Národní úložiště šedé literatury Nalezeno 11 záznamů.  1 - 10další  přejít na záznam: Hledání trvalo 0.00 vteřin. 
Origin of “rock cities”, pillars and cleft-conduits in kaolinite-bonded sandstone: New insight from study in sandstone quarry where landforms recently evolve
Bruthans, J. ; Soukup, J. ; Schweigstillová, Jana ; Vaculíková, J. ; Smutek, D. ; Mayo, A. L. ; Falteisek, L.
Based on measurements of relative erodibility, ambient and water-saturated tensile strength at natural and quarry exposures three distinct kinds of surfaces were distinguished (erodible sandstone, sub-vertical fracture surfaces and case hardened surfaces). Erosion proceeded along highly fractured zones.
16th International Congress of Speleology : Czech Republic, Brno July 21–28,2013 : proceedings
Filippi, Michal ; Bosák, Pavel
Proceedings of the 16th International Congress of Speleology consist of 3 separate Volumes. The Congress was visited by 1007 participants from 53 countries across the world. Volume III also starts with traditional, heavily attended topics organized in two sessions: “Karst and Caves in Carbonate Rocks, Salt and Gypsum” and “Karst and Caves in Other Rocks, Pseudokarst”. These topics are supplemented by the related session “Speleogenesis”. This last volume of the Proceedings is ended by the study of cave minerals, included in a specific session “Cave Minerals”.
16th International Congress of Speleology : Czech Republic, Brno July 21–28,2013 : proceedings
Filippi, Michal ; Bosák, Pavel
Proceedings of the 16th International Congress of Speleology consist of 3 separate Volumes. The Congress was visited by 1007 participants from 53 countries across the world. Volume II contains the traditionally heavily attended session “Exploration and Cave Techniques” and by the related session “Speleological Research and Activities in Artificial Underground”. These topics are supplemented with contributions from the field of “Karst and Cave Survey, Mapping and Data Processing”. The content of the second Volume is completed with sessions “Modelling in Karst and Cave Environments” and “Cave Climate and Paleoclimate Record”.
16th International Congress of Speleology : Czech Republic, Brno July 21–28,2013 : proceedings
Filippi, Michal ; Bosák, Pavel
Proceedings of the 16th International Congress of Speleology consist of 3 separate Volumes. The Congress was visited by 1007 participants from 53 countries across the world. Volume I starts with three plenary lectures representing three global cave and karst topics. Further it contains papers concerned with history of research, archeology, paleontology, topics focused on management and preservation of caves and karst areas and other social-related aspects and also it contains a small part devoted to extraterrestrial karst. Volume I is ended by a large portion of biology-oriented papers.
New localities of coarsely crystalline cryogenic cave carbonates in Slovakia
Orvošová, M. ; Vlček, L. ; Žák, Karel
Three new localities of coarsely crystalline cryogenic cave carbonates (CCCcoarse) have been recently discovered in the Western Carpathians, Slovakia. CCCcoarse are secondary mineral formations in the cave and belong to speleothems. They occur in the form of loose accumulations of calcite crystals and crystal aggregates freely deposited on the bottom of the cavities. Their genesis is interpreted as related to slow karst-water freezing in pools inside the caves, in relation to the existence of a permafrost zone during Quaternary glacials. The newly discovered CCCcoarse localities in Četníkova svadba Cave, Demänovská j. mieru Cave and Zlomísk Cave are characterized by description and photodocumentation of the present crystal forms, by preliminary C and O isotope data, and by their U-series ages. The ages of the cryogenic crystals are in the range between 47 and 12 ka BP, corresponding to the latter half of the Last Glacial. Any new locality of CCCcoarse formed during the Last Glacial represents an important source of information about paleoclimatic conditions of adjacent areas. The U-series ages of the new localities support the earlier conclusion that the formation of CCCcoarse is related to transitions from cold to warm climate periods within the Last Glacial.
Magnetic fabric and mineralogy of cave deposits in Botovskaya Cave (Eastern Siberia, Russian Federation)
Kadlec, Jaroslav ; Hercman, H. ; Chadima, Martin ; Lisá, Lenka ; Oberhänsli, H. ; Osintsev, A.
The Botovskaya Cave is a typical example of a two-dimensional maze with a total length of explored passages exceeding 60 km, which represents the longest limestone cave system in the Russian Federation. The clastic cave sediments filling the cave passages differ in both mineral and mineral magnetic properties and were deposited under different hydrological conditions. The older portion of the clastic cave fills was derived from overlying sandstones, whereas the properties of younger cave sediments show closer affinity to the soils and weathering products originating on the sandstone plateau above the cave. The cave sediments underwent repeated periods of deposition and erosion during the Tertiary and Pleistocene.
