Moulas, Evangelos and Burg, Jean-Pierre and Kostopoulos, Dimitrios and Schenker, Filippo (2012) Chemical zoning and ductility of natural garnet at lower crustal conditions: An example from the Rhodope Massif. In: Abstract Volume, 10th Swiss Geoscience Meeting 10th Swiss Geoscience Meeting, Bern, Switzerland.
Full text not available from this repository.Abstract
The Kesebir-Kardamos gneiss dome in the Rhodope Massif (northern Greece – southern Bulgaria) is a late orogenic extensional structure that deformed an Alpine, synmetamorphic nappe complex containing high-pressure (HP) metamorphic rocks. Microdiamond inclusions in garnet of quartzofeldspathic rocks from one of the thrust sheets suggests equilibration at ultrahigh-pressure metamorphic conditions (P>2.5GPa). This study aims at delimiting the P-T conditions of the metamorphic evolution experienced by these rocks. Garnets (10-15% vol, pyrope: 15% grossular:10% almandine:65%) from the aforementioned quartzofeldspathic rocks are chemically zoned. Biotite and kyanite are other major phases of the rock paragenesis. Garnet-biotite-plagioclase-quartz geobarometry and garnet-biotite geothermometry confine the recorded peak conditions at ca 1.0 ±0.1 GPa and 690 ±50 ºC in the stability field of kyanite. The consistency of these results with the metamorphic overprint of HP-metapelites from central Rhodope indicates that the low-pressure (1GPa) metamorphic overprinting event has a regional significance. The lensoid shapes of the chemically zoned garnet crystals place recrystallisation of this mineral phase before the extensional evolution of the Kesebir-Kardamos gneiss dome. Furthermore, the shapes of garnet grains indicate that the ductile deformation of natural garnet crystals is not restricted to ultrahigh-temperature conditions.
| Item Type: | Article in conference proceedings or Presentation at a conference (Poster) |
|---|---|
| Subjects: | Physical sciences > Geology Physical sciences > Geology > Earth science Physical sciences > Geology > Earth science > Geoscience Physical sciences > Geology > Geochemistry |
| Department/unit: | Dipartimento ambiente costruzioni e design > Istituto scienze della terra |
| Depositing User: | Filippo Luca Schenker |
| Date Deposited: | 15 Jan 2018 09:03 |
| Last Modified: | 15 Jan 2018 09:03 |
| URI: | http://repository.supsi.ch/id/eprint/9133 |
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