Václav ProcházkaCzech Technical University in Prague | ČVUT
Václav Procházka
Ph.D.
About
63
Publications
15,040
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
259
Citations
Publications
Publications (63)
Depressions containing partially molten rocks were investigated in Quaternary pebbly sedi-ments in Alpine foreland in Bavaria, Germany. Ruins of limekilns from 18-19th centuries are abundant around Seeshaupt. They are usually associated with earthworks for fuel feeding and protection from wind. Depressions contain partially molten stones from furna...
The theory of mantle convection currents as the cause of lithospheric plate movements has several major problems, including the absence of an adequate energy source. As shown in our previous contribution, an unbiased interpretation of geochemical data does not support the assumptions of a significant amount of radionuclides in the lower mantle or e...
Cesium is the heaviest stable alkali metal (with only one stable isotope – 133Cs) and it occurs mainly as a potassium-substituting cation. It is an important trace element in rocks typical for the Earth crust, and its content in biomass is also relatively high compared to those abiogenic elements which are little soluble. Low-cost analytical method...
The theory of continental drift was published as early as 1912, but the mechanism and energy source of this motion has not yet been elucidated. In many cases, the generally accepted model of convection currents in the mantle contradicts observations such as the spreading of the ocean floor, the extension of rifts from triple points to all sides, th...
The theory of continental drift was published as early as 1912, but the mechanism and energy source of this motion has not yet been elucidated. In many cases, the generally accepted model of convection currents in the mantle contradicts observations such as the spreading of the ocean floor, the extension of rifts from triple points to all sides, th...
The presentation deals mainly with melting and its relation to deformation phenomena in two craters at Emmerting, whose impact origin has been recently confirmed. See also abstract here: https://www.hou.usra.edu/meetings/lpsc2023/pdf/2102.pdf
Kráterem číslo 4 u Emmertingu v pozdně glaciální terase řeky Alz se podrobněji zabývali Rösler et al. (2006). Přímé důkazy o impaktu nenašli, v podstatě však ukázali, že neexistuje životaschopná alternativa. Nic na tom nemění ani pochopitelné námitky proti teorii považující tento kráter za součást dopadového pole s více než 100 dochovanými impaktní...
Some information about two impact craters at Emmerting (Germany), including the first meteorite fragment found. The text is in Czech.
Rocks affected by very short thermal pulse, commonly with deformation, at several sites in eastern Bavaria (south-eastern Germany). For comparison, also expansion of mica in plasma torch is shown. Presentation in Czech.
The entirely granitic catchment of the Plešné Lake is an exception from other lake catchments in the Bohemian Forest (Šumava Mts, Böhmerwald), dominated by metamorphic bedrock. No remarkable enrichment of the local granite (the Plechý/ Plöckenstein type) with any trace elements has been noted. However, the literature data including monazite and zir...
Data of 41 or more elements in superficial as well as drill-core samples of the peraluminous Lipnice and Melechov granites, located several kilometers apart in northern Moldanubian Batholith, are evaluated. Weathering of both granite types proceeded in virtually identical time and environment, but it shows very different patterns. In the weathered...
Results of ICP-Vegetation monitoring program were
previously interpreted mainly for estimation of environmental
pollution loads. The biochemical monitoring included determination
of 36–40 elements in the mineral soil, forest-floor humus and
biomass of selected plants of coniferous forests at ca. 250 sites
across the Czech Republic. Here, we interpr...
The Late Glacial sedimentary sequence of the Stará Jímka paleolake (Bohemian Forest, Czech Republic) is characterized by the prevalence of detrital minerals with an elevated proportion of organic matter and abundant diatom valves in relatively warm periods. The mineral debris originated mainly from local migmatites and mica-schists (or glacial and...
The Younger Dryas (YD) climate episode (∼12,850–11,650 calendar years before present [cal BP]) is an event recorded widely across the Northern Hemisphere. We conducted multiple analyses at high resolution of a YD-age sedimentary sequence from Stara Jimka, a paleolake in the Bohemian Forest, Czech Republic. Age-depth modeling indicates that a centra...
