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Localization of deformation in rocks with existing anisotropy: consequences for geodynamic interpretations
Bukovská, Zita ; Jeřábek, Petr (advisor) ; Stünitz, Holger (referee) ; Grasemann, Bernhard (referee)
Localization of deformation occurs in Earth's crust as a consequence of applied stress and is widespread phenomenon that can be found in crustal rocks. Such localization of deformation can be mostly seen in a form of shear zones. Small shear zones referred as shear bands or S-C structures are often used as kinematic indicators. However, the evolution and kinematic continuity of such structures is not well identified, which makes it problematic when interpreting regional geodynamic evolution. Two possible cases were distinguished and described in this thesis: a) kinematically discontinuous S-C structures formed during two deformation events and b) kinematically continuous S-C structures formed during single deformation event. Kinematically unrelated S-C structures were studied in westernmost part of Tauern Window in Eastern Alps and in Gemer-Vepor Contact Zone in Central West Carpathians where previous geodynamic interpretations might have misinterpreted localization structures. Kinematically continuous shear bands were studied in South Armorican Shear Zone where the S-C fabrics were originally defined and described (Berthé et al., 1979). Two fabrics that crosscut each other at small angles forming S-C geometries were documented during field work and studied from macroscale down to microscale or...
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Localization of deformation in rocks with existing anisotropy: consequences for geodynamic interpretations
Bukovská, Zita
Localization of deformation occurs in Earth's crust as a consequence of applied stress and is widespread phenomenon that can be found in crustal rocks. Such localization of deformation can be mostly seen in a form of shear zones. Small shear zones referred as shear bands or S-C structures are often used as kinematic indicators. However, the evolution and kinematic continuity of such structures is not well identified, which makes it problematic when interpreting regional geodynamic evolution. Two possible cases were distinguished and described in this thesis: a) kinematically discontinuous S-C structures formed during two deformation events and b) kinematically continuous S-C structures formed during single deformation event. Kinematically unrelated S-C structures were studied in westernmost part of Tauern Window in Eastern Alps and in Gemer-Vepor Contact Zone in Central West Carpathians where previous geodynamic interpretations might have misinterpreted localization structures. Kinematically continuous shear bands were studied in South Armorican Shear Zone where the S-C fabrics were originally defined and described (Berthé et al., 1979). Two fabrics that crosscut each other at small angles forming S-C geometries were documented during field work and studied from macroscale down to microscale or...
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Localization of deformation in rocks with existing anisotropy: consequences for geodynamic interpretations
Bukovská, Zita ; Jeřábek, Petr (advisor) ; Stünitz, Holger (referee) ; Grasemann, Bernhard (referee)
Localization of deformation occurs in Earth's crust as a consequence of applied stress and is widespread phenomenon that can be found in crustal rocks. Such localization of deformation can be mostly seen in a form of shear zones. Small shear zones referred as shear bands or S-C structures are often used as kinematic indicators. However, the evolution and kinematic continuity of such structures is not well identified, which makes it problematic when interpreting regional geodynamic evolution. Two possible cases were distinguished and described in this thesis: a) kinematically discontinuous S-C structures formed during two deformation events and b) kinematically continuous S-C structures formed during single deformation event. Kinematically unrelated S-C structures were studied in westernmost part of Tauern Window in Eastern Alps and in Gemer-Vepor Contact Zone in Central West Carpathians where previous geodynamic interpretations might have misinterpreted localization structures. Kinematically continuous shear bands were studied in South Armorican Shear Zone where the S-C fabrics were originally defined and described (Berthé et al., 1979). Two fabrics that crosscut each other at small angles forming S-C geometries were documented during field work and studied from macroscale down to microscale or...
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Localization of deformation in rocks with existing anisotropy: consequences for geodynamic interpretations
Bukovská, Zita
Localization of deformation occurs in Earth's crust as a consequence of applied stress and is widespread phenomenon that can be found in crustal rocks. Such localization of deformation can be mostly seen in a form of shear zones. Small shear zones referred as shear bands or S-C structures are often used as kinematic indicators. However, the evolution and kinematic continuity of such structures is not well identified, which makes it problematic when interpreting regional geodynamic evolution. Two possible cases were distinguished and described in this thesis: a) kinematically discontinuous S-C structures formed during two deformation events and b) kinematically continuous S-C structures formed during single deformation event. Kinematically unrelated S-C structures were studied in westernmost part of Tauern Window in Eastern Alps and in Gemer-Vepor Contact Zone in Central West Carpathians where previous geodynamic interpretations might have misinterpreted localization structures. Kinematically continuous shear bands were studied in South Armorican Shear Zone where the S-C fabrics were originally defined and described (Berthé et al., 1979). Two fabrics that crosscut each other at small angles forming S-C geometries were documented during field work and studied from macroscale down to microscale or...
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Exhumation of mid-crustal rocks by a brittle-ductile unroofing mechanism, an example from the Veporic crystalline complex in the West Carpathians
Bukovská, Zita ; Jeřábek, Petr (advisor) ; Milovský, Rastislav (referee)
Study of the structural and metamorphic record of the eastern part of contact zone within Vepor and Gemer units in Central West Carpathians has interpreted the burial and exhumation in the evolution of alpine orogeny. The studied area is built by granitoid rocks of Vepor basement and metapelites of cover sequences both Vepor and Gemer units. Three structural fabrics have been identified in the area, which are correlated with so far described deformation stages. Higher metamorphosed rocks with presence of two generation garnets were found out within lower metamorphosed metapelites of cover sequences. From the garnet - biotite thermometry the metamorphic conditions for the rims were established to 550-580řC. Whereas muscovite and in some case chlorite, are the only metamorphic phases in neighbouring cover rocks. Three generations of white micas are documented within structural fabrics. The oldest muscovites, magmatic in origin (Ms1), younger phengites (Phg) present in fabrics S1 and youngest muscovites (Ms2) present in fabric S2. The study of quartz microstructures distinguished aggregates and from aggregates coming band microstructures. These are mostly found in deformed granitoids, sometimes also in cover quartzites and can have sigma-shape geometry. The aggregate microstructure, representing S1...
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