Jakub Jirásek

The northernmost occurrence of the Lower Berriasian ammonite Pseudosubplanites grandis (Štramberk Limestone, Outer Western Carpathians, Czech Republic)

Abstract The first finding of the index ammonite Pseudosubplanites grandis (Mazenot, 1939) in the Lower Berriasian Štramberk Limestone (Outer Western Carpathians, northeastern Czech Republic) is important from the point of view of both the paleogeographical distribution of this species and of more precisely defining the upper boundary of the Štramberk Limestone (Early Berriasian Berriasella jacobi Zone) formerly regarded as Late Tithonian in age. From the taxonomical point of view, new data on a non-deformed cross-section of the adult whorl and above all on the shape of the adult suture line of this species have been obtained.

Genetic aspects of barite mineralization related to rocks of the teschenite association in the Silesian Unit, Outer Western Carpathians, Czech Republic

Abstract Barite is a relatively uncommon phase in vein and amygdule mineralizations hosted by igneous rocks of the teschenite association in the Silesian Unit (Western Carpathians). In macroscopically observable sizes, it has been reported from 10 sites situated only in the Czech part of the Silesian Unit. Microscopic barite produced by the hydrothermal alteration of rock matrix and also by the supergene processes is more abundant. We examined four samples of barite by mineralogical and geochemical methods. Electron microprobe analyses proved pure barites with up to 0.038 apfu Sr and without remarkable internal zonation. Fluid inclusion and sulphur isotope data suggests that multiple sources of fluid components have been involved during barite crystallization. Barite contains primary and secondary aqueous all-liquid (L) or less frequent two-phase (L+V) aqueous fluid inclusions with variable salinity (0.4-2.9 wt. % NaCl eq.) and homogenization temperatures between 77 and 152 °C. The higher-salinity fluid endmember was probably Cretaceous seawater and the lower-salinity one was probably diagenetic water derived from surrounding flysch sediments during compaction and thermal alteration of clay minerals. The δ34S values of barite samples range between -1.0 ‰ and +16.4 ‰ CDT suggesting participation of two sources of sulphate, one with a near-zero δ34S values probably derived from wall rocks and another with high δ34S values being most probably sulphate from the Cretaceous seawater. All results underline the role of externally derived fluids during post-magmatic alteration of bodies of rock of the teschenite association.

An SEM-EDX and Raman spectroscopic study of the fibrous arsenate mineral liskeardite and in comparison with other arsenates kaňkite, scorodite and yvonite.

The mineral liskeardite, an arsenate mineral with major cations of iron and aluminium, has been studied by a combination of scanning electron microscopy with energy dispersive spectroscopy and Raman spectroscopy. The mineral shows a fibrous nature. Semi-quantitative chemical analysis shows an Al and Fe arsenate phase with minor amounts of K, Cu, S and Si. Scanning electron microscopy shows a fibrous material. Intense Raman bands at 893, 867 and 843 cm(-1) are assigned to the ν1 and ν3 AsO4(3)(-) and HOAsO3(2)(-) symmetric and antisymmetric stretching vibrations. Raman bands are observed at 514, 499, 485 and 477 cm(-1) and are assigned to the ν4 out of plane bending modes of the AsO4(3)(-) and HOAsO3(2)(-) units. The series of bands at 373, 356 and 343 cm(-1) are assigned to the ν2 symmetric bending modes. Two groups of OH stretching bands are observed and assigned to OH unit and water stretching vibrations. A comparison of the Raman spectrum of liskeardite with scorodite, kaňkite and yvonite is made.

Minerals formed by the weathering of sulfides in mines of the Czech part of the Upper Silesian Basin

Abstract This study describes the occurrences of sulfate minerals in mines of the Czech part of the Upper Silesian Basin. This mineralization originates from the oxidation of Fe disulfides contained in the coal matrix and enclosing sediments. The oxidation occurs in the presence of formational brines and chemotrophic bacteria. The brines have a pH between 6.3 and 8.5 and total solute content of up to 300 g/l. They are rich in Na, Ca, K, Mg, Ba and Sr and Cl- is the major anion. The minerals of the pickeringite-halotrichite series with coexisting magnesiocopiapite are formed primarily in drier places and areas where the water is only slightly mineralized. In more humid places where the brines are more concentrated, a diverse assemblage of up to 20 different sulfates are found (e.g. natrojarosite, sideronatrite, metasideronatrite, tamarugite, magnesiocopiapite, bílinite, starkeyite, blödite, rozenite and siderotil). These sulfates are accompanied by halite, sulfur, goethite and a number of phases of uncertain identity, such as sulfates containing Sr and REE. This is an example of mineral paragenesis formed by weathering in a saline evaporite environment, which is extremely rare in Europe but is found in arid regions elsewhere (e.g. in the Atacama Desert in Chile).

