ABSTRACT
Formerly known as “Altenberg granite porphyry” (GP), the multiple intrusion of dykes and subvolcanic stocks of the Upper Carboniferous porphyritic microgranite of Altenberg-Frauenstein is characterized through its large textural variability. Most enigmatic appear plagioclase mantled K-feldspars so that the microgranite may be considered as rapakivi granite. Its geochemical characteristics and petrographic evidence indicate magma mixing and mingling processes. The microgranites show field, textural and geochemical evidence suggesting that they have formed as a result of the interaction between felsic and mafic magmas.
