Showing papers in "Bollettino Della Societa Geologica Italiana in 2013"

Stratigraphic and structural features of the Sibillini Mountains (Umbria-Marche Apennines, Italy)

Abstract: In this paper we illustrate the stratigraphic and structural features of the Sibillini Mountains on the basis of a 1:40.000 geological map. Following the “Foglio 132 Norcia” (Geological Map of Italy at 1:100.000 scale; [Scarsella, 1941][1]), this new geological map is the first cartographic document that covers the whole area of the Sibillini Mts. This area is key for understanding the geological evolution of the external zones of the Apennine orogen, mostly owing to the pronounced structural elevation of the Apennine ridge at the Sibillini Mts. area. This allowed us to: a ) carry out stratigraphic and structural analyses for the Umbria-Marche sedimentary cover to the oldest units; b ) analyze the paleotectonic setting of this sector of the Afro-Adriatic continental margin and the behavior of pre-existing structures during the subsequent deformation events; c ) investigate in depth the major Apennine thrust front (“Sibillini Mountains Thrust”) exposed in several sites (Fiastrone, Ambro, Tenna and Tronto valley) and its relationship with the units of the adjacent Messinian foredeep. Inherited (pre-thrusting) structures played an important role on the tectonic evolution of the study area. In addition to those of Jurassic age, associated to thinning of the Adriatic continental margin (the most frequent), there are also some Cretaceous-Eocene extensional faults and others probably related to Miocene foreland deformation. These extensional faults show very limited, or none, reversal of slip during contractional neogenic deformation. Usually they were tilted and, subsequently, displaced by thrust faults; locally they were deformed by buttressing processes. The paleotectonic setting also influenced the development of minor folds, as is evident in the Mt. Bove anticlinorium. Shortening-related structures are mainly represented by asymmetric, northeast-verging thrust-related anticlines involving Mesozoic-Tertiary sedimentary successions. Among these structures, the most important and well-known is the Sibillini Mts. Thrust, which bounds the Apennine mountain front, separating it from the Marche-Abruzzi foothills. This major fault affects the eastern, vertical to overturned, limb of the arcuate shaped Mt. Fiegni-Mt. Vettore anticline, which shows several complications, mostly due to the occurrence of minor thrust splays forming isolated lens-shaped tectonic slices up to several kilometers-long. The geological cross sections show that in the southernmost part of the Sibillini Mts. Thrust the displacement is partly buried and forms a detachment located at the base of the Laga Fm. Much of the Neogene compressional structures has been dissected by NNW-SSE trending Quaternary normal and oblique-slip faults, some of which reactivated older extensional structures. These faults do not seem to crosscut the Sibillini Mts. Thrust. Some of them show fresh fault scarps in the substrate and/or affect recent continental deposits and are considered responsible for the intense seismic activity of the area. [1]: #ref-141

Deformations and slope instability on Stromboli volcano: integration of GBInSAR data and analogue modeling

Abstract: Deformazioni e instabilita di versante sul vulcano di Stromboli: integrazione tra i dati del GBInSAR e la modellazione analogica.Per capire la relazione tra le deformazioni del vulcano, le sovrapressioni del magma e l’instabilita dei fianchi del vulcano stesso, sono stati analizzati e comparati i risultati ottenuti con la modellizzazione analogica sperimentale ed i dati registrati dal sistema GBInSAR, posto sul fianco occidentale del vulcano di Stromboli, durante un periodo di acquisizione compreso tra il 2009 e il 2011. I modelli analogici riproducono quelli che sono i meccanismi d’innesco dei movimenti franosi sui fianchi del vulcano, come l’accumulo di materiale sul versante, in ambiente sia subaereo che subacqueo, o la presenza di dicchi intrusivi che determinano il fenomeno del bulging. L’analisi comparata derivata dai modelli analogici e dai dati di monitoraggio svela quelle che sono le relazioni tra le sovrapressioni nei condotti magmatici e le deformazioni registrate. I risultati fanno pensare che i movimenti superficiali osservati dal sistema GBInSAR rappresentino la risposta del vulcano di Stromboli ai cambiamenti di pressione nel condotto magmatico. I movimenti franosi osservati sulla Sciara del Fuoco sono fenomeni d’instabilita dove la componente gravitazionale produce un movimento costante sul versante, mentre i cambiamenti di pressione nel magma spiegano perche, certi particolari periodi siano caratterizzati da accelerazioni che inducono l’instabilita del fianco esterno dell’area craterica e della Sciara del Fuoco, portando infine anche allo sviluppo di movimenti franosi.

The Upper Valdarno Plio-Pleistocene vertebrate record: an historical overview, with notes on palaeobiology and stratigraphic significance of some important taxa

Abstract: The Plio-Pleistocene fossiliferous mammal sites of the Upper Valdarno Basin (Tuscany, Italy) have been known since Renaissance times. Several mammal collections from there are housed at various Museums and Institutes. Various scientists or “fossil-hunters” collected all this material from Upper Valdarno over a long period of time up to the present days. We present here an overview of the history of these collections, as well as information on biochronology, taxonomy and palaeoecology on a selection of vertebrate taxa.

The Plio-Pleistocene fluvio-lacustrine Upper Valdarno Basin (central Italy): stratigraphy and Basin fill evolution

