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The geomagnetic polarity pattern for the Carboniferous is incompletely known with the best-resolved parts in the Serpukhovian and Bashkirian. Hence, data from both igneous and sedimentary units are also used in an additional polarity bias evaluation. In the Tournaisian to mid Visean interval polarity is mainly derived from palaeopole-type palaeomagnetic studies, allowing identification of polarity bias chrons. Seven polarity bias chrons exist in the Mississippian (MI1n B to MI4n B ) with an additional 33 conventional magnetochrons and submagnetochrons (MI4r to MI9r). The Moscovian and Gzhelian polarity is best resolved in magnetostratigraphic studies from the Donets Basin and the southern Urals. Dispute about the reliability of these data is ill-founded, since an assessment of supporting data from palaeopole-type studies suggests that these datasets currently provide the best magnetic polarity data through the Pennsylvanian. Polarity bias assessment indicates a normal polarity bias zone in the Kasimovian. In the Pennsylvanian there are 27 conventional magnetochrons and submagnetochrons (PE1n to CI1r) and one normal polarity bias chron (PE8n B ). The Kiaman Superchron begins in the mid Bashkirian, with clear data indicating brief normal polarity submagnetochrons within the Superchron. The magnetochron timescale is calibrated using 31 U–Pb zircon dates and a quantitative Bayesian-based age-scaling procedure.

A new gastropod genus Alanstukella gen. nov., from the family Trochonematidae is described. The type species A. rossica (Stuckenberg, 1905), belongs to a small group of the largest Late Paleozoic representatives of the class Gastropoda. A. rossica has been shown to have pedomorphic features. Despite the extreme rarity of finds, the species has a wide geographical and stratigraphic distribution: the East European Craton, the South Urals and the Fergana Valley; Upper Pennsylvanian–Lower Permian (from the basal Kasimovian to the basal Sakmarian).

An integrated study of biostratigraphy, microfacies, and stable carbon isotope stratigraphy was carried out on the late Famennian-early Asselian carbonates of the Long’an section in Guangxi, South China. Stable carbon isotope studies in the Long’an section have revealed four major positive shifts of δ13C values in the Carboniferous strata in South China. The first shift occurred in the Siphonodella dasaibaensia zone in the Tournaisian, with an amplitude of 4.19‰. The second shift occurred near the Visean/Serpukhovian boundary, with an amplitude of 2.63‰. The third shift occurred in the Serpukhovian, with an amplitude of 3.95‰. The fourth shift occurred in the Kasimovian, with an amplitude of 3.69‰. Furthermore, there were several brief positive δ13C shifts during the late Famennian to early Tournaisian. All of these shifts can be well correlated globally, and each corresponds to sea-level regressions in South China and Euro-America, indicating increases in ocean primary productivity and global cooling events. Chronologically, the four major positive excursions of δ13C, together with several brief positive δ13C shifts that were observed during the late Famennian to the early Tournaisian, correspond to the well-accepted Glacial I, II, and III events.

Carboniferous conodonts from the candidate GSSPs of the four stages Serpukhovian, Moscovian, Kasimovian and Gzhelian in the Naqing and the adjacent sections of South China have been intensely studied in recent decades. The Carboniferous conodont zonation of China is updated based on the conodont material from South China; 39 conodont zones including 11 Tournaisian zones, 4 Visean zones, 3 Serpukhovian zones, 6 Bashkirian zones, 5 Moscovian zones, 5 Kasimovian zones and 5 Gzhelian zones are separated and discussed in detail. Species of the genera Siphonodella, Polygnathus, Protognathodus and Gnathodus dominate the zonation for Early Mississippian (Tournaisian) strata, Pseudognathodus, Lochriea and Gnathodus are most important for the zonation for Middle and Late Mississippian (Visean and Serpukhovian) strata, Declinog-nathodus, Idiognathoides, Neognathodus provide the zonation of early Bashkirian strata and Diplognathodus, Mesogondolella, Idiognathodus and the related genera Swadelina and Streptognathodus provide the zonation for late Bashkirian through the middle and late Pennsylvanian interval. In South China, the Carboniferous conodont zonation is mainly characterized by deep-water conodont biofacies with Siphonodella, Lochriea, Gnathodus, Declinognathodus, Idiognathoides, "Streptognathodus" expansus group, Diplognathodus and Streptognathodus. The updated Carboniferous conodont zonation of China is dominated mainly by cosmopolitan species, which may eventually allow refined global correlation.

