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Solid phase inclusions in minerals from eclogites, peridotites and granulites in the Kutná Hora Complex
Jedlička, Radim ; Faryad, Shah Wali (advisor) ; Svojtka, Martin (referee)
Studium pevných inkluzí vybraných minerálů eklogitů, peridotitů a granulitů Kutnohorské oblasti English abstract Felsic granulites with lenses and boudins of garnet peridotites and eclogites, for which UHP conditions have been obtained, commonly occur in the Moldanubian Zone of the Bohemian Massif. However, it is not clear when and how the HP-UHPM rocks were emplaced into the host granulites. The most important question that remains is, whether the felsic granulites also experienced UHP metamorphism. By studying solid phase inclusions and compositional zoning in resistant phases as garnet, we provide evidence of prograde metamorphism of felsic rocks prior to their granulite facies overprint. Finding mono-mineral inclusion of Ti-rich phengite point to prograde evolution of the rocks.Polyphase inclusions of phengite and biotite indicate that it was previously Ti-poor phengite. Another important inclusion is graphite, which could be remnant of micro-diamond inclusion. Well-preserved prograde zoning of major elements in garnet from the felsic granulites is supported by zoning patterns of trace elements, such as titanium, chromium and yttrium and rare earth elements. Both these groups of elements remain heterogeneous at a micro-scale. The garnet profiles reveal that the rocks preserved signs of multiple stages...
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Solid phase inclusions in minerals from eclogites, peridotites and granulites
Jedlička, Radim ; Faryad, Shah Wali (advisor) ; Jelínek, Emil (referee)
English abstract Felsic granulites in the Bohemian Massif are characterized by the presence of small (from decimetres to several houndred metres in size) boudins and lenses of garnet peridotites and high-pressure eclogites. Pressure conditions of the granulites and their mutual metamorphic history with garnet peridotites and eclogites are subject of long discussion. For this purpose, minerals and textures formed at peak pressure conditions were investigated using thin-sections and mineral separates of these rocks from the Kutná Hora complex. As all these rocks underwent granulite facies reequilibrium and subsequent cooling, most inclusions are transformed to lower pressure and temperature phases. In addition to olivine, orthopyroxene and clinopyroxene, garnet from garnet peridotites contains frequent chromium spinel. The host garnet around inclusions shows Cr-rich domains as result of diffusion from spinel to garnet. Rare ilmenite inclusions with high MgO content and pentlandite were also observed in garnet. Orthopyroxene in matrix and rims of large grains have low amounts of Al and the associated clinopyroxene has relatively high jadeite content. Two varieties of eclogites are present in the granulite: eclogites with pyroxenites and garnetites occur within or adjacent to garnet peridotites. Garnets of...
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Tracing of the pre-exhumation history of strongly re-equilibrated high-ultrahigh pressure rocks in a collision orogeny
Jedlička, Radim ; Faryad, Shah Wali (advisor) ; Janák, Marian (referee) ; Schertl, Hans-Peter (referee)
English abstract The investigation of high- to ultrahigh-pressure rocks in the Bohemian Massif occurring as small bodies enclosed in surrounding rocks with a low degree of metamorphism was always focused on their main metamorphic event in granulite facies conditions at very high temperatures. However, recent studies have shown that these rocks underwent a high-pressure metamorphism that preceded the subsequent high-temperature overprint and exhumation of those rocks. The scientific publications that comprise this dissertation thesis present petrological, mineralogical and geochemical research of these (ultra)high pressure rocks from various parts of the Bohemian Massif that have the potential to preserve information about their pre-exhumation history. The findings of the inclusions of high-pressure phases in metamorphic minerals and, in particular, the study of major and trace elements zoning in garnets together with thermodynamic modelling allowed us to describe new temperature-pressure conditions and to refine the metamorphic paths of these rocks. The felsic and mafic granulites of the Kutná Hora Complex in the Moldanubian Zone and the Rychleby Mountains in the East Sudetes preserve the evidence of prograde metamorphism. In addition to the inclusions of phengite and omphacite in the garnet cores, the...
