Литология среднеюрских пород Странджанской зоны в Болгарии

G. Čatalov. Lithology of Middle Jurassic rocks from Strandža zone in Bulgaria. The paper reviews the lithology of the Middle Jurassic rocks belonging to Zvezdec (Bajocian Stage), Kazanska (Bajocian Stage), Brašljan Iron-bearing (Bathonian) and Hranova (Bathonian? Stage) Formation. They form the larger part of the East Thracian Group. Data on the petrographic, mineralogical and geochemical composition, texture, metamorphism and conditions of origin of the Middle Jurassic rocks are presented. The sediments of the Middle Jurassic were laid down in open shallow to moderately deep epicontinental sea of normal salinity under conditions of humide climate and active tectonic regime. Two sedimentary zones are distinguished - northern and southern. The southern zone is characterized by the occurrence of iron-bearing sediments and the northern - by intensive gravitalite consedimentary processes (olistostrome phenomena). During the Bajocian Stage there was a tendency to stagnant water basin. The Middle Jurassic rocks were affected by regional (s. s) dynamothermal metamorphism of very low grade. The Circum-Rhodope belt of K a u f m a n n et al. (1976) is not extending in Strandža, more probably it continues into the territory of Turkey (but south of Turkish Strandža Mountain).