This diploma thesis deals with the oldest recognized deformation microstructure of felsic granulites of Blanský les (southern Bohemian Massif) in order to understand their lower crustal deformation history later altered during exhumation. Moreover, the study is focused on decomposition of ternary feldspars in the proto-phase of evolution of granulite microstructure. Based on the structural and microstructural analyses of the less developed cleavage I. and the more developed cleavage II., it was possible to distinguish between two deformation structures. The S1 is defined by compositional banding of alternating quartz bands with bands rich in plagioclase, garnets and with porphyroclasts of alkaline feldspars. The S1 cleavage is transposed into the S2 cleavage. During intense reworking of S1 into S2, the quartz bands were decomposed and recrystallized into the ribbons. The feldspar thermometry of the cleavage I. and II. allowed to distinguish the three stages of decomposition of feldspars. A continuous temperature decrease was observed as reflected by the individual microstructures. The quantitative microstructural analysis indicate the shape preferred orientation of the grain boundaries of two-feldspar matrix. The shape preferred orientation of cleavage I. is controlled by the albite rim, however after its...
Identifer | oai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:388354 |
Date | January 2018 |
Creators | Jirků, Markéta |
Contributors | Jeřábek, Petr, Závada, Prokop |
Source Sets | Czech ETDs |
Language | Czech |
Detected Language | English |
Type | info:eu-repo/semantics/masterThesis |
Rights | info:eu-repo/semantics/restrictedAccess |
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