Sinkhole susceptibility evaluation in Apulia, southern Italy

In some regions in Italy sinkholes are frequent and pose a serious threat to structures and infrastructures. Apulia region is largely affected by sinkholes of both natural and anthropogenic origin, due to the karst nature of large portions of the regional territory and to high diffusion of artificial cavities. For this reasons, susceptibility, hazard and risk posed by sinkholes must be estimated in order to gain more insights into their spatial and temporal distribution, and to apply appropriate risk management and to take proper mitigation strategies. In order to estimate the susceptibility to sinkholes in Apulia, the ensemble statistical modelling proposed by Rossi et al. (2010) and later refined by Rossi & Reichenbach (2016) is used. This allows assessing susceptibility using differentiated statistical approaches, quantifying accurately the modelling performances, and evaluating the associated uncertainty. In order to obtain accurate and reliable results thematic layers related to the sinkholes occurrence were carefully evauated and selected. This contribution shows the preliminary results of the analyses to evaluate the susceptibility to natural sinkholes, which used as training dependent (i.e. grouping) set, data extracted from the regional inventory of natural caves, edited by the Apulian Speleological Federation (www.catasto.fspuglia.it), and as validation set the natural sinkholes occurred in Apulia, collected in the chronological catalogue of sinkholes in Italy (Parise & Vennari, 2013, 2017). Appropriate thematic layers, were selected heuristically on the base of the knowledge on the triggering mechanisms and the nature of the phenomenon gained previously in the study area. Resulting regional-scale susceptibility map will be appropriately validated. The methodological procedure will be applied to the evaluation of susceptibility for anthropogenic sinkholes as well

Amonoideos y nanofósiles calcáreos del Tithoniano de la Formación Vaca Muerta en Arroyo Durazno, centro-oeste de Mendoza, Argentina

Las sedimentitas jurásicas de la Formación Vaca Muerta del perfil Arroyo Durazno (35°05?S, 69°45?O) de 152m de espesor se caracterizan por la alternancia de niveles de mudstones microbianos, mudstones y wackestones bioclásticos concrecionales, laminares y masivos, packstones y algunas intercalaciones delgadas de areniscas medias con bancos de margas y lutitas castañas a oscuras. El paleoambiente comprende un sistema de rampa mixta, con un predominio de facies de rampa externa sobre las facies de cuenca. Se reconocen diferentes asociaciones de amonoideos y nanofósiles, junto con nautiloideos, bivalvos, gastrópodos y vertebrados. Los amonoideos dominan en abundancia y diversidad a lo largo de todo el perfil. De acuerdo al esquema de biozonación tradicional se reconocen 6 biozonas de asociación: Virgatosphinctes mendozanum (0-11m), Pseudolissoceras zitteli (11-42m), Aulacosphinctes proximus (42- 54m), Windhauseniceras internispinosum (54-85m), Corongoceras alternans (85-94m) y Substeueroceras koeneni (94-152m). A partir del estudio micropaleontológico se reconocieron 17 especies de nanofósiles calcáreos. En la biozona de V. mendozanum (Tithoniano temprano), la asociación de nanofósiles hallada es poco diversa y aumenta gradualmente hasta la base de la biozona de S. koeneni (Tithoniano tardío), donde se reconocen las primeras apariciones (FOs) de Eiffellithus primus Applegate y Bergen y Hexalithus noeliae Loeblich y Tappan, bioeventos secundarios de la Zona de nanofósiles NJKA. Hacia el tope de la biozona de S. koeneni, se registra un marcado incremento en la diversidad de los amonites y nanofósiles, destacándose la FO de Rhagodiscus asper (Stradner), definido como un bioevento secundario de la Zona NJKB (Tithoniano tardío). A partir del estudio integrado de amonoideos y nanofósiles se estableció una edad tithoniana temprana a tithoniana tardía para las sedimentitas de la Formación Vaca Muerta en esta clásica localidad.Simposio VI: Microfósiles del Mesozoico y Cenozoico de América del Sur y Antártida. Nuevas aplicaciones y problemáticas asociadasFacultad de Ciencias Naturales y Muse

New marine reptile assemblage from the Jurassic-Cretaceous boundary beds of the High Andes, Argentina

Jurassic marine reptiles from the southern margin of the Eastern Pacific have been documented since the XIX century. Most of them have been recorded at the Neuquén Basin (west-central Argentina) in sedimentary rocks of the Vaca Muerta Formation (lower Tithonian-lower Valanginian). Outcrops of this lithographic unit in the southern sector of the basin have proven to be highly fosiliferous in marine reptiles (e.g. Cerro Lotena, Los Catutos and Pampa Tril, in the Neuquén Province; Gasparini and Dellapé, 1976; Pol and Gasparini, 2009; Gasparini and Fernández, 2011; Herrera et al., 2013). By contrast, exposures of the Vaca Muerta Formation in the northern sector of the Neuquén basin (Mendoza Province), though widely distributed, had not been prospected for marine reptiles since the middle of the XX century (e.g. Rusconi, 1938, 1948a, b, 1967).Facultad de Ciencias Naturales y Muse