Uranium and the Energy Strategy of the Czech Republic in Electricity Production

The structure of the production of electricity in the Czech Republic is based on the structure of its raw material basis that includes reserves of lignite, steam coal, coking coal and uranium. On the other hand, there are only small reserves of crude oil and natural gas in the Czech Republic, a limited potential of hydroelectric power plants, and a relatively small potential for the development of renewable energy. The current production of electricity is therefore based on two pillars: coal-burning and nuclear power plants. With respect to the lignite reserves that are time-limited, the Czech Republic will be obliged to modify its power production strategy in the future and change its energy best mix, i.e., the portfolio of the energy sources used so far. This article analyzes the possible role of uranium in creating the future energy portfolio of the Czech Republic.

Traditional energy resources in India (coal, crude oil, natural gas): A review

ABSTRACT India is a developing country with a growing population and economy. For sustainable growth, it will need to secure its supply of energy minerals. In 2013, India ranked 5th in terms of coal reserves, 21st in crude oil reserves, and 23rd in natural gas. At the same time, India was the 3rd largest producer of bituminous and lignite, 22nd largest producer of crude oil, and the 25th largest producer of natural gas. In addition, India was also the 4th largest energy consumer in the world. The total primary usage in India is dominated by coal followed by oil and natural gas. In the period from 2000–2013, the total annual energy consumption doubled to 595.0 million tons oil equivalent. Coal increased its share from 49 to 54% and oil decreased its share from 36 to 30% of the total. The share of the natural gas remains at the same value of 8%.

Lifting lignite mining limits – correction of the Czech Republic energy policy

ABSTRACT In its decision from October 2015, the Government of the Czech Republic corrected its raw material and energy policies by modifying the scope of the territorial ecological limits placed on the mining of lignite. Such action is impacting the energy sector operating in the North Bohemian Basin, the largest region for lignite production in the Czech Republic. This article explains the background of the mining restrictions and the significance of the Czech government’s decision to amend them for the district heating industry; the composition of the future energy portfolio for electricity production; and the energy security of the Czech Republic.

Geotouristic attractions of the Ostrava part of the Upper Silesian Basin: geological and environmental sites

Abstract In the Ostrava part of the Upper Silesian Basin there are many geotouristic sites connected with the underground mining of Carboniferous bituminous coal. Text is focused on those related to the geology of the Basin and environmental issues connected to coal mining. Of great intrest are outcrops of Mississippian sediments of the paralic Ostrava Formation, as well as two most important museums with permanent geological exhibitions. Some interesting geological features conncted to younger periods of Quarternary glaciation are also mentioned. Two types of publicly accessible sites related to the environmental burdens (burning coal heaps, saline mine water drainage system) are also described.

METODIKA SESTAVENÍ MAPY MOCNOSTÍ SEDIMENTŮ AUTOCHTONNÍHO KARPATU NA ÚZEMÍ ČESKÉ ČÁSTI HORNOSLEZSKÉ PÁNVE A BLÍZKÉHO OKOLÍ A NĚKTERÉ JEJÍ PROBLÉMY

Sedimentary formations of Karpathian represent the oldest widespread unit of the autochtonous Tertiary in the Czech part of the Upper Silesian Basin. Occurrence and distribution of thickness of the Karpatian point to complicated geological development. It was probably formed in tectonically predisposed sedimentary depressions with large infl uence of the Old Styrian nappes, which were thrusted over the area of original sedimentary cover in the north-eastern part of the Carpathian Foredeep. Main topic of our work is evaluation of possible mistakes in interpretation of the autochtonous Karpatian thickness. Original contour line maps of the autochtonous Karpatian distribution and thickness in the area of interest are based on exploratory borehole profiles.

UHLONOSNOST SVRCHNÍCH HRUŠOVSKÝCH VRSTEV (NAMUR) V ČESKÉ ČÁSTI HORNOSLEZSKÉ PÁNVE

Map of the thickness of the Lower Hrusov Member (Namurian, Mississippian) was made. It is based on exploratory boreholes´ information from the Czech part of the Upper Silesian Basin. The thickness varies from 52.55 m to 415.48 m. The highest values are situated in a NNE–SSW trending zone west of the Orlova Structure in the northern part of the Přibor area and in the western part of the Ostrava area. The lowest values are reached in the Frenstat area east of the Kozlovice Saddle, in the Mořkov area south of the Janovice Fault and west of the Kozlovice Saddle, and in the Těsin and Karvina areas east of the Orlova Structure. Total thickness of the Lower Hrusov Member is decreasing from the West to the East and shows evident west-east polarity. The western part of the post-erosive area of the Lower Hrusov Member represents the axis of maximum subsidence of the basin in times of sedimentation. The zone of reduced thickness is the original eastern part of the basin. The western part of the basin is not preserved due to the post-Carboniferous erosion.