Enclaves in the S-type granites of the Kosseine Massif (Fichtelgebirge, Germany): implications for the origin of granites

The Hercynian peraluminous granites of the Kosseine massif differ in composition and content of enclaves from the other granites of the Fichtelgebirge. They are garnet-, cordierite- and andalusite-bearing S-type granites containing at least five different types of enclaves. Based on petrography and geochemical data, including radiogenic isotopes, it is concluded that the Kosseine granites represent an independent intrusion among the Fichtelgebirge granites formed by a combination of incomplete restite unmixing, assimilation and probably fractional crystallization in the course of magma formation, ascent and emplacement.