Abstract: The Upper Valdarno Basin stands out from the Neogene-Quaternary basins of the Northern Apennines given its outstanding fossil mammal record, good quality of natural and artificial outcrops and remarkable chronological control on the basin-fill succession. The present paper aims to summarize the stratigraphic and sedimentological studies focused on the Upper Valdarno Basin during the past decades, and integrate them with recent investigations. The Upper Valdarno Basin is located about 35 km SE of Florence between the Chianti Mountains and the Pratomagno Ridge. It consists of a main asymmetric tectonic depression filled with 550 m of Plio-Pleistocene fluvio-lacustrine deposits (Upper Valdarno Basin s.s.) and a minor basin known as the Palazzolo sub-basin. The Upper Valdarno Basinfill is made of three unconformity-bounded units, named Castelnuovo dei Sabbioni (CSB), Montevarchi (VRC), Torrente Ciuffenna (UFF) synthems, whereas the Palazzolo sub-basin fill consists of the Fosso Salceto (OLC) and Torrente Ciuffenna (UFF) synthems. The Upper Valdarno Basin formed during Late Pliocene because of the tectonic damming of a northeastward flowing drainage. The early phase of basin development is recorded by the accumulation of fluvial gravels in vallive settings, whereas the definitive of these streams damming caused the development of lacustrine conditions at about 3.1 Ma. The accumulation of deltaic sand fed from the SW margin caused the lake filling and stopped the deposition of the CSB Synthem.Before 2.58 Ma, a tectonic phase caused uplift of the basin and partial erosion of the CSB deposits. Deposition of the lower part of the VRC Synthem occurred during a marked basin broadening and accumulation of alluvial fan successions, which were capped by aeolian-reworked alluvial sand deposited at about 2.5 Ma. At about 2.3 Ma, a new deformative phase caused further basin widening, erosion along the SW margin and development of a small lake inthe central areas. Deposition of the upper part of the Montevarchi Synthem started just after this tectonic phase and was characterized by development of axial fluvial drainage and marginal alluvial fans.During the Early Pleistocene (Olduvai Subchron, 1.95-1.78 Ma) a subsidence pulse promoted development of floodplain lakes and swamps in the axial part of the basin, where thick organic-rich mud were accumulated. During late Early Pleistocene the capture of the paleo-Arno River, which started to flow into the basin, caused the development of a marked unconformity. This unconformity was covered by fluvial and alluvial fan deposit in the axial part and along the margin respectively.

The occurrence of glaucony in the stratigraphic record: Distribution patterns and sequence-stratigraphic significance

Abstract: Severe restrictions to the practical use of glaucony in sequence stratigraphy are provided by a number of factors. These include: i) correct mineral characterization, ii) controversial sequence-stratigraphic interpretation of the host deposits, iii) distinction between in situ (autochthonous) and transported (allochthonous) glaucony, iv) identification of a hierarchy of glaucony-bearing depositional units.

Tectonic and sedimentary evolution of the Upper Valdarno Basin: new insights from the lacustrine S. Barbara Basin

Abstract: We describe stratigraphic, structural and kinematic data from the sediments of the Upper Pliocene Santa Barbara Basin and from its substratum. The results shed light on the relationships between tectonics and sedimentation in the larger Late Pliocene-Middle Pleisto cene Upper Valdarno Basin of which the Santa Barbara Basin is considered a precursor. The sediments filling up the Santa Barbara Basin are made up of alluvial to deltaic and lacustrine deposits, grouped in the Castelnuovo dei Sabbioni (CSB) Synthem, related to Late Pliocene. This synthem was deposited in a tectonic depression reasonably delimited to the East by a west-dipping normal fault system and delimited to the North and to the South by left-lateral transtensional shear zones, which controlled the main directions of the alluvial drainage. During Early Pleistocene, a new master normal fault system (Trappola fault system) developed further to the East, determining the widening of the previous tectonic depression, now delimited to the North and to the South by the regional Piombino-Faenza and Arbia-Val Marecchia transfer zones, respectively. In this new tectonic depression, with a dominant axial drainage direction, alluvial, fluvio-aeolian and fluvial sediments (Montevarchi Synthem, VRC) deposited during Early Pleistocene. The VRC Synthem, being located in the hanging-wall of the Trappola normal fault system, is slightly tilted to the NE. Finally, during Early-Middle Pleistocene, axial fluvial deposits (Torrente Ciuffenna Synthem, UFF), sealed the previously formed brittle structures. Our kinematic and structural data allow us to confirm the interpretation that the Santa Barbara Basin is the precursor of the Upper Valdarno Basin and that both basins developed in structural depressions formed by the interplay between normal and transfer faults, framed in the extensional tectonics which characterizes Tuscany since Miocene.

Landslide Mapping Using SqueeSAR Data: Giampilieri (Italy) Case Study

Abstract: Multi-temporal analysis of space-borne radar images through Persistent Scatterer Interferometry (PSI) is exploited for detecting and mapping slope instability at basin scale in the south-western part of the province of Messina, hit by the intense storm events on October 1st 2009. Available PSI data provide estimates of yearly deformation velocity, referred to both historical (1992–2001; ERS images) and recent (2003–2009; ENVISAT images) scenarios. PSI techniques have recently demonstrated their suitability for the analysis of extremely to very slow moving landslides, and their complementarity with field campaigns, at both regional and local scales, allowing spatial and temporal characterization of the detected phenomena. Coupling and integrating deformation measurements extracted by means of SqueeSAR technique, thematic maps and optical data enabled to identify 26 sites (hotspot mapping), characterized by high hydro-geological hazard related to the occurrence of pre-event, extremely to very slow moving landslides.

Initiation and propagation of the 2005 debris avalanche at Nocera Inferiore (Southern Italy)

Abstract: Pyroclastic deposits covering most of the carbonate relief of the Campania Apennines are prone to develop frequent high-velocity flow instabilities. The present study investigates the debris avalanche that occurred at Nocera Inferiore (Campania Region, Southern Italy) on March 4, 2005 which claimed three casualties. The landslide involved the 1.5 to 2 m thick layered pyroclastic mantle which overlies the carbonate hill slopes. The slope movement initiated as adebris slide, then producing a debris avalanche on the 40°-dipping open slope, which had never been affected by a landslide of the same type as the one that occurred. Landslide initiation is linked to a morphological change of the slope due to the building of a carriage path to be used as access for the nearby open quarry. Reconstructionscarried out on aerial and ground photographs of different dates highlighted that the road construction likely took place around 1998, increasing the landslide susceptibility at this location. The propagation characteristics of the landslide were modelled by using 2D and 3D dynamic codes (DAN-W and DAN 3D, respectively), in order to investigate the applicability of the 3D model with the rheological parameters of previous calibration of DAN-W in Campania Region.Although, these analyses are well comparable with those implemented in the past, they highlight that it is unlikely to derive a unique set of values for the rheological parameters to be used on similar landslides over the entire region. Accuracy of back-analysis results strongly depends on the quality and availably of comparative input data, suggesting the need to improve calibration for each site within the region, enlarging information from similar cases and using statistical treatments.