The general tectonic features of the Baltic-Mezen zone developed along the border of the Fennoscandian shield and the Russian Plate in the north of the East European platform, are considered. The geophysical remote methods and structural analysis were used. It has been established that the zone has a length of more than 1000 km with a width of 10–40 km and can be traced from the Gulf of Finland in the sub-latitudinal direction along the southern shores of the Lake Ladoga and the Lake Onega in the valley of the River Onega.The Baltic-Mezen zone is represented by a system of folds and faults, fracture zones and brecciation, complicating the complexes of the Archean–Paleoproterozoic basement and the Vendian–Phanerozoic cover. Throughout the zone, changes in the configuration and displacement of the axes of the magnetic anomalies are noted; on seismic sections, the systems of discontinuities penetrating the basement and cover complexes are decrypted. On the surface, the discontinuous structures of the zone are expressed in the various forms of relief, often violate and displace glacial morphostructures. Based on the analysis of materials on the nature of the paleoseismites distribution and surfaces of unconformity in the sediments of the cover, as well as the structural features of various rock complexes, a long period of development of the Baltic-Mezen zone was established during the Caledonian, Hercynian and the latest stages of deformation. The Caledonian stage was associated with the formation of paleoseismites horizons of Kukruz phase (~ 460 Ma), as well as the folded-fault structures formed in the Late Silurian–Early Devonian. The Hercynian stage was manifested by several seismic and tectonic events in the Late Devonian (Frasnian age), in the Early (Visean age) and Late (Kasimovian century) Carboniferous. The newest stage was associated with Neopleistocene glaciodynamic processes and two stages of seismic events in the late and post-glacial period, which were accompanied by activation of ancient faults and local development of folded structures. The developed scale of paleoseismic and deformation events of the Baltic-Mezen zone can be used for tectono-dynamic reconstructions based on additional analysis of materials of structural-kinematic research.

Kasimovian (Upper Pennsylvanian) conodonts are studied from the Shcherbatovka section (Oka-Tsna Swell, Ryazan Region). The Khamovnikian and Dorogomilovian substages are exposed in this section. The presence of the conodonts Idiognathodus turbatus and I. heckeli was established in the deeper-water facies, compared to the type area of the Khamovnikian Substage. These species are considered as the potential markers for the lower boundary of the global Kasimovian Stage of the Carboniferous. A similar assemblage is established in the sections of US Midcontinent and South China.

The transgressive part of the Finis Shale cycle (Graham Formation, Cisco Group, Virgilian, Pennsylvanian) in North-Central Texas contains abundant conodonts of the group Idiognathodussimulator, the species I. simulator being the global marker of the Kasimovian–Gzhelian boundary. The interval also has a dominantly agglutinated foraminiferal fauna with scarce calcareous taxa. A thin calcareous unit with a diverse Triticites fusulinid fauna directly underlies the Finis Shale.

The Kasimovian Stage is a stage in the Pennsylvanian Subsystem, originally recognized in Russia. Its type area, despite the stage name (which is after the town of Kasimov in the Ryazan Region), is in the vicinity of the Voskresensk Region in the lower reaches of the Moscow River for the Krevyakian and Khamovnikian regional substages and the former village of Dorogomilovo (Moscow Region) for the Dorogomilovian Regional Substage. The stratotypes of the subdivisions of the Krevyakinian and Khamovnikian regional substages were established in the Voskresensk Region and no longer exist. The conodont assemblages of the Krevyakian and Khamovnikian and the lower part of the Dorogomilovian were studied in the neostratotype of the Kasimovian Stage (Afanasievo Section) and the Perkhurovo Reference Borehole drilled near the town of Voskresensk.

The origin of Reptilia and the biostratigraphic and palaeobiogeographic distribution of its early representatives are still poorly understood. An independent source of information may come from the extensive Carboniferous footprint record of reptiles, which is arguably richer and more complete than the skeletal record. Nevertheless, previous studies often failed to provide useful information because they were based on poorly preserved material and/or characters non-exclusive of reptile tracks. In fact, a large part of the supposed early reptile tracks can be assigned to the anamniote ichnotaxon Hylopus hardingi. Here, we revise the ichnotaxon Hylopus hardingi based on anatomy-consistent material, attribute it to anamniote reptiliomorphs, and distinguish it from Notalacerta missouriensis, the earliest ichnotaxon that can be attributed to reptiles, and the somewhat younger Varanopus microdactylus (attributed to parareptiles, such as bolosaurians) and Dromopus lacertoides (attributed to araeoscelid reptiles and non-varanodontine varanopids). These attributions are based on correlating morphofunctional features of tracks and skeletons. Multivariate analysis of trackway parameters indicates that the late Bashkirian Notalacerta missouriensis and Hylopus hardingi differ markedly in their trackway patterns from Late Mississippian Hylopus hardingi and Late Pennsylvanian reptile tracks, which appear to share a derived amniote-like type of gait. While the first occurrence/appearance of reptile tracks in the tetrapod footprint record during the late Bashkirian corresponds to the first occurrence/appearance of reptiles in the skeletal record, footprints significantly enlarge the paleobiogeographic distribution of the group, suggesting an earlier radiation of reptiles during the Bashkirian throughout North America and possibly North Africa. Dromopus appeared in the Kasimovian together with the diapsid group Araeoscelidia, but footprints from Western-European occurrences enlarge the paleobiogeographic distribution of diapsids and varanopids. Varanopus and bolosaurian parareptiles appear in the Gzhelian of North America. Older parareptiles are, however, known from the late Moscovian. In all, the footprint record of early reptiles supplements the skeletal record, suggesting possible future lines of research.

