Kazan Stage

(named after the city of Kazan), one of the stages of the Upper Permian system. The name was introduced by the Russian geologist A. V. Nechaev in 1915. The Kazan stage is divided into two horizons: the lower, or Kama, horizon contains brachiopods (Spirifer rugulatus, Productus hemi-sphaeriumX and the upper, or Krasnovidovo, horizon has pele-cypods (Pseudomonotis speluncaria ) and gastropods. Deposits of the Kazan stage are widespread in the eastern and northern parts of the Eastern European Platform, where they are represented by marine and lagoon-marine strata and by continental red formations (Belebei formation). Deposits of petroleum and hard coal are found in the Kazan stage. Analogues of the Kazan stage are found in the coal-bearing deposits of the Tungus formation (Eastern Siberia) and may also be identified among the Permian deposits of Western Europe (Zechstein).