Sudden environmental catastrophes pose a considerable threat to the human society. In Central Europe, the Late Glacial period (⁓14,700-11,650 cal. yr. BP) was characterized by abrupt climatic changes. It ended with the Greenland Stadial 1 (12850-11650±99 cal. BP; ⁓Younger Dryas biozone) whose onset is associated with identification of cosmic impact...
The mineral, chemical and Pb-isotope composition were investigated in the host granite and low-temperature open-fracture fillings from the 100 m deep borehole PDM-1 located in the Melechov Massif of the Moldanubian Batholith. The fillings are dominated by limonite and clay-mineral (illite, montmorillonite, nontronite, chlorite) mixtures, accompanie...
We recognised during the deformation measurements in the underground so called "thermoelastic waves", which are generated on the surface by solar irradiance.
We derived the recursive procedure for the heat transfer and accumulation in the whole crust.
We showed that the accumulation of the solar irradiance is not in the form of heat, but in the for...
The Younger Dryas (YD) is well-documented cold period recorded over the Northern Hemisphere. Reasons for this sudden climate change are widely discussed by the scientific community [e.g. 1, 2]. Climate cooling began ~12,900 years ago and lasted ~1,200 years [3]. Recent discoveries [e.g. 4, 1] have revealed new evi-dence of impact proxies (incl. gla...
The disastrous Tunguska explosion (TE) in 1908 uprooted trees in a radial pattern. Several trees in this area survived and kept growing in the post-Tunguska environment. We collected samples from surviving trees (14 and 131 years old at the time of the TE) that lived until collection in 2008 and another sample from a control tree farther from the b...
Results of geophysical and mineralogical analyses from impact strewn field Chiemgau.
We present Pb-isotope composition of parent granite and 25 samples of low-temperature mineral assemblages filling open fractures in a granite from southern part of the Melechov Massif of the Moldanubian Batholith, sampled over the 100 m deep borehole PDM-1). The fillings have usually higher U/Pb and 206Pb/207Pb ratios than the granite, which mostly...
Cold-stage cathodoluminescence spectra from various geological units of Bohemian Massif, prevalently of rock-forming minerals from silicate rocks of the Moldanubian zone, are presented. Apatite spectra are dominated by broad emission band of Mn2+, narrow peaks of REE, or both. In spectra of biogenic phosphate only REE-related peaks are important. F...
Cold-stage cathodoluminescence spectra from various geological units of Bohemian Massif, prevalently of rock-forming minerals from silicate rocks of the Moldanubian zone, are presented. Apatite spectra are dominated by broad emission band of Mn2+, narrow peaks of REE, or both. In spectra of biogenic phosphate only REE-related peaks are important. F...
It has been shown previously (Procházka et al., 2011) that strongly weathered Melechov granite (collected from the base of soil cap) is in comparison to the fresh rock significantly depleted in quartz, i.e. the most resistant major mineral. On the other hand it is not significantly depleted in Na or Ca. Thus the mineral and chemical composition of...
The deformation measurement of rock mass in the depth and mathematical modelling solved the old question of Wegener´s theory “What is the main engine for the lithosphere movement?”.The solar energy, which reaches the Earth, is two orders higher than the energy of all earthquakes and volcanoes. Only a small part of the solar energy is accumulated in...
We present a new model of lithosphere-plates movement based on three pillars:
1) The thermoelastic wave, which was described first of all by Berger (1975),
2) The ratcheting mechanism, which was described for asphalt buckling and/or lithosphere evolution by J. Croll (2006, 2007), and
3) the solar irradiance energy, as quantified by IPCC (2007).
The...
The town of L´Aquila was hit by earthquake on April 6, 2009 (M6.4) and 309 people were killed. Gianpaolo Giuliani predicted such an earthquake on March 23 based on his radon and local seismicity measurement in L´Aquila and its surrounding. He detected two anomalies – one in the beginning of March and the second between March 19 and March 23, 2009....
The earthquake prediction must fulfill at least three parameters: time window, focal area and minimal magnitude of future earthquake. The new measurements of tilt by vertical static pendulums confirm that the best model of the processes inside of focal area before the mainshock could be model of asperity. This model show that quite before the failu...
