We'd like to understand how you use our websites in order to improve them. Register your interest. Whereas the transition zone between both tectonical units was intensely investigated by means of electromagnetic methods in the past, the image of electric conductivity of the EEC itself has not been detailed so far. In the present study the lithospheric structure beneath the northeast of Poland is investigated by means of three parallel magnetotelluric profiles.
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We'd like to understand how you use our websites in order to improve them. Register your interest. The research included geometric measurements of vertical discontinuity zones of selected rock outcrops and the electrical resistivity tomography ERT measurements of strongly weathered subsurface layers.
In addition, the main crack directions for the gneiss occurring in the studied mountain region were identified. Interpretation of the ERT models allowed to characterise the structure of the rock mass, including the reach of the rainwater infiltration level and the depth of the weathering front.
It is the second highest mountain range in the Czech Republic, located in the north-eastern part of the Bohemian Massif. The mountain valley Skalni Potok has a variable course of the riverbed, and the stream creates numerous rapids, i.
In order to understand the morphology of the studied area, particular attention should be paid to the process of creating any discontinuities associated with the structure of rock massifs acquired under the influence of endogenous factors. They have become weak zones predisposing directions of potential disintegration.
The tertiary displacements of rock masses along faults led to the creation of a diversified sculpture with high lithological variability, including the shape of the main leveling surfaces Czudek The warming up of the climate and the increase in humidity have triggered the processes of deep weathering by producing the significantly thick weathered cover Goodfellow ; Hall et al.
As a result of progressive weathering along the primary surfaces of the discontinuity associated with the processes of swelling and shrinkage, freezing and thawing during cyclic cooling and heating, progressive crumbling of rocks occurred not only at the surface, but also included the subsurface zone Harris et al.
Unlike the endogenous fractures that create a repetitive spatial system unique for a particular rock mass weathering, the exogenous cracks are generally characterised by irregular shape and instability of directions Liszkowski and Stochlak The successive discharge of the weathered material in the periglacial climatic conditions in the area with limited vegetation led to the preservation of the most resistant to deep weathering outcrops with poorly developed divisibility of the rock.
Therefore, in view of the above, direct measurements of cracks have been carried out to determine the role of lithology and rock structure occurring in the Skalni Potok Reserve in the relief formation.
The structure of the residual frost-riven cliffs was study using the electrical resistivity tomography ERT. Geophysical methods such as the electrical resistivity tomography ERT , the ground penetrating radar GPR or the seismic refraction tomography are used in the study of cliffs.
Deparis et al. Authors underlined that applicability of geophysical techniques depends on the site characteristics, but they, however, significantly contributed to delineate the geometry and the volume of the potential unstable blocks.
Jeannin et al. Examples of such research can be found in the literature, but it should be noted that they also concern the study of sea cliffs Leucci ; Udphuay et al. In the studied area, in the period from August to September and from July to September , geomorphological mapping and geological mapping were performed to identify the highland forms. On the basis of visible outcrops and available exposures, such as frost-riven cliffs and isolated rocks, the rock types were recognised.
The fracture measurements were taken on available rocks and cliffs. The strike azimuth and the dip angle were measured by a geological compass on randomly selected cracks in the exposure walls. From 30 to , cracks were measured at each measurement point. Their number is associated primarily with the availability of the studied outcrops and the uneven distribution of the crack set assemblies in the measured morphological forms.
This allowed to obtain a representative sample and the measured dip azimuth as well as to determine the directions of main crack systems occurring in the studied rock mass. In order to illustrate the subsurface structures of rock, the electrical resistivity tomography ERT was used as a non-destructive and non-invasive method of measurement Schrott and Sass ; Akca ; Amini and Ramazi ; Kowalczyk et al. The profiles were made on a steep, southern slope of the valley in accordance with the counter line.
As a result, two-dimensional 2D geoelectric cross sections were obtained Loke Their orientation is related to the occurrence of primary discontinuity zones. The analysis does not take into account cracks resulting from primary partibility schistosity. In the highest parts of the valley, the cliffs with WSW—ENE and W—E orientation exist, where their formation is very likely determined by bedding, not vertical cracking.
These cliffs most probably represent the primary surface being the oldest forms within the valley. The development of forms within the study rock mass, apart from the orientation of cracks, was also influenced by the processes of selective mechanical weathering frost , especially during the impact of the cold periglacial climate. It should be stated that the comparison of the crack directions in both locations is compatible with predicting cliffs for weathering in these directions.
On this basis, the authors conclude that the NW—SE and NE—SW fracture systems are gneiss dominant directions in this area, and thus, they are responsible for the current valley morphology.
In order to identify subsurface discontinuity zones within the gneissic cliffs, measurements of ERT were taken. In the remaining part, loosely packed rock material was stabilised with fine-grained material and partially covered with vegetation. The next layer with the electrical resistivity values from 1. The P2 profile made on the roof of the cliff has a two-layer structure of the rock mass Fig. The first layer with the electrical resistivity from 1.
The middle part of the profile lens of much smaller resistivity values 0. The P3 profile was located parallel to the P2 profile at the foot of the studied cliff. The floor of weathered layer was not reached Fig. Compared to previous profiles, the P3 profile does not have a layered structure.
