Speleothems in 6 sandstone caves in the Bohemian Paradise (Český ráj) were dated by means of 14C and U-series methods. Stable isotopes of C and O, FAAS, IR, XRD, XRF and SEM were used to characterize the carbonate material and its source. Stable isotopes (C and O) composition of speleothems in two caves corresponds to values characteristic for cave speleothems in Central Europe. In other caves they indicate evaporation and fast carbon dioxide escape during carbonate precipitation. The speleothems from the Krtola Cave were deposited between 8 and 13 kyr BP. Speleothems were deposited 5-8 kyr BP in the Sintrová, Mrtvé Údolí and U Studánky caves. Calcite coatings on smooth sandstone surfaces in studied caves demonstrate that cave walls did not retreat even a few mm in the last 5-8 kyr since speleothem deposition and are thus not evolving under recent climatic conditions. Most of the cave ceilings and walls are at present time indurated by hardened surfaces, which protect the sandstone from erosion. Sandstone caves probably intensively evolved either during or at the end of the Last Glacial period. There are two different erosion mechanisms which might have formed/reshaped the caves at that time: A) In the case of permafrost conditions: Repeated freeze/melt cycles affecting sandstone pore space followed by the transport of fallen sand grains by minor temporary trickles. We expect that heat was transmitted by air circulating between the cave and the surface; B) Seepage erosion of sandstone during the melting of permafrost, prior forming of case hardening., Jiří Bruthans, Jana Schweigstillová, Petr Jenč, Zdeňka Churáčková and Petr Bezdička., and Obsahuje bibliografii
This paper examines the results of fault microdisplacement analyses obtained from sites located both at the surface and underground in western Slovakia. The results of surface monitoring showed significant annual climatic effects on the various displacement components. In contrast, the results of underground monitoring in caves showed minimal climatic effects. It is seen that the influence of climate decreases markedly with depth. The yearly peak-to-peak amplitude of climatic variations may be as high as 1 mm at the surface but only 0.1 mm underground. The amount of tectonic displacement can be determined once such climatic considerations have been taken into account. Our fault displacement measurements show horizontal strike-slip rates of tenths of mm or hundredths of mm per year. In addition, vertical displacements have been recorded at Prekážka Quarry, Driny Cave, and Slopy Cave. The network is sufficiently dense to identify changes in displacement activity recorded during recent, significant, earthquake events. Furthermore, three gauges have also helped to determine the local stress orientation in Driny Cave., Miloš Briestenský, Blahoslav Košťák, Josef Stemberk, Ľubomír Petro, Jozef Vozár and Lucia Fojtíková., and Obsahuje bibliografii
The paper presents the results of monitoring study undertaken during the period 2008 - 2010. The study recorded the displacement of tectonic structures in the Strašín Cave (SW Bohemian Massif). The derived results were compared, among others, with data recorded over the same time period across the Bohemian Massif in the EUTecNet (tectonic displacement monitoring net - see www.tecnet.cz), which is managed by IRSM ASCR. The rate of recorded displacement is mostly in order of hundredths mm/year with maximal value recorded in vertical component at site Strašín 2, about 0,16 mm/2,5 years. Whilst recorded displacement can indicate blocks subsidence into the cave empty space, the periods when displacement occurred correspond to periods of increased movement activity recorded for example at the opposite side of the Bohemian Massif, along the Sudetic Marginal Fault. Moreover, both periods are simultaneous with extraordinary earthquakes that affected western and southern part of the Bohemian Massif in 2008 and 2009., Josef Stemberk and Filip Hartvich., and Obsahuje bibliografii
The medieval Jeroným Mine is a mine working in which places of various degrees of rock mass disintegration are there. Time-lapse recording, which has been performed in the Jeroným Mine since the year 2009, was induced by a necessity of documenting both areas of flaking-off and caved areas owing to an increased rate of occurrence of flaking-off phenomena in mine workings - rooms K3 and K4 of this mine. The methodology of recording, which uses as a basis repeated recording in time in the framework of geotechnical measurements carried out quarterly, is based on the principle of maintenance of not only parameters of images themselves, but also of location of a photo device used for documentation provision. This process is followed by the creation of information sheets of areas of flaking-off and caved areas and their classification. The method of recording was used owing to a high degree of disintegration of the rock mass in selected mine workings, a possibility of extension of caved areas and also the high rate of occurrence of subsidence phenomena occurring above those workings and even sporadically reaching the mine workings. Time-lapse recording is thus performed primarily in mine workings with reduced stability, situated very close to the surface. With regard to the principle of this method, results will be known only in further years., Radovan Kukutsch, Petr Žůrek and Martin Stolárik., and Obsahuje bibliografii
Studovali jsme výskyt pavouků v půdě, v puklinách v hornině, v kamenitých sutích a v jeskyních České republiky, to jest v podzemních biotopech na hloubkovém gradientu od 10 cm do 100 m. Třináct druhů vykazovalo nějaká morfologická přizpůsobení k životu v podzemí. Druhy s výrazně redukovanýma očima jsme našli jak v hlubokých jeskyních, tak i v povrchových biotopech daleko od krasu. Údaje o morfologii a rozšíření ukazují na to, že troglomorfní druhy musely v průběhu zalednění opakovaně migrovat z jeskyní do povrchových biotopů., Using data from the Czech Republic, we studied the distribution of spiders in soils, crevice systems, scree and caves, i.e. subterranean habitats at depths spanning from 10 cm to 100 m. Thirteen species exhibit morphological adaptations to life in subterranean habitats. Advanced troglomorphic characters occur in deep caves as well as in surface habitats far from karst regions. We hypothesize that troglomorphic populations of spiders in Central Europe repeatedly migrated from caves to subsurface and surface habitats during glaciations., and Vlastimil Růžička.
