Search results for "Caves"

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.

The Complex of tectonic caves of the Vallone di Margi Paolino (Valle Grovello) area - Sant'Angelo Muxaro (AG).

2010

Chronology for the Cueva Victoria fossil site (SE Spain): Evidence for Early Pleistocene Afro-Iberian dispersals

2014

Cueva Victoria has provided remains of more than 90 species of fossil vertebrates, including a hominin phalanx, and the only specimens of the African cercopithecid Theropithecus oswaldi in Europe. To constrain the age of the vertebrate remains we used paleomagnetism, vertebrate biostratigraphy and (230)Th/U dating. Normal polarity was identified in the non-fossiliferous lowest and highest stratigraphic units (red clay and capping flowstones) while reverse polarity was found in the intermediate stratigraphic unit (fossiliferous breccia). A lower polarity change occurred during the deposition of the decalcification clay, when the cave was closed and karstification was active. A second polarit…

Two new species of the genus Ochroconis, O. lascauxensis and O. anomala isolated from black stains in Lascaux Cave, France

2012

In the year 2001, some conspicuous black stains appeared on the walls of Lascaux Cave in France, which progressively disseminated throughout the cave. These black stains were so evident by 2007 that they have become one of the cave's major problems. In a mycological study of the black stains, Ochroconis strains were abundant among the isolates and constituted the major group of melanised fungi. Two new species of the genus Ochroconis, O. lascauxensis and O. anomala, were isolated and described. The description is based on the morphology of the fungi and the phylogenetic relationships of two of its gene regions internal transcribed spacer (ITS) and RNA polymerase II subunit B (RPB2). In addi…

Zinc isotopes in Late Pleistocene fossil teeth from a Southeast Asian cave setting preserve paleodietary information

2020

Significance Dietary habits, especially meat consumption, represent a key aspect in the behavior and evolution of fossil hominin species. Here, we explore zinc (Zn) isotope ratios in tooth enamel of fossil mammals. We show discrimination between different trophic levels and demonstrate that Zn isotopes could prove useful in paleodietary studies of fossil hominin, or other mammalian species, to assess their consumption of animal versus plant resources. We also demonstrate the high preservation potential of pristine diet-related Zn isotope ratios, even under tropical conditions with poor collagen preservation, such as the studied depositional context in Southeast Asia. However, assessing the …

No room for males in caves : Female‐biased sex ratio in subterranean amphipods of the genus Niphargus

2021

Sex allocation theory predicts that the proportion of daughters to sons will evolve in response to ecological conditions that determine the costs and benefits of producing each sex. All else being equal, the adult sex ratio (ASR) should also vary with ecological conditions. Many studies of subterranean species reported female-biased ASR, but no systematic study has yet been conducted. We test the hypothesis that the ASR becomes more female-biased with increased isolation from the surface. We compiled a dataset of ASRs of 35 species in the subterranean amphipod Niphargus, each living in one of three distinct habitats (surface-subterranean boundary, cave streams, phreatic lakes) representing …

Some Considerations on 3-D and 2-D Numerical Models for the Assessment of the Stability of Underground Caves

2014

The application of numerical modeling to the analysis of the stability of both natural and man-made underground caves is rapidly increasing due to the availability of powerful numerical codes, that can account for either continuum or discontinuum behavior of the rock masses. Numerical methods allow to overcome traditional methods for cave stability analysis that assume too simplified geometrical, geological and geomechanical conditions. Further, they are also able to assess the potential failure mechanisms of underground systems. On the other hand, the application of numerical methods requires availability of a detailed geo-structural survey of the cave, as well as a proper geomechanical ch…

Energy and speleogenesis: Key determinants of terrestrial species richness in caves

2017

Abstract The aim of this study was to unravel the relative role played by speleogenesis (i.e., the process in which a cave is formed), landscape‐scale variables, and geophysical factors in the determination of species richness in caves. Biological inventories from 21 caves located in the southeastern Iberian Peninsula along with partial least square (PLS) regression analysis were used to assess the relative importance of the different explanatory variables. The caves were grouped according to the similarity in their species composition; the effect that spatial distance could have on similarity was also studied using correlation between matrices. The energy and speleogenesis of caves account…

Aerobiology: an ecological indicator for early detection and control of fungal outbreaks in caves

2011

5 pages, 1 table, 13 references.