New insights on secondary minerals from Italian sulfuric acid caves

Sulfuric acid minerals are important clues to identify the speleogenetic phases of hypogene caves. Italy hosts ~25% of the known worldwide sulfuric acid speleogenetic (SAS) systems, including the famous well-studied Frasassi, Monte Cucco, and Acquasanta Terme caves. Nevertheless, other underground environments have been analyzed, and interesting mineralogical assemblages were found associated with peculiar geomorphological features such as cupolas, replacement pockets, feeders, sulfuric notches, and sub-horizontal levels. In this paper, we focused on 15 cave systems located along the Apennine Chain, in Apulia, in Sicily, and in Sardinia, where copious SAS minerals were observed. Some of the…

Examples of anthropogenic sinkholes in Sicily and comparison with similar phenomena in southern Italy

A sinkhole, occurred in June 2011 and related to an underground quarry in the eastern sector of Marsala, is described in this paper as a case study (Figure 2). The site was selected for the availability of topographic data of the underground quarry, prior to the formation of the Abstract Anthropogenic sinkholes affect several built-up areas of Sicily (southern Italy) representing a great risk to people, buildings, and infrastructures. These phenomena are generally associated with the presence of ancient underground quarries for the extraction of calcarenite rock, used for building or ornamental materials. These quarries were poorly constructed and abandoned throughout history.

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

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…

KARST OF SICILY AND ITS CONSERVATION

Evaporite karst in Italy: A review

none 16 si Although outcropping rarely in Italy, evaporite (gypsum and anhydrite) karst has been described in detail since the early 20th century. Gypsum caves are now known from almost all Italian regions, but are mainly localised along the northern border of the Apennine chain (Emilia Romagna and Marche), Calabria, and Sicily, where the major outcrops occur. Recently, important caves have also been discovered in the underground gypsum mines in Piedmont. During the late 80s and 90s several multidisciplinary studies were carried out in many gypsum areas, resulting in a comprehensive overview, promoting further research in these special karst regions. More recent and detailed studies focused…

The Coastal Sulfuric Acid Cave System of Santa Cesarea Terme (Southern Italy)

Santa Cesarea Terme in Salento is the only area in which hypogenic caves have been recognized in the Apulia region. In this spa area, the rising of sulfidic thermal waters that mix with both recent fresh infiltration waters and coastal salt water has formed four active sulfuric acid speleogenesis (SAS) caves. These caves are characterized by the typical set of sulfuric acid meso- and micromorphologies, and also by the presence of both gypsum and native sulfur. In all caves, biofilms are visible in the sulfidic thermal waters and on the cave walls.

A review on hypogene caves in Italy

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 caves of Italy: A review

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…