such an ephemeral phase of lateral growth of a carbonate factory. The clinoforms are sigmoidal, and form low-relief (maximum 5–7m) bodies representing a shallow-water slope that was productive due to development of a Lithocodium-dominated factory. Continued faulting and hangingwall subsidence then decoupled the slope from the platform top, halting the growth of clinoforms and causing the platform margin to switch from accretionary to bypass mode as the pre-rift substrate became exposed along a submarine fault escarpment. The downfaulted clinoform slope was then buried by base-of-escarpment proximal turbidites, forming a bypass wedge. Such a contact would be imaged along a seismic section as an unconformity, suggestive of shut-off of the local carbonate factory and onlap by pelagic mud. The composition of the turbidites, however, at least initially duplicates that of the clinoforms, indicating that the footwall top was still productive, yet the mechanisms of sediment shedding into the basin had changed due to the modifications of submarine topography induced by synsedimentary tectonics. [Copyright &y& Elsevier]

The western Lucretili Mts. in the central Apennines (Latium, Italy) have been recently re-mapped in great detail and are the subject of combined stratigraphic, sedimentological and structural investigations. In this paper, we present a new stratigraphic interpretation of the Jurassic paleogeography of western Lucretili Mts., where a rift-derived intrabasinal paleo-high of the Alpine Tethys has been identified for the first time by means of facies analysis and biostratigraphic dating. Recognised facies associations, combined with dated stratigraphic sections, allow to define the morphology of the structural paleo-high and to identify the associated gravity-driven deposits (olistoliths) accumulated in the surrounding basin. Furthermore, we investigated the modes of interaction between Jurassic extensional structures and the subsequent contractional patterns developed during the Tertiary mountain building. In detail, the role played during Apennines tectonics by the paleo-escarpments bounding the paleo-high and by the surrounding olistoliths has been analysed. The paleo-escarpments either acted as focussing features for ENE-directed frontal thrust ramp localisation and were offset with small shortening amounts or reactivated as NNE striking high angle transpressional faults or preserved the original geometries as a result of variable orientation of paleo-escarpments with respect to the Neogene compressive stress field (with ENE oriented sigma1). Newly formed ENE striking tear faults connect these either inherited or neo-formed discontinuities. This complex stratigraphic and structural pattern is substantially different from the previous interpretations of this portion of the central Apennines based on a hypothesised layer-cake stratigraphy deformed by neo-formed Neogene thrusts. This contribution strengthens the importance of integrating facies analyses and structural investigations to detect the influence of pre-orogenic structures on compressive structural patterns, in an area where commercial seismic lines are not available and cannot help in reconstructing the subsurface geometries. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a seismic microzonation study performed in an area of the Northern Apennines (Italy) in order to reduce the level of risk from landslide hazard, to support decisions in urban planning and to provide useful information for building design. The area in question measures about 2.6km2 and is characterised by considerable landslide susceptibility also in non seismic conditions as evidenced by a number of surveys carried out over the past years. The slope deposit, lying over a marley-arenaceous formation, shows a variable thickness from a few metres to 30m and consists of fine silty-clay, clay-sandy and silty-sandy soil in a variable amount. Quiescent and active landslide areas with ground movements involving the shallowest layers of the soil deposit have been detected. Given the relatively high seismicity of the region, the aim of this study is to describe the principles and criteria adopted in a seismic risk analysis conducted over a limited area in order to carry out a very high and detailed level of zonation for ground motion and slope stability (i.e., Grade 3 according to the definition in the Manual for Zonation on Seismic Geotechnical Hazards). For this purpose, reliable expected earthquakes were assumed and in-depth geologic, geomorphologic, geotechnical and geophysical analyses were carried out to define a subsoil model for performing numerical analyses of local seismic response and slope stability in both non-seismic and seismic conditions. The proposed methodology consists of the following three steps: (i) identification of a number of seismic inputs for the numerical analyses; (ii) implementation of numerical analyses to evaluate the amplification of ground shaking and to assess potential for slope failure; (iii) mapping of homogeneous areas with respect to expected site amplifications and landslide risk. The study allowed the mapping of four zones which are expected to be homogeneous in terms of both amplification factor of seismic motion (FA) and safety factor against landslide (FS). Quiescent and active landslide zones were thus identified with greater accuracy together with the most probable sliding surfaces. For this purpose, a 1-D numerical code was adopted for seismic response analyses and limit equilibrium methods were implemented and numerically solved in static and pseudo-static slope stability analyses. [Copyright &y& Elsevier]