The paper presents the results of a paleophytosociological substantiation of the interregional correlation of the Kasimovian and Gzhelian deposits of the Donets Basin in connection with consideration of the question of a difference in stratigraphic volumes of the Sphenopteris mathetii (= Alethopteris zeilleri) and Sphenophyllum angustifolium Zones in the Donets Basin and the Sabero Coalfield of Spain due to a diachronicity of the lower boundary of the Sphenophyllum angustifolium Zone. Paleophytosociological data about a composition and spatio-temporal dynamic of ancient plant communities give an understanding of the process of a flora development, which is recorded in the phytostratigraphic scale, and make it possible to carry out the substantiation of the correlation of phytozonal units taking into account ecological-cenotic features of vegetation cover. Based on the analysis of the literary paleoclimate and lithological-facial data and own paleophytosociological studies, it was concluded that during the early Gzhelian time, corresponding to more or less stable glacio-climatic conditions of the middle part of the interglacial interval of the Late Paleozoic glacial period, the diachronicity of the floristic changes in the basins with different types of tectonical and sedimentation processes within a single paleophytochoria may be due to the differences in ecological-landscape conditions that determined the composition and spatial differentiation of vegetation cover. The paleophytosociological studies have shown that the marking taxa of the Sphenophyllum angustifolium Zone, defining its lower boundary by the limestone O5 at the base of the Gzhelian Stage in the Donets Basin, are the diagnostic species of the paleophytocenoses, which dominated in the vegetation cover of the Donets Basin during the early Gzhelian time. The base of the Sphenophyllum angustifolium Zone in the Donets Basin corresponds to the temporal level of an appearance of these new paleophytocenoses, which were spread within coastal lowlands and delta plains. At the beginning of the Gzhelian time, these dominant plant communities of lowlands in the Donets Basin occupied less humid and waterlogged environments than the existing environments at the same time in the Sabero Coalfield of Spain where the marking fern and pteridosperm species of the Alethopteris zeilleri Zone continued to grow. The lower boundary of the Sphenophyllum angustifolium Zone in the Sabero Coalfield, which according to radiometric dating corresponds to the level located close to the limestone Р2 in the Donets Basin, is consistent with the base of the upper Odontopteris schlotheimii Subzone of the Sphenophyllum angustifolium Zone. The lower boundary of the Odontopteris schlotheimii Subzone in the Donets Basin records the temporal level reflecting а change of distribution areas of the paleophytocenosis, i.e. а change of the dominant paleophytocenosis, namely, a reduction of the plant communities on coastal lowlands and a wider distribution of the plant communities within delta plains.

A new conchostracan species Pemphilimnadiopsis cheni sp. nov. is found in the upper section of the Pennsylvanian Benxi Formation in Kaiping, Tangshan City, Hebei Province, China and is closely related to the type species of the genus, P. ortoni. This finding is the fifth record of the Carboniferous conchostracans in China. Its finding gives evidence that the Benxi Formation in Kaiping, Tangshan City can be restricted into middle-late Moscovian to early Kasimovian and the present conchostracan layers more likely correspond to the early Kasimovian. Moreover, the first described Palaeozoic insects come from the same layers in the Kaiping Basin. This study indicates the age of these fossil insects would be close to the boundary of Moscovian and Kasimovian and more likely the early Kasimovian.

The Late Pennsylvanian (Kasimovian, early Stephanian) sub- to perimontaneous Souss basin, situated in the present-day southwestern High Atlas mountains of Morocco, contains the hitherto only known late Paleozoic entomofauna from North Africa, which is simultaneously also the southernmost Euramerican entomofauna. The present study provides descriptions, identifications, and revisions of several species belonging to the generaPhyloblattaandAnthracoblattina(family Phyloblattidae) and of the genusCompsoblatta(family Compsoblattidae). A relatively large number of well-preservedPhyloblattaforewings, compared with congeneric species from several insect localities in Europe and North America, permits insights into the individual, intraspecific, and interspecific variability of the venation pattern as indispensable base for the description of the new specimens and the revision of several older species. The Souss insect beds cover a wide range of potential habitats. They are situated in different paleogeographical positions within the Souss basin and scattered across a 900 m thick succession of sediments. The single insect beds represent different sedimentary and biotic subenvironments from swamps and mires to shallow and deep lakes within a fluvial-dominated megaenvironment.