Valley incision in the Nízké Tatry Mts. (Slovakia) estimated based on paleomagnetic and radiometric cave sediment datings
Kadlec, Jaroslav ; Bella, P. ; Čížková, Kristýna ; Granger, D. E. ; Hercman, H. ; Holúbek, P. ; Chadima, Martin ; Orvošová, M. ; Pruner, Petr ; Schnabl, Petr ; Šlechta, Stanislav
Up to eleven horizontal cave levels occur at different altitudes in Jánska, Demänovská and Mošnická karst valleys in the Nízke Tatry Mts. Most of the caves are filled with allochthonous sediments transported from the area formed mostly by granite. The cave levels were filled with fluvial sediments in dependence on the valleys incision caused by Neogene and Pleistocene uplift of the mountain range. The fluvial sediments are intercalated with, or capped, by flowstone layers in the caves. The paleomagnetic polarities measured both in clastic and chemogenic sediments indicate the age of deposition. Based on obtained polarity data we are able to distinguish cave sediments deposited during the Brunhes, Matuyama and Gauss chrons. The paleomagnetic interpretation was partly verified by U-series datings of flowstones preserved in the sedimentary sections. Except for the horizontal cave levels located in the karst valleys, additional large cave systems were found at extremely high altitudes in the Nízke Tatry Mts. 600–700 m above the lowest horizontal cave level.
Miocene-Pliocene age of cave Snežna Jama na Raduhi, Southern Alps, Slovenia
Mihevc, A. ; Horáček, I. ; Pruner, Petr ; Zupan Hajna, N. ; Čermák, Stanislav ; Wagner, Jan ; Bosák, Pavel
Snežna jama cave is 1,600 m long horizontal cave at about 1,500 m a.s.l. in Raduha Massif (Kamnik-Savinja Alps) rich in cave deposits (both allogenic sediments and massive flowstones). The cave size, shape and deposits show (1) formation of the cave in different conditions, and (2) its substantial age. A 4.8 m deep pit was excavated in allogenic sediments. Samples were taken both for palaeomagnetic analysis and palaeontological screening. Sediments consist of rhythmically arranged layers deposited in phreatic conditions. Fragments of rodent teeth and a well-preserved molar of genus Baranomys were identified. Fossil remains indicate mammalian zone MN 16 and MN 14. A high-resolution palaeomagnetic analysis revealed total of 3 principal normal polarized and 2 principal reverse polarized magnetozones. If we accept the palaeontologic calibration, the deposition took place within Gauss and Gilbert chrons, from about 2.6 to more than 5 Ma. Long sedimentation period is in concordance with the cave rocky relief that shows phreatic and epiphreatic morphology and predates the main uplift of the area for about 900 m.
Na Javorce Cave - a new discovery in the Bohemian Karst (Czech Republic): unique example of relationships between hydrothermal and common karstification.
Dragoun, J. ; Žák, Karel ; Vejlupek, J. ; Filippi, Michal ; Novotný, J. ; Dobeš, J.
The Na Javorce Cave is located in the Bohemian Karst, Czech Republic, about 25 km SW of Prague. The cave was formed in vertically dipping layers of Lower Devonian limestone; it is 1,723 m long and 129 m deep, of which 9 m is permanently flooded. The cave is polygenetic, with several clearly separable evolutionary stages. Cavities discovered to date were mostly formed along the tectonic structures of two main systems. One of these systems is represented by vertical faults of generally N-S strike, which are frequently accompanied by vein hydrothermal calcite with crystal cavities. The second fault system is represented by moderately inclined west-dipping faults. Smaller tube-like passages of phreatic morphology connect the larger cavities. The fluid inclusion data obtained for calcite developed along both fault systems in combination with C and O stable isotope studies indicate that the hydrothermal calcite was deposited from moderately NaCl-type basinal fluids (0.5 to 8.7 wt. % NaCl equ
Project Namak: some of the most spectacular findings in the Iranian salt karst
Filippi, Michal ; Bruthans, J. ; Jager, O. ; Zare, M. ; Asadi, N.
Project (“namak” means salt in Persian language) is an informal association of geologists and speleologists who cooperate on exploration and scientific research of the salt karst in southern and southwestern Iran. During the Project(from 1998 until 2013) about 16 salt diapirs were visited and more than 60 caves were discovered, 30 of which were mapped. The most exciting scientific and speleological discoveries were made in the Namakdan, Hormoz and Jahani salt diapirs; however, many other remarkable discoveries have been made on other several Iranian salt diapirs. This contribution summarizes the most interesting findings achieved during the ten expeditions carried out by the NAMAK team.

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