Compression-to-extension record in the Late Pliocene-Pleistocene Upper Valdarno Basin (Northern Apennines, Italy): structural and thermochronological constraints

Abstract: We use new structural and apatite fission-track data together with apatite fission-track and (U-Th)/He data from literature to examine the tectonic evolution of the continental Upper Valdarno Basin, in the hinterland sector of the Northern Apennines fold-and-thrust belt. This basin is located in-between two structural ridges, the Chianti Mountains to the southwest and the Pratomagno to the northeast. In our interpretation, the Upper Valdarno Basin developed at ca. 3.4-3.3 Ma as pop-down synformal-shaped depression bounded and controlled by oppositely-verging thrust-related structures, namely the thrust system lifting the Chianti Mountains and the southwest-facing backfolds at the base of the Pratomagno. This evolution is compatible with the accelerated exhumation rates at 4-5 Ma documented through apatite fission-track data along both the Pratomagno and Chianti ridges. Shortening suffered by basin deposits is clearly manifested by the outcrop-scale reverse faults and thrust-related folds affecting the Late Pliocene sediments (Castelnuovo dei Sabbioni Synthem), which are well exposed in the Santa Barbara mine. These strongly folded deposits are overlain unconformable by Early Pleistocene sediments (Montevarchi Synthem), which display evidence for syn-depositional normal faulting. This suggests that the Upper Valdarno Basin experienced a phase of normal faulting that started at the base of Pleistocene (ca. 2.6-2.5 Ma) and likely produced the large southwest-dipping “Trappola Fault”, which affects the southwestern margin of the Pratomagno displacing the earlier backthrusts and backfolds. Basin evolution can be thus basically framed into a two-phase history, with extensional tectonics superposed onto compressional structures that were deactivated by ca. 2.7 Ma. Being the Chianti Mountains part of the 250 km-long regional line of thrusts and thrust-related folds (the so-called “Tuscan Nappe front”), the results of this study may also involve regional implications, as they would also hint for the tectonic history of other sectors and basins settled along-strike this regional element.

SPH modeling of fast muddy debris flow: numerical and experimental comparison of certain commonly utilized approaches

Abstract: SPH (Smoothed Particle Hydrodynamics) is a particle, purely mesh-free Lagrangian method, proposed by different authors, well suited to the computing of highly transitory free surface flows of complex fluids in complex geometries. Different approaches have been proposed in order to better simulate the mutual interaction between particles and their interactions with boundaries. Therefore, the main target of this article is to discuss and explore the numerical performance of certain commonly utilized SPH approaches, based essentially on mass and momentum balances, in the simulation of a 2D fast mudflow in fast motion, composed of fluid and solid material, assumed to be just one equivalent phase (fluid-solid). The “Herschel-Bulkley”, non Newtonian constitutive equations, describing a viscoplastic material suitable to reproduce the rheological behaviour of mudflows, has been selected. Hence, a laboratory experimental test, already proposed in literature and, after properly scaling, representative of a real fast flow phenomenon, was considered for comparison with numerical outcomes carried out by a research code that has already been tested and discussed in previous papers. A simple but effective statistical approach was developed and applied in order to identify and utilize a numerical index suitable for the quantitative measurement of the degree of matching between numerical results and measurement data affected by experimental errors. More than thirty numerical experiments were performed, of which the most significant eleven simulations are discussed. Satisfactory results were achieved. As outcomes, it was verified that, in particular for the selected experimental test, Rusanov flux addition within the continuity equation with the proper choice of both the viscosity term of momentum and the SPH boundary conditions, is suited to enhancing the performance of this type of numerical simulation of a fast flow.

Climate and vegetation in the Upper Valdarno Basin (central Italy) as a response to Northern Hemisphere insolation forcing and regional tectonics in the late Pliocene-early Pleistocene

Abstract: The pollen record from the Upper Valdarno contributes to the documentation of the main palaeonvironmental changes in one of the best known basins of the Northern Apennines where lacustrine and fluvial sediments deposited since 3.3 Ma. During the Piacenzian the lacustrine system (CSBb of the Castelnuovo dei Sabbioni Synthem) was characterized by the expansion of swamp formations where humid, subtropical to warm temperate forest taxa largely spread. Such assemblages suffer a major decrease under the effect of a gradual cooling since about 2.8 Ma, as testified by the spread of altitudinal coniferous taxa. However, repeated resurgences of subtropical forest taxa have been recorded in the overlain fluvio-deltaic sandy deposits (CSBc), from 2.7 Ma onwards. The first notable expansion of a dry-climate vegetation type consisting of mostly treeless open herbaceous vegetation has been observed in the lower portion of VRC fluvio-lacustrine deposits (Montevarchi Synthem); in fact, the major pulse of Artemisia in the aeolian sands of Rena Bianca is associated to the first glacial cycles that occurred after 2.6 Ma and the tectonic phase that involves the CSB lacustrine deposits.Both climate and tectonics strongly interplay driving the changes in the structure and floral composition of wetlands associated to successive depositional environments. Since 2.6 Ma swamps notably change in structure, with a large reduction of subtropical taxa especially Ta xodium/Glyptostrobus type and the progressive expansion of warm temperate forest taxa. At the same time, marshes expanded with plants able to resist in dynamic environments affected by river action. The palynological documentation of the glacial/interglacial cycles (G/I) younger than 1.7 Ma becomes ever more discontinuous when the effects of tectonics and climate (including the associated interactions) promote successive erosional processes during the emplacement of the lower portion of UFFa (ciottolami di Laterina, Auctt.; Torrente Ciuffenna Synthem). The age of the latter still controversial could fall within an interval of time including the Mid-Pleistocene transition.