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Tracing of the pre-exhumation history of strongly re-equilibrated high-ultrahigh pressure rocks in a collision orogeny
Jedlička, Radim
English abstract The investigation of high- to ultrahigh-pressure rocks in the Bohemian Massif occurring as small bodies enclosed in surrounding rocks with a low degree of metamorphism was always focused on their main metamorphic event in granulite facies conditions at very high temperatures. However, recent studies have shown that these rocks underwent a high-pressure metamorphism that preceded the subsequent high-temperature overprint and exhumation of those rocks. The scientific publications that comprise this dissertation thesis present petrological, mineralogical and geochemical research of these (ultra)high pressure rocks from various parts of the Bohemian Massif that have the potential to preserve information about their pre-exhumation history. The findings of the inclusions of high-pressure phases in metamorphic minerals and, in particular, the study of major and trace elements zoning in garnets together with thermodynamic modelling allowed us to describe new temperature-pressure conditions and to refine the metamorphic paths of these rocks. The felsic and mafic granulites of the Kutná Hora Complex in the Moldanubian Zone and the Rychleby Mountains in the East Sudetes preserve the evidence of prograde metamorphism. In addition to the inclusions of phengite and omphacite in the garnet cores, the...
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Tracing of the pre-exhumation history of strongly re-equilibrated high-ultrahigh pressure rocks in a collision orogeny
Jedlička, Radim
English abstract The investigation of high- to ultrahigh-pressure rocks in the Bohemian Massif occurring as small bodies enclosed in surrounding rocks with a low degree of metamorphism was always focused on their main metamorphic event in granulite facies conditions at very high temperatures. However, recent studies have shown that these rocks underwent a high-pressure metamorphism that preceded the subsequent high-temperature overprint and exhumation of those rocks. The scientific publications that comprise this dissertation thesis present petrological, mineralogical and geochemical research of these (ultra)high pressure rocks from various parts of the Bohemian Massif that have the potential to preserve information about their pre-exhumation history. The findings of the inclusions of high-pressure phases in metamorphic minerals and, in particular, the study of major and trace elements zoning in garnets together with thermodynamic modelling allowed us to describe new temperature-pressure conditions and to refine the metamorphic paths of these rocks. The felsic and mafic granulites of the Kutná Hora Complex in the Moldanubian Zone and the Rychleby Mountains in the East Sudetes preserve the evidence of prograde metamorphism. In addition to the inclusions of phengite and omphacite in the garnet cores, the...
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Tracing of the pre-exhumation history of strongly re-equilibrated high-ultrahigh pressure rocks in a collision orogeny
Jedlička, Radim ; Faryad, Shah Wali (advisor) ; Janák, Marian (referee) ; Schertl, Hans-Peter (referee)
English abstract The investigation of high- to ultrahigh-pressure rocks in the Bohemian Massif occurring as small bodies enclosed in surrounding rocks with a low degree of metamorphism was always focused on their main metamorphic event in granulite facies conditions at very high temperatures. However, recent studies have shown that these rocks underwent a high-pressure metamorphism that preceded the subsequent high-temperature overprint and exhumation of those rocks. The scientific publications that comprise this dissertation thesis present petrological, mineralogical and geochemical research of these (ultra)high pressure rocks from various parts of the Bohemian Massif that have the potential to preserve information about their pre-exhumation history. The findings of the inclusions of high-pressure phases in metamorphic minerals and, in particular, the study of major and trace elements zoning in garnets together with thermodynamic modelling allowed us to describe new temperature-pressure conditions and to refine the metamorphic paths of these rocks. The felsic and mafic granulites of the Kutná Hora Complex in the Moldanubian Zone and the Rychleby Mountains in the East Sudetes preserve the evidence of prograde metamorphism. In addition to the inclusions of phengite and omphacite in the garnet cores, the...
