Search results for "PELE"
showing 10 items of 139 documents
Hypogenic caves of Sicily (Southern Italy)
2013
First results of a study on hypogenic caves in Sicily are presented. Inactive water-table sulphuric acid caves and 3D maze caves linked to rising of thermal waters rich in H2S were recognized. Cave patterns are guided by structural planes, medium and small scale morphological features are due mainly to condensation-corrosion processes. Calcite and gypsum represent the most common cave minerals. Different types of phosphates linked to the presence of large bat guano deposits were analyzed.
Secondary Minerals From Italian Sulfuric Acid Caves
2017
Italy is a country hosting a large number of hypogenic sulfuric acid (SAS) speleogenesis caves, mostly located along the Apennine chain, but also in Campania (along the coastline of Capo Palinuro), Apulia (along the coastline of Santa Cesarea Terme) and Sicily. Besides the typical morphologies related to their special geochemical origin (cupolas, replacement pockets, bubble trails, etc), these caves often host abundant secondary mineral deposits, mainly gypsum, being the result of the interaction between the sulfuric acid and the carbonate host rock. Native sulfur deposits are also well visible on the ceiling and roof, and peculiar sulfuric acid minerals such as jarosite, alunite, and other…
Religious Self-definition, Mass Attendance, Importance of God, and Hopelessness among Spanish Undergraduates
2011
The aim of this work was to examine the relationship between religious self-definition, attending Mass, the importance of God, and hopelessness under the hy-pothesis that these religious variables and hopelessness are negatively related. The par-ticipants were 273 Spanish undergraduates who were incidentally recruited. and who completed three religious items and the Spanish version of a Hopelessness Scale. The Chi-squared test and Bonferroni test were used in the statistical analysis. The results indicate that there were no statistically significant differences between the religious self-definition and attending Mass groups in relation to hopelessness, whereas there were differences between…
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…
Influence of the Plio-Pleistocene tectonics on the evolution of the Purgatorio polje (north-western Sicily)
2013
The evolution of large landforms such as polje are related in most cases to geological events affecting a specific areal context and/or to climatic events which, in combination with the tectonics, affect the karst base level, in a more or less pronounced manner depending on the proximity of limestone karst mountains to the coastline. The genesis of these aforementioned forms depends primarily on structural and lithological factors, their evolution is instead controlled by tectonic and climaticeustatic factors in the reliefs close to the coast. In the inland, due to the distance from the coast, the effects of the latter factors on the karstification process could be less, or very bland, in r…
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, …
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…
A reappraisal of the Early to Middle Pleistocene Italian Bovidae
2013
Abstract During the Quaternary, bovids are common elements in the Italian local faunal assemblages (LFAs). Representatives of Bovini tribe are continuously present, albeit with different lineages. Caprini are sporadically recorded by several genera, and Antilopini are less represented, only during the Early Pleistocene in the middle and early late Villafranchian local faunal assemblages (LFAs). Diversity and ecological role of continental representatives of Italian Bovidae varied with LFAs as well as in faunal units (FUs) throughout the Early and Middle Pleistocene. Species richness and diversity peaked during the early late Villafranchian land mammal age (LMA) and then decreased in the pos…
(Supplementary Table 1) 230Th/U results for stalagmite Cuba Grande (CG) from Pinar del Rio
2010
We present 22 U-series ages for a stalagmite from north-western Cuba based on multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS) and thermal ionisation mass spectrometry (TIMS). Our results reveal that the stalagmite continuously grew within the last ~1400a. Low uranium content of the sample and thus, extremely low 230Th concentrations limit the precision and accuracy of 230Th/U-dating by TIMS. Samples measured by MC-ICPMS show a high variability of 232Th content along the growth axis with some sections significantly affected by initial 230Th from a detrital phase. An a-priori bulk earth ratio for (238U/232Th) cannot be used to accurately account for this initial 230Th.…