VOLUME 20 (3)/June 1990

P. V. Tchoumatchenco, S. P. Cernjavska. The Jurassic System in East Stara Planina. II. Palaeogeographic and palaeotectonic euolution. A reconstruction of the palaeogeographic environment during the deposition of the Lower Jurassic sediments indicates the existence of a turbidite trough infilled with proximal sediments (forming the deep-sea Hadzievdol Fan Delta) and distal basin turbidites. This trough originated as a result of extension during the Pliensbachian and Toarcian. South of it there was a shelf basin bounded on the south by the exotic Zlatarski Ridge. These isopic zones are grouped into a new Early-Middle Jurasic tectonic unit – the Matorids, bordered on the south by the Vardar ocean. The destruction of the Matorids, in conditions of convergence, began during the Aalenian and their main uplift occurred during the Bajocian and in the beginning and the middle of the Bathonian when olistolites of different size were transported into the basin. During the collisional stage, which began in the end of the Bathonian, the areas emerged above sea level – a phenomenon probably related to subduction of the Vardar ocean below the Pontids and their prolongation – the Zlatarski Ridge.
   At present, in the area of East Stara Planina, the Jurassic sediments form a long and narrow Austrian tectonic structure – Mator Mts. anticline, with preserved northern, southern or in rare cases – both limbs.
   The contribution is accompanied by 4 appendices which describe in detail the Early-Middle Jurassic dynocysts (Dodekova), miospores (Cernjavska) and foraminifers (Trifonova) in the Luda Kamčija Group. Correlations are also made between Kotel Formation and some Upper Cretaceous olistostrome formations in East Stara Planina and Elena-Tvârdica Stara Planina which were incorrectly referred in the past to the Kotel Formation (Sapunov).