Abstract: This paper accounts for a new finding of High Pressure–Low Temperature (HP-LT) metamorphism documented in continental-derived rocks exposed in the central part of the Middle Tuscan Range, representing the easternmost location, in the Tyrrhenian Region, where blueschist facies metamorphism has been documented. It describes the development mechanism of Mg–carpholite bearing quartz veins in the framework of the deformational events described for the inner Northern Apennines. The HP-LT peak metamorphism can be estimated in P≥1.1GPa and T=370°–420°C as supported by the mineralogical assemblage consisting of quartz–muscovite–chloritoid–pyrophylite–hematite±chlorite±paragonite±Ti-oxides, documented in the aluminous metasediments (pelites and quartzose sandstones) of the Triassic Verrucano succession. This paragenesis defines the S1 schistosity, an axial planar tectonic foliation associated to map- and mesoscale isoclinals folds (F1); S1 schistosity is a composite foliation resulted from a non-coaxial progressive deformation associated to the DE1 collisional event (Late Oligocene–Early Miocene). Mg–carpholite bearing quartz veins developed as tension gashes in en-échelon arrays within brittle/ductile shear zones. The development of quartz veins was guaranteed by the high volumes of Si-rich fluids produced by the dynamic recrystallization process on the siliciclastic rocks. [Copyright &y& Elsevier]

Abstract: The aim of this paper is to propose an alternative model for the Pliocene-Quaternary to present evolution of the Northern–Central Apennines by combining geometrical requirements (Riedel shear system) with existing structural and geological geometries (fault systems and their tectonic associations). We define three sectors characterized by different geological, seismological, geodetic and geothermal signatures: the North-Western Sector (NWS), the Western Central Sector (WCS) and the Eastern Central Sector (ECS). According to GPS data derived from literature the three blocks move independently. In particular, the NWS is bound between the ECS/WCS and the Alps; this constraint leads to a stress accumulation responsible for a fragmentation into further several blocks, which move either to the NE or SW. The WCS is relatively stable; the ECS moves towards NE and is characterized by the presence of numerous releasing and restraining bends, which can be related to the action of a main NNW–SSE left-lateral shear zone. Accordingly, the recent and active tectonic setting of the Northern–Central Apennines is rather related to the dynamics of the introduced blocks, caused by the push of the African plate against Europe, than to subduction processes. [Copyright &y& Elsevier]

Abstract: This paper presents new chemical data of hydrocarbon-rich gases discharged from mud volcanoes and CH4-rich emissions located in different areas of Italy (Northern Apennines and Sicily). The determination of C5–C10 alkanes, cyclics and aromatics was carried out by GC–MS, while the main gas species and C1–C4 hydrocarbons were analyzed by GC-TDC and GC-FID, respectively. Methane is by far the most abundant component of all the investigated gas emissions, with the exception of part of those discharging close to Mt. Etna volcano, which are CO2-rich. The gas samples collected from the Emilia Apennine and Sicily show δD–CH4 and δ13C–CH4 values typical of thermogenic gases. Most gases from the Romagna Apennine discharge methane with a biogenic isotopic signature. Non-methane hydrocarbons of biogenic gases are almost exclusively C2–C4 alkanes, with minor amounts (fraction of μmol/mol) of C4+ compounds, including few aromatics and cyclics, likely deriving from minor thermogenic contribution not evidenced by the δ13C–CH4 and δD–CH4 values. The Etnean gases, whose R/Ra and δ13C–CO2 values indicate a strong contribution from a hydrothermal fluid source related to the nearby volcanic system, show a significant enrichment of aromatics compounds (up to 36% of the non-methane organic gas fraction), which is likely produced by catalytic reforming processes, such as dehydrocyclization of alkanes. The thermogenic gases from the Apennines and southwestern Sicily are characterized by the presence of more than 20 different cyclic compounds with concentrations up to several μmol/mol. Cyclic compounds are likely formed by i) thermal cracking and ii) uncompleted aromatization of alkanes occurring at depth>3km and temperatures not exceeding 120–150°C. [Copyright &y& Elsevier]