High-precision U–Pb ages in the early Tithonian to early Berriasian and implications for the numerical age of the Jurassic–Cretaceous boundary

The numerical age of the Jurassic–Cretaceous boundary has been controversial and difficult to determine. In this study, we present high-precision U–Pb geochronological data around the Jurassic–Cretaceous boundary in two distinct sections from different sedimentary basins: the Las Loicas, Neuquén Basin, Argentina, and the Mazatepec, Sierra Madre Oriental, Mexico. These two sections contain primary and secondary fossiliferous markers for the boundary as well as interbedded volcanic ash horizons, allowing researchers to obtain new radioisotopic dates in the late Tithonian and early Berriasian. We also present the first age determinations in the early Tithonian and tentatively propose a minimum duration for the stage as a cross-check for our ages in the early Berriasian. Given our radioisotopic ages in the early Tithonian to early Berriasian, we discuss implications for the numerical age of the boundary.</p

Sedimentología y estratigrafía de la Formación Vaca Muerta (Tithoniano-Berriasiano) en el área del cerro Domuyo, norte de Neuquén, Argentina Sedimentology and stratigraphy of the Vaca Muerta Formation in the Cerro Domuyo area, Northern Neuquén, Argentina

Los depósitos de la Formación Vaca Muerta en el área del cerro Domuyo muestran una interesante interca-laclón de depósitos con paleocorrientes opuestas. La unidad está representada por facies de cuenca y rampa externa con dirección de progradación hacia el oeste. Sin embargo, en su parte media se intercalan depósitos de talud, con desarrollo de deslizamientos sinsedimentarios hacia el NE, que pueden asignarse al Miembro Huncal. Este intervalo se compone de facies carbonáticas que probablemente se asocien con el desarrollo de un talud relacionado con una plataforma carbonática o una rampa distalmente profundizada. A partir de la fauna de amonites reconocida, la Formación Vaca Muerta se extiende desde el Tithoniano temprano hasta el Berriasiano tardío, aunque podría alcanzar el Valanginiano temprano. El Miembro Huncal contiene representantes de la Biozona de Substeueroceras koeneni (Tithoniano tardío), por lo que su edad sería más antigua que la propuesta en la localidad tipo y permitiría su correlación con las unidades aflorantes en el territorio chileno.<br>The Vaca Muerta Formation in the Cerro Domuyo area shows an interesting intercalation of facies with opposite paleocurrents. The unit is represented by outer ramp to basinal facies with a westward direction of progradation. However, in its middle section, slope deposits correlatable with the Huncal Member, are intercalated with slumped strata verging NE. This interval is composed of carbonate facies and it is probably associated with the development of a slope related to a carbonate platform or a distally steepened carbonate ramp. Based on the ammonoid fauna, the age of the Vaca Muerta Formation ranges from the early Tithonian to the late Berriasian, but it could also reach the early Valanginian. The Huncal Member yields representatives of the Substeueroceras koeneni Biozone (late Tithonian), hence its age is older than that proposed in its type locality allowing its correlation with units exposed in the Chilean territory

Cricosaurus (Thalattosuchia, Metriorhynchidae) survival across the J/K boundary in the High Andes (Mendoza Province, Argentina)

Metriorhynchidae is an extinct group of Jurassic–Cretaceous crocodylomorphs that developed a fully pelagic lifestyle. Its Jurassic record is outstanding (it includes around 40 nominal species), while the records that can be restricted to the Cretaceous are particularly sparse. Here we describe a partial skull of a new species of Cricosaurus, Cricosaurus puelchorum sp. nov., from the lower Berriasian of the Vaca Muerta Formation (Neuquen Basin, Argentina). The description of the specimen reveals a series of autapomorphies and a unique combination of characters that justify the creation of a new species. Phylogenetic analysis places Cricosaurus puelchorum sp. nov. closer to three upper Kimmeridgian–lower Tithonian species of southern Germany. The new taxon was recovered in connection with an accurate ammonoid-based biostratigraphic control and allows confirming the survival of Cricosaurus across the J/K boundary at the southeastern Pacific.Facultad de Ciencias Naturales y Muse

A new species of Andiceras Krantz (Cephalopoda: Ammonoidea) from the Late Jurassic-Early Cretaceous of the Neuquén Basin, Mendoza, Argentina: Systematics and Biostratigraphy Una nueva especie de Andiceras Krantz (Cephalopoda: Ammonoidea) del Jurásico Tardío-Cretácico Temprano de la Cuenca Neuquina, Mendoza, Argentina: Sistemática y bioestratigrafía

