The problems about the conditions, sequence of events and age of the metamorphism in the Rhodope Massif are amongst the critical issues of the geological evolution of the Balkan Penisula and the Eastern Mediterranean. Many geologists have recognized mineral parageneses belonging to several metamorphic events although the interpretation differs from the attribution of these events to a single and relatively short process to their referring to different phases and even orogenic cycles. The radio geochronological evidence being still scarce, the age of the metamorphic events is sought for within a large time interval: from the Precambrian (Early, Middle or Late Proterozoic), through the Paleozoic (Hercynian cycle) to Mid- of Late Cretaceous time.
The Editorial Board of Geologica Balcanica hopes that the opening of the present discussion would stimulate more colleagues in submitting and publishing their results on the pages of the journal. Therefore, the first two papers published hereafter step out of the pure comments on a previously published paper and the due answer, and are aiming at such a wider discussion.