National Repository of Grey Literature 28 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
New data on the origin of the Fe-Cu-As skarn deposit at Obří důl, West Sudetes, Bohemian Massif
Pašava, J. ; Veselovský, F. ; Dobeš, P. ; Erban, V. ; Pour, O. ; Žák, Karel ; Ackerman, Lukáš ; Haluzová, Eva ; Creaser, R. ; Tásler, R.
The Obří důl Fe-Cu-As sulfide deposit is hosted in metamorphosed lenses of marble, calc-silicate rocks and skarns. The deposit is located up to a few hundred meters away from the contact of the large, late-orogenic Variscan Krkonoše-Jizera Plutonic Complex (KJPC). Mineralogical and fluid inclusion studies of the Gustavská ore lens show that the main sulfide stage, dominated by pyrrhotite, chalcopyrite and arsenopyrite, originated from water-rich hydrothermal fluids with salinities up to 8 wt.% NaCl eq. at temperatures ranging from 324 to 358°C.These fluids replaced mainly the carbonate-rich lithologies. The 34S values indicate a magmatic source of sulfur and Re/Os dating of molybdenite are consistent with simultaneous formation of the main sulfide stage ore and the KJPC.
Provenance Determination of Marbles: A Methodology Based on a Complex Analytical Approach
Šťastná, Aneta ; Přikryl, Richard (advisor) ; Žák, Karel (referee) ; Török, Ákos (referee)
This PhD thesis is focused on methodology for the provenance determination of marbles from historic quarries and marble artefacts, respectively. Various petrographic, geochemical, and physical data were compiled to distinguish among different marble types, as well as to explore the suitability and limits of experimental techniques for such provenance studies. Moreover, by comparing the data obtained with the results from the artefacts the importance of the selected methodology was tested in detail. The correct determination of the source locality for marbles represents a difficult task, due mainly to both the variable characteristics of marbles coming from any one locality; and the converse, the similarity in properties between samples from different areas. Facing this complex situation, a multivariate approach proved to be necessary. Most of the previous analytical studies on marble provenance have been conducted on pure white marbles from the Mediterranean area where the methodology, based upon a combination of various mineralogical-petrographic and chemical criteria, was originally established. However, the Czech Republic is also rich in 'impure' crystalline limestones containing common noncarbonate admixtures (e.g. silicates, magnetic minerals, and carbonaceous matter) which led to the...
Isotope composition of fluids extracted from fluid inclusions
Drahota, Jakub ; Žák, Karel (referee) ; Zachariáš, Jiří (advisor)
Gold-bearing mineralizations and gold deposits in the Bohemian Massif are restricted mainly to Central Bohemian metallogenic zone. In this thesis, the quartz gangue from Mokrsko, Kašperské hory, Jílové u Prahy and Kasejovice deposits was studied, which originated from H2O-CO2±CH4±N2 fluids at temperatures from about 500 to about 300 řC. Quartz was mechanically and chemically purified and CO2 for subsequent isotopic analysis of carbon, was cryogenic separated in a vacuum line for thermal decrepitation of fluid inclusions. Measured value of δ13 C-CO2 varies from -15,7 to -6,5 ‰ PDB. The spread of δ13 C-CO2 data excludes single source of carbon. Up to two different carbon sources can be demonstrated for most of the studied localities. The most likely source appears to be carbon of homogenized upper crust, and organic carbon mobilized during metamorphic processes.
Autosalon in Jihlava
Žák, Karel ; Mizerová,, Lenka (referee) ; Smolka, Radim (advisor)
This diploma thesis addresses the project documentation of a autosalon. This building is situated in the region Vysočina, the city Jihlava. Autosalon is projected for a car dealerdealership and a comon administration. Building has two floors. Structure is column beam system. Building is covered with flat roof.
Detached House in Štoky
Žák, Karel ; Vojta, Martin (referee) ; Smolka, Radim (advisor)
This thesis addresses is the project documentation of a family house. This building is situated in the region Vysočina, the town Štoky. It is a three-store family house with one underground store and twoo up ground stores. Family house is projected for four-five people. Vertical structures are designed from lime-sand fittings. The residential part of the building is covered with a shed roof over the garage roof is flat.
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.
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

National Repository of Grey Literature : 28 records found   1 - 10nextend  jump to record:
Interested in being notified about new results for this query?
Subscribe to the RSS feed.