(after the railroad station Gzhel’ in Moscow Oblast), the second layer from the beginning of the upper series of the Carboniferous system, identified in 1890 by the geologist S. N. Nikitin. The Gzhel’ stage is composed chiefly of dolomites, including brachiopods (Choristites supramosquensis, Buktonia gjeliensis, and others). Of the fusulinids (protozoa) the triticites are characteristic of the Gzhel’ stage (Triticites stuckenbergi, T. jigulensis). Some authors use “Gzhel’ stage” to refer to any series of rock-bearing triticites; however, recently the lower part of these deposits have been considered a separate layer, called the Kasimov stage. In the Urals the deposits corresponding to the Kasimov and Gzhel’ stages are called the Zhiguli and Orenburg stages.
B. M. KELLER