The earthquake prediction must fulfill at least three parameters: time window, focal area and minimal magnitude of future earthquake. The new measurements of tilt by vertical static pendulums confirm that the best model of the processes inside of focal area before the mainshock could be model of asperity. This model show that quite before the failu...
The town of L´Aquilla was hit by earthquake on April 6, 2009 (M6.4) and almost 300 people were killed.
Giampaolo Giuliani predicted such earthquake on March 23 based on his radon and local seismicity measurement in L´Aquilla and it’s surrounding. He detected two anomalies – one in the beginning of March and the second between March 19 and March 23,...
Abstract. Distribution of elements, mainly of the radioactive ones, in minerals of different grain size and possibly density was compared by washing the slightly crushed rock (Melechov type granite of the Moldanubian Batholith). The silt (fraction, which has sedimented within one day) is enriched relatively to the whole rock in the most of measured...
It has been documented in last decades that mean temperatures of the Earth's surface have been comparable with the actual ones throughout the most of geological history. During time of much lower solar luminosity this was possible only thanks to the much stronger greenhouse effect. That means, however, that temperatures were temporally as well as s...
Cell wall polysaccharide suspensions (mainly β-glucan) was isolated from baker's yeasts (Saccharomyces cerevisiae) and used for the preparation of films. Glycerol was added as a plasticizer. Purity and composition of the films were tested by elemental analysis, enzymatic assay of α- and β-glucans, monosaccharide composition analysis (total hydrolys...
Read more about the monograph and the related research in supplementary material.
Contents:
1. INTRODUCTION
2. EARTHQUAKE PREDICTABILITY / ACCIDENTALITY (Kalenda)
3. THEORY OF EXTERNAL FORCES (Neumann, Kalenda, Skalský, Kopf, Wandrol)
4. EXPERIMENTS WITH SEISMICITY AND TESTS OF EFFECTS (Kalenda, Málek, Skalský, Ostřihanský)
5. VERTICAL STATIC PEND...
Water-rich glass with radioactive inclusions was fabricated to mimic very slow radiochemical processes in natural minerals and rocks (and potentially in artificial silicate materials, e.g. in radioactive waste disposal). A mixture of sodium silicate (Na2SiO3.5 H2O) and uraninite (~UO2) was added to molten soda-lime silicate glass. The uraninite pow...
Ukázka z úvodní kapitoly:
"V této knížce chceme ukázat, že predikce zemětřesení je možná, budeme prezentovat vlastní výsledky měření mikrodeformací masívu pomocí vertikálních statických kyvadel a na jejich základě ukážeme, jak by bylo možno predikovat místo, čas a magnitudo budoucího zemětřesení. Následující kapitoly proto budou na sebe volně nava...
Effects of strongly radioactive primary minerals (mainly monazite) on the surroundings are compared in various rocks of similar chemical and mineral composition (mainly granites and paragneisses) of the Moldanubian area in the Bohemian massif. All these rocks cooled to <150 °C at similar time (300-250 Ma b.p.). aureoles of secondary phases formed w...
Frequency-dependent magnetic susceptibility, its anisotropy (AMS), its temperature variation, natural remanent magnetization and time-dependent isothermal remanent magnetization as well as Mössbauer spectroscopy of a small collection of Celtic and Mediaeval graphitic pottery from Southern Bohemia were investigated. The mineral composition of the po...
Prevalently archived whole-rock analyses of marbles, paragneisses, calc-silicate rocks and metavolcanics were evaluated to trace the original non-carbonate fraction of Ca-rich metasediments. The less mobile major components – Al2O3 and TiO2 – show the same trend in all metasedimentary rocks and completely different from metavolcanics, which exclude...
Chemical weathering of the Melechov granite was evaluated on the basis of a) differences in the composition of fresh and weathered rocks, which are results of processes lasting for 10 000 years at least, b) mass balance of a small catchment (covered by spruce production forest) which is much more sensitive to short-term effects. Relatively low disc...
