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Geochemistry of mantle xenoliths of the České středohoří Mts.
Kohoutová, Iveta ; Ackerman, Lukáš (advisor) ; Jelínek, Emil (referee)
The České středohoří Mts. forming the most important and active part of Ohře/Eger rift are formed by volcanic rocks of Tertiary age containing upper mantle xenoliths which can provide us information about internal structure of upper mantle. This diploma thesis is focused on the study of mantle xenoliths from this part of Bohemian massif close to the city Litoměřice (4 locations: Dobkovičky, Prackovice, Kuzov, Medvědí hill) and for comparison another 4 locations of mantle xenoliths from the northern Bohemia locaties Brtníky in Šluknovský ledge, Kraslice and Zámeček at Fláje in Krušné Mts. and Venuše volcano in Nízký Jeseník at Bruntálská Highlands. Almost all studied xenoliths are spinel harzburgites or lherzolites with mineral association olivine + orthopyroxene + clinopyroxene + spinel (the most often Cr-spinel). They have usually protogranular texture followed by porfyroclastic texture (porfyroclasts are represented by olivine, orthopyroxene and in some cases also by clinopyroxene, and fine-grained matrix of all these minerals with olivine showing undulose extinguishes). An equigranular texture is the least common. Host rock of the xenoliths is always basanite. The most abundant mineral in peridotite xenoliths is olivine with #Mg value 89,4-91,5; followed by orthopyroxene with #Mg value 90,8-92,1...
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Geochemistry of upper mantle rocks from Mohelno-Biskoupky locality
Kovács, Andrea ; Ackerman, Lukáš (advisor) ; Jelínek, Emil (referee)
Peridotites occuring in orogenic massifs provide important insights into geochemical processes of the Earth's upper mantle by providing direct evidence of mantle evolution throughout Earth history. It has been previously demostrated (e.g. Medaris et al., 1990, 2005) that the uppermost tectonic unit of the Bohemian Massif - the Gföhl Nappe hosts a variety of peridotites that originated from different sources, including subcontinental lithosphere, suboceanic asthenosphere, and possible ultramafic layered intrusive complex. The Czech peridotites of the Gföhl Nappe has been divided into three groups, defined by Medaris et al. (1999), according to their chemical compositions, identity and relations of the aluminous phases, ortopyroxen compositions and estimated P-T conditions. According to Medaris et al. (2005) "Type I" peridotites - represented by Mohelno and Biskoupky bodies - equilibrated in low P-T regime (recording the highest equilibration temperatures - up to 1335 ⁰C at 29 kbar - among the Gföhl peridotites) consist of spinel peridotite with garnet appearing only at its margins. Peridotites are enclosed in granulites that have been extensively recrystallized mostly at amphibolite-facies conditions. Many studies have been done on this locality and a wide range of mineralogy and P-T histories has...
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Solid phase inclusions in minerals from eclogites, peridotites and granulites
Jedlička, Radim ; Faryad, Shah Wali (advisor) ; Jelínek, Emil (referee)
English abstract Felsic granulites in the Bohemian Massif are characterized by the presence of small (from decimetres to several houndred metres in size) boudins and lenses of garnet peridotites and high-pressure eclogites. Pressure conditions of the granulites and their mutual metamorphic history with garnet peridotites and eclogites are subject of long discussion. For this purpose, minerals and textures formed at peak pressure conditions were investigated using thin-sections and mineral separates of these rocks from the Kutná Hora complex. As all these rocks underwent granulite facies reequilibrium and subsequent cooling, most inclusions are transformed to lower pressure and temperature phases. In addition to olivine, orthopyroxene and clinopyroxene, garnet from garnet peridotites contains frequent chromium spinel. The host garnet around inclusions shows Cr-rich domains as result of diffusion from spinel to garnet. Rare ilmenite inclusions with high MgO content and pentlandite were also observed in garnet. Orthopyroxene in matrix and rims of large grains have low amounts of Al and the associated clinopyroxene has relatively high jadeite content. Two varieties of eclogites are present in the granulite: eclogites with pyroxenites and garnetites occur within or adjacent to garnet peridotites. Garnets of...