Abstract: The aim of this paper is to draw attention to the real number and distribution of strike-slip earthquake focal mechanisms that are displayed in the recent seismicity of the Northern-Central Apennines. Their relation to the superficial normal fault plane solutions and thrust front along the Eastern side of the Apenninic chain can be described by a geometrical model (Riedel-System, also Riedel shear model). First we define three sectors characterized by their different seismological signatures: the North-Western Sector (NWS), the Western Central Sector (WCS) and the Eastern Central Sector (ECS). These three blocks, according to the available data, act independently from each other as a consequence of interaction among themselves, the forces induced by plate tectonics in the Mediterranean area and the blocking effect of the Alpine Chain, leading to an increased amount of transpressional, pure strike-slip and transtensional tectonics below 10km depth. [Copyright &y& Elsevier]

Abstract: The study of cave clastic sediments has been considered one of the hottest topics during the last years because of their importance in paleoclimatic reconstructions and archaeological surveys. This paper focuses on clastic deposits of the Mugnano Cave, a small cave located in the Siena district (Northern Apennines, Italy), showing unique features regarding the sedimentary fill, mostly made of grey-blue dolomitic silts. The sedimentary succession was investigated through a detailed sedimentological analysis aimed at a better understanding of sedimentary processes active during the deposition. The entire succession was subsequently reinterpreted through an allostratigraphic approach: the recognition of an important erosional surface, associated with a significant change in sedimentation, allowed the distinguishing of two main allounits labelled MG1 and MG2. Furthermore, the different kinds of sediments collected in the cave were analysed using the XRF and XRD techniques, in order to establish their chemical and mineralogical compositions. The integration of lithological, sedimentological, allostratigraphic and mineralogical data permits formulation of an interesting hypothesis about speleogenetic processes that influenced the cave, with particular reference to the processes capable of generating the underground space. In this context, most of the current available space results from a complex interplay between different processes: disintegration of a particular lithofacies of the bedrock, consequent production of sediments and deposition into a subterranean lake. These sediments were removed from the cave during some non-depositional and erosive phases, which led to a positive balance in the available space. [Copyright &y& Elsevier]

This paper describes an application of the geological strength index (GSI) method to the San Mauro formation, which is characterized by sandstones alternating with argillaceous marls. The Sandstone/Pelite (S/P) ratio and structural complexity were determined. Geo-structural and geo-mechanical surveys were undertaken in situ and rock samples were tested in the laboratory. A map of the S/P ratio was produced showing the bedrock divided in four classes. Three ranges of GSI values were identified. The values of the intact UCS and of the constant m were appropriately reduced to reflect the variable presence of sandstone compared with the pelitic fraction. A 'weighted average' of the intact strength properties of the hard and weak layers was adopted. The values for the intact materials were reduced from 20 to 60% depending on the GSI categories of the heterogeneous rock mass. In this way, seven classes of rock masses characterized by different values of GSI, reduced UCS and m values were identified. [ABSTRACT FROM AUTHOR]

