Abstracts for Annual Meeting of Japan Association of Mineralogical Sciences
2012 Annual Meeting of Japan Association of Mineralogical Sciences
Session ID : R8-13
Conference information

R8: Metamorphic rocks and tectonics
Microstructural records of multiple retrograde local fluid infiltrations in the pelitic gneiss
Aya NakamuraMasao Kitamura*Tetsuo Kawakami
Author information
CONFERENCE PROCEEDINGS FREE ACCESS

Details
Abstract
The alkali-feldspar (Akfs) and biotite in the pelitic gneiss preserves characteristic microstructural evidence of multi-stage H2O supplement during the retrograde metamorphism. The first one is ‘zoned feldspar’, in which mesoperthitic, anti-perthitic and lamella-free plagioclase zones coexist within single crystal. It is occasionally found next to biotite, and is always depleted in orthoclase component toward biotite. The second one is the serrate boundary between Akfs and biotite. These microstructures formed as the biotite grew by consuming potash in Akfs when H2O-bearing fluid passed through the grain boundaries. The former was formed at 825-900 oC. The former will be reported in detail. 
Content from these authors
© 2012 Japan Association of Mineralogical Sciences
Previous article Next article
feedback
Top