Evidence of glaucophane-schist facies metamorphism in the East Karkonosze complex, West Sudetes, Poland

1995 ◽  
Vol 84 (4) ◽  
pp. 720 ◽  
Author(s):  
W. Smulikowski
Keyword(s):  
Glaucophane Schist ◽  
Facies Metamorphism ◽  
West Sudetes

Geochemistry and 40Ar–39Ar geochronology of the mafic metavolcanic rocks from the Rýchory Mountains complex (west Sudetes, Bohemian Massif): palaeotectonic significance

1997 ◽  
Vol 134 (5) ◽  
pp. 703-716 ◽  
Author(s):  
HENRI MALUSKI ◽  
FRANTIšEK PATOCČKA
Keyword(s):  
High Pressure ◽  
Low Temperature ◽  
Shear Zone ◽  
Regional Metamorphism ◽  
Variscan Orogeny ◽  
Metamorphic Overprint ◽  
Metavolcanic Rocks ◽  
Facies Metamorphism ◽  
West Sudetes ◽  
Oceanic Island Basalts

The mafic metavolcanic rocks (blueschists and greenschists) of the Rýchory Mountains crystalline complex (West Sudetes) experienced sea-floor hydrothermal alteration (spilitization?) prior to regional metamorphism. The metabasite geochemistry (namely trace element and REE abundances) indicates that the protolith was comparable in composition with (1) tholeiitic to transitional ocean-floor basalts and (2) transitional and alkaline intra-oceanic island basalts. Two main metamorphic events affected the Rýchory Mountains metabasites. In an earlier high pressure–low temperature metamorphic event, the rocks experienced blueschist facies metamorphism. The results of 40Ar–39Ar geochronology studies on phengites from the mafic blueschists date the end of the earlier metamorphism to 360 Ma. The greenschist metamorphic overprint followed around 340 Ma. The elongated bodies of mafic metavolcanic rocks are situated within the prominent NNE–SSW Leszczyniec shear zone following the trend of the Rýchory Mountains and the Rudawy Janowickie Mountains. Both the geochemical affinities and the blueschist facies metamorphism of the metabasites suggest that this shear zone evolved from the Variscan suture dividing western and central terranes of the West Sudetes. According to the radiometric age for the end of the high pressure–low temperature metamorphism, the terranes accreted during the Famennian. A considerable time-span between the formation of the metabasite protolith and the blueschist metamorphism may indicate long-lasting subduction of a large oceanic plate between Gondwana and Laurussia, possibly accompanied by terrane accretion, prior to the Variscan orogeny.

AGE OF ECLOGITE-FACIES METAMORPHISM AND EXHUMATION IN NORTHWESTERN BHUTAN

2016 ◽  
Author(s):  
David J. Young ◽  
◽  
Daniele Regis ◽  
Clare Warren ◽  
Andrew R.C. Kylander-Clark
Keyword(s):  
Facies Metamorphism ◽  
Eclogite Facies

DIVING DEEPER INTO THE PICURIS OROGEN: UPPER AMPHIBOLITE FACIES METAMORPHISM AND BRITTLE DEFORMATION ALONG THE PLOMO SHEAR ZONE

2020 ◽  
Author(s):  
Adrian E. Castro ◽  
◽  
Chloe Bonamici ◽  
Christopher G. Daniel ◽  
Danielle Shannon Sulthaus
Keyword(s):  
Shear Zone ◽  
Amphibolite Facies ◽  
Brittle Deformation ◽  
Facies Metamorphism
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