The paper presents the results of experimental examination of the weathering grade of granite rock mass in the medieval Jeroným Mine (Czech Republic). This mine is declared as a cultural heritage site of the Czech Republic therefore, non-destructive methods for determination of the Schmidt hammer rebound value and the ultrasonic pulse velocity were used to minimize negative impact on the historical workings during in situ exploration. Weathering grade of selected parts of the rockmass in underground spaces was classified visually according to the assumed classification (Hencher and Martin, 1982 in Vahed et al., 2009) and the above mentioned measurements were performed in these parts. Results show that the rebound value and the ultrasonic pulse velocity are decreasing with increasing weathering grade for all investigated parts. Therefore this result is possible to use as a supplementary method for evaluation of weathering grade of rock massif in this mine., Markéta Lednická and Zdeněk Kaláb., and Obsahuje bibliografické odkazy
This paper is dealing with a detection of ground water flow in a granite massif. The flow was studied between boreholes of a testing polygon situated in a granite quarry. So called cross-hole (C-H) tests were used to detect fracture based connection between the boreholes. The tests were proceeded in steady-state ground water flow conditions. There were TV cameras used to detect a uranine tracer. The cameras were equipped by an orange filter and well defined blue light. A geometrical model of the fracture system in the area of interest was proposed according to C-H tests data. A hydrogeological model was calibrated using the very same data. Results pointed out subhorizontal fracture connection between the boreholes. Main advantages of the TV camera usage are possibil ities of accurate localization onto a structure, an immediate detection of tracer onset time and a continual data record., Karel Sosna, Milan Brož, Michal Vaněček and Michal Polák., and Obsahuje bibliografické odkazy
We studied the geophysical, physical, and geomechanical parameters of the Podlesí granites in the western part of the Krušné hory Mts., near the village of Potůčky. The granites represent a fractionated intrusion within the Nejdecký Massif. In total, the studied borehole is about 300 m deep. The samples were collected at depths of between 35 and 105 metres. Seismic P-wave and S-wave velocities were measured using ultrasonic scanning. The samples were water-saturated, unsaturated, and dried. The ultrasonic scanning system consisted of four piezoelectric sensors and a digital oscilloscope recorder. The wave frequency was 1 MHz. P-wave velocities range from 4400 m.s-1 to 6500 m.s-1 while S-wave velocities range from 2800 m.s-1 to 3800 m.s-1. These data were used to calculate dynamic Young’s modulus, dynamic shear modulus, and Poisson’s ratio. The deformational characteristics of the rock were specified from experimental loading of the sample with uniaxial strain. The shear and longitudinal deformation of each sample was measured using a resistive strain gauge fixed directly on the sample. Intermittent loading of the samples proceeded using a uniform gradient of axial stress of 1 MPa.s-1. The samples were subjected to five separate loads. During the tests, following parameters were recorded: stress, longitudinal deformation, and shear deformation. These data were used to calculate static Young’s and shear modulus, and Poisson’s ratio., Lucie Nováková, Karel Sosna, Milan Brož, Jan Najser and Petr Novák., and Obsahuje bibliografii
A brittle tectonic study has been carried out in the crystalline limestone and granite quarries near Vápenná village in the Rychlebské hory Mts. in the NE part of the Bohemian Massif. The quarries are situated along the Sudetic Marginal fault zone - the most important tectonic structure of the area. At the lo cality, the Sudetic Marginal fault separates Devonian crystalline limestones of the Branná group and Paleozoic granites of the Žulová pluton. Hundreds of measurements of joints and small-scale faults were taken in three limestone quarries on the west side of the fault. Kinematic indicators were observed as well. Equivalent measurements and observations have been performed on the fault east side in several small granite quarries. In the limestones three sets of fault have been identified (the W-E subvertical, the Sudetic NW-SE falling 45° to NE and the N-S falling 75° to W). The W-E direction of faults is the most importa nt direction there. There are two sets of faults in the granites (the subvertical Moravo-Silesian NE-SW and the Sudetic NW-SE). The NE-SW direc tion is dominant. There are almost none subhorizontal faults in the studied area., Lucie Nováková., and Obsahuje bibliografické odkazy
The aim of the paper is to present the results of measurements of 40K, 208Tl, 212Pb, 214Pb, 214Bi and 228Ac activity concentrations of selected rocks co llected from the contact zone of the Karkonosze massif with the Szklarska Poręba schist-belt. Activity concentrations were obtained using a gamma-ray spectrometry system. Determined activity concentrations of 40K and nuclides from 238U and 232Th series in measured samples were compared with average activity concentrations of these radionuclides in the continental crust and in the soil and with data concerning investigated area available in the selected literature. In all rock samples very high activity concentrations associated with decay of 232Th and 238U series were observed. These values twice exceed the average activity concentrations refer to continental crust and are distinctly higher than activity concentrations measured in typical rocks of the Izera block., Aleksandra Bieda and Grzegorz Lizurek., and Obsahuje bibliografické odkazy
The character of modern pedogenesis in the territory of the Brdská and Křivoklátská vrchovina Highlands was studied on silicate rocks such as Paleozoic granite and Proterozoic mudstone and greywacke. The parent materials were evaluated on the basis of petrography, X-ray diffractometry of powder samples of rock forming and heavy minerals. The soils were described as for their macromorphological characterics and the results of a variety of analyses of organic and anorganic components. Pedogenesis proceeded in acid conditions. The values of base saturation are mostly below 50 % for the Ah horizons. The intensity of soil development on individual parent material decreases in the order: mudstone (Ah-AhBw-Bw-C)granite (Oi-Oe-Oa-Ah-Bw-C)greywacke 1 (Oi-Oe-Oa-Ah-AhC-C)greywacke 2 (Oi-Oe-Oa-Ah-C). The process of humification was documented at all study sites. Evidence of pedogenetic alteration is present in soils developed on granite and mudstone. High amounts of chlorite and elevated contents of illite are characteristic for Cambic Leptosols (Dystric, Skeletic) on mudstone. Weddellite and whewellite were found in relatively large amounts in O horizons of soils except for the Červený kríž site. The predominant from of calcium oxalate minerals at these sites is whewellite. Weddellite occurs in small amount, which is probably due to its lower stability., Anna Žigová, Martin Šťastný, Petr Mikysek., and Obsahuje bibliografické odkazy
To verify possibilities of the thermic sinking technology the experiments with magmatic rocks (muscovite-biotite granite, amphibole-pyroxene andesite, pyroxene basalt) were made in the preliminary research phase. The contribution presents the microscopic study results of petrographic and structural observations of the rocks after their thermic reworking. Mainly distribution of melted rocks in the form of glass, forming of brittle deformations (fractures) on the level of mineral and rock, and penetration of melt into fissures were observed., Roman Farkašovský and Michal Zacharov., and Obsahuje bibliografii