Paleogeography and Sediment Formation during the Paleogene in the Eastern Rhodope Mountains

The paleogeographic and facial conditions during the Paleogene in the East Rhodopes and their significance for the formation of sediments is analysed. In most cases the conditions in the basin are typified by the presence of three well-individualized facial zones: littoral, reefy and internal.
   The carbonate forming processes were of reef character and occurred in the confines of the reefy facial zone. According to its shape the latter was of linear (coastal or barrier) and areal type.
   The clay-forming processes developed in specific conditions: in the confines of the internal facial zone, by dominant terrigenous sedimentation and presence of well-developed reef barrier along the land which supplied the terrigenous material.
   Pure volcanic tuffs formed thick deposits also in the confines of the internal facial zone, independently of the depth of the basin, in the presence of intensive volcanism and a well-developed reef barrier along the neighboring Iand.
   Intensified coarse terrigenous (psephitic and psammitic) sedimentation occurred in the confines of the littoral facial zone and particularly in trough-like depressions, intermontane basins and graben-like depressions characterized by intensive subsidence.