Магматические формации Болгарии

E. Dimitrova, D. Bahneva, B. Mavrudciev, B. Kamenov. Y. Yanev. Magmatic Formations in Bulgaria. In the present paper the results of the detailed petrographic study of the igneous rocks of Bulgaria are summarized. The magmatic development and its relationship to the tectonic is discussed from the formation analysis viewpoint. Representatives of three major structural types are known on Bulgarian territory: platforms (Moesian 'plate'), folded zones (the Balk anides and Srednogorie, the Sakar-Strandža zone included), and activation zones (the Rhodope massif). Three main stages in the tectonic development of the folded zones are determined: geosynclinal, inversional and consolidation stages. The inversional stage is subdivided into early and late substages. In the course of the formation analysis the definitions of Yu. A. K u z n e t c o v (1964) have been used. Two classes of igneous rock associations (formations) have been determined: effusive and intrusive ones. Within the folded zones of Bulgaria the following formations are characterized: spilite-diabase and ultramafic-alpinotypic (geosynclinal stage), basalt-andesitic and gabbro-plagiogranitic (early inversional stage), granit-granodioritic (batholitic), gabbro-diorit-granodioritic and gabbro-monzonite-syenitic (late inversional stage), and basalt-rhyolitic and alkaline gabbro-syenitic (for the consolidation stage). The activization zones are characterized by the andesite-trachyandes iterhyolitic, the rhyolitic, and the gabbro-monzonite-syenitic formations.