Stanislav Jacko

The ongoing European energy transition and the restructuring of energy markets are increasing pressure on energy-intensive industries to reduce greenhouse gas emissions while maintaining secure and reliable energy supplies. In this context, local geothermal resources represent a promising low-carbon energy source for strengthening industrial energy resilience. This study investigates the geothermal potential of a heavy industrial area located at the northwestern margin of the Bohemian Massif (Czech Republic), where elevated heat flow is associated with the interaction of Variscan structures, post-orogenic magmatism, and Cenozoic rifting. Due to safety restrictions related to industrial infrastructure, including pipelines and zones with explosive substances, a combination of controlled-source magnetotellurics and gravimetric surveying was applied. Magnetotelluric measurements conducted in the frequency range of 8–8192 Hz identified a major fault-controlled boundary between the crystalline basement of the Saxothuringian Zone and the Neogene sedimentary fill of the Most Basin. Gravimetric modeling revealed a pronounced negative residual Bouguer anomaly that can be explained by variations in sediment thickness and/or the presence of a low-density body within the crystalline basement. The integrated interpretation of geophysical data, regional heat-flow distribution, and existing geological knowledge suggests that this low-density body may be associated with granite porphyry intrusions of the Altenberg–Teplice Collapse Caldera. The results indicate that the northwestern Bohemian Massif contains geological structures favourable for geothermal exploration and demonstrate the applicability of low-impact geophysical methods in complex industrial environments. The study provides a scientific basis for future geothermal development aimed at supporting industrial decarbonization, regional energy resilience, and long-term energy security.

Jacko Stanislav, Dirnerová Diana, Milovský Rastislav, Aimbetov Izzet Kallievich, Bekimbetov Ruslan Tursinbaevich, Iskenderov Bakhtiyar Kauenderovich, Dospanov Rakhim Rauaj uli. Episodes -0001;0:. https://doi.org/10.18814/epiiugs/2025/025049

The Neogene evolution of the Pannonian extensional back-arc basin was associated with the development of transform faults. These faults significantly modified the sedimentary and structural evolution of the basin. The key developmental factors were related to pull forces and to the tilting of the subducted slab. The transitions from upper crustal contraction of upper crustal extension affected the depositional space, which had opened subparallel NW–SE normal faults along the southern contact with the Carpathian collision zone. The entire transition process was controlled by the closing of the rear part of the accretionary space, which changed the dip of the subducted slab. Basin subsidence, which occurred from west to east via N–S steps, generated a system of subparallel-oriented faults, which were connected by relay ramps. The relay ramps had four developmental phases: (a) initial crustal bending, (b) intact ramp formation with structural integrity disturbance, (c) breaching with crustal breakage, and (d) final fault growth. The genesis of the relay ramps of the Eastern Slovak Basin was closely linked to the initial strike-slip movements. The strike-slip movements caused a counterclockwise rotation of the northern edge of the Alpine–Carpathian–Pannonian block. This rotation was later compensated by the tectonic subsidence of the basin, primarily during the Middle Miocene.

The exploration of the geothermal potential of a geological unit has multiple aspects. The most important elements are the geological structure, the hydrogeological conditions, and heat flow. The analysis of the above-mentioned elements attempts to help maximize the use of a geothermal aquifer’s potential. When choosing the most appropriate geophysical method, it is important to consider various factors, such as basic structural parameters as well as the total cost of exploration. This is especially true for low-thermal areas. Comparison of multi-geophysical exploration methods used in the study of the carbonate aquifer of the Humenné Unit identified the advantages and weaknesses of each method. The Humenné Unit is the north basement unit of the Eastern Slovak Basin (with a heat flow value ranging from 100 to 125 mW·m⁻²), which is part of the Pannonian Basin (with a high heat flow ranging from 50 to 130 mW·m⁻²). The calculation of the geothermal potential was based on the results of several methods. Some important geophysical survey methods resulted in: (a) deep seismic cross-sections which clarified the position and overall internal structure of the aquifer (b) gravimetric measurements in the form of a map of the Complete Bouguer Anomalies (calculated for density 2.67 g·cm⁻³) which confirmed the presence of structural elevations and depressions. These elevations and depressions intensified the water yield, heat flow and raised the overall temperature (c) the use of geoelectric resistivity profiling, which is a fast and cheap method, but is limited by depth. The similar resistivities ρ: 80–360 Ωm of carbonates and andesites was a serious problem. The specific heat-energy potential has a wide range of 0.337–19.533 GJ/m². The highest values above 15 GJ/m² are reached in areas where the temperature on the surface of the Triassic carbonates exceeds 90 °C.

