Structural position of high-pressure felsic to intermediate granulites from NE Moldanubian domain (Bohemian Massif)
- Author(s)
- Lucie Taj¿manová, I Soejono, J. Konopásek, Jan Kosler, Urs Kloetzli
- Abstract
At the northeastern edge of the Moldanubian Zone, a large body of felsic to intermediate granulite with relics of high-pressure mineral assemblage is exposed within medium-grade paragneisses, micaschists and metagranites. A polyphase tectonic evolution in the study area resulted in three deformation phases (D1–D3). Peak metamorphic conditions (860–1000 °C and 16 kbar) in granulites are interpreted as reflecting an early stage of the high-grade evolution of the orogenic lower crust. These conditions were followed by exhumation of the orogenic lower crustal block to mid-crustal levels (6–8 kbar). In contrast to this, the study of metamorphic conditions in the surrounding micaschists (660 °C and 8 kbar) shows that these rocks never experienced pressures and temperatures of the orogenic lower crust. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) U–Pb dating of zircon from the granulite yielded a concordia age of 354 ± 7 Ma, whereas the conventional isotope dilution thermal ionization mass spectrometry (ID-TIMS) and LA-ICP-MS dating of xenotime gave identical concordia ages of 336.2 ± 1.2 and 339 ± 3 Ma, respectively. Combination of new structural and petrological results with LA-ICP-MS zircon and xenotime dating leads to development of a well-constrained exhumation model and brings new insights into the behaviour of lower crustal rocks during orogenesis.
- Organisation(s)
- Department of Lithospheric Research
- External organisation(s)
- Charles University Prague
- Journal
- Geological Society Special Publications
- Volume
- 167
- Pages
- 329-345
- No. of pages
- 17
- ISSN
- 0305-8719
- Publication date
- 2010
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 1051 Geology, Mineralogy
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/4facde0e-d37a-4560-8669-f22863e2ac9c