This paper presents the results of a study on a deep-seated gravitational slope deformation affecting the eastern slope of the Mt. Rocchetta ridge (central Apennines, Italy). Fieldwork identified the ongoing deformational process and assisted in defining its mechanisms, evolution and controlling factors. An equivalent continuum approach was adopted to characterize the rock mass with some modification for the temporal and spatial scale of the process. A visco-elastic-plastic rheological model was adopted for the numerical analysis, which also took into account the groundwater flow feeding the Capo Volturno spring. The results of the numerical analysis are consistent with the observed geomorphic evidence and suggest a morpho-evolutionary model of the ridge characterized by an initial phase of rock mass creep followed by a rock mass spreading process, mainly controlled by the viscous behaviour but with a significant contribution from groundwater for the smaller scale instabilities. [ABSTRACT FROM AUTHOR]

SUMMARY In this paper we investigate nature and properties of narrow-band, transient seismic signals observed by a temporary array deployed in the Val Tiberina area (central Apennines, Italy). These signals are characterized by spindle-shaped, harmonic waveforms with no clear S-wave arrivals. The first portion of the seismograms exhibits a main frequency peak centred at 4.5 Hz, while the spectrum of the slowly decaying coda is peaked at about 2 Hz. Events discrimination is performed using a matched-filtering technique, resulting in a set of 2466 detections spanning the 2010 January-March time interval. From a plane-wave-fitting procedure, we estimate the kinematic properties of signals pertaining to a cluster of similar events. The repetition of measurements over a large number of precisely aligned seismograms allows for obtaining a robust statistics of horizontal slownesses and propagation azimuths associated with the early portion of the waveforms. The P-wave arrival exhibits horizontal slownesses around 0.1 s km−1, thus suggesting waves impinging at the array almost vertically. Separately, we use traveltimes measured at a sparse network to derive independent constraints on epicentral location. Ray parameters and azimuths are calibrated using slowness measurements from a local, well-located earthquake. After this correction, the joint solution from traveltime inversion and array analysis indicates a source region spanning the 1-3 km depth interval. Considerations related to the source depth and energy, and the occurrence rate which is not related to the daily and weekly working cycles, play against a surface, artificial source. Instead, the close resemblance of these signals to those commonly observed in volcanic environments suggest a source mechanism related to the resonance of a fluid-filled fracture, likely associated with instabilities in the flux of pressurized CO2. [ABSTRACT FROM AUTHOR]

Abstract: Fault slip-rates are of decisive importance for seismic hazard assessment. However, sensitivity analysis in geological fault slip-rate seismic hazard maps demonstrates that the uncertainty in the attenuation relationships is much higher than the implied uncertainty in slip-rates, so that even if more accurate slip-rate estimation is achieved, it would have little impact on the final outcomes. This paper quantifies these outcomes using as a test site the area of the Southern Apennines and shows that this uncertainty that is inherent within the traditional intensity scales cannot be reduced. In the area of the southern Apennines, the uncertainty extracted from the expected intensity and the attenuation relationships can modify the final results and the estimated recurrence intervals by as low as 10–25% and as high as 1000%, out-pacing the 20% error of the fault slip-rates. Moreover, in such cases the hazard pattern follows an irregular spatial distribution and cannot be extrapolated uniformly to the entire map. On the other hand, the recent introduction of the Environmental Seismic Intensity scale (ESI) 2007, due to its quantitative nature, promises to offer higher objectivity in the process of assessing macroseismic intensities particularly in the epicentral area than do traditional intensity scales that are influenced by human parameters. The ESI 2007 scale follows the same criteria-environmental effects for all events and can compare not only events from different settings, but also contemporary and future earthquakes with historical events, offers higher spatial resolution and coverage and incorporates also site effects. As a result, a re-appraisal of historical and recent earthquakes so as to constrain the ESI 2007 scale may prove beneficial for the seismic hazard assessment by reducing the uncertainty implied in the attenuation laws and eventually in the seismic hazard maps. As more data from recent and historical events are gathered, the compilation of an ESI 2007 intensity attenuation relationship should be one of the future goals for seismic hazard assessment. [Copyright &y& Elsevier]