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Geochemistry and petrology of plagiogranites from the Jílové belt
Santolík, Václav ; Ackerman, Lukáš (advisor) ; Jelínek, Emil (referee)
This thesis is focused on the study of the subvolcanic rocks from the northern part of the Jílové belt. The Jílové belt is a strip of magmatic rocks belonging to the Davle Volcanic Complex situated in the center of the Bohemian Massif, south of Prague, close to the border between the Teplá-Barandian and Moldanubian units. The sub-volcanic facies of its northern part has been previously ascribed to trondhjemite, alaskite or plagiogranite. In this study, we provide new geochemical data such as major and trace element analyses paralleled by Sr-Nd isotopic data, which indicate the origin of these rocks in the mantle wedge. They probably represent a final product of a magmatic differentiation of an island arc series. Here, we consider two possible models for their origin, according to which we could also choose the correct classification of these peculiar rocks: adakite, or plagiogranite. Adakites are rocks formed by melting of a subducted slab which are predominantly related to the volcanic arc settings. In comparison, plagiogranites are rocks formed by an extreme differentiation of a mantle- derived basaltic melt in the oceanic crust environment. Our new geochemical data, especially the low degree of light rare earth enrichment (LaN/YbN = 0.8-1.3), is clearly inconsistent with the genetic association...
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The vitrification methods used for the high active waste from spent nuclear fuel reprocessing.
Machová, Pavlína ; Goliáš, Viktor (advisor) ; Jelínek, Emil (referee)
This thesis summarizes the general concepts regarding the High-level waste vitrification. It describes the one-stage and two-stage principles of vitrification and special method "cold crucible". There are summarized advantages and disadvantages of these methods. In this thesis are specific of vitrification facilities around the world. There are the general characteristics of glass used for immobilization High- level waste. Most countries use borosilicate glass, but only in Russia are used phosphate glass. There is shown the composition range of glass and compare their typical properties. This thesis ends with an example of the chemical composition of certain ending vitrification products.
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Geochemistry of upper mantle rocks from Kozákov and Horní Bory, Bohemian Massif
Ackerman, Lukáš ; Jelínek, Emil (advisor) ; Faryad, Shah Wali (referee) ; Becker, Harry (referee)
The purpose ofthis dissertation is geochemical study ofupper mantle rocks at two sites from diÍlěrent geological settings of the Bohemian Massif (Czech Repub|ic) - Koziíkov and Homí Bory. The first part of dissertation represents a review of petrological and geochemical studies of upper mantle Íocks found in the Bohemian Massi{ which have been pub|ished or presented so far' These include information about ýpe and occuÍTences of mantle{erived rock with individual Bohemian Massif units and summarized present state of knowledge on depletion and metasomatism ofthese rocks. The principal questions related to the mantle beneath the Bohemian Massif which remďn opened are presented at the end of this part. The most important paÍt of the dissertation represents three comprehensive papers on geochemical studies of upper mant|e rocks from Koziíkov and Horní Bory. In the second part, a geochemical study of major elements, trace elements, and Sr-Nd isotopes combined with mineral chemistry of upper mantle xenoliths from the Koziíkov volcano have been presented. This unique suite of xenoliths samples upper 2/3 of the upper mantle in this region and, therefore' provides a great possibility to study uppeÍ mantle composition variations with depth. The results show that upper mantle beneath Koziíkov volcano underwent...
