Search results for "Karst"
showing 10 items of 150 documents
Two new species of the genus emNemaspela/em Šilhavý from caves in Georgia (Opiliones: Nemastomatidae).
2021
Two highly specialized endemic troglobiotic harvestman species of the genus Nemaspela Šilhavý, 1966 are described. N. melouri sp. nov. from Melouri Cave and N. prometheus sp. nov. from Prometheus Cave (Sataplia-Tskaltubo karst massif, Imereti region, western Georgia), respectively. Despite the fact that the entrances of the caves are positioned only 2.5 km apart, the new taxa differ from each other distinctly by presence vs. absence of male cheliceral apophysis, which is lacking in the second species. A key to the Caucasian species of the genus is provided. Relationships of Nemaspela species within the genus and with hypothetical epigean ancestors are discussed.
Dissolution Process: When Does the Process Start
2019
Dissolution process is a complex phenomenon controlled by several factors as like lithology, porosity, stress orientation, environmental conditions and networks of fractures. Then, fault zone and fractures play an important role in fluid circulation and in dissolution, acting as barriers or conduits. In fact, the fault zone has a high permeability only in the early stages of the movement, but shortly the process of recrystallization and reprecipitation reduces the permeability greatly within them. Despite this, traditionally (Cucchi and Forti in In Att. e Mem. Comm. Grotte “E: Boegan” 87–93, 1988; Bini et al. in Varese Lake and the Quaternary 6:3–14, 1993; Ferrarese and Meneghel in Aspetti …
Problems of soil and groundwater pollution in the disposal of “marble” slurries in NW Sicily
2007
This work deals with disposal of slurries generated during the cutting and polishing processes of slabs of decorative sedimentary carbonate rocks in the north western Sicily. At present, they are used as fillers of dismantled quarries near the sawmills and, as a final step of reclamation, are covered with earth layers. In spite of such inexpensive solution, there is lack of knowledge about the composition of the waste. In order to assess if there is any threat for the environment and to suggest indications for alternative solutions, such as recycling or inactivation processes, the slurries were analysed by XR diffraction, simultaneous thermal analysis, ICP/MS, ionic chromatography, FTIR, UV…
Une spéléogenèse à acide sulfurique dans le piémont nord-pyrénéen ?
2018
Tout au long de l’histoire de structuration des Pyrénées, le jeu des grands accidents tectoniquesfont de la zone de piémont nord-pyrénéen une aire privilégiée de circulation de fluides. Parmiceux-ci, la présence de saumures profondes riches en CO2 et H2S a été attestée dans les réservoirspétroliers sud-aquitains d’âge Crétacé. Impliqués dans des processus de migration vers les margesde bassin, ces fluides sont susceptibles de former des cavités dans l’encaissant calcaire là où lesremontées d’H2S entrent en contact avec du dioxygène, produisant ainsi du H2SO4. C’est cettehypothèse de spéléogenèse à acide sulfurique (SAS) que la présente étude cherche à explorer dansles Pyrénées.Les premières…
REPRISES PLIO-PLEISTOCENES DU PALEOKARST QUERCINOIS
2005
11 pages; National audience; L'investigation du paléokarst du Sud-Quercy (France) a révélé en de nombreux points une reprise d'érosion et remblaiement superficiels de la plateforme karstique jurassique, succédant à celle plus généralisée du Paléogène. Cette reprise est marquée par la présence de fossiles, notamment de grands et petits mammifères. La note dresse un inventaire de ces localités dans leur contexte géologique et de leurs restes fossiles. Leurs âges sont distribués depuis le Pliocène supérieur jusqu'à l'Holocène et principalement dans la période du Pléistocène moyen et supérieur (de 0,5 à 0,1 Ma).
New, Rare and Constant Habitats for Endangered Aquatic Plant Communities: The Importance of Microhabitats for Global biodiversity
2019
Natural water reservoirs are very valuable floristic sites, with springs particularly important for the preservation of floral biodiversity. This paper presents, as a case study, a community of water plants that is new to limnocrene karst springs in Europe: Potametum alpini (Potametea), found in Poland. The paper provides the floristic composition and ecological requirements of this plant association, which is rare and endangered in Europe. According to our knowledge, the habitat data presented here are unique as they are published for the first time for this plant community, and thus it is currently not possible to compare them with data from other authors. Our study confirms the importanc…
Karstologie et remplissage sédimentaire du gisement pléistocène de Romain-la-Roche (Doubs, France).
2010
19 pages; International audience; Le gisement pléistocène du site de Romain-la-Roche (commune de Romain dans le Doubs) correspond au remplissage épikarstique d'un aven affectant les calcaires du Jurassique moyen d'un plateau situé au nord du massif jurassien. Cette cavité, située en dehors de l'extension de la calotte du dernier maximum glaciaire, a été façonnée par un flux hydrologique en liaison avec un drainage de surface qui a vraisemblablement disparu au cours du Pliocène lors d'une phase d'inversion du relief de part et d'autre de la faille normale qui délimite la partie ouest du plateau. Avant son colmatage au cours du Pléistocène la cavité était reliée à un réseau dense de conduits …
Obiektywny, ale nie neutralny. Robert Fisk o misji dziennikarstwa
2014
The aim of this paper is to analyze Robert Fisk’s point of view on the mission of journalism. Robert Fisk is a based in Beirut foreign correspondent of London's newspaper “The Independent”. The text starts with Douglas Dowd’s differentiation between objectivity and neutrality and describes the issue of objectivity in social science. Then the author describes Fisk's statement on duties of a decent journalist, not only foreign correspondent in the Middle East: What journalism is really about is to monitor power and the centres of power. He criticizes cosy relations between media people and so-called reliable sources of information, i.e. government officials. In the summary the author hopes th…
Fossil micromammals of the early Pliocene locality of Almenara MB: biostratigraphical and palaeoecological implications
2020
In this work, we have studied the fossil rodent, insectivore and chiropteran faunas, of a new locality from the AlmenaraCasablanca karstic complex, named ACB MB (Castellón, east Spain). We consider an early Ruscinian age for this site, close to the Miocene/Pliocene boundary, and infer warm and relatively humid conditions from the analysis of the micromammal assemblage. We remark the presence of two species of Eliomys in ACB MB, rare in localities of this age, and the lack of any gerbil remains, fossil markers of faunal interchanges between Africa and Europe in the context of the Messinian Salinity Crisis, recorded in the nearby late Miocene site of ACB M
Génesis y evolución de las forma parakársticas de vallada a partir del estudio sedimentológico de sus rellenos
1984
Se estudia la génesis y episodios evolutivos de un aparato kárstico desarrollado sobre materiales yesíferos en Vallada (Valencia), a partir de su estudio geomorfológico y análisis sedimentológicos. Esto permite diferenciar tres terrazas subterráneas y correlacionarlas con otros depósitos fluviales epigeos (río Cànyoles). Finalmente se establece una interpretación paleoclimática considerando datos polínicos y dos fechaciones radiocarbónicas.