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The late Carboniferous–early Permian represents a key period in the Phanerozoic history, given the major global geodynamic and climate modifications. The aim of this work is to better understand the context and characteristics of the sedimentation recorded in the continental environments of eastern equatorial Pangea at this time, through the example of the Autun Basin (northeastern Massif Central, France). The Autun Basin contains the historical stratotype of the Autunian continental stage, and its stratigraphy was recently improved by accurate numerical ages. This basin formed in an extensional tectonic context during the latest stages of the Variscan orogeny, and it is essential to study its paleoenvironmental evolution to provide new insights into the sedimentary evolution of contemporaneous surrounding basins. Using field and subsurface data, we propose a refined sedimentological model for the Autun Basin, relying on updated facies interpretations, organic matter content fluctuations, and sequence stratigraphy concepts and correlations. The continental environments of the lower sedimentary succession of the Autun Basin, previously considered to be fluvial and lacustrine, are herein re-interpreted as mainly lacustrine, comprising fine-grained organic matter-rich deposits, and supplied by coarser-grained deltaic siliciclastic sediments, without preservation of strict fluvial sedimentation. The determination of the sequence stratigraphy cycles, strengthened by the quantification of the organic matter content, and reflected by the temporal succession of progradational and retrogradational trends, is used to determine new correlations between several sections, as well as to reconstruct the paleoenvironment evolution at the Carboniferous–Permian transition. This study provides evidence that the sedimentation area of the Autun Basin at the time of its filling was much larger than the preserved basin area, and suggests connections with contemporaneous neighboring French basins, pointing to a large sedimentary system in the northeastern Massif Central area rather than narrow and isolated basins. [ABSTRACT FROM AUTHOR]

The biostratigraphy of the latest Gzhelian‒Asselian fusulinoid fauna from the Banarizeh section located in the Abadeh region of the Sanandaj–Sirjan Zone is investigated. The most characteristic species among the fusulinoids are the species of Pseudoschwagerina?, Nonpseudofusulina, and Praepseudofusulina; the last one is represented by four species, namely, Praepseudofusulina kljasmica (Sjomina), P. cf. saratovensis (Chernova), P. incomperta (Scherbovich), and P. cf. impercepta (Jagofarova). A biostratigraphic correlation shows that the latest Gzhelian–Asselian fusulinoid assemblage from the Banarizeh section shares some common species with the contemporaneous assemblages of the Russian Platform and Southern Urals. It can also be compared to those of the Alborz, Tabas Block (East Iran), and Yazd Block (Central Iran). [ABSTRACT FROM AUTHOR]

Abstract: The age of the Upper Paleozoic radiolarian Latentifistula crux Ecozone is revised. The Latentifistula crux assemblage was originally established by Nazarov and Ormiston (1985, 1990, 1993; Nazarov, 1988) in 1985 in the basal deposits of the Asselian Stage of the Nikolskoe section on the Ural River. The new biostratigraphic position of the radiolarian Latentifistula crux Ecozone corresponds to the terminal Streptognathodus bellus and Streptognathodus wabaunsensis conodont zones of the Gzhelian Stage (Chernykh, 2012, 2016). [ABSTRACT FROM AUTHOR]

The latest Carboniferous-Early Permian Dorud Group in the Chaman-Saver area of eastern Alborz, Iran is more than 222 m thick and includes thick sequences of oncolitic limestone, sandy limestone, sandstones and shales. The Emarat and Ghosnavi formations of this Group are dated here as latest Gzhelian to early Sakmarian Stages. During the Asselian Stage, the sea level fell abruptly and epeirogenic episodes occurred. These events generated a broad, shallow carbonate platform suitable for the growth and diversity of smaller foraminifers in the Chaman-Saver area which, consequently, displays faunal differences with the rest of the Alborz Mountains. Three foraminiferal biozones are proposed: Nodosinelloides potievskayae-Vervilleina bradyi Zone (latest Gzhelian), Calcitornella heathi-Nodosinelloides sp. Zone (latest Gzhelian-Asselian), and Rectogordius iranicus n. gen. n. sp.- Hemigordius schlumbergeri Zone (early Sakmarian). The new taxa described herein include: Pseudovidalina iranica n. sp., P. damghanica n. sp., Rectogordius iranicus n. gen. n. sp. and Tezaquina sp. 1. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

• During the latest Gzhelian–Asselian Iran was located at the northern margin of the Palaeotethys. • The studied assemblage is comparable to other areas in the Peri-Tethyan realm. • This assemblage indicates the low latitude position with the warm and humid conditions. The taxonomic diversity of smaller foraminiferal faunas of the uppermost Carboniferous–lowermost Permian (upper Gzhelian–lower Asselian interval) has been accurately investigated in the Sanandaj-Sirjan Zone, Iran. They predominantly contain three foraminiferal classes: Fusulinata, Miliolata and Nodosariata, and six orders: Tuberitinida, Earlandiida, Archaediscida, Endothyrida, Cornuspirida, and Nodosariida. The presence of some remarkable taxa in palaeobiogeography such as Hemidiscus carnicus , that is reported for the first time in Iran, along with Rectogordius is noticeable. Furthermore, these smaller foraminifers are associated with significant fusulinid genera including Praepseudofusulina , " Nonpseudofusulina ", Pseudoschwagerina , and " Schellwienia ?", which indicated that during the latest Gzhelian–Asselian, the Sanandaj-Sirjan Zone was in the northern margin of the Palaeotethys, in a relatively low latitudinal position (ca. 30°S), with warm and humid conditions. This claim can also be evidenced by the presence of sandstones with high degree of chemical weathering, together with the limonite accompanied with a palaeosol in the Upper Carboniferous strata. The presence of a red earthy laterite with lenses of pisolitic bauxite along with a piece of fossil wood in the lowermost Permian beds, confirms the Peri-Tethyan position of the Sanandaj-Sirjan Zone during this period. This study also shows that the first appearance of Frondicularia in the Iranian material, that is the latest Gzhelian–early Asselian, is probably older than what is argued in materials from north-central Siberia (Late Permian and Triassic) and Germany (Sakmarian to Anisian, up to the Jurassic). [ABSTRACT FROM AUTHOR]