The proposed Triassic age of oceanic subduction and high-pressure/low-temperature (HP-LT) metamorphism in the South Tianshan orogen (STS) of the southwestern Central Asian Orogenic Belt needs to be re-examined on the basis of field relationship and precise age dating. Our biostratigraphic study in the Atbashi Range of southern Kyrgyzstan indicates that sedimentary strata unconformably overlie the HP-LT metamorphic rocks within the Turkestan suture zone and have a late Kasimovian (ca. 305 Ma) age. This constrains the minimum age of eclogite metamorphism in the HP-LT metamorphic complex. A Late Pennsylvanian to early Permian (Asselian) hinterland basin overlaps the margins of the Middle and South Tianshan and the ophiolitic suture between them, thus leaving no space for an oceanic basin in the northern STS in the late Permian or Triassic. In the south, overlap assemblages stitching the STS with the Tarim Craton consist of late Asselian to early Sakmarian limestones and early Permian rhyolites. Early Permian (ca. 295–265 Ma) post-collisional A-type granites and sub-alkaline plutons are widespread in the STS and are not affected by thrust deformation. These facts indicate that thrust packages of the STS were stacked together and welded to the margin of the Tarim Craton by the early Permian. The widespread occurrence of early Permian sub-alkaline granites is also not compatible with an oceanic accretionary wedge setting in the STS during the Permian or Triassic. Permian and Triassic zircon ages for subduction-related HP-LT metamorphic rocks and ophiolitic gabbro from the Atbashi and Djandjir ranges reported in two recent papers contradict geological relationships. A review of reported analytical data shows that anomalously young ages in all studied samples are based on geologically meaningless single zircon analyses and/or discordant data, which cannot be used for age calculation. The suggestion that an oceanic basin in the STS remained open and subduction continued until the Middle Triassic is erroneous because of insufficient consideration of basic regional geological relationships and incorrect interpretations of analytical results.

The transgressive-regressive events due to changes in the eustatic sea level represent the occurrence of an epeiric sea in Western Gondwana. This event is recorded in the carbonate-siliciclastic succession exposed in the central portion of the Parnaiba Basin, Northern Brazil, mainly represented by densely fossiliferous deposits, with mollusks, brachiopods, corals and microfossils, related to the upper member of the Piaui Formation. Outcrop-based facies/microfacies and stratigraphic analysis of this succession allowed the individualization of two facies associations (FA), representative of a shallow carbonate platform system adjacent to a coastal dune field. The FA1– dune field/interdune, comprises well sorted, intensely biortubated, fine to medium-grained sandstone with even parallel and tabular cross stratification, as well as translatent climbing ripple cross-lamination. FA2-shallow sea deposits consist of fossiliferous pelletal carbonate and microspar carbonate layers, laterally continuous for hundreds of meters, interbedded with centimetric beds and lenses of organic shale with small pyrite crystals. Covariant values of positive δ18Ocarb and negative δ13Ccarb for the carbonate profiles, together with intense substitution of primary constituents by dolomite and an abundance of associated organic matter contributed towards determining an organogenic dolomitization model. Although the Pennsylvanian records a long icehouse event, glacioeustatic fluctuations were common during the Moscovian and Kasimovian. The icehouse periods contributed to the semi-arid to desert conditions that shaped the aeolic environments of the Piaui Formation. Later greenhouse events favored a rise in the sea level and development of an extensive epicontinental Pennsylvanian sea that extended throughout Western Gondwana called the Itaituba-Piaui sea in this paper, which connected the Andean, Solimoes, Amazonas and Parnaiba basins.

Wildfires occurred more or less regularly in many Pennsylvanian ecosystems, not only in seasonally dry regions but also in the ever wet tropics. One of the reasons for this was probably the relatively high atmospheric oxygen conditions prevailing during this period. The present study reports evidence for the occurrence of wildfires during deposition of the Upper Pennsylvanian Heusweiler Formation (“Stephanian B”, Kasimovian–Gzhelian) in the intramontane Saar-Nahe (or Saar-Lorraine) Basin in SW-Germany. Based on anatomical features of the charcoal, as well as the co-occurring adpression flora, it seems possible that some of the fires occurred in an ecosystem inhabited by Cordaites. Some of the charcoal fragments exhibit traces of pre-charring decay by fungi, indicating either the consumption of litter by ground or surface fires, or of still standing (partly) dead trees by crown fires., Senckenberg Forschungsinstitut und Naturmuseum Frankfurt (3507)

Lower Kasimovian organic buildups in the Moleben-Iz section on the Ilych River, Northern Urals, were studied. Two levels of buildups development have been established, that are composing by algal and palaeoaplysinid boundstones and biocementstones. They are probably a part of long (up to 10 km) and complexly constructed biostromes. Lithological data indicate the formation of these buildups in the normal marine sutidal conditions on the carbonate ramp.

Late Paleozoic macroevolutionary crinoid faunas were dominated by dendrocrinids, replacing most of the camerata crinoids that had dominated the Early and Middle Paleozoic macroevolutionary crinoid faunas. Two dendrocrinid taxa, the Cromyocrinidae and Pirasocrinidae, first recognized in the Mississippian (Visean), attained their greatest generic diversity in the late Moscovian to early Kasimovian, declined in the Late Pennsylvanian and Early Permian, and became extinct in the Late Permian or end-Permian extinction event. The paleontologic record of the Cromyocrinindae and Pirasocrinidae is best documented from the Midcontinent of the United States and both are recognized worldwide in the Late Paleozoic. Their diversity in the latest Pennsylvanian and Early Permian is probably greater than currently recognized because disarticulated ossicles that are ascribed to one or the other of the two families in described faunas are commonly not recognizable at the genus level. Both families show individual evolutionary trends while following the general evolutionary trends of the dendrocrinids.