Depositional environments of the Plio-Pleistocene Upper Valdarno Basin (Tuscany, Italy)

Abstract: The Upper Valdarno Basin is located about 35 km SE of Florence between the Chianti Mountains and the Pratomagno Ridge. The basin fill is made of four synthems named as Castelnuovo dei Sabbioni, Montevarchi, Fosso Salceto and Torrente Ciuffenna synthems. The Castelnuovo dei Sabbioni Synthem (Late Pliocene) consists of coarse-grained, stream gravels grading upwards into sheet-like, alluvial sand. These sands are overlain by a muddy lacustrine unit bearing, at its base, two well-developed lignitiferous seams accumulated in a coastal marsh setting. The lacustrine mud grades upwards into deltaic sand accumulated in a shallow-water delta under repeated lake-level oscillations. The Montevarchi Synthem (Late Pliocene to Early Pleistocene) consists of two portions separated by an unconformity surface passing basinward into a correlative conformity. The lower portion of the Montevarchi Synthem is made of alluvial fan gravel and sand passing upwards into fluvio-aeolian sandsheet deposits, consisting of aeolian-reworked, alluvial sand bearing isolated channels. Fluvio-aeolian sandsheet deposits are covered by mollusc-rich, alluvial sand which makes lateral transition into lacustrine muddy deposits. The upper portion of the Montevarchi Synthem consists of fluvial and alluvial fan deposits. Fluvial deposits occupy the axial part of the basin and are referred to sandy channels wandering through a muddy floodplain hosting shallow lakes and swamps. Alluvial fan deposits occur along the basin margins and consist of proximal gravels grading downfan into gravelly sand and a variety of sandy facies. Floodplain lakes deposits are well-developed in the middle part of the upper Montevarchi Synthem and in the Palazzolo sub-basin (Fosso Salceto Synthem), where they are overlain by alluvial-fan gravels. The Torrente Ciuffenna Synthem (Early to Middle Pleistocene) consists of fluvial sediments in axial part of the basin and alluvial fans deposits along the basin margins. The axial fluvial deposits were accumulated by the paleoArno River and consist of gravel and overlying sand. The basal gravels were deposited by low-sinuosity channels, whereas sandy deposits were formed by moderate to high-sinuous channels. The alluvial fan deposits consist of proximal gravels passing downfan into gravelly sand and sandy facies.

Use of unmanned aerial vehicles (UAVs) for photogrammetric surveys in rockfall instability studies

Abstract: L’utilizzo del drone (UAV) per l’esecuzione di rilievi fotogrammetrici nello studio delle frane da crollo.Si riportano i risultati preliminari di uno studio geostrutturale effettuato su due costoni rocciosi per i quali e stato realizzato un rilievo fotogrammetrico (DTP) basato sull'utilizzo di un drone (UAV). Tale rilievo ha consentito di ricostruire in maniera dettagliata la geometria del fronte e di risalire al pattern fessurativo dell'ammasso roccioso individuando un elevato numero di discontinuita, la loro orientazione nello spazio, le famiglie rappresentative nonche i volumi di roccia potenzialmente instabili.Le pareti, localizzate sul promontorio di Posillipo (Napoli) ed in una stretta gola a Praiano (Costiera amalfitana), risultano essere state interessate in passato da numerose frane da crollo. Esse risultano molto articolate con settori posizionati ad altezze elevate e spesso variamente orientati rispetto alla direzione generale del fronte.I risultati preliminari raccolti evidenziano i numerosi vantaggi della tecnica DSP-UAV in quanto consente di ricostruire topograficamente pareti localizzate in zone difficilmente raggiungibili con tecniche tradizionali vuoi per la localizzazione geomorfologica della stessa (Gola di Praiano) vuoi per la quota e la orientazione di alcuni settori rispetto al versante (Coroglio, Capo Posillipo). Il drone puo volare autonomamente su traiettorie di volo prestabilite oppure no ed e per questo molto versatile alla logistica dei luoghi. Esso restituisce coppie di foto stereoscopiche sia zenitali che variamente angolate rispetto al fronte. Infine esso e in grado di raggiungere distanze molto piccole rispetto al fronte (poche decine di metri) e cio si traduce nella restituzione di una nuvola di punti (xyz) molto densa che permette di ricostruire, con tecniche automatiche e/o manuali, la geometria degli elementi geomorfologici (nicchie di frana, diedri e pinnacoli isolati) e geostrutturali (giacitura dei piani di discontinuita) e di definire i volumi delle masse rocciose instabili.

Geotechnical and stratigraphic aspects of shallow landslides at Cinque Terre (Liguria, Italy)

Abstract: Caratteri geotecnici e stratigrafici delle frane superficiali nelle Cinque Terre (Liguria, Italia).In questo lavoro si analizzano le caratteristiche stratigrafiche e geotecniche delle coltri detritiche coinvolte nei dissesti causati dall’evento meteorologico del 25 ottobre 2011 nel bacino costiero di Vernazza (Cinque Terre, Liguria orientale), assai noto per la presenza di un paesaggio agricolo, terrazzato fin da tempi storici. Su un’area di circa 5.7 km2 le precipitazioni di forte intensita hanno innescato oltre 500 fenomeni franosi di varia tipologia e diffusi processi erosivi. La grande quantita di materiale solido trasportata (terra e detrito) ha causato l’ostruzione del tratto terminale del Canale di Vernazza, tombinato, causando la successiva inondazione del centro abitato. La realizzazione di indagini in situ e di prove in laboratorio sulle coltri detritiche ha consentito di proporre 4 modelli stratigrafici e geologicotecnici, rappresentativi dei contesti geologici e di uso del suolo piu diffusi all’interno del bacino di Vernazza. Tali modelli potranno essere utilizzati come base per una cartografia in chiave geologicotecnica dell’area di studio.

