MELEKHOVO HORIZON: A NEW STRATIGRAPHIC UNIT OF THE GZHELIAN STAGE, UPPER CARBONIFEROUS (EAST EUROPEAN PLATFORM)

Abstract

The decision of March 9, 1992, of the Bureau of the Interdepartmental Stratigraphic Committee to change the position of the Carboniferous-Permian boundary, and, hence, of the upper Gzhelian boundary, in the general stratigraphic scale necessitated the identification of a new Gzhelian horizon in a stratotype locality of the Russian Platform. A stratotype was chosen in the Melekhovo-Fedotovo quarry, in outcrops from the Moshachikha ravine, and in an open pit near the Klyazminskii Gorodok village, all in the vicinity of Kovrov City, Vladimir District, the Oka-Tsna arch. The new unit is suggested to be termed as the Melekhovo Horizon. Type sections with fusulinids and conodonts were described bed by bed in outcrops and boreholes. The boundary deposits between the Noginsk and newly identified Melekhovo horizons were correlated in the Moscow, Ivanovo, and Yaroslavl districts and in Tatarstan. New fusulinid species are described, and photomicrographs of typical species from the Daixina bosbytauensis-D. robusta Zone are presented.