Abstract: This paper describes an indirect method to calculate the isotopic composition of rainfall by using the isotopic composition of karst springs fed by waters circulating in the most important regional aquifer of central Italy, i.e. the Mesozoic limestone sequence that forms the backbone of the Apennines. By using δ18O and δD data and the δ18O (and/or δD) average gradient for elevation, evaluated through the use of literature rainfall data and new measurements from a typical Alpine valley in northern Italy, the altitude of precipitation of their parent water has been re-calculated. Vertical descents of more than 2000m, from recharge to discharge, have been assessed in some high flow-rate cold springs in the morphologically steep Adriatic sector of central Italy. A clear correlation between the vertical descents and more negative isotopic compositions at their relative emergence elevations is highlighted. In contrast, in the Tyrrhenian sector lower karstic drops (generally lower than 500m) correlate with less negative isotopic composition of recharge areas. The δ18O iso-contour map of the “recalculated” parent rainfall in central Italy is more detailed than any possible isotopic map of rainfall made using pluviometers, unless large number of rainfall collectors were deployed on mountaintops. The data also show that the isotopic composition of rainfall depends on the source of the storm water. In particular, precipitation is isotopically heavier when originating in the Mediterranean Sea, and lighter when formed in the Atlantic Ocean. Consequently, the collision between air masses with such a different isotopic signature results in a relatively small latitudinal fractionation effect. The peninsular part of central Italy is very narrow, with several mountains and massifs more that 2000m high, and any latitudinal variation in the isotopic composition between rainfall sourced in the Atlantic Ocean and in the Mediterranean Sea is much lower than that due to the isotopic fractionation due to elevation. [Copyright &y& Elsevier]

Abstract: This paper deals with the tectonic evolution of a bowl-shaped Neogene basin (Siena Basin) located in the inner Northern Apennines and developed during an articulated tectonic evolution. This basin was controversially interpreted by different authors as graben, half-graben or thrust-top basin. Structural and stratigraphic data from the basin substratum and filling sediments, integrated with the interpretation of reflection seismic profiles and borehole logs, highlight that the Siena Basin consists of a tectonic depression with a complex internal architecture. Such a basin developed on a multilayered substratum deeply affected by extensional tectonics since the Middle Miocene. Extensional detachments produced a widespread thinning of the basin substratum and superimposed on contractional structures developed during the Northern Apennines collisional events. Extensional detachments accommodated within weak horizons and gave rise to the lateral segmentation of most competent stratigraphic horizons. Sediments filling the Siena Basin mainly deposited on the Ligurian Units (the topmost tectonic units forming the tectonic pile) in the gap between two laterally segmented geological bodies made up of the Triassic siliciclastic succession of the Verrucano Group. Such a lateral segmentation produced a synformal structural depression, not delimited by faults, filled by Late Serravallian–Late Messinian marine to continental sediments which deposited during the extensional faulting. From the latest Early Pliocene to the Middle Pliocene the architecture of the basin was modified by an high-angle normal fault system which affected the eastern side of the basin and produced new accommodation space for marine sediments. In sum, the Siena Basin consists of a sin-tectonic basin developed on the hanging wall of staircase extensional detachments, later affected by high angle normal to oblique faults. The latter faults defined a half-graben during the latest evolution of the basin. The tectonic evolution of the Siena Basin made it possible to point out some differences with respect to the types of bowl-shaped basins related to extensional detachments and named as supradetachment basins. [Copyright &y& Elsevier]