Výzkumem v jeskyni Pod hradem v Moravském krasu byla získána nevelká, leč zajímavá kolekce kamenných štípaných artefaktů (Valoch 1965). Předmětem příspěvku je revize určení a provenience suroviny části souboru kamenné štípané industrie, analýza plošně retušovaného bifaciálního artefaktu a zpřesnění chronostratigrafické pozice nálezových horizontů. Nová zjištění přinesla další podněty ve studiu chování člověka na počátku mladého paleolitu. and The research in the Pod hradem Cave in the Moravian Karst yielded a small but interesting assemblage of chipped stone artefacts (Valoch 1965). The article aims to revise the identification and provenance of the raw material of part of the chipped stone industry; to analyze a bifacial artefact, and to refine the chrono – stratigraphical position of the archaeological horizons. The new data brought further incentives for the study of human behavior at the beginning of the Early Upper Palaeolithic.
The results obtained by four years long TM 71 extensometer monitoring of 3D micro-tectonic displacements of Dinaric Fault Zone on two sites, being 260 m apart in Postojna Cave, were statistically evaluated with different methods (Kolmogorov- Smirnov test, comparison between relative displacement and earthquakes, linear regression, Kruskal-Wallis one-way analysis of variance, histograms and correlation coefficients). Responses to stress changes regarding x, y and z-axes are not the same on two monitoring sites even if we are monitoring the same fault zone. Kolmogorov-Smirnov test for comparing the two curves is applicable only for three axes combination (Postojna 1 z - Postojna 2 z, Postojna 2 y - Postojna 1 z, and Postojna 2 z - Postojna 2 y). Kruskal-Wallis analysis is most representative for z-axes. Some sharp peaks coincide with earthquake occurrences (Krn M=5.2, Cerkno M=4.0, Ilirska Bistrica M=3.9, Brežice M=2.9 and Krško M=3.1). Generally we detect very small tectonic deformations, dextral horizontal movement of 0.05 mm in 4 years for Postojna 1 and extension of 0.03 mm in 4 years for Postojna 2. Discrepancies between two sites can be attributed to complex geological structure and by the fact that studied fault zone is cut by cross-Dinaric fault zone., Stanka Šebela, Janez Turk, Janez Mulec, Blahoslav Košťák and Josef Stemberk., and Obsahuje bibliografii
This paper combines morphostructural analysis and geophysical methods in order to link the faults monitored inside Strašín Cave with faults and lineaments in the vicinity of the cave. The studied site is situated in SW Bohemia, at the foothills of the Bohemian Forest Mts. Main goal is to combine the morphostructural, morphometrical and geophysical methods in order to identify the fault system, monitored inside the cave. This will allow relevant interpretation of the observed movements in the frame of the local tectonic environment. The results show that the monitored faults are observable in the geophysical profiles and, using our knowledge of the structural setting, we have been able to link them with mapped tectonic structures in the vicinity of the cave. Thus, it has been demonstrated that even where outcrops are absent, the faults can be traced and that the monitored faults are significant enough to yield relevant data on tectonic movements. In addition, the combined resistivity and gravimetry profiles reveal a possible new, presently unknown, cave located 20 m below the surface about 200 m northnortheast of Strašín Cave., Filip Hartvich and Jan Valenta., and Obsahuje bibliografii