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Record of assimilation of migmatite xenoliths in the Lipnice granite
Jirků, Markéta ; Jeřábek, Petr (advisor) ; Jedlička, Radim (referee)
This bachelor thesis presents new results on characterization of migmatite xenoliths assimilation, which occurs in the heterogeneous Lipnice granite of the Melechov massif in form of lenses, schlierens and biotite clusters, and aims to identify the relicts of assimilated migmatites in the homogeneous granite. The thesis consists of three main chapters. The first one focuses on a broad introduction into the geology central European Variscides, brief characterization of the Bohemian Massif, lithology of Moldanubian Unit, and evolution of the associated Variscan granite magmatism. Second part of the thesis deals with the granite petrogenesis, and characterization of granite plutons of the Moldanubian batholith, including the northernmost exposure, the Melechov massif. The third part presents results of my own research, which comprises petrography of studied thin-sections and chemical analysis of whole rock and minerals, in particular the micas and feldspars in the Lipnice granite of the Melechov massif. The research is based on analysis of four thin-sections of the Lipnice granite using optical polarization and electron microscope as well as the microprobe. Observing of the chemistry of biotite in xenoliths and in granite and their correlation shows, that biotite in the Lipnice granite is rather homogeneous...
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Solid phase inclusions in minerals from eclogites, peridotites and granulites in the Kutná Hora Complex
Jedlička, Radim ; Faryad, Shah Wali (advisor) ; Svojtka, Martin (referee)
Studium pevných inkluzí vybraných minerálů eklogitů, peridotitů a granulitů Kutnohorské oblasti English abstract Felsic granulites with lenses and boudins of garnet peridotites and eclogites, for which UHP conditions have been obtained, commonly occur in the Moldanubian Zone of the Bohemian Massif. However, it is not clear when and how the HP-UHPM rocks were emplaced into the host granulites. The most important question that remains is, whether the felsic granulites also experienced UHP metamorphism. By studying solid phase inclusions and compositional zoning in resistant phases as garnet, we provide evidence of prograde metamorphism of felsic rocks prior to their granulite facies overprint. Finding mono-mineral inclusion of Ti-rich phengite point to prograde evolution of the rocks.Polyphase inclusions of phengite and biotite indicate that it was previously Ti-poor phengite. Another important inclusion is graphite, which could be remnant of micro-diamond inclusion. Well-preserved prograde zoning of major elements in garnet from the felsic granulites is supported by zoning patterns of trace elements, such as titanium, chromium and yttrium and rare earth elements. Both these groups of elements remain heterogeneous at a micro-scale. The garnet profiles reveal that the rocks preserved signs of multiple stages...
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Solid phase inclusions in minerals from eclogites, peridotites and granulites
Jedlička, Radim ; Faryad, Shah Wali (advisor) ; Jelínek, Emil (referee)
English abstract Felsic granulites in the Bohemian Massif are characterized by the presence of small (from decimetres to several houndred metres in size) boudins and lenses of garnet peridotites and high-pressure eclogites. Pressure conditions of the granulites and their mutual metamorphic history with garnet peridotites and eclogites are subject of long discussion. For this purpose, minerals and textures formed at peak pressure conditions were investigated using thin-sections and mineral separates of these rocks from the Kutná Hora complex. As all these rocks underwent granulite facies reequilibrium and subsequent cooling, most inclusions are transformed to lower pressure and temperature phases. In addition to olivine, orthopyroxene and clinopyroxene, garnet from garnet peridotites contains frequent chromium spinel. The host garnet around inclusions shows Cr-rich domains as result of diffusion from spinel to garnet. Rare ilmenite inclusions with high MgO content and pentlandite were also observed in garnet. Orthopyroxene in matrix and rims of large grains have low amounts of Al and the associated clinopyroxene has relatively high jadeite content. Two varieties of eclogites are present in the granulite: eclogites with pyroxenites and garnetites occur within or adjacent to garnet peridotites. Garnets of...
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