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7478244 
Journal Article 
Metamorphic history and geochemistry of a low-grade amphibolite in the Kaserer formation (marginal Bundner Schiefer of the western Tauern window, the Eastern Alps) 
Frisch, W 
1984 
0 
Schweizerische Mineralogische und Petrographische Mitteilungen
ISSN: 0036-7699 
64 
1-2 
193-214 
English 
The study of a low-grade amphibolite probably representing an original dolerite sill from the Lower Cretaceous Kaserer formation of Austria is reported. Microprobe analyses of relict amphiboles of an early metamorphic event show that the later regional metamorphism is of low-grade type, with a lower P-T regime. Studies of amphibole, plagioclase, epidote and chlorite demonstrate that the low-grade metamorphism was prograde, increasing from NE to SW. Chemical compositions of the amphiboles correspond largely with those of ocean-floor basalt (MORB), which has been partly spilitized and contaminated with potassium. In geological terms, the depositional environment of the Kaserer formation is regarded as a small basin on the thinned slope of the south margin of the Middle Penninic microcontinent.