The layer with the electrical resistivity from 1. Similarly, to the P2 profile, the waterlogged places are noticeable as an accumulation of water feeding neighbouring watercourses. On the P1 and P2 profiles made on the cliffs, the cracks zone has a smaller thickness than at the foot of the cliff, which is a water reservoir transported down the slope.
The activation of both primary tesktural and secondary tectonic areas of discontinuity in directly exposed outcrops depends both on temperature and humidity.
The gneiss occurring in the studied area, as a crystalline rock of increased resistance due to the fact that it was exposed to cyclic freezing and thawing during the Pleistocene period Czudek , significantly reduced its mechanical strength Rapp by increasing porosity and microcracks Le Pera et al. This led to the fragmentation and increase in the weathering front and, as a consequence, the disappearance of some of the drained outcrops.
The evolution of the Skalni Potok landforms did not end with the decline of the Ice Age. The electrical resistivity tomography ERT measurements indicated that despite the occurrence of primary discontinuity zones, the reactivated secondary fractures played a decisive role in the evolution of the valley, i. The ERT method was not used before in this area in the study of relict relief. This method proved to be excellent in the study of metamorphic rocks with a dense crack system and allowed to determine the depth of the weathering frontage and water infiltration zones.
Studies also claimed that not insignificant in the presence and location of the measured rock outcrops are quartz intrusions that determine the selective way of sharp weathering. It should be remembered that the obtained results are qualitative and it is difficult to determine the exact thickness of the layer or the degree of the cliff weathering, and therefore, it would be worth completing the obtained results with other available information e. Acta Geophysicavol 64 2 — Amini A, Ramazi H Application of electrical resistivity imaging for engineering site investigation.
Acta Geophysica 64 4 — Google Scholar. Demek J Comarison of cryoplanation terraces in Siberia and Europe.
Deparis J, Jongmans D, Garambois S et al Geophysical detection and structural characterization of discontinuities in rock slopes. In: Rockfall engineering.
Wiley, ISTE, pp 1— Ehlen J Some effects of weathering on joints in granitic rocks. Goodfellow BW Relict non-glacial surfaces in former glaciated landscapes. Earth Sci Rev 80 1—2 — Geomorphology —— Harris Ch, Arenson L, Christiansen HH et al Permafrost and climate in Europe: monitoring and modelling thermal, geomorphological and geotechnical responses.
Earth Sci Rev — In: Lacerda et al eds Landslides: evoluation and stabilization. Acta Geophysica 65 1 , Springer, Cham, pp — Leucci G Geophysical investigations to study the physical—mechanical characteristics of the rock in a coastal environment: the cliff of Roca Lecce, Italy. J Geophys Eng — Geotomo Softw Manual, Penang. Pearson Hall, Harlow.
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Prirodovedecky sbornik Ostravskeho kraje 15 1 :1—15 in Czech. Rapp A Recent development of mountain slopes in Karkevagge and surroundings, in Northern Scandinavia. Geogr Ann 42A— Fundamentals and principles of petrophysics, vol Elsevier, Amsterdam. Schrott L, Sass O Application of field geophysics in geomorphology: advances and limitations exemplified by case studies.
Relict landslide development as inferred from speleothem deformation, tectonic data, and geoelectrics. Effects of lithology, relief and glacial history. Acta Univ Carol Geogr — Geophys J Int —
Regionalizacja tektoniczna Polski-Polska południowo-zachodnia
Organic matter occurring in Lower Palaeozoic rocks of variable lithology was investigated for its origin, depositional environment and thermal maturity. Samples from nine boreholes located in the Polish part of the Peribaltic Syneclise were collected for performing Rock-Eval Analysis, palynological investigation for Thermal Alteration Index TAI , solvent extraction, preparative layer chromatography PLC and gas chromatography-mass spectrometry GC-MS of aliphatic and aromatic compound fractions. It was found that kerogen belongs to either type I or commonly, to type II. Organic matter is in the thermal evolution stage from late diagenesis to advanced metagenesis.
Regional geology of Poland
The student should know the principles of geology. Basic knowledge of structural analysis, geological mapping, plate tectonics and knowledge gained during geological field courses is required. Definition and classification of tectonic units used in a hierarchic structure of regional sub-divisions. Localization of tectonic units of Poland in the geological structure of Europe. Hierarchic sub-division of Poland into tectonic units and their detailed characteristics. Structure of the lithosphere, origin, definitions and classification of high-rank tectonic units within the lithosphere lithospheric plates, platforms, young orogenic belts.
According to the definition by Depciuch and Lis it is "a set of tectonic structures formed by a single, distinct tectonic phase". Formations which together form a structural stage are not a result of continuous sedimentation, but were tectonically deformed together. They are also characterised by a similar stage of metamorphosis. Therefore, any structural level is a product of one phase of the tectonic evolution of a continental platform which relates both to the crystalline basement and the sedimentary cover. This structural stage constitutes a single sedimentary-diastrophic cycle. The term has been introduced in the context of geosynclinar theory, and was related to one cycle of a closing geosyncline.
Barmuta J. Dokumentacja otworowa, — Multi parameter seismic signature of reef-like objects within the permian carbonate deposits. Extended Abstracts, 1, PO Karnkowski P.