Abstract—

This paper presents new data on the biostratigraphy and sedimentology of upper Viséan and Serpukhovian deposits (Lower Carboniferous) from boreholes in the southeast of the East European Platform around the Sol-Iletsk Swell (Orenburg oblast). Using rock lithology, sublatitudinal facies zones are recognized in the studied area. The deposits are represented by open shallow shelf facies, up to 500 m thick, in the area of the Sol-Iletsk Swell and near-side zone of the Preuralian Foredeep. To the south, at the margin of the Northern Pericaspian, their thickness sharply decreases to 36 m, and the succession is composed of carbonate-clay sediments of the relatively deep shelf. On the basis of foraminifers and conodonts, the upper Viséan and Serpukhovian are subdivided using the regional substages of the stratigraphic scheme of the East European Platform, and foraminiferal zones are recognized. The base of the Serpukhovian in the high-energy shallow-water facies of the open shelf is drawn by the entry of the foraminifers Janischewskina delicata and Endothyranopsis plana; in lower energy facies, it is placed at the level of the first appearance of Neoarchaediscus postrugosus; in the clay-carbonate facies of the relatively deep shelf, it is drawn according to the appearance of the conodont Lochriea ziegleri. The distribution of microfauna from five boreholes, the characteristics of the foraminiferal zonal assemblages, and the interregional correlation are discussed.

中文翻译：

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东欧平台东南部的上维森和塞尔普科霍维亚生物地层学及岩相

摘要—

本文介绍了来自东欧平台东南部Sol-Iletsk隆起（奥伦堡州）东南部钻孔的维森系和塞尔普霍霍维河上（上石炭纪）沉积物的生物地层学和沉积学新数据。利用岩石岩性，在所研究的地区可以识别出次纬度相带。在Sol-Iletsk隆起区和Preuralian Foredeep的近侧区域，以开放的浅层相为代表，该沉积层的厚度最大为500 m。在南部，在北Pericaspian的边缘，它们的厚度急剧减小到36 m，并且演替过程由相对较深的陆架的碳酸盐粘土沉积物组成。根据有孔虫和牙形石，使用东欧平台地层方案的区域子阶段将维森河和塞尔普霍霍维亚河的上层细分，和有孔虫区被识别。露天架高能浅水相中的Serpukhovian基底是由有孔虫进入而绘制的Janischewskina delicata和Endothyranopsis平面; 在能量较低的相中，它处于新古生藻的首次出现的水平。在相对较深的陆架的碳酸盐黏土相中，它是根据牙形石Lochriea ziegleri的外观绘制的。讨论了五个钻孔中微动物区系的分布，有孔虫带状组合的特征以及区域间的相关性。