Subduction and continental collision events in the southern Apennines: constraints from two crustal cross-sections

Abstract: Subduzione e collisione continentale in Appennino meridionale: vincoli da due sezioni crostali.Mediante l’integrazione di dati geologici di superficie e sottosuolo, sono state realizzate due sezioni crostali attraverso il sistema catena-avanfossa-avampaese dell’Appennino meridionale. Di tali sezioni, quella settentrionale e stata elaborata dall’interpretazione del profilo sismico a riflessione CROP 04, mentre quella meridionale attraversa i giacimenti petroliferi della Val d’Agri e di Tempa Rossa, in Basilicata. Le due sezioni mostrano la presenza, nel sottosuolo del Cilento, di unita di basamento continentale coinvolte nella strutturazione della catena appenninica. Queste evidenze suggeriscono che, dopo l’iniziale fase di subduzione oceanica, l’evoluzione tettonica dell’Appennino meridionale e stata caratterizzata da due eventi di subduzione continentale alternati a due stadi di collisione continentale.

The influence of Mesozoic palaeogeography on the variations in structural style along the front of the Albanide thrust-and-fold belt

Abstract: The front of the W-verging Albanide fold-and-thrust belt and its adjacent foreland have been investigated using a grid of seismic reflection profiles, purposely acquired in the Southern Adriatic Sea. This convergent margin is part of the continental collision that extends from former Yugoslavia to North-Western Greece. At the front of the Albanides, both the structural style of the external part of the fold-and-thrust belt, and the evolution of the related foredeep basin, are strongly controlled by the nature of the Mesozoic units that are progressively accreted to the belt, namely the Apulian Platform and its adjacent deep-water basins. Where a thick carbonate platform is accreted (souther Albania) the frontal mountain range presents a high topography, whereas the foredeep basin is relatively shallow. On the other hand, where the basinal domain is accreted (northern Albania), the topography of the fold-and-thrust belt is subdue, whereas the foredeep basin is very deep.

Thermal history of the Aragón-Béarn basin (Late Paleozoic, western Pyrenees, Spain); insights into basin tectonic evolution

Abstract: Organic and inorganic thermal indicators throughout the Late Paleozoic sedimentary fill of the Aragon-Bearn Basin in the western Pyrenees, integrated with stratigraphic and structural data, point to a two-stage tectonic evolution:(i) High heat flow values and widespread magmatic intrusions driven by deeply rooted strike-slip faults characterized the first stage. This regime accompanied the rapid and localized deposition of the lower sedimentary succession and ended with uplift and erosion.(ii) The second stage was characterized by lower heat flow values, shallower strike-slip faults active during the deposition of an upper transgressive sedimentary succession and minor magmatic intrusions.The lower portion of the succession (Unidad Gris, Unidad de Transito and Unidad Roja Inferior, mainly Stephanian-Early Permian in age) records maximum temperatures between 170°C and 220°C as shown by clay mineral-based geothermometers (KI between 0.40 and 0.52°?2?, conversion of mixed layer illite-smectite to discrete illite), vitrinite reflectance (about 2.5%), and total homogenization temperatures from host-rock quartz cements between 160 and 180°C.The upper portion of the succession (Unidad Roja Superior, mainly Upper Permian in age) records maximum temperatures between 100-110° and 150°C as indicated by KI values between 0.57 and 0.94°?2?, illite content in mixed layer illite-smectite of 85-92%, and fluid inclusions in host-rock quartz-calcite cements.Local thermal maturity anomalies affected selected portions of the Late Paleozoic sedimentary succession with organic matter and clay minerals reaching respectively Ro%: 4.2-4.7% and KI up to 0.32°?2??in the lower sequence, and Ro% 2.9% in the upper sequence. These localized anomalies with respect to the basin thermal signature are the result of contact metamorphism related to the emplacement of magmatic intrusions across the sedimentary fill during two different magmatic events.

Why can rockfall normal restitution coefficient be higher than one

Abstract: Perche nell’analisi del moto di caduta massi il coefficiente di restituzione normale puo essere maggiore di uno?La modellazione del fenomeno di caduta massi e solitamente svolta con l’ausilio di simulazioni cinematiche, che consentono di calcolare le traiettorie dei blocchi potenzialmente instabili. Sui pendii molto acclivi i risultati sono fortemente influenzati dal valore dei coefficienti di restituzione, che quantificano la dissipazione di energia durante l’impatto; poiche l’urto blocco-pendio e prevalentemente anelastico, tali coefficienti dovrebbero sempre essere minori di uno. Tuttavia evidenze sperimentali mostrano l’occorrenza di valori superiori ad 1 nella direzione normale al pendio. La presente nota analizza le relazioni che intercorrono tra i coefficienti di restituzione e le caratteristiche del pendio, del blocco e del moto di caduta, partendo da prove in situ svolte in Val Grosina (SO).

SID&GRID: integrating hydrological modeling in GIS environment

Abstract: SID&GRID: modellistica idrologica integrata in ambiente GIS.Il sistema SID&GRID consiste in un modello idrologico (basato su codici gratuiti e di pubblico dominio come MODFLOW, VSF, LGR e altri algoritmi appositamente sviluppati) inserito in una piattaforma GIS, anch'essa gratuita e di pubblico dominio. In quest'ultima tutti i dati di input e output sono gestiti tramite il collegamento ad un DBMS (Data Base Management System). Il risultato e un modello idrologico distribuito e fisicamente basato che permette di valutare la variazione delle variabili idrologiche nello spazio e nel tempo, al fine di effettuare simulazioni per la gestione e la pianificazione delle risorse idriche.

Derivation of preliminary natural background levels for naturally Mn, Fe, As and NH4+ rich groundwater: the case study of Cremona area (Northern Italy)

Abstract: Derivazione dei valori naturali di fondo preliminari in acque sotterranee naturalmente ricche in Mn, Fe, As e NH4+: il caso studio dell'area cremonese.Il presente lavoro riguarda la definizione di valori naturali di fondo preliminari per le specie manganese, ferro, arsenico ed ammonio nelle acque sotterranee del sistema acquifero multistrato della zona di Cremona. La metodologia applicata ha previsto la raccolta dei dati storici e di dati rilevati in campo attraverso una campagna di misure (luglio 2010), la definizione delle caratteristiche del sistema acquifero tramite modellazione tridimensionale dei parametri idrogeologici, la caratterizzazione idrodinamica ed idrochimica del sistema acquifero, la derivazione dei valori di fondo. I valori di fondo sono stati definiti in maniera distinta su due insiemi di dati differenti (campagna di luglio 2010 e serie storiche) considerata la diversa qualita dei dati che i due insiemi presentano. In questo senso i valori naturali di fondo definiti vengono considerati come “preliminari”, essendo comunque in grado di fornire indicazioni utili alle Autorita competenti. La proposta di una campagna di monitoraggio dedicata per la derivazione dei valori naturali di fondo definitivi e in fase di valutazione da parte della Provincia di Cremona.