In Hercynian peraluminous S-type granites of the Melechov Massif (Moldanubian Batholith, Czech Republic), Zn-rich ilmenite with up to 20 wt. % ZnO formed mainly as a product of subsolidus alteration of biotite into muscovite. Ilmenite usually fills the cleavage of muscovitized biotite. It is often accompanied by a TiO2 phase, Zn-rich pseudorutile a...
Magnetic properties as well as the magnetomineralogy were investigated in rocks underlying a 7 km long aeromagnetic anomaly
situated in the Moldanubian crystalline unit of the Bohemian Massif. The anomaly is caused by highly magnetic cordierite gneiss
forming a stripe of NE — SW direction east of the town of Humpolec, eastern Bohemia. Magnetic susc...
Lechatelierite inclusions in moldavites are isolated by weathering of the less
resistant surrounding moldavite mass and then exposed to selective weathering at
which sculptation forms (see also KNOBLOCH & al. 1987, 2009). The sculptation
can be longitudinal (Fig. 1a) as well as transversal (Fig. 1b). This contribution, however,
is intend on the rat...
This study describes and discusses the origin of fluorapatite–zircon–monazite–xenotime associations from the Melechov granite
massif, Czech Republic. The Melechov massif consists of a series of peraluminous two-mica granite intrusions subdivided into
the Stvořidla, Melechov, Kouty, and Lipnice granites. Fluorapatite in these granites occurs in thre...
The aim of this work was to check whether the ASTM D 3359 is a suitable method for adhesion measurement of the layers formed on Yi6Al4Vsurfaces by a) alkali treatment in 10 mol/l NaOH, b) precalcification in SCS (supersaturated calcification solution) and c) in vitro tests in SBF (simulated body fluid). Tape-test is suitable for evaluation of adhes...
Available geochemical data (mainly from the Litogeochemical database of ČGS) from carbonates with no major clastic contamination have been evaluated. Some important differences between the Barrandian lower Paleozoic and the Varied group of Moldanubicum cannot be explained by metamorphism. The Moldanubian marbles which are not dolomitized have usual...
The accessory mineral associations in granites of the Melechov Massif are typical of peraluminous granites with high P content. The chemical compositions of minerals exhibit some specific features, including the occurrence of Zn-rich ilmenites (up to 29% of the ZnTiO3 component - the highest Zn content known in ilmenite in a granitoid). The less fr...
The several km long magnetic anomaly E from Humpolec (ZEMÁNEK 1964) is probably caused by Ti-hematite, 1-2 % content of which in cordierite-rich paragneisses from the hill Orlík is documented. The portion of exsolved ilmenite in the hematite exceeds 35-40 %, which indicates a minimum crystalli- zation temperature > 550-600 °C. Other major minerals...
Relatively early stages of chemical weathering in gran- ites of the Melechov massif are evaluated mainly by comparison of fresh samples from boreholes with weathered samples from soil cap (collected from depth close to 2 m). Weathered granites are depleted in SiO2, whereas their Al2O3 and loss of ignition (LOI) increase; there are two very differen...
Questions
Questions (2)
Una questión a mineralogos y expertos de meteoritos suramericanos:
Sabe alguien qué son las piedras "Hiwaya" que se venden en Cusco (Perú) como "meteoritos"?
Son oscuros, pesados, frágiles y un poco magnéticos. Pero no he encontrado ningúna informaciön científica. No necesito más pruebas - sólo me interesa si realmente puede ser un meteorito.
Gracias
I am interested in clay minerals formed in plutonic rocks (mainly granites) prior to obvious weatherig processes. If we look at wet analyses, there is mostly 1 wt. % "H2O+" (even in samples from boreholes >100 m below the surface). Taking into account the amount of micas (and, if present, other nominally hydrous minerals), it is usually not enough for > 0.5 % H2O+. I could refer to own publications about clay mineral formation by radiochemical alteration, but this is still very small volume and not rule everywhere. So - where is the water: in submicroscopic secondary minerals, in fluid inclusions, other form in anhydrous minerals (e.g., water complex in quartz according to N.G.Stenina...), or strongly adsorbed water which had been in pores? Many thanks for answers and ideas!