Faunal composition and correlation of the late Carboniferous and Permian fusulines contained in exotic limestone blocks of the Sakamototoge area, Gifu Prefecture, Japan were reconsidered. Main alterations of the previous results are summarized as: (1) Moscovian fusulines are confined to the Myachkovian; (2) many species collectively included in Triticites are attributed to Protriticites, Montiparus, Rauserites, Triticites, or Schwagerina; (3) “Triticites” faunas designated as the Carboniferous–Permian are reorganized into three faunas: Protriticites subschwagerinoides (early Kasimovian), Montiparus mesopachus-Protriticites kiyomiensis (middle Kasimovian), and Rauserites arcticus-Carbonoschwagerina nakazawai-Quasifusulina longissimi (late Kasimovian to possibly early Gzhelian); and (4) the species assigned to Pseudoschwagerina is now attributed to late Gzhelian Carbonoschwagerina, implying the probable absence of the Asselian in the area. In addition, the Capitanian Yabeina fauna heterogeneous to the coeval neoschwagerinid faunas in the Permian terranes of Japan is ascertained.

The Carboniferous period lasted about 60 Myr, from ~358.9 Ma to ~298.9 Ma. According to the International Commission on Stratigraphy, the Carboniferous System is subdivided into two subsystems, i.e., Mississippian and Pennsylvanian, including 6 series and 7 stages. The Global Stratotype Sections and Points (GSSPs) of three stages have been ratified, the Tournaisian, Visean, and Bashkirian stages. The GSSPs of the remaining four stages (i.e., the Serpukhovian, Moscovian, Kasimovian, and Gzhelian) have not been ratified so far. This paper outlines Carboniferous stratigraphic subdivision and correlation on the basis of detailed biostratigraphy mainly from South China, and summarizes the Carboniferous chronostratigraphic framework of China. High-resolution biostratigraphic study reveals 37 conodont zones, 24 foraminiferal (including fusulinid) zones, 13 ammonoid zones, 10 brachiopod zones, and 10 rugose coral zones in the Carboniferous of China. The biostratigraphic framework based on these biozones warrants the precise correlation of regional stratigraphy of China (including 2 subsystems, 4 series, and 8 stages) to that of the other regions globally. Meanwhile, the Carboniferous chemo-, sequence-, cyclo-, and event-stratigraphy of China have been intensively studied and can also be correlated worldwide. Future studies on the Carboniferous in China should focus on (1) the correlation between shallow- and deep-water facies and between marine and continental facies, (2) high-resolution astronomical cyclostratigraphy, and (3) paleoenvironment and paleoclimate analysis based on geochemical proxies such as strontium and oxygen isotopes, as well as stomatal indices of fossil plants.

U–Pb (SHRIMP) detrital zircon ages from the Pennsylvanian–Permian meta-sedimentary rocks of the Zemplinicum Unit were used to characterise the provenance and the tectono-thermal evolution of the basement. The magmatic zircon ages from the contemporaneous rhyolite pyroclastics, ranging from 308 to 305 Ma, dated the Pennsylvanian sedimentary formations to the Moscovian and Kasimovian Ages. Two brakes in sedimentation within the Pennsylvanian–Permian sequence are presumed, first, flanked by Gzhelian–Asselian and second, intra-Permian. The detrital zircon age spectrum demonstrates two prominent populations: (i) Middle/Late Ordovician (age peak 459 Ma), (ii) Ediacaran–Cryogenian (age peaks 592 and 641 Ma). These, together with minor clusters from ~ 773 to 950 Ma, evidently document the Pan-African multiple magmatic events. The 1.1–1.8 Ga age gap and isolated zircons of Mesoproterozoic ages (1036–1361 Ma) are characteristic. Two populations, 1.8–2.2 Ga and 2.5–2.8 Ga, are presented within the Paleoproterozoic–Neoarchean zircons. The Zemplinicum Neoproterozoic arc crust had been affected by the extensional thermal relaxation and melting during Middle/Late Ordovician. The subsequent reworking had been connected with the Mississippian collision, followed by the Pennsylvanian/Permian extension. The presence of the Neoproterozoic detrital zircon ages including the Tonian ones permit to compare the Zemplinicum basement with the eastern peri-Gondwanan domain, which was situated at the northern margin of the Saharan Metacraton or the Arabian Nubian Shield during Neoproterozoic time.