Remarks on the 25 October 2011 rainstorm in Eastern Liguria and Northwestern Tuscany (Italy) and the related landslides

Abstract: Osservazioni preliminari sull’evento pluviometrico e sulle frane del 25 ottobre 2011 in Liguria orientale e Toscana nord-occidentale.Il 25 ottobre 2011 la Liguria orientale e la Toscana nordoccidentale sono state colpite da un evento pluviometrico estremo. La straordinaria quantita d’acqua precipitata in poche ore ha causatoalluvioni, frane e vittime nelle province della Spezia (Val di Vara e Cinque Terre) e di Massa-Carrara (Lunigiana). In questa nota sono descritte le principali caratteristiche dell’evento e gli effetti indotti sui versanti.

Just a few: rodents and lagomorphs in the Plio-Pleistocene fossil record of the Upper Valdarno Basin

Abstract: The Plio-Pleistocene vertebrate fossil record of the Upper Valdarno Basin (Tuscany, Italy) is well known because of the large mammal collections. Although the small mammals have a documentation that is not even comparable with that of the large mammals; their record from Upper Valdarno Basin is known since early 1800's papers and includes a number of type specimen of species named by early researchers. We present here an overview of the rodents and lagomorphs distribution within the stratigraphic framework of the Upper Valdarno Basin.

Evolution of an Upper Pleistocene aeolianite in the northern Mediterranean (Liguria, NW Italy)

Abstract: Based on a 19th century scientific report, a recent geological survey has highlighted the presence of a complex, mostly Aeolian deposit along the coast of Liguria (Laigueglia, Savona Province, NW Italy). This finding was recognized to be a relevant palaeoclimatic marker, being the northernmost aeolianite outcrop ever reported from the Mediterranean Basin. The investigated deposit is spread along a steep sea-facing slope from 2-3 m up to almost 60 m a.s.l.; it is strongly reworked due to recent urbanization of the area. Its stratigraphic features were recognized thanks to its exposure in different sections and analysed in order to obtain reliable indications on the sedimentary environments. Facies analysis suggests that the sedimentary body is a relict cliff-top dune evolved on top of a foreshore deposit in temperate-cold and moist climate conditions. Two samples from the upper, strictly aeolian part of the sequence were subjected to OSL (Optically Stimulated Luminescence) dating and yielded an age consistent with its deposition during the Marine Isotopic Stage (MIS) 5.2 and 5.1 substages (88-83 and 83-71 ka). This paper contributes to the increase of the number of Upper Pleistocene coastal aeolianites accounted for in literature. Being located at the northern border of the occurrence of aeolianites in the northern Mediterranean, it helps to outline climatic and environmental boundary conditions for the formation of this type of deposit.

Monitoring the soil suction regime of landslide-prone ash-fall pyroclastic deposits covering slopes in the Sarno area (Campania - southern Italy)

Abstract: Monitoraggio del regime della suzione nei depositi piroclastici suscettibili a franare ricoprenti i versanti dell’area di Sarno (Campania - Italia meridionale).I versanti delle aree montuose circostanti i centri eruttivi della Piana Campana sono notoriamente contraddistinti da una peculiare tipologia di frane superficiali da flusso a cinematica rapida che, in concomitanza di eventi pluviometrici straordinari, coinvolgono le coltri piroclastiche. Al fine di comprendere la dinamica dei processi idrologici di versante che causano l’instabilita del pendio, in un’area campione dei Monti di Sarno, e stata effettuata una campagna di monitoraggio delle pressioni di poro nella coltre piroclastica, estesa per circa un anno idrologico.I risultati ottenuti hanno finora evidenziato un regime delle pressioni di poro, sempre ricadenti nel dominio insaturo, caratterizzato da ampie escursioni stagionali nell’intera coltre piroclastica. Tale osservazione sperimentale e spiegata sia dalle peculiari proprieta di ritenzione idrica dei depositi piroclastici che dalla presenza di vegetazione boschiva decidua, che contribuisce ad accentuare il processo di evapotraspirazione nella stagione primaverile-estiva.L’approccio seguito ha consentito di affinare le conoscenze dei processi idrologici a scala di versante e costituisce la base per l’implementazione e la calibrazione di modelli numerici finalizzati alla stima delle condizioni idrologiche critiche per la stabilita dei pendii ricoperti da coltri piroclastiche.

The non-marine molluscs of the Plio-Pleistocene Upper Valdarno Basin (Tuscany, central Italy): depositional environments, palaeoecology and biochronology

Abstract: Since the beginning of the nineteenth century, rich non-marine molluscan faunas have been recognized in the Plio-Pleistocene Upper Valdarno Basin (Tuscany, central Italy). Further research has improved the palaeoecological and biochronological meaning of these faunas, which are often associated with significant Villafranchian vertebrate remains. The Upper Valdarno Basin fill consists of four unconformity-bounded units: Castelnuovo dei Sabbioni, Montevarchi, Fosso Salceto (occurring in the Palazzolo sub-basin) and Torrente Ciuffenna synthems. Rich molluscan assemblages of alluvial and palustrine environment are recorded from the Lower Pleistocene Montevarchi Synthem deposits. Extinct and archaic freshwater gastropods and bivalves characterising the Middle and Upper Villafranchian thermophilous assemblages of intermountain basins of central Italy, such as the Plio-Pleistocene Tiberino Basin, occur. The new record of the extinct genus Neumayria [De Stefani, 1877][1] is reported. A humid-temperate climatic phase is recognized in concomitance with the major expansion of these assemblages in the Upper Valdarno Basin. The fluvial deposits of the Torrente Ciuffenna Synthem, Middle Pleistocene in age, yielded poor mixed assemblages composed of terrestrial and freshwater species. The recorded land species, represented by Pupillidae and Vertiginidae associated with a dry exposed environment, point to an arid or semiarid cool climatic phase. [1]: #ref-18