The Pannonian basin is a major geothermal heat system in Central Europe. Its peripheral basin, the East Slovakian basin, is an example of a geothermal structure with a linear, directed heat flow ranging from 90 to 100 mW/m² from west to east. However, the use of the geothermal source is limited by several critical tectono-geologic factors: (a) Tectonics, and the associated disintegration of the aquifer block by multiple deformations during the pre-Paleogene, mainly Miocene, period. The main discontinuities of NW-SE and N-S direction negatively affect the permeability of the aquifer environment. For utilization, minor NE-SW dilatation open fractures are important, which have been developed by sinistral transtension on N–S faults and accelerated normal movements to the southeast. (b) Hydrogeologically, the geothermal structure is accommodated by three water types, namely, Na-HCO₃ with 10.9 g·L⁻¹ mineralization (in the north), the Ca-Mg-HCO₃ with 0.5–4.5 g·L⁻¹ mineralization (in the west), and Na-Cl water type containing 26.8–33.4 g·L⁻¹ mineralization (in the southwest). The chemical composition of the water is influenced by the Middle Triassic dolomite aquifer, as well as by infiltration of saline solutions and meteoric waters along with open fractures/faults. (c) Geothermally anomalous heat flow of 123–129 °C with 170 L/s total flow near the Slanské vchy volcanic chain seems to be the perspective for heat production.

A frequently recurring problem in the extraction of mineral resources (especially heterogeneous mineral resources) is the rapid operative determination of the extracted quantity of raw material in a surface quarry. This paper deals with testing and analyzing the possibility of using unconventional methods such as digital close-range photogrammetry and terrestrial laser scanning in the process of determining the bulk density of raw material under in situ conditions. A model example of a heterogeneous deposit is the perlite deposit Lehôtka pod Brehmi (Slovakia). Classical laboratory methods for determining bulk density were used to verify the results of the in situ method of bulk density determination. Two large-scale samples (probes) with an approximate volume of 7 m³ and 9 m³ were realized in situ. 6 point samples (LITH) were taken for laboratory determination. By terrestrial laser scanning (TLS) measurement from 2 scanning stations, point clouds with approximately 163,000/143,000 points were obtained for each probe. For Structure-from-Motion (SfM) photogrammetry, 49/55 images were acquired for both probes, with final point clouds containing approximately 155,000/141,000 points. Subsequently, the bulk densities of the bulk samples were determined by the calculation from in situ measurements by TLS and SfM photogrammetry. Comparison of results of the field in situ measurements (1841 kg∙m⁻³) and laboratory measurements (1756 kg∙m⁻³) showed only a 4.5% difference in results between the two methods for determining the density of heterogeneous raw materials, confirming the accuracy of the used in situ methods. For the determination of the loosening coefficient, the material from both large-scale samples was transferred on a horizontal surface. Their volumes were determined by TLS. The loosening coefficient for the raw material of 1.38 was calculated from the resulting values.

Uranium ore mineralisation occurrences at the Western Carpathians/Slovakia are deposited within Permian volcano-sedimentary sequences. The mineralisation principally consists of two genetic types, the stratiform one and U-Mo vein mineralization linked to andesite volcanites. Geological exploration of uranium mineralization in Slovakia is subject to rigorous assessment of Ministry of Environment and municipalities. The limited energy sources and dependence to foreigner, open space for prospection of new energy sources (reneweable, uranium or traditional from coal, oil, gas).

The prediction of landslides and other events associated with slope movement is a very serious issue in many national parks around the world. This article deals with the territory of the Malá Studená Dolina (Little Cold Valley, High Tatras National Park—Slovakia), where there are extensive talus cones, through which seasonally heavy hiking trails lead. In the last few years particularly, there have been frequent falls and landslides in the mountainous environment, which also caused several fatal injuries in 2018. For the above reasons, efforts are being made to develop a methodology for monitoring the changes of the talus cones in this specific alpine area, to determine the size, speed, and character of the morphological changes of the soil. Non-contact methods of mass data collection (laser scanning with Leica P40 and aerial photogrammetry with unmanned aerial system (UAS) DJI Phantom 4 Pro) have been used. The results of these measurements were compared and the overall suitability of both methods for measurement in such terrain evaluated. The standard deviation of the difference of surface determination (represented by the point cloud) is about 0.03 m. As such accuracy is sufficient for the purpose of monitoring talus cones and the use of UAS is easier and associated with lower risk of damage of expensive equipment, we conclude that this method is more suitable for mapping and for repeated monitoring of such terrain. The properties of the outputs of the individual measurement methods, the degree of measurement difficulty and specific measurement conditions in the mountainous terrain, as well as the economy of the individual methods, are discussed in detail.