Description:
<jats:p>In the Lozen Mountain the rocks of the Ordovician System differ from the Ordovician rocks in the western Balkan Mts. in their composition, structure and relationship to the underlying diabase-phyllitoid complex. In the present paper they are described as a formal lithostratigraphic unit named Kroushovitsa Formation, which comprises four members. In ascending order these members are: Souha Gabra Member comprising metaconglomerates, meta-psammites with fragments of green schists, meta-tuffs and quartzites of the diabasephyllitoid complex; Choukite Member built of graygreenish phyllitized siltstones; Chouchouralchal Member comprising red phyllitized siltstones intercalated with yellow to light red meta-psammites, and Kitka Member represented by gray-greenish phyllitized siltstones intercalated with lamina of dark-gray to black argillites and siltstones. All rock varieties in the Kroushovitsa Formation have been subjected to week metamorphic alteration in greenschist facies that progressively attenuates from the lower to the upper levels of the section. The rock composition, structure and texture of the sequence in the Kroushovitsa Formation indicate for predominantly deep-sea sedimentation. In the lower part of the formation coarse clastic rocks indicate a shallowwater shelf environment.</jats:p>