Late Viséan foraminiferal assemblages from a section in the Sikasya (Sikaza) River Valley (South Urals) are studied to provide a reliable framework for stratigraphy and correlation of the Viséan-Serpukhovian boundary beds on the western slope of the South Urals. The middle–upper Viséan deposits on the Sikasya River are composed of shallow shelf carbonates with abundant foraminifers, corals, and brachiopods, and are represented by four regional substages: Tulian, Aleksinian, Mikhailovian, and Venevian. This section is known as the “Sikaza Section”. The upper Viséan deposits are overlain by Serpukhovian beds composed mainly of dolomites. The Tulian and Aleksinian successions consist of bioclastic and foraminiferal wackestone and packstone. In the Mikhailovian, there are packages of dolomites with interbeds of bioclastic grainstone to packstone, containing foraminifers. The Venevian is represented by bioclastic and foraminiferal grainstone and packstone. The following foraminiferal units are discussed: in the middle Viséan: (1) Paraarchaediscus koktjubensis–Endothyranopsis compressa; in the upper Viséan: (2) Ikensieformis proikensis–Archaediscus gigas, (3) beds with Vissarionovella (corresponding to the Ikensieformis ikensis Zone), and (4) Ikensieformis tenebrosa; the Serpukhovian is represented by (5) beds with Eostaffellina decurta.

研究了来自 Sikasya（Sikaza）河流域（南乌拉尔）一个剖面的晚 Viséan 有孔虫组合，为南乌拉尔西坡 Viséan-Serpukhovian 边界层的地层学和对比提供了可靠的框架。Sikasya 河中上上游 Viséan 沉积物由浅层碳酸盐岩组成，具有丰富的有孔虫、珊瑚和腕足类动物，以四个区域亚阶为代表：Tulian、Aleksinian、Mikhailovian 和 Venevian。该部分被称为“Sikaza 部分”。上部 Viséan 矿床被主要由白云岩组成的 Serpukhovian 层所覆盖。Tulian 和Aleksinian 层序由生物碎屑和有孔虫的碎屑岩和碎屑岩组成。在米哈伊洛维阶中，有大量的白云岩，其中夹杂着生屑颗粒岩到灰岩，含有有孔虫。Venevian 以生物碎屑和有孔虫颗粒石和颗粒石为代表。讨论了以下有孔虫单位：在中间 Viséan：(1)Paraarchaediscus koktjubensis-Endothyranopsis compressa；在 Viséan 上游：(2) Ikensieformis proikensis-Archaediscus gigas，(3) Vissarionovella床（对应于Ikensieformis ikensis区），和 (4) Ikensieformis tenebrosa；Serpukhovian 由 (5) 张带有Eostaffellina decurta 的床代表。