New data on the Pleistocene of Trani (Adriatic Coast, Southern Italy)

Abstract: Along the Apulian Adriatic coast, in a cliff south of Trani, a succession of three units (superimposed on one another) of marine and/or paralic environments has been recognised. The lowest unit I is characterised by calcareous/siliciclastic sands ( css ), micritic limestones ( ml ), stromatolitic and characean boundstones ( scb ), characean calcarenites ( cc ). The sedimentary environment merges from shallow marine, with low energy and temporary episodes of subaerial exposure, to lagoonal with a few exchanges with the sea. The lagoonal stromatolites ( scb subunit) grew during a long period of relative stability of a high sea level in tropical climate. The unit I is truncated at the top by an erosion surface on which the unit II overlies; this consists of a basal pebble lag ( bpl ), siliciclastic sands ( ss ), calcareous sands ( cs ), characean boundstones ( cb ), brown paleosol ( bp ). The sedimentary environment varies from beach to lagoon with salinity variations. Although there are indications of seismic events within the subunits cs , unit II deposition took place in a context of relative stability. The unit II is referable to a sea level highstand. Unit III, trangressive on the preceding, consists of white calcareous sands ( wcs ), calcareous sands and calcarenites ( csc ), phytoclastic calcirudite and phytohermal travertine ( pcpt ), mixed deposits ( csl, m, k, c ), sands ( s ) and red/brown paleosols ( rbp ). The sedimentation of this unit was affected by synsedimentary tectonic, attested by seismites found at several heights. Also the unit III is referable to a sea level highstand. The scientific literature has so far generally attributed to the Tyrrhenian (auct.) the deposits of Trani cliff. As part of this work some datings were performed on 10 samples, using the amino acid racemization method (AAR) applied to ostracod carapaces. Four of these samples have been rejected because they have shown in laboratory recent contamination. The numerical ages indicate that the deposits of the Trani cliff are older than MIS 5. The upper part of the unit I has been dated to 355±85 ka BP, thus allowing to assign the lowest stromatolitic subunit ( scb ) at the MIS 11 peak and the top of the unit I at the MIS 11-MIS 10 interval. The base of the unit II has been dated to 333±118 ka BP, thus attributing the erosion surface that bounds the units I and II to the MIS 10 lowstand and the lower part of the unit II to MIS 9.3. The upper part of the unit II has been dated to 234±35 ka BP, while three other numerical ages come from unit III: 303±35, 267±51, 247±61 ka BP. At present, the numerical ages cannot distinguish the sedimentation ages of units II and III, which are both related to the MIS 9.3-MIS 7.1 time range. However, the position of the units, superimposed one another, and their respective age, allows us to recognise a subsidence phase between MIS 11 and MIS 7, followed by an uplift phase between the MIS 7 and the present day, which led the deposits in their current position. This tectonic pattern is not in full agreement with what is described in the literature for the Apulian foreland.

Ligurian-derived olistostrome in the Pseudomacigno Formation of the Stazzema Zone (Alpi Apuane, Italy). Geological implications at regional scale

Abstract: In the Stazzema Zone (southern part of the Alpi Apuane tectonic window) an olistostrome of kilometric extent (here informally called Ricavo olistostrome) incorporating blocks and slides of Lower Cretaceous limestones referable to the “Argille a Palombini” Formation of the Internal Ligurian Units forms a well-defined lens-shaped body in the upper portion of the Pseudomacigno Formation. The Pseudomacigno Formation is an Oligo-Miocene siliciclastic foredeep deposit making up the upper portion the Alpi Apuane metamorphic sequence. In spite of the greenschist metamorphic imprint of the sequence, the exotic limestones included in the olistostrome have locally escaped recrystallization so that their primary depositional texture and microfossil content are still recognizable. The microfacies of these limestones are represented by mudstones/wackestones with abundant calcitized radiolarians and sponge spicules associated with rare calpionellids and some planktonic forams indicative of the Valanginian. The occurrence of exotic materials derived from the Internal Ligurian Units in the Pseudomacigno Formation is consistent with the current model of forward migration of the thrust belt-foredeep system in the Northern Apennines according to which the tectonic transport of the Ligurian/Subligurian Nappes was accompanied by the emplacement of olistostromes in the flysch deposits. The presence of an olistostrome derived from the Ligurian Nappes in the Pseudomacigno Formation contributes in a roundabout way to highlight some contradictions existing between the 27 Ma age of metamorphism of the Alpi Apuane Unit obtained from radiometric measurements, widely accepted in the literature, and the regional paleogeographic model currently adopted by the Apennine geologists. The mere presence of Ligurian-derived materials in the Pseudomacigno Formation, in fact, establishes new constraints that make a 27 Ma age of the metamorphic peak incompatible with the paleogeographic reconstruction of the Northern Apennines that relocates the domain of the metamorphic Tuscan Units east of the original domain of the Tuscan Nappe. Following this restoration, ages of metamorphism not older than 13–14 Ma would be expected.

Hydrocarbon occurrences and petroleum geochemistry of Albanian oils

Abstract: Oil accumulations occur in the Ionian zone limestone section and in the Adriatic Basin sandstone reservoirs of Tortonian and Messinian age, respectively.A large set of geochemical compositional data of Albanian oils have been analysed. Oil entrapment occurred during two main phases: 1) during the Early Miocene, when the main part of source rocks were in the oil maturity window; 2) during the Pliocene, when the source rocks were in a more advanced stage of oil genesis. The multiphase genesis has resulted in hydrocarbon accumulations with a broad range of geochemical characteristics. Both individual fieldsand in field complexes, biodegraded and non-biodegraded heavy oils, light oils, condensates, wet and dry gas may occur. In general, oil density and sulphur content decrease with depth.Oil grouping is evident from the data set, although stable carbon isotope values suggest that the Berat Belt oils and the Adriatic Basin oils are slightly different from the majority of oils in the Kurveleshi Belt. No exact correlations between the oils and the individual carbonate source rock levels could be established.The Tertiary humid source rock has been matured probably in the early stage, and has generated dry gas and some immature condensates.The gas accumulations in the Adriatic Basin consist mostly in pure biogenic and mixed thermogenic/ biogenic gases. The deeper classic reservoirs contain relatively less dry gas.

