Kungurian Stage

▪ geology

      last of the four stages of the Lower Permian (Cisuralian) Series, encompassing all rocks deposited during the Kungurian Age (275.6 million to 270.6 million years ago) of the Permian Period. Rock exposures from this stage are well developed in the Ural region in both Kazakhstan and Russia.

      In the Mughalzhar Hills (Kazakhstan) and southern Ural mountain (Ural Mountains) regions (Russia), Kungurian deposits are primarily terrigenous (formed by erosion), consisting of red beds and lagoonal sediment types. Many different kinds of shallow marginal marine, evaporitic (evaporite), and nonmarine strata were deposited here as lateral sedimentary facies to one another. Elsewhere, conglomerates (conglomerate), sandstones (sandstone), and other red beds occur. To the east, thick evaporite sequences of gypsum, halite, and potash form the salt basin of the upper Kama River in Russia. Marine limestones occur in the Russian province of Perm, and reef carbonates occur in the western portions of the Mughalzhar Hills.

      The Kungurian Stage represents the final phase of the Uralian geosyncline as the Uralian orogenic belt continued to move west, closed, and overrode part of the Uralian marine seaway. Evaporites became predominant after this time. In order to establish a consistent Cisuralian conodont-based zonal scheme that would include a definition of the Kungurian, the base of the stage was lowered from its traditional (nonfossiliferous) horizon to contain the first appearance of Neostreptognathodus pnevi and N. exculptus.

      The Kungurian Stage overlies the Artinskian Stage and is, in turn, overlain by the Roadian Stage of the Middle Permian (Guadalupian) Series.

June R.P. Ross Charles A. Ross

 

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