Two Late Pennsylvanian conodont species, Gondolella sublanceolata Gunnell and Idiognathodus sulciferus Gunnell, were extracted from limestone boulders in the Mizuboradani Valley, Fukuji district, central Japan. These provide the first evidence of Missourian (Kasimovian) cosmopolitan conodonts in the Akiyoshi and Hida Gaien belts, Inner Zone of Japan. The limestone boulders might be derived from the Ichinotani Formation and/or from limestone clasts in conglomerates of the Permian Sorayama Formation that crop out in the Mizuboradani Valley.

The first phase in the stepwise collapse of the Carboniferous Coal Forests occurred near the Desmoinesian–Missourian boundary (early Kasimovian, ~ 307 Ma), and involved extirpation of Lycospora-producing lepidodendrids, and some other lycopsids, across most of tropical Euramerica. In this paper, we follow-up on historical reports of silicified tree-stumps in Peoria County, northwest-central Illinois, USA, which have significant implications for understanding Carboniferous Coal Forest collapse. Rooted near the paleoweathered top of the Lonsdale Limestone, and widespread across an area of ~ 250 km2, the silicified tree-stumps belong to Amyelon-type coniferopsids. A key feature of the fossil wood is the occurrence of abundant axial parenchyma arranged along irregular growth interruptions, suggestive of climatic seasonality, an inference consistent with silicic preservation. The silicified fossil forest directly underlies the Exline Limestone and Athensville Coal, the horizons that mark the US-wide loss of Lycospora, and demonstrate that lowland areas were colonized by dryland coniferopsid forests following Coal Forest collapse. Placed in a cyclothem context, the silicified fossil forest horizon lies above the Maria Creek mudstone paleosol (top of Piasa cyclothem), in which earlier d18O analyses have identified a major pulse of global warming, and coincides with the ‘Hanna City’ paleosol (top of Lonsdale cyclothem), which is correlative with the Seminole Sandstone, a Midcontinent incised valley-fill representative of one of the most profound glacioeustatic falls seen in the Pennsylvanian record. Our new findings therefore demonstrate that Coal Forest collapse was closely linked to intensification of glacial cycle amplitude near the Desmoinesian–Missourian boundary, involving both extreme episodes of global warming and cooling.

The Junggar–Balkhash Ocean was a major branch of the southern Paleo-Asian Ocean. The timing of its closure is important for understanding the history of the Central Asian Orogenic Belt. New sedimentological and geochronological data from the Late Paleozoic volcano-sedimentary sequences in the Barleik Mountains of West Junggar, NW China, help to constrain the closure time of the Junggar–Balkhash Ocean. Tielieketi Formation (Fm) is dominated by littoral sediments, but its upper glauconite-bearing sandstone is interpreted to deposit rapidly in a shallow-water shelf setting. By contrast, Heishantou Fm consists chiefly of volcanic rocks, conformably overlying or in fault contact with Tielieketi Fm. Molaoba Fm is composed of parallel-stratified fine sandstone and sandy conglomerate with graded bedding, typical of non-marine, fluvial deposition. This formation unconformably overlies the Tielieketi and Heishantou formations and is conformably covered by Kalagang Fm characterized by a continental bimodal volcanic association. The youngest U–Pb ages of detrital zircons from sandstones and zircon U–Pb ages from volcanic rocks suggest that the Tielieketi, Heishantou, Molaoba, and Kalagang formations were deposited during the Famennian–Tournaisian, Tournaisian–early Bashkirian, Gzhelian, and Asselian–Sakmarian, respectively. The absence of upper Bashkirian to Kasimovian was likely caused by tectonic uplifting of the West Junggar terrane. This is compatible with the occurrence of coeval stitching plutons in the West Junggar and adjacent areas. The Junggar–Balkhash Ocean should be finally closed before the Gzhelian, slightly later or concurrent with that of other ocean domains of the southern Paleo-Asian Ocean.

Terrestrial carbonate deposits associated with exposed limestone are potential recorders of paleoclimates and karst paleohydrology. Here we examine the depositional process of the Omi rhythmite layers, which filled karstic cavities in the Pennsylvanian (middle Kasimovian) section of the Omi Limestone, a seamount-type limestone in central Japan. The laminated rhythmite layers accompanied signatures of subaerial exposure, including Microcodium, which indicates a seasonally dry climate in the late Kasimovian. The rhythmite layers are calcareous, low in siliciclastic content, and composed of millimeter-scale laminae. In each lamina, the grain size decreases and the δ18O value increases upwards. We inferred that each lamina corresponds to a single cave flood event followed by a dry and evaporative interval. 87Sr/86Sr ratios of the rhythmites are almost identical to the ratio of the surrounding limestone, but clearly lower than the Kasimovian seawater ratio. This indicates that the rhythmites and the surrounding limestone were subjected to the same post-depositional alteration, before the subduction of the seamount in the Guadalupian (middle Permian). The sedimentary and isotopic features of the Omi rhythmite and occurrence of Microcodium support repetition of wetting and drying on an equatorial Panthalassan island during the Pennsylvanian (late Carboniferous).