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Mafic and intermediate intrusions accompanying peraluminious granites of the Krušné hory Mts.batholit
Holečková, Pavla ; Jelínek, Emil (advisor) ; Ackerman, Lukáš (referee) ; Leichmann, Jaromír (referee)
Mafic and intermediate intrusions commonly accompany Variscan granitoid plutons in Europe. They are documented from different localities of Iberian Peninsula, from the French Massif Central, Schwarzwald, from different parts of the Bohemian Massif, in Romania, Greece, Corsica and Sardinia. They comprise wide petrographic varieties from quartz gabbros, diorites, granodiorites to monzonites. They usually constitute small bodies or veins, they often occur as mafic microgranular enclaves (MME) in granodiorites and in some granites. Dioritic intrusions are characterized by a relatively high amounts of lithophile elements (Rb, Sr, Ba, Cs, LREE), and they are simultaneously high in compatible elements (Ni, Cr, V a Co). Their isotopic ratios 87 Sr/86 Sr are in all compared locations similar and are close to the Bulk Earth (0.704 - 0.708). εNd values show larger scatter, some intrusions have more crustal composition (to -8), on the other hand, another intrusions have εNd positive, that points to a contribution of basic magma. The age of dioritic intrusions differs according to individual locality suggesting more than one magmatic episode. The oldest occur in the French Massif Central (361 - 365 Ma), whereas the youngest are documented in Iberia (312 - 310 Ma). The oldest mafic intrusions in the Bohemian...
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Geochemical study of processes, relevant to safety assessment of deep geological repository: Uranium forms and enrichment scenario in a sedimentary system at the Ruprechtov natural analogue site
Havlová, Václava ; Jelínek, Emil (advisor) ; Pačes, Tomáš (referee) ; Zeman, Josef (referee)
U migration was studied in order to better understand to processes of safety relevant elements, particularly U. The rock sequence on the site can be analogous to a potential rock overburden of deep geology repositories. A multidisciplinary approach was undertaken in order to identify and characterise U mobilisation/immobilisation processes within sedimentary clayey rocks with organic matter enriched interlayers. Both conventional methods and modern sophisticated spectroscopic methods were combined. Sequential extraction, wet chemical method and even spectroscopic methods proved that U prevailed in the U(IV) form in low-oxidised samples. It moved towards more easily releasable fractions with sample ageing (oxidation). The combination of SE, µ-XRF and µ-XAFS results proved U to be unexpectedly associated with As and P, leading to the presumption that U(VI) from groundwater was reduced to U(IV) on As pyrite. The evaluation of the hydrogeochemical conditions and isotope analyses then brought the results into broader context: Sedimentary organic matter within the sedimentary layers was microbially oxidised, releasing dissolved organic matter and providing H+ in order to dissolve sedimentary inorganic carbonates. SO4 2- could be reduced under reducing groundwater conditions, thus causing FeS2 formation....
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Water and sediment chemistry of fluvial lakes of the Elbe River
Chalupová, Dagmar ; Janský, Bohumír (advisor) ; Jelínek, Emil (referee) ; Benešová, Libuše (referee)
The presented paper aims at the problems of fluvial lakes in middle course of the Elbe River which has been influenced by the human activity since the Middle Ages. The oxbow lakes which are extremely precious ecosystems contributing to the stability of the river ecosystem show not only the changes of the course of the Elbe River. With regard to sedimenting a great amount of pollutants, these lakes also tell about the industrial pollution to which the river was exposed mainly in the second half of the 20th century due to insufficient precautions on industrial sources causing contamination. 5 cut lakes between Hradec Králové and Mělník have been studied within this research. These lakes differ in the intensity of communication with the river, in the distance from significant sources of industrial pollution and in the use of nearby land. The research included morphometric and bathymetric measures, observation of hydrological regime, seasonal measures in the water column and regular analysis of surface water samples. Profiles of sediments in the length that the used technology allowed were sampled, so that older anthropogenic load could be found out. The amount of organic carbon and concentration of selected metal and arsenic (Ag, Cd, Cr, Cu, Fe, Hg, Mn, Pb and Zn) were stated apart from grain size...
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