Abstract: The present paper refers to research conducted in the tectonic-karst depression of Campo Felice in the central Apennines (Italy), in which glacial, alluvial and lacustrine sediments have been preserved. Stratigraphic interpretations of sediments underlying the Campo Felice Plain are based on evidence obtained from nine continuous-core boreholes. The boreholes reach a depth of 120m and provide evidence of five sedimentation cycles separated by erosion surfaces. Each cycle is interpreted as an initial response to a mainly warm stage, characterized by low-energy alluvial and colluvial deposition, pedogenesis, and limited episodes of marsh formation. In turn, a mainly cold stage follows during which a lake formed, and glaciers developed and expanded, leading to deposition of glacial and fluvioglacial deposits. The chronological framework is established by eleven accelerator mass spectrometer 14C ages and three 39Ar–40Ar ages on leucites from interbedded tephra layers. These age determinations indicate five glacial advances that respectively occurred during marine oxygen isotope stages 2, 3–4, 6, 10 and 14. [ABSTRACT FROM AUTHOR]

Abstract: This paper describes the geometrical structure and the main kinematic features of an ancient and active landslide which develops in structurally complex formations of the Southern Apennines (Italy): a scaly clayey formation in the medium and lower part of the slope, and a stratified marly–calcareous rock formation in the upper part. The landslide 3D geometry was reconstructed by using topographic data, stratigraphies from continuous coring boreholes and inclinometer data. The analysis of the kinematic features was based on the measurement of deep and superficial displacements. Laboratory tests were carried out to evaluate shear strength parameters. It was found that in each investigated transversal section of the landslide channel the displacements can be considered uniform, and that the decrease of the displacement rates, from upslope to downslope, mostly depends on the increase in the areas of transversal sections, the “soil discharge” variations being slight. Stability analyses confirmed that shear strength close to the residual value is available on the slip surface. The large difference between residual strength and peak strength of the landslide material is consistent with the displacement uniformity. [Copyright &y& Elsevier]

Argille scagliose (scaly clay) is a geological term first used in 1840 to describe rocks in the Northern Apennines of Italy. The term was originally created to stress the mesoscopic scaliness of a type of rock that commonly outcrops in this area. The rock is also typified by a chaotic assemblage of blocky components that are embedded within the scaly matrix. Before the advent of plate tectonic concepts, the extreme complexity of these rocks posed an extreme challenge to interpret with then-standard concepts of deposition processes in sedimentary basins. Similar rocks were recognized in many other mountain belts, thus the term became widely used. At the same time, the emphasis of the term changed from a description of the matrix to a term with multiple, intensely debated, genetic associations. Only after the discovery of plate tectonics was it accepted that these rocks are formed at subduction boundaries, and that the multiple types of embedded blocks can have an origin from both slope-instabilities within an accretionary prism, and from tectonic reworking/deformation processes near the base of an active accretionary prism. This paper reconstructs the scientific evolution of thinking about argille scagliose during the years when it was one of the supreme challenges to sedimentary geologists. The often strong debate between competing hypotheses for the origin of these rocks led to many myths that still outcrop in the geological literature. We explore why this happened, the apparent future of modern research on chaotic rocks in the Apennines and other fossil accretionary prisms, and what is and should productively remain from the long geological controversy over argille scagliose. [ABSTRACT FROM AUTHOR]

Abstract: Palaeobotanical specimens in private or public historical collections include important fossils, and modern studies involving taxonomic revisions can renew the scientific value of forgotten records. In Italy, information on past floras can be also obtained through the re-examination of the published drawings and pictures, or survey of the original collections. This paper presents the taxonomic revision of the macrofossils in the palaeobotanical collection, originally from San Venanzio (Modena), collected by Francesco Coppi at the end of the 19th century. Fossils were taken from the Argille Azzurre formation (Lower Pliocene–Lower Pleistocene). Re-sampling was not carried out because the sampling point at present lies under the houses of a village, increasing the importance of the museological collection. Descriptions of 76 fossil leaves are reported. Sporomorphs were extracted from the clayey limestone where three macrofossils had fossilized. Though only scattered information on the past plant cover has been randomly preserved, the plant macro- and microfossils provide a contribution to the research on the Plio–Pleistocene flora of Northern Apennines, and add information which can be useful to improve knowledge on local palaeoenvironmental reconstructions. Animal and plant fossils were deposited in a coastal or delta area. Pollen flora mainly reflected the vegetation distributed in the highest belts, far from the site of deposition, while macrofossils prevalently reflected local vegetation. [ABSTRACT FROM AUTHOR]