Abundant conodonts occur in the Naqing section, southern Guizhou, South China, which has been selected as the candidate of the Carboniferous Kasimovian GSSP. Swadelina subexcelsa, Idiognathodus heckeli, I. turbatus and I. sagittalis, which are potentially index taxa for the Moscovian-Kasimovian boundary, are all recorded in the Naqing section. The lineages from their ancestors have been discussed in this paper, and furthermore, based on their lineages the conodont zonation is established for the global correlation. The provincialism of the Moscovian-Kasimovian boundary interval is also analyzed. The Tethyan and American Midcontinent provinces, can be identified to differentiate conodont faunas among major basins. The Tethyan Province can be further subdivided into the South China and Eastern European Platform subprovinces. By incorporating and evaluating varying aspects of the taxonomy, biostratigraphy and palaeobiogeography of the potential index taxa, I. heckeli might be the best marker for the base Kasimovian in term of its clear taxonomic definition and phylogenetic lineage, as well as its wide geographic range.

Southwestern Laurentia experienced intraplate deformation during the Pennsylvanian and early Permian, an orogenic event termed the Ancestral Rocky Mountains (ARM). Deformation consisted of uplifted Precambrian-cored basement blocks separated from adjacent basins by high-angle faults. The tectonic drivers of this orogen are debated, which is likely in part due to significant changes to the chronostratigraphy of the geologic time scale since many of the models have been proposed. To better understand the orogen, we assess spatial subsidence patterns with 1-D backstripped tectonic subsidence curves from eight ARM basins across the orogen using the 2020 Geologic Time Scale for temporal calibration. These patterns indicate the following: 1) basins largely initiated in the late Morrowan—early Atokan (Bashkirian); 2) most subsidence curves suggest flexure from a fixed-load foreland basin that steadily increased until the Missourian (Kasimovian) where most basins reached peak subsidence; 3) diminished subsidence occurred in most basins in the Late Pennsylvanian and shut off across most of the orogen by the end of the Wolfcampian (Asselian—early Artinskian); and 4) basin subsidence renewed in the southern basins during the Leonardian (late Artinskian—Kungurian). The synchronous start to basin subsidence is coeval to the initiation of highly oblique convergence between the Laurentia and Panthalassan plates along the southwestern margin. Influences from the Ouachita-Marathon margin are best reflected by Late Mississippian subsidence of the Anadarko Basin and transpressional deformation in the Orogrande Basin during the Late Pennsylvanian. The decrease in early Permian subsidence is coeval to the cessation of movement on most ARM faults and burial of Precambrian-cored highlands indicating that classical ARM tectonics is mostly a Pennsylvanian event. The increase in subsidence observed during the Leonardian (late Artinskian—Kungurian) in the southern basins may reflect renewed oblique convergence along the southwestern margin.

The Anadarko Basin of Oklahoma represents a major Paleozoic depocenter that existed along the rifted margins of southwestern Laurentia. In its infancy it accumulated a thick series of Cambrian through Mississippian detritus while further subsidence caused by inversion of the Cambrian Southern Oklahoma Aulacogen resulted in voluminous Pennsylvanian to Permian sediment. This contribution reports new data on K-Ar ages and trace-element geochemistry of detrital illite from middle and upper Pennsylvanian shale used to reconstruct sediment origins at the peak period of subsidence of the Anadarko Basin. X-ray diffraction was used to unveil mineral compositions and abundances of illite polytypes in two size fractions of separated illite (˂1 and 2-1 μm). K-Ar isotopic analyses were completed for both fine fractions, while the laser ablation inductively coupled plasma mass spectrometry was done for the latter. All illite separates consisted of mixtures of authigenic (1Md) and detrital (2M1) illite. The Illite Age Analyses showed that the detrital age of Desmoinesian (Moscovian) shale is the late Ediacaran (584 Ma), while the age of Missourian (Kasimovian) shale is the middle Cambrian (512.5 Ma). Trace-element abundances of all analyzed illite, irrespectively of stratigraphic age, are consistent with those of mica from metamorphic rocks. Based on illite detrital age and geochemistry it was inferred that Desmoinesian (Moscovian) shale represents a mixture of Neoproterozoic and Cambrian detritus sourced locally, whereas Missourian (Kasimovian) shale records a provenance shift toward more distal easterly sources from the Ouachita-(Marathon) foreland. This study has proposed a sediment source transition between the middle and upper Pennsylvanian that likely reflected major changes in the basin paleogeography and progressive development of the east-west (transcontinental) fluvial systems.

