Search results for "Geomorfologia"

A three-dimensional back-analysis of the collapse of an underground cavity in soft rocks

2017

Abstract The assessment of stability of man-made underground caves, excavated in the past and later on abandoned, represents a serious challenge for land and urban planning operations, especially for the areas of possible interaction of the caves with overlying structures and infrastructures. Several areas of Southern Italy are characterized by the presence of abandoned underground quarries for the extraction of soft calcarenite rocks, which now threatens the overlying environment due to the risk of collapse and the consequent generation of sinkholes. This work presents a back-analysis of a sinkhole occurred in 2011 in the town of Marsala, caused by the collapse of an underground quarry, as…

FROM SLOPE MORPHOMETRY TO MORPHOGENETIC PROCESSES: AN INTEGRATED APPROACH OF FIELD SURVEY, GIS MORPHOMETRIC ANALYSIS AND STATISTICS IN ITALIAN BADLAN…

2016

Calanchi (singular calanco) represent a typical example of badlands in the Italian peninsula, which rapidly evolve on clayey terrains such as the widespread Pliocene-Pleistocene marine clays. The present study aimed at investigating the role of the slope morphometry on the typology and distribution of morphogenetic processes in a calanchi area located in southern Italy. The research included detailed geomorphological surveying, morphometric and statistical analysis. The study area was first subdivided into individual hydrographic units (HUs), for which field survey allowed to identify the dominant denudation processes, their intensity and the distribution of the associated landforms (pipes,…

Water erosion assessment and modeling in two calanchi areas in Sicily, Italy

I badlands sono forme di erosione localizzate principalmente nelle regioni aride e semi-aride e sono formati da una complessa combinazione di processi morfogenetici. La loro origine coinvolge processi di erosione idrica ma anche tunnel erosion e movimenti di massa. Inoltre, tali forme possono anche essere correlate a fenomeni di erosione accelerata che hanno luogo laddove le azioni antropiche disturbano l'equilibrio naturale tra processi morfogenetici e suolo. I badlands, con i loro versanti ripidi, sono spesso inseriti all’interno di paesaggi più dolci, in mezzo a colture o bosco, localizzati in aree dove i processi responsabili del loro modellamento sono di solito piuttosto attivi determi…

Analisi ed effetti sul territorio dei fenomeni franosi che coinvolgono il suolo

2011

Sulfuric acid speleogenesis (SAS) close to the water table: Examples from southern France, Austria, and Sicily

2016

Caves formed by rising sulfuric waters have been described from all over the world in a wide variety of climate settings, from arid regions to mid-latitude and alpine areas. H2S is generally formed at depth by reduction of sulfates in the presence of hydrocarbons and is transported in solution through the deep aquifers. In tectonically disturbed areas major fractures eventually allow these H2S-bearing fluids to rise to the surface where oxidation processes can become active producing sulfuric acid. This extremely strong acid reacts with the carbonate bedrock creating caves, some of which are among the largest and most spectacular in the world. Production of sulfuric acid mostly occurs at or…

Sulfuric acid caves of Italy: A review

2019

Abstract In Italy, especially along the Apennine Chain, numerous active and inactive sulfuric acid speleogenetic (SAS) caves have been documented in the last two decades. Here we present an overview of these peculiar hypogene systems, illustrating their main geomorphological and mineralogical features, and the microbial signatures observed in the active underground environment. SAS caves are widely distributed in the northern and central Apennines, whereas they are less abundant in the southern Apennines, in the Apulian foreland, in Sicily and in Sardinia. Their location is significantly influenced by lithological and structural rock properties, as they occur in carbonate areas where acidic…

A review on hypogene caves in Italy

2014

Although hypogene cave systems have been described since the beginning of the 20th century, the importance in speleogenesis of ascending fluids that acquired their aggressiveness from in-depth sources has been fully realized only in the last decades. Aggressiveness of waters can be related to carbonic and sulfuric acids and the related corrosion-dissolution processes give rise to different types of caves and underground morphologies. The abundance of hydrothermal springs and associated travertine deposits, and the widespread interaction between volcanic or sub-volcanic phenomena and karst in many sectors of the Italian peninsula are a strong evidence of hypogene speleogenesis. Furthermore, …

Sulfuric acid water table caves (Grotte du Chat / Acqua Fitusa /Bad Deutsch Altenburg + Kraushöhle).

2014

Sulfuric acid caves can display a variety of forms, from 3D maze systems, to isolated chambers, and more or less maze-like water table caves. Most of the voids are normally generated at or immediately above the water table, where condensation-corrosion processes are dominant, creating a set of characteristic meso- and micromorphologies. This paper deals with the description of four very typical sulfuric acid water table caves: the Grotte du Chat in Provence (France), the Acqua Fitusa Cave in Sicily (Italy), and the Bad Deutsch Altenburg and Kraushöhle caves in Austria.

Morphology and evolution of sulphuric acid caves in South Italy

2016

Sulphuric acid speleogenesis (SAS) related to the upwelling of acid water enriched in H2S and CO2 represents an unusual way of cave development. Since meteoric infiltration waters are not necessarily involved in speleogenesis, caves can form without the typical associated karst expressions (i.e. dolines) at the surface. The main mechanism of sulphuric acid dissolution is the oxidation of H2S (Jones et al., 2015) which can be amplified by bacterial mediation (Engel et al., 2004). In these conditions, carbonate dissolution associated with gypsum replacement, is generally believed to be faster than the normal epigenic one (De Waele et al., 2016). In Italy several SAS caves have been identified…

PELIGROSIDAD A LOS MOVIMIENTOS DE LADERA EN LA VERTIENTE MERIDIONAL DE SIERRA NEVADA (GRANADA) A PARTIR DE LA ESTIMACIÓN MULTI-TÉCNICA DE LA ACTIVIDAD

2012

El presente trabajo aborda la cartografía de la susceptibilidad y la peligrosidad a los movimientos de ladera, en un ambiente montañoso, con información limitada sobre su actividad. El análisis y validación de la susceptibilidad se realizada mediante un modelo elaborado a partir del ModelBuilder™ de ArcGIS basado en el Método de la Matriz en un SIG. Dicho modelo necesita una cartografía previa de los movimientos, un MDE y un análisis discriminante de los factores determinantes de la estabilidad. Los datos del análisis reflejan que el 15% de la zona estudiada muestra una susceptibilidad a los movimientos de moderada a muy alta que, a su vez, coincide con lugares donde se encuentran la mayorí…