A new ammonoid species of the Andean endemic genus Andiceras Krantz is here described from upper Tithonian-lower Berriasian levels of the Vaca Muerta and Chachao Formations of the Mendoza Group, in north-western Mendoza Province, Argentina. Andiceras planulatus sp. nov. lies between the last beds with representatives of the Substeueroceras koeneni Assemblage Zone of late Tithonian age and the first bed yielding elements of the Argentiniceras noduliferum Assemblage Zone of early Berriasian age, according to the traditional Andean ammonoid zonation scheme. The particular stratigraphic position of Andicerasplanulatus, together with its easily recognizable morphology makes this species a good potential biostratigraphic marker for the Jurassic-Cretaceous boundary in the Andean region.<br>Se describe una nueva especie de amonoideo perteneciente al género andino endémico Andiceras Krantz. Los restos asignados a Andiceras planulatus sp. nov. se disponen estratigráficamente entre los últimos niveles con representantes de la Biozona de Asociación de Substeueroceras koeneni de edad tithoniana tardía, y los primeros elementos de la Biozona de Asociación de Argentiniceras noduliferum de edad berriasiana temprana, de acuerdo al esquema clásico de biozonación andina. La posición estratigráfica particular de esta nueva especie, junto con su morfología de fácil identificación, la convierten en un potencial buen marcador bioestratigráfico para el reconocimiento del límite Jurásico-Cretácico en la región andina

The influence of slope instability processes in demographic dynamics of landslide-prone rural areas

To assess the relationships existing between landslide evolution and economical development of a rural, highly prone to landslides, area in southern Italy, a demographic analysis covering the time span from 1861 to 2011 has been performed on about 30 municipalities. The work consisted in a detailed description of the demographic features of the studied area, aimed at analysing the growing/decreasing trend in the local populations, as a function of the main historical and hydrological events. The combined analysis of the above elements with data about landslide distribution and their temporal occurrence allowed to evaluate the influence played by slope instability processes in this sector of Apulia regio

Soglie pluviometriche per l’innesco di fenomeni franosi alla scala nazionale e regionale: il caso del Sub-Appennino Dauno (Puglia settentrionale).

Il presente lavoro illustra i risultati allo stato ottenuti nelle attività di defi nizione di soglie pluviometriche preliminari per il possibile innesco di frane superfi ciali nell’area del Sub-Appennino Dauno (Puglia settentrionale) avviate dall’Istituto di Ricerca per la Protezione Idrogeologica (CNR IRPI) in collaborazione con il Centro Funzionale Decentrato del Servizio Protezione Civile della Regione Puglia nell’ambito del progetto nazionale “Soglie Pluviometriche per il possibile innesco di fenomeni franosi superfi ciali” previsto dall’intesa operativa tra il Dipartimento della Protezione Civile (DPC) e l’IRPI, Centro di Competenza del Dipartimento stesso. Nella prima sezione vengono presentate le attività di previsione, monitoraggio e sorveglianza che svolge il Centro Funzionale Decentrato della Regione Puglia nell’ambito del sistema di allertamento. Nella seconda sezione, relativa alle soglie pluviometriche, dopo aver illustrato i differenti criteri di defi nizione delle soglie di innesco di fenomeni franosi e le fi nalità della loro applicazione, vengono trattati i dati ed il metodo usato per tentare di stabilire soglie per l’area del Sub-Appennino Dauno, il settore a più elevata suscettibilità da frane nella Regione Puglia. Infi ne vengono discussi i risultati ottenuti e riportate le conclusioni

Back-analysis of a large earth-slide in stiff clays induced by intense rainfalls

On December 2013, the town of Montescaglioso (Basilicata, Southern Italy), located at the top of a prominent hill within a highly landslide-prone setting, was affected by reactivation of a large earth-slide along the south-western slope. The slope is formed of stiff clays, belonging to the Argille Subappennine formation, covered by sands and conglomerates, with these latter being chaotically dislocated into arenaceous blocks resulting from ancient gravitational processes. The sliding movement started rapidly, accordingly to eyewitness accounts, and in a time span lower than 1 hour destroyed more than 500 m of the main road connecting the town of Montescaglioso to the Province Road SP175, and involved a few warehouses, a supermarket, and private homes. Surface displacement analysis jointly with detailed field surveys, and with visual analysis of post-event terrestrial and helicopter-based photographs, carried out soon afterward the landslide activation, allowed to identify the main effects produced by the slope movement, and to compile a map of the landslide surface deformations, aimed at identifying the landslide zones characterized by different kinematical features. Both geomorphological evidences and post-event inclinometric measurements have indicated that the failure surface has presumably developed at high depths and specifically in the clay substratum. Laboratory tests have been carried out for the characterization of the mechanical behavior of the clays involved in the sliding process. Both a two-dimensional and a three-dimensional finite element analysis were carried out in order to investigate the overall failure mechanism, the factors that could have controlled the landslide triggering and the spatial directivity of the landslide movement. The modeling results are in very good agreement with the observed landslide process as regards the conditions leading to the slope reactivation and the displacement field occurred in situ and highlight the role of the slope saturation as the main triggering factor of the landslide proces