The axial zone of the Apenninic belt in central Italy is a tectonically active region affected by post-orogenic Quaternary extension. The present-day stress field is characterized by a minimum horizontal stress (Shmin) ∼ NE–SW oriented, derived mainly from earthquake focal mechanisms and secondarily from borehole breakouts and fault data. The paper describes the computation of the Shmin orientation along two deep boreholes located in the vicinity of the area hit by the 2009 April 6, Mw 6.3 L’Aquila earthquake. The analysed wells show breakout zones at a depth range between 1.4 and 4.6 km, giving precious information on a depth interval usually not investigated by any other data. The results show an Shmin N81 ± 22° and N74 ± 10° oriented for Varoni 1 and Campotosto 1 wells, respectively. The comparison among the breakouts, the 2009 seismic sequence, the past seismicity and the Quaternary faults indicates a small rotation of Shmin orientation from ∼ NE, in the southern, to ∼ ENE in the northern sector of the study area, where the wells are located. These differences are linked both to the natural variations of data and to the orientation of the main tectonic structures varying from NW–SE in the Abruzzi region to ∼ N–S moving toward the Umbro-Marchean Apennines. The identification of constant Shmin orientations with depth derived from all the examined active stress data, confirms the breakouts as reliable stress indicators also for aseismic areas. [ABSTRACT FROM AUTHOR]

Abstract: This paper describes the results of a rockfall hazard assessment for the village of San Quirico (Abruzzo region, Italy) based on an engineering-geological model. After the collection of geological, geomechanical, and geomorphological data, the rockfall hazard assessment was performed based on two separate approaches: i) simulation of detachment of rock blocks and their downhill movement using a GIS; and ii) application of geostatistical techniques to the analysis of georeferenced observations of previously fallen blocks, in order to assess the probability of arrival of blocks due to potential future collapses. The results show that the trajectographic analysis is significantly influenced by the input parameters, with particular reference to the coefficients of restitution values. In order to solve this problem, the model was calibrated based on repeated field observations. The geostatistical approach is useful because it gives the best estimation of point-source phenomena such as rockfalls; however, the sensitivity of results to basic assumptions, e.g. assessment of variograms and choice of a threshold value, may be problematic. Consequently, interpolations derived from different variograms have been used and compared among them; hence, those showing the lowest errors were adopted. The data sets which were statistically analysed are relevant to both kinetic energy and surveyed rock blocks in the accumulation area. The obtained maps highlight areas susceptible to rock block arrivals, and show that the area accommodating the new settlement of S. Quirico Village has the highest level of hazard according to both probabilistic and deterministic methods. [Copyright &y& Elsevier]

Abstract: In this paper, different characteristics of runoff and eroded sediments were investigated as well as changes in textural composition of the original soil, on experimental plots. The objectives were to investigate the particle size distribution of the eroded sediments, as a function of soil, crop, and meteorological variables, and changes in texture due to water erosion over time. The study was performed on experimental plots in the Apennines mountain range, in northern Italy, where an automated system for measuring runoff water and sediment was installed. Runoff water, sediment yield and sediment mean diameters were analyzed as a function of land cover, rainfall kinetic energy and stream power. In particular, the study investigated: (a) the sediment particle size distribution using laser diffraction, (b) the effect of rainfall kinetic energy, stream power and crop coverage on runoff, sediment yield and sediment particle size distribution and (c) the changes in soil texture on the cultivated field plots, over a period of 15years. The results of this study showed: (a) the particle size distribution of the eroded sediment was generally unimodal and the dominant fraction characterizing the eroded sediments was the one with a mean particle diameter ranging from 4.3 to 13.1μm, comprised in the silt range, (b) the mean particle diameter changed depending on the rainfall kinetic energy and the stream power, with a positive correlation between particle diameter and rainfall kinetic energy under bare soil, and (c) the effect of long-term erosion showed that the original soil textural composition experienced a statistically significant change over a period of 15years, with a decrease in the silt fraction and a relative increase in the clay fraction, due to losses of silt in the eroded sediments. [Copyright &y& Elsevier]

