Vydřiduch - Vydřiduch

Zavírka is a natural monument ev. No. 1163 east of the village Svojkovice in the district Rokycany. The reason for the protection is an important site of fauna fossils in the Klabava Formation of the Czech Ordovician. From the stratigraphic point of view, it is around the boundary of the Corymbograptus v-similis and Holograptus tardibrachiatus biozones, one of the richest habitats of the Corymbograptus v-similis biozone. The Zavírka natural monument is also a typical locality with the occurrence of the species Corymbograptus pigeons. The natural monument is located at an altitude of 396–408 meters approximately one kilometer northeast of the village of Svojkovice on the left bank of the Chejlava brook, [3] also called Chýlava, Těškovský brook, Úzký brook or Vydřidušský brook. From the geomorphological point of view, this area is part of the Holoubkov basin district, which belongs to the sub-district Hořovická brázda. [2] The protected site is located on land owned by a private owner. [2] The protected area consists of a partially exposed steep, almost perpendicular slope, 2-3 meters high. Above the upper edge of the escarpment, this area continues through a sloping terrain - a scree slope covered with spruce thickets - with a site of Ordovician fauna. The main rocks here are Paleozoic clay shales along with Quaternary sediments. [2]