National Repository of Grey Literature 11 records found  1 - 10next  jump to record: Search took 0.00 seconds. 
Cave of the Krkonoše National Park: cave fill and speleogenesis
Bosák, Pavel ; Tásler, R. ; Šťastný, Martin ; Hercman, H. ; Mikysek, Petr ; Pruner, Petr ; Kdýr, Šimon ; Matoušková, Šárka ; Rohovec, Jan
Sub-/vertical phreatic channels dominate in original cave morphologies together with ceiling half-channels, scallops and ceiling cupolas. Infiltration cave sediments are composed of lutitic component with some coarser authochthonous admixture. Sediments were locally re-distributed by intensive drip from open fissures. According to clay and heavy minerals, the primary source was in weathering products of crystalline rocks, mature and immature or polycyclic mixed in different proportions. No allogenic sediments were detected. Speleothem dating indicates, that caves were filled and exhumed several times, partially or fully. Normal polarization of samples proved the deposition within the Brunhes Chron (<773 kyr). Speleothems and rare paleontological remains date clastic sediments to >400 kyr. Speleothems crystallized mostly during interglacials, but also in cold and extremely cold periods in glacials (MIS 2, MIS 6c to 6a, MIS 8b, MIS 10c to 11a). Tectonical near-surface rock fissuration and corrosion substantially contributed to cave re-shaping by rock falls. Cryogenic processes modified the morphology of cave walls and damaged speleothems. Mostly ascending speleogenesis took part in substantial depths under the surface without any link to the present morphology. Present near-surface position of most of caves reflects the gradual uplift during younger tectonic phases and incision of river systems.
2TDK Railway, profile P18. Datings. Final Report.
Bosák, Pavel ; Zupan Hajna, N. ; Hercman, H. ; Horáček, I. ; Kdýr, Šimon ; Kogovšek, B.
Samples for datings were taken in the railway construction (2TDK) near village of Divača, Classical Karst on October 12, 2021: (1) vertebrate bones in cave 2TDK – 002 at the profile P18, cave entrance appeared during the construction operations on cleaned karst surface in a wall of karst depression. Samples of mammal bones and gastropods were collected in situ on cave bottom, and (2) pieces of speleothems occurring in non in situ position on artificially planated surface near the cave opening were collected. U-series: no numerical date was obtained as geochemistry of sample indicate open system, probably due to recrystallization of sample in soil cover. Paleomagnetism: The transition of N- and R-polarized samples cannot be identified more precisely as U-series radiometric dating yielded no numerical results. The transition easily can represent Brunhes/Matuyama boundary (at 773 ka) as well as any of older such transitions (e. g., base of Jaramillo, base of Olduvai). In any case the speleothem grew in a closed cave space with roof, probably as flowstone (inclusion of red soils above the base) and later as baldachin on eroded allogenic fill of the paleocave. Vertebrate paleontology: bone remains of small and larger vertebrates represent subrecent to Holocene species. Sorex alpinus represents the species quite rare in fossil record, but recetly limited to variegated woodland habitats with high surface humidity. A chamois Rupicapra rupicapra represents a resident species present in Slovenia throughout all stages of a glacial cycle, recently restricted to mountain habitats.
Use of handheld Raman spectrometers for identification of secondary minerals in situ
Kdýr, Šimon ; Jehlička, Jan (advisor) ; Culka, Adam (referee)
Summary: The sulfates are secondary minerals, that are occurring in the different terrestrial conditions. Their study is useful for understanding of the processes, that are leading to occurence the acid mine drainage. Next sphere of research is out of our globe (it means Mars). The Raman spectroscopy is nondestructive analytical method, that it is advantage of this method. It has occured great development on the field of miniaturisation in a few last years. It is opportunity for aplication out of laboratory and it is possible to make a study in field conditions. At the introduction, this work is occupied with instrumentations, advantages and disadvantages of the use mobile Raman spectrometers. You find there summarises publications, that are occupied with mineralogy, origin of sulfates and opportunities of application mobile Raman spectrometers for their study. At the end of the recherche, it shows some particular localities, where it could be applicable for study sulfates by Raman spectroscopy and where mobile Raman spectrometers were used for identification of sulfate minerals.
Estimation of structural state of carbonaceous matter of metasedimentary rocks using Raman spectroscopy
Kdýr, Šimon ; Jehlička, Jan (advisor) ; Machovič, Vladimír (referee)
Metamorphic processes can transform the organic matter in sedimentary rocks into structurally organized carbonaceous matter, in ideal conditions to graphite. In the centre of West Alpine arch, the metasedimentary rocks are rich in dispersed carbonaceous matter and were used in this thesis to specify the thermal range of metamorphism based on the structural state. Previous studies have used mainly the Raman spectrometers to determine the structural state of carbonaceous matter. Unfortunately this method doesn't allow in-situ analyses which, in addition to Earth studies, can be essential for studying other planetary bodies and moons of our solar system. As only the smallest and lightest instruments are required for analyses during potential planetary missions to Mars, it is important to verify that the small instruments are able to detect even the small concentrations of carbonaceous matter. Currently available miniature and portable Raman spectrometers have started to become more precise but are still not as precise as laboratory Raman microspectrometers. This thesis is divided into two parts. First part aims to duplicate the results from previous studies by Raman microspectrometers in the West Alpine arch. Furthermore, the excitation laser wave length dependence of spectral signs in carbonaceous...
Use of handheld Raman spectrometers for identification of secondary minerals in situ
Kdýr, Šimon ; Jehlička, Jan (advisor) ; Culka, Adam (referee)
Summary: The sulfates are secondary minerals, that are occurring in the different terrestrial conditions. Their study is useful for understanding of the processes, that are leading to occurence the acid mine drainage. Next sphere of research is out of our globe (it means Mars). The Raman spectroscopy is nondestructive analytical method, that it is advantage of this method. It has occured great development on the field of miniaturisation in a few last years. It is opportunity for aplication out of laboratory and it is possible to make a study in field conditions. At the introduction, this work is occupied with instrumentations, advantages and disadvantages of the use mobile Raman spectrometers. You find there summarises publications, that are occupied with mineralogy, origin of sulfates and opportunities of application mobile Raman spectrometers for their study. At the end of the recherche, it shows some particular localities, where it could be applicable for study sulfates by Raman spectroscopy and where mobile Raman spectrometers were used for identification of sulfate minerals.

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