The Montagna dei Fiori has received attention by geologists through the past decades because of both its Jurassic stratigraphy and its complex present-day structure. The latter is the result of multiple phases of deformation, from the Early Jurassic, during the rift phase, which led to the opening of the Tethyan Ocean, to compression in Neogene, linked with the evolution of the Apennines fold and thrust belt. In this paper, we present a new stratigraphic interpretation of the Jurassic palaeogeography, based on a new geological mapping project in the area. Using this new stratigraphy, we constructed two forward models of the Montagna dei Fiori fault-related fold, using a combination of different kinematic models. We followed two different approaches: the first model was constructed manually starting from the construction of a balanced cross section and its restoration, followed by a definition of the main steps for the forward model; the second was constructed using 2DMove (Midland Valley), starting from a simplified version of the same stratigraphy and using the same main steps imposed in the other section. [ABSTRACT FROM AUTHOR]

Abstract: We analyze the seismicity of a small sector of the Northern Apennines merging data from the Italian seismic bulletin with original data collected by temporary seismic networks. Our attention is focused on the region enclosed between the Apenninic watershed and the Adriatic Sea. This portion of belt is interested by the occurrence of diffuse crustal seismicity and small-to-moderate earthquakes. In this paper we study the five small sequences with mainshock having M w <4.7 that in the past 15 years hit the area. Our interest is addressed to better understand the relationship between these events and the regional seismotectonic setting in terms of seismicity distribution and stress field. Two regions with different behavior in the seismic release can be distinguished: (i) along the watershed where seismicity is clustered at shallow depths (<15 km) and where strong earthquakes occurred in the past, (ii) an eastern portion where the seismicity is distributed across all of the crustal volume, locally reaching depths down to 30 km. The focal mechanism of the seismic sequences shows mainly normal fault kinematics coherent with the regional stress field. Detailed stress field analysis suggests a rotation of the principal stress axis moving from the axial part of the chain toward the Adriatic Sea to the east. [Copyright &y& Elsevier]

Abstract: In this paper we present and discuss an improved picture of the seismicity distribution of the Umbria–Marche–Abruzzi Apennines as obtained through the integration of the national and the regional seismic networks operating from 2002 to 2006. During this period, both the Istituto Nazionale di Geofisica e Vulcanologia (INGV) National Seismic Network and the regional networks have been greatly improved. We compare the results of the integrated catalogue obtained in this study with the Catalogue of the Italian Seismicity between 1981 and 2001 [Castello, B., Selvaggi, G., Chiarabba, C., Amato, A., 2006. CSI Catalogo della sismicità italiana 1981–2002, versione 1.1. INGV-CNT, Roma.http://legacy.ingv.it/CSI )], confirming the basic known features of the seismic activity in the region, but also evidencing some original and interesting results. In particular, the new data set allows us to better define the geometry and kinematics of the crustal seismicity, which is confined to the upper 20 km and shows a clear general deepening from west to east. In the crust, we find additional evidence of extensional seismicity below the central portion of the belt and thrust/reverse faulting mechanisms at the outer fronts of the Apennines. Looking at the seismicity along the belt, it is also possible to observe aseismic regions, which could be due to either locked or creeping portions of the Apenninic fault system. At greater depth, the west-dipping seismicity distribution down to about 70 km confirms the hypothesis of a slab of Adriatic lithosphere subducted below the Apennines, but also suggests that there are strong lateral heterogeneities and possibly tears in the slab. [Copyright &y& Elsevier]