Magmatic muscovite in felsitic parts of rhyolites from Southwest Germany

In felsitic parts of rhyolites from the Permian volcanism in Southwest Germany muscovite phenocrysts of magmatic origin were observed. They occur besides two other light-mica components of secondary formation. A Permian tuff from the SaarNahe area also contains this primary muscovite type.The muscovite, though mainly euhedral, is in some cases corroded by magmatic resorption. Combined with uncorroded, sharp-edged dihexahedric quartz, however, it proves that the acid host lavas during the Saalian tectonic phase rose and extruded in an unusually rapid manner.