The late Paleozoic ice age (LPIA) during the Carboniferous and Permian (ca. 360–260 Ma) was vegetated Earth's only recorded icehouse-to-greenhouse transition and provides a deep-time perspective for climate-glaciation-environment coevolution and future climate change. During the LPIA, changes in glacial-interglacial cycles have been closely linked to atmospheric pCO2. In this paper, we investigate the relationship between volcanism and glacial to interglacial climate cycles during the Pennsylvanian to earliest Cisuralian in the Liujiang Coalfield from the North China Plate (NCP). We use integrated data from Zircon U-Pb dating, Hg/TOC ratios and δ13Corg to recover temporal trends in volcanic intensity and relate these to fluctuations in the global carbon cycle and atmospheric pCO2. Four new radiometric dates from tuffaceous claystones provide a precision stratigraphic framework and constrain the succession to ~322 to 301 Ma. Results date the Benxi Formation to the Bashkirian–Moscovian stages of the Carboniferous, and the Taiyuan Formation ranging from the Kasimovian stage of the Carboniferous to the Asselian stage of the Permian. Results from Hg/TOC ratios record four peaks of volcanic intensity from the Bashkirian to the Carboniferous-Permian (C-P) transition period, and two low ebbs during the early-middle Bashkirian and the early-middle Moscovian. Peaks in volcanic intensity coincide with the four negative excursions of δ13Corg and correlate with volcanism in the North China Plate and NW Europe, inferring volcanic drivers for the carbon isotope excursions and perturbations in the global carbon cycle. Periods of higher atmospheric pCO2 correlate to interglacial intervals, the two lower ebbs in pCO2 correlate with two positive isotope plateaus, while periods of lower atmospheric pCO2 and cooling correlate with glacial intervals C3 and C4 recognized from other sections globally. Results suggest volcanism to be a significant driver for late Pennsylvanian to earliest Cisuralian shifts in global climates from glacial to interglacial through greenhouse gas emissions and changes to the global carbon cycle. Our results represent an important contribution to the development of an accurate chronostratigraphy for the continental facies of the NCP during the Pennsylvanian and earliest Permian, enabling correlation of volcanic and climate events including glacial and interglacial cycles.

Largely terrestrial Pennsylvanian strata (Macharetí and Mandiyutí groups) in Bolivia and northern Argentina contain a brief marine incursion. Dominated by glacio-fluvial and glacial diamictites, much of the thick succession is peri-glacial in origin and deposited within a basin with paleohighs. In southernmost Bolivia (Balapuca section), new discoveries of poorly preserved orthotetacean brachiopods (Derbyoides sp.) document the marine systems. Without the brachiopod, co-occurrence of numerous in situ gastropods (Mourlonia balapucense), with all ontogenetic growth stages, could not be confirmed as marine. Palynomorphs corresponding to the TB Zone di Pasquo stratigraphically below the megafossil occurrence place the age of the assemblage in the Kasimovian/Gzhelian Stage. Many units show extensive recycling of Devonian and Mississippian palynomorphs (Retispora lepidophya, and others) and a brachiopod demonstrate pre-Gzhelian erosion and high energy deposition in diamictites during deposition of the Tarija Formation, and through much of the succession. This brief marine transgression in this basin corresponds to regionally more long-lived marine transgressions in western Argentina, characterized by the Tivertonia-Streptorhynchus Fauna (Moscovian-Gzhelian) linked with the beginning of a global major sea level rise as an interlude in the Gondwana glaciations. The marine transgression exceeded isostatic rebound. Further in Bolivia, the transgression from the north produced the Copacabana Formation carbonates. Coeval siliciclastics of the San Telmo Formation in the south show contrasting in lithologic facies and faunal composition as a result of thermal barriers (warm – cold waters). Fil: Di Pasquo Lartigue, Maria. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; Argentina Fil: Anderson, Heidi. University of Montana; Estados Unidos Fil: Isaacson, Peter. University of Idaho; Estados Unidos

The Pennsylvanian to lower Permian succession at Madiyi, South China, represents a nearshore mixed siliciclastic-carbonate system characterized by cyclic sedimentation patterns along a depth gradient from continental siliciclastics to marine open platform carbonates. Various palaeokarst features related to subaerial exposure are widely distributed. Additionally, pedogenesis was pervasive. The identification of twenty-eight sedimentary cycles grouped into five sequences allows the reconstruction of a relative sea-level curve. The cycles represent higher frequency changes superimposed on the long-term evolution. After the initial transgression, the sea level remained relatively low in the late Bashkirian to early Moscovian. Then, it rose stepwise until a major drop occurred in the late Moscovian. Afterwards, the sea level rose again, but marine sedimentation ceased during at least the early Kasimovian. The area was flooded in the late Kasimovian, and the sea level rose until a late Gzhelian sea-level drop. The subsequent marine sequence contains uppermost Gzhelian to upper Asselian deposits, which are capped by lower Permian continental facies associated with a major regional regression. Shallow to deeper marine sedimentary settings recorded high-frequency sea-level changes throughout South China during the late Bashkirian to Asselian. The main transgression–regression cycles are clearly associated with different depositional settings during several time intervals. Furthermore, the good correlations among South China, Ukraine, and the U.S. Mid-continent are rooted in the impact of Gondwanan glaciations on the global sedimentation patterns. However, not all changes at Madiyi are the result of glacio-eustatic sea-level fluctuations; some are related to the local subsidence history and the rise of the Xuefeng Uplift.