Hydrocarbon evaluation aspects in Neogene clastic reservoirs, Vlora-Elbasan Region, Albania

Abstract: The Neogene clastic deposits contain more than half of the reserves discovered in the Albanian territory, from which more than 25÷30% are still undeveloped. This paper describes the spatial distribution and the reservoir characteristics of these molasse deposits in relation with the regional geological and structural evolution. These reservoirs constitute transgressive sequences deposited on the top of underlying Mesozoic and Paleogene limestones above a major erosional surface. The paleorelief, mainly shelf, controlling the distribution of the molasse, is made up of terraces and paleo-valleys, which developed by erosion of the continental margin of the Ionian plate during episodes of thrust-related tectonic uplift. The links between tectonics, erosion and sedimentation have controlled boththe distribution of the main molasse depocenters, and the coeval depositional environments. The molasse deposits were initially devoided of organic matter precluding any in situ generation of hydrocarbons. As a consequence, the oil currently found in the Neogene reservoirs results from a secondary migration from underlying limestone reservoirs at places where the intervening Oligocene flysch has been entirely removed by erosion. The reservoir characteristicsof the Neogene clastics are mainly related to lateral and vertical lithological changes controlled by the paleo-environments and tectonics. From the regional viewpoint, the deposits relate to the presence of bays and tectonics uplifts, with erosion, transport and sedimentation processes operating both at regional and local scales.The oil accumulations are concentrated in dominantly stratigraphic traps within the bays and outside them, as a result of lithological changes that made possible their preservation. The main migration pathways are located along the transgressive contacts in Patos-Verbas, Kucove and Selenica fields. In general, sandstone thickness increases from south to north and from east to west. The reserve estimates made until now for the hydrocarbon potential of the Neogene molasse deposits, have been based using the former Eastern European classification, but they lack a modern economical evaluation. Often, the analogy with other, better known and more mature Petroleum provinces has been used. When re-evaluating the hydrocarbon potential of Albania the reserve estimates of the Neogene clastic deposits have been determined in accordance with the requirements of the western classification into proven, probable and possible reserves with increasing reliability. Attention has been paid also to account for lateral and vertical shifts of the water-oil contacts operating during the deformation of the reservoirs due to regional tilting, folding and/or thrusting.

High-resolution δ13C stratigraphy through the Selli Oceanic Anoxic Event (OAE1a) in the Apulia carbonate platform: the Borgo Celano section (western Gargano Promontory, Southern Italy)

Abstract: We show that the global-scale environmental perturbations leading to the Selli OAE1a were clearly recorded in the middle Bedoulian Apulia carbonate platform at Borgo Celano, in the western Gargano Promontory (Southern Italy). The studied section (Bari Limestones), which is 72.45 m thick and spans the Late Barremian p.p. -latest Early Aptian time interval, has been logged with an average resolution of 3 samples per metre for chemostratigraphic analyses and up to 7 samples per metre for facies analysis in the aim of detailed paleocologic and paleoceanographic investigation. It contains the complete biosedimentary and chemostratigraphic record across the Selli OAE1a, as suggested by a consistent match of the observed isotope excursions with those documented in the Cismon pelagic reference section and the lack of significant non-depositional or erosional hiatuses within the chemostratigraphic Selli level: biostratigraphic and sedimentary-diagenetic analyses document a continuous record of fully subtidal conditions. Furthermore, the Borgo Celano section allows correlation of the shallow- and deep-water records without intervening stratigraphic breaks. Upper Barremian-Lower Bedoulian, chlorozoan-type carbonates showing subtidal-intertidal Milankovitch-type cyclicities characterize the lower part of the Borgo Celano section (C2 pro parte isotopic segment). Starting from the latest C2 segment, a remarkable Crisis Interval (CI) about 4 m thick shows an increasing frequency of bivalves ( Chondrodonta and requieniids), the disappearance of green algae and a reduced diversity of foraminiferal assemblages (foramol-type carbonates). This interval is sharply overlain by an interval, about 3.70 m thick, that is largely dominated by “out-of-balance” microbial limestones almost devoid of metazoans, apart from sparse, small-sized requieniids and Chondrodonta , which accompanies the C3-middle C4 isotope segment. It is interpreted to reflect a sharp hyperthermal and acidification event induced by excess p CO 2 . Starting from the upper C4 segment, less severe but still threatening environmental conditions permitted the deposition throughout the lower C5 segment of peculiar shallow-water tropical-like carbonates, which are dominated by oncoidal floatstones and microbial wackestone/packstone emphasizing the enduring influence of benthic cyanobacteria during the Selli OAE1a. Upsection guilds are dominated by foraminiferal and peloidal wackestones/packstones with sparse bivalves and green algae (upper C5-lowermost C7 isotope segments). Similarly to other carbonate platforms of the central Tethyan Realm (e.g., Apennine and Adriatic), the resilience of the Apulia carbonate platform inner shelf to the environmental perturbations that led to the coeval drowning of its margin, the starvation of its slope and to the deposition of black shales in the bounding Ionian basin is a striking supraregional feature. The inception of the resilience of the Apulia carbonate platform inner shelf is coincident with the lithostratigraphic boundary in between the Borgo Celano and Chondrodonta and requieniids members of the Bari Limestones and physically corresponds in the field with the base of a significant, 1 m thick, Chondrodonta -rich marker bed. These observations confirm the value of routinely applied field and laboratory studies for precise chemostratigraphic and bio-chronostratigraphic correlations on a regional scale. Furthermore, chemostratigraphic data presented here corroborate recent paleoceanographic and stratigraphic models proposed for the Lower Aptian across the transition between the Apulia carbonate platform and the bounding Ionian basin, and provide further elements for regional reconstructions of historical patterns.