caa a22 4500 47582783X CHVBK 20180406123833.0 cr unu---uuuuu 170329e20000301xx s 000 0 eng 10.1007/s005310050307 doi (NATIONALLICENCE)springer-10.1007/s005310050307 Microstructural evolution and geologic significance of garnet pyriclasites in the Hoher-Bogen shear zone (Bohemian Massif, Germany) [Elektronische Daten] [C. Bues, G. Zulauf] Ductile extensional movements along the steeply inclined Hoher-Bogen shear zone caused the juxtaposition of Teplá-Barrandian amphibolites, granulites, and metaperidotites against Moldanubian mica schists and paragneisses. Garnet pyriclasites are well preserved within low-strain domains of this shear zone. Their degree of metamorphism is significantly higher than that of the surrounding rocks. Microstructural and mineral chemical data suggest in situ formation of the garnet pyriclasite by dehydration of pyroxene amphibolite at T>750-840°C and P<10-13 kbar including recrystallization-accommodated grain-size reduction of plagioclase and clinopyroxene, nucleation of garnet, and breakdown of amphibole into garnet+clinopyroxene+rutile. Subsequent decompression and retrograde extensional shearing led to the formation of mylonitic epidote amphibolite. The presence of lower crustal and mantle-derived slices within the Hoher-Bogen shear zone supports the view that (a) in Upper Devonian times the Teplá-Barrandian unit was thrust over Moldanubian rocks as a complete crustal unit, and (b) that during the subsequent Lower Carboniferous orogenic collapse, the garnet pyriclasite and metaperidotite were scraped off from the basal parts of the Teplá-Barrandian unit being dragged into the Hoher-Bogen shear zone due to dramatic and large-scale elevator-style movements. Springer-Verlag Berlin Heidelberg, 2000 Key words Pyriclasite nationallicence Granulite nationallicence Amphibolite nationallicence Shear zone nationallicence Metamorphism Dehydration nationallicence Hoher-Bogen nationallicence Teplá-Barrandian nationallicence Moldanubian nationallicence Bohemian massif nationallicence Bues C. Celtesstr. 14, D-85051 Ingolstadt, Germany, DE aut Zulauf G. Institut für Geologie und Mineralogie, Universität Erlangen-Nürnberg, Schlossgarten 5, D-91054 Erlangen, Germany, e-mail: zulauf@geol.uni-erlangen.de, Tel.: +49-91 31-8 52 2617, DE aut https://doi.org/10.1007/s005310050307 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s005310050307 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Bues C. Celtesstr. 14, D-85051 Ingolstadt, Germany, DE aut NATIONALLICENCE 700 1- Zulauf G. Institut für Geologie und Mineralogie, Universität Erlangen-Nürnberg, Schlossgarten 5, D-91054 Erlangen, Germany, e-mail: zulauf@geol.uni-erlangen.de, Tel.: +49-91 31-8 52 2617, DE aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer