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Isolated teeth of two janassid petalodonts collected from cave passages within the Middle Mississippian (Viséan) Joppa Member of the Ste. Genevieve Formation at Mammoth Cave National Park, Kentucky represents the first record of this group of chondrichthyans from this formation. A new janassid, Strigilodus tollesonae, gen et sp. nov., is recognised from isolated teeth, representing all tooth families, and are characterised by their rounded spoonlike cusps and V- to U-shaped lingual cristae. Janassa sp. is also present within the Joppa Member of the Ste. Genevieve Formation. Dental reconstructions are proposed for Strigilodus tollesonae and Cypripediodens cristatus, modelled after previous observations for Janassa dentitions. Strigilodus had a dental arrangement more similar to Janassa, while Cypripediodens was uniquely adapted for a possible extreme form of durophage feeding. We propose that within Janassidae, there were two unnamed subfamilies with Janassa and Strigilodus forming the Janassinae, while Cholodus, Cypripediodens, and Cavusodus forming Cholodinae subfam. nov. [ABSTRACT FROM AUTHOR]

During the initial stages of Pangea amalgamation in the Carboniferous period, the Rheic Ocean basin experienced subduction prompted by the convergence between Gondwana and Laurasia, culminating in the basin's closure that preceded the paleocontinent collision. This tectonic episode promoted the Carboniferous (Mississippian and Pennsylvanian) tholeiitic to calc-alkaline magmatism, represented in the Colombian Andes through the tonalite and diorite-gabbro facies of the El Carmen Pluton. We investigate the two main facies (felsic and mafic facies) of the plutonic body, which crop out in the Central Cordillera of the Colombian Andes. U-Pb zircon crystallization ages are 326 ± 1 Ma for the mafic facies and 313 ± 1 Ma for the felsic facies. Positive ɛHf(i) isotopes ranging from +5.4 to +10.9 suggest mantle-derived magma with low crustal assimilation. The progressive increase in Eu anomaly (Eu × 0.64 to 1.15) and high LREE/HREE ratios underscore a continental magmatic arc formation in congruence with a subduction context. Thermobarometric analyses of mineral geochemistry across both facies reveal the magmatic emplacement at temperatures spanning 753–910°C, pressures between 3 and 4.65 kbar, and depths approximating 9–14 km. The simultaneous presence of two magmatic facies bearing tholeiitic and calc-alkaline characteristics, separated by ~13 Ma crystallization gap, infers a magmatic recharge episode. The results highlight a slightly thickened crust due to the arc maturity, or a transition from shallow-dipping to steep-angle subduction, consistent with tectonic slab-rollback mechanisms. The modest crustal thickening, indicative of low arc maturation between 326 and 313 Ma, is concomitant with the closure of the western part of the Rheic Ocean basin. [ABSTRACT FROM AUTHOR]

Fires have been shown to have been common in many Carboniferous ecosystems worldwide yet we still have little understanding of the detail of what, where and how such fires occur or indeed their effects both on the local ecosystem as well as on the Earth System as a whole. The Kingswood Limestone, of late Viséan (Mississippian age) found near Pettycur in Fife, Scotland, is interpreted as being deposited within a crater lake. The limestone contains a range of volcanic clasts together with charcoalified and uncharred plants. Two distinctive communities existed. One dominated by the small scrambling lycopsid Oxroadia that is permineralised and a second dominated by a range of pteridosperms and other gymnosperms preserved as charcoal. Fires surrounding a crater lake charred the plants that were then washed into the lake by post-fire erosion. All plant organs are found as charcoal including woody axes, leaves, pollen organs and ovules. Oxroadia that was living close to the lake was not affected by fire. Rising lake and sea levels allowed saline water to be introduced to the lake and connection to the sea was established. Many new charcoalified plants have still to be formally described. The Kingswood flora, together with the nearby Pettycur flora represents two of the most important Mississippian plant sites globally. [ABSTRACT FROM AUTHOR]

The Late Viséan (mid-Mississippian) anatomically preserved flora from Pettycur, Fife, Scotland is one of the most significant plant assemblages (lagerstätte) from this period anywhere in the world. It has been known from the later 19th century, mainly from loose limestone blocks found on the beach. Thin sections of limestones showing outstanding permineralised plants offered a number of the most eminent British palaeobotanists of their day to describe many of the plants. Most of the thin sections were made commercially so that an understanding of the formation of the deposit as a whole proved difficult. The peel technique developed in the 1950s allowed large slices of limestone to be peeled but only small pieces of the peels were ever mounted and studied by the new authors. Large collections (more than 100) of loose blocks on the beach and from in situ from within basaltic lava flows by the author and colleagues from the late 1970s onwards have been slabbed and peeled and provide the opportunity for new studies and an assessment of the plant assemblages and possible communities present. At least 25 plant organ species are present representing more than 13 whole plant species. Of particular significance is the occurrence of the four main lycopsid tree types that dominate later Pennsylvanian peats and the occurrence of five ferns. It is shown also that a number of the plants may also be preserved as charcoal, especially zygopterid ferns such as Metaclepsydropsis. Of particular importance is the occurrence of true permineralised peats that provide evidence of the botanical composition of the earliest peat-forming mire at a time of rapid global change with a sudden fall of atmospheric CO 2 and rise in O 2 that would have also had an effect upon wildfire systems. [ABSTRACT FROM AUTHOR]

The northwestern margin of the Junggar Basin has a complex tectonic history, which is challenging for hydrocarbon exploration. This study highlights the structural patterns, tectonic evolution, and controlling factors of the Karamay-Baikouquan Fault Zone (KBFZ) in the northwestern margin of the Junggar Basin based on well-log and 3D seismic data. The main findings of this study include the following: spatially, we have divided the structural patterns of KBFZ into three zones on the plane, namely, northern, central, and southern zones; temporarily, the tectonic evolution has been divided into five stages from Late Carboniferous to Cretaceous, namely, Early-Middle Carboniferous, Late Carboniferous-Early Permian, MiddleLate Permian, Triassic-Middle Jurassic, and Late Jurassic-Cretaceous. During the Hercynian and Indochina orogeny, the compressional stress from the movement of the Dalabute strikeslip fault and the Genghis-Junggar strike-slip fault produced various degrees of deformation in different locations in the KBFZ. The general structural style is a mixture of strike-slip and thrustnappe. The main controlling factors include stress period, stress direction, and stratigraphiclithologic associations. This study has implications for hydrocarbon exploration and development in the northwestern margin of the Junggar Basin. [ABSTRACT FROM AUTHOR]

The Unazuki Belt, Southwest Japan, is a part of the Hida Belt, which is characterized as a plutono-metamorphic complex with a continental affinity formed between the late Paleozoic and early Mesozoic. The Unazuki Belt is known to be an important tectonic unit for the tectonic correlation between the proto-Japan and East Asian continents as it records Permo–Triassic tectono-thermal events, however, comprehensive chronology of the Unazuki Belt including the timing of the initiation of this Belt is yet unclear. The present study reveals certain Carboniferous magmatic and sedimentation events from the Unazuki Belt and their tectonic implications for the first time as follows. Zircon U–Pb age dating results and whole-rock geochemical compositions show that the protoliths of metagranite and metatrachyandesite in the Unazuki Belt formed at 328.2 ± 4.4 Ma and 332.8 ± 2.2 Ma, respectively, in an arc tectonic setting. Most metasedimentary rocks of the Unazuki Belt have the youngest detrital zircon grains of ~ 300 Ma with the Carboniferous single cluster at ~ 340–300 Ma without any Pre-360 Ma detrital zircon grains. However, one metasedimentary rock with Precambrian detrital zircons (~ 20%) has the youngest detrital zircon age of ~ 252 Ma, and ~ 66% of detrital zircons show a Permian age. Most of the εHf(t) values of zircon grains from all the studied Unazuki Belt samples, including the metasedimentary and metaigneous rocks with Carboniferous ages (~ 360–300 Ma) are positive (+ 6– + 18), whereas those of the zircon grains with Permian ages (~ 280–260 Ma) show wide variations between + 16 and -23. The whole-rock geochemical compositions of the ~ 300 Ma metasedimentary rocks of the Unazuki Belt show an island arc tectonic setting, whereas those of ~ 252 Ma metasedimentary rock have a continental arc affinity. These new data suggest that (1) igneous and sedimentary rocks in the Unazuki Belt formed in the island arc tectonic setting separated from the margin of continental crust during the Carboniferous but shifted to the continental arc tectonic setting during the latest Permian, (2) the collision between the island arc and continental arc may have caused the intermediate-P/T metamorphism during the Permian in the Unazuki Belt. The Carboniferous island arc tectonic setting in the Unazuki Belt indicates that the Hida Belt, including the Unazuki Belt, formed not at the margin of the South China Craton where Carboniferous subduction is absent but on the continuous subduction zone located along the eastern margin of the North China Craton, including the eastern margin of the northern Korean Peninsula where Carboniferous subduction occurred. [ABSTRACT FROM AUTHOR]

The Carboniferous rocks in the eastern part of El Galala El Bahariya were investigated using integrated field and laboratory techniques to determine their mineralogy, rare earth elements (REEs) distribution, and structural lineament density. The succession is mainly composed of argillaceous and minor arenaceous rocks, exhibiting variations in lithology across the study area. The essential minerals of these rocks are quartz, kaolinite, and illite. The accessory minerals include microcline, gypsum, anhydrite, halite, barite, hematite, pyrite, anatase and gibbsite, in addition to, the radioactive and REEs-bearing minerals such as uranophane, xenotime, monazite, and zircon. These minerals are reported in the rocks of the study area for the first time. The types, forms, habits, and modes of occurrence of the recorded minerals indicate multiple origins: allogenic–authigenic, and primary-secondary. REEs in the rocks exhibit enriched patterns with a negative Eu anomaly, likely due to low plagioclase content or and/or Eu removal by alteration processes. The distribution of REEs is influenced by textural attributes, with finer sediments in the southern part showing higher REEs content, ascribed to the high clay content and presence of gibbsite. The preferential mobility of LREEs is evident, explaining elevated LREEs/HREEs ratios in the rocks. Utilizing remote sensing techniques, lithological units and alteration zones were determined using decorrelation stretch and band ratio methods. The structural features, identified by Laplacian filter and edge enhancement, revealed the presence of NW–SE, N–S, and NE–SW faults that structurally regulate alteration zones and REEs distribution. These alteration zones are associated with clay minerals, REEs concentrations, and high lineament structure density. Spatial distribution maps highlight higher REEs concentrations in the southern part of the study area. These findings were validated using various analytical methods, including mineralogical and geochemical investigations, main component analysis, minimum noise fraction, decorrelation stretch, and spectral reflectance studies. They provide new insights into the REEs potential of the Carboniferous rocks and heighten our understanding of REEs genesis and distribution in the region.Article Highlight: Collaborative use of remote sensing, mineralogy, and geochemistry to explore REEs distribution. LREEs demonstrate higher mobility than HREEs in surface environments. Multiple origins revealed through mineral types, forms, habits, and modes of occurrence. [ABSTRACT FROM AUTHOR]

Accretionary complexes in the Japanese Islands preserve material from parts of the oceanic plates of Panthalassa that have subducted and are now lost. The age of the oceanic plate that is incorporated into the Jurassic accretionary complex of Japan has been previously estimated from scant data on Carboniferous bedded chert. In this study, we investigated a Carboniferous to Permian basalt-chert sequence in the Jurassic accretionary complex of the North Kitakami-Oshima belt in Northeast Japan. The sequence is composed of basaltic rocks, red bedded chert and grey bedded chert in ascending order. The basaltic rocks at the base contain red cherty nodules that yielded conodonts indicating the Bashkiran to early Moscovian, the latter age being more likely (late Carboniferous). The red bedded chert yielded middle Sakmarian (early Permian) radiolarians. The grey bedded chert yielded conodonts indicating the latest Kungurian to earliest Roadian. Thus, our study section demonstrates a formation of the oceanic plate in the late Carboniferous and a following deposition of pelagic siliceous sediments. This is the first time that basaltic rocks within the Jurassic accretionary complex of Japan are directly dated. While previous data need careful reviewing, our results demonstrate that the oldest part of the oceanic plate within the Jurassic accretionary complex is Serpukhovian or older and the youngest part may be as young as the Sakmarian. [ABSTRACT FROM AUTHOR]

Problems Statement and Purpose. The colouration (when pigment is distributed more or less uniformly within skeletal substance) and colour patterns (when pigment is concentrated or arranged in bands, lines, spots, patches, etc.) of fossil brachiopod shells is poorly understood, since its preservation in the fossil record requires the coincidence of several, sometimes random, taphonomic factors. However, the study of the original colouration of fossil invertebrates is of great palaeoecological and taphonomic importance (e.g., to study of the evolution of vision, the development of predator-prey relationships). Records of Palaeozoic brachiopod shells with preserved colouration are quite rare and the shell colouration and colour patterns are currently known for only 15 genera. Data and Methods. Studied isolated valves of the lingulid brachiopods Lingularia mytiloides from the lower Moscovian Kamensk Formation of Luhansk Region (Ukraine) show a preserved colour pattern on the outer surface, represented mainly by light concentric bands. Studied remains are represented by small, 8–10 mm long and 6–7 mm wide, moderately convex ventral thin-shelled valves with elongate elliptical outlines, a rounded anterior margin, subparallel lateral margins and a small, pointed umbo. Valve surface is covered with thin concentric growth lines and weakly developed rugae. Results and Discussion. The studied specimens were divided into two groups based on shell colouration features, which may reflect some details of the colouration and colour patterns. However, these differences may be taphonomic artefacts. It is quite possible that the colour bands on the surface of the valves are evidence of sulphide oxidation, but even so, they likely still reflect the original colour patterns. Environmental conditions were important factors for the preservation of the colouration on the shells of the studied lingulid brachiopods. Among these conditions, the most important were slow sedimentation, absence of agents of mechanical and chemical destruction, such as high-energy water activity, encrustation by epibionts, etc., dysaerobic conditions, and rapid burial apparently accompanied by the activity of bacterial communities. The studied colour patterns on the shells of Lingularia mytiloides are similar to those on other fossil lingulids. The adaptive significance of this colouration for the studied lingulids, which lived infaunally, remains unclear and cannot be resolved with the available material.

In the global carbon cycle, atmospheric carbon emissions, both ‘natural’ and anthropogenic, are balanced by carbon uptake (i.e., sequestration) that mostly occurs via photosynthesis, plus a much smaller proportion via geological processes. Since the formation of the Earth about 4.54 billion years ago, the ratio between emitted and sequestered carbon has varied considerably, with atmospheric CO2 levels ranging from 100,000 ppm to a mere 100 ppm. Over this time, a huge amount of carbon has been sequestered due to photosynthesis and essentially removed from the cycle, being buried as fossil deposits of coal, oil, and gas. Relatively low atmospheric CO2 levels were the norm for the past 10 million years, and during the past million years, they averaged about 220 ppm. More recently, the Holocene epoch, starting ~11,700 years ago, has been a period of unusual climatic stability with relatively warm, moist conditions and low atmospheric CO2 levels of between 260 and 280 ppm. During the Holocene, stable conditions facilitated a social revolution with the domestication of crops and livestock, leading to urbanisation and the development of complex technologies. As part of the latter process, immense quantities of sequestered fossil carbon have recently been used as energy sources, resulting in a particularly rapid increase in CO2 emissions after 1950 CE to the current value of 424 ppm, with further rises to >800 ppm predicted by 2100. This is already perturbing the previously stable Holocene climate and threatening future food production and social stability. Today, the global carbon cycle has been shifted such that carbon sequestration is no longer keeping up with recent anthropogenic emissions. In order to address this imbalance, it is important to understand the roles of potential biological carbon sequestration systems and to devise strategies to facilitate net CO2 uptake; for example, via changes in the patterns of land use, such as afforestation, preventing deforestation, and facilitating agriculture–agroforestry transitions.

The Bonaventure Formation is an early Carboniferous fossil-bearing rock unit that crops out in northern New Brunswick and eastern Quebec, eastern Canada. Here, we describe CMNFV 10013, a tetrapod trackway found in Bonaventure Formation outcrops on Heron Island, New Brunswick, by Robert Wheelock Ells in 1879. The specimen shows at least seven prints including two pes–manus couples, one of which is sufficiently well preserved to be attributable to Hylopus isp. Several underprints significantly depart from typical Hylopus tracks and emphasise the importance of considering taphonomy when identifying fossil trackways. CMNFV 10013 is the first described fossil reported from the Bonaventure Formation. It extends the Carboniferous Maritimes Basin tetrapod trackway record northwards and represents one of the oldest tetrapod trackways from Canada. Reviewing the global record of Hylopus isp. reveals CMNFV 10013 is also one of the earliest Hylopus found. This global record also reveals that Hylopus occurrences are clustered around the paleotropics, possibly suggesting a biogeographical preference. This specimen highlights the importance of describing forgotten museum specimens. Future research should focus on undescribed museum specimens and contributing to existing collections through fieldwork in the promising rocks of Heron Island. [ABSTRACT FROM AUTHOR]

In the global carbon cycle, atmospheric carbon emissions, both 'natural' and anthropogenic, are balanced by carbon uptake (i.e., sequestration) that mostly occurs via photosynthesis, plus a much smaller proportion via geological processes. Since the formation of the Earth about 4.54 billion years ago, the ratio between emitted and sequestered carbon has varied considerably, with atmospheric CO2 levels ranging from 100,000 ppm to a mere 100 ppm. Over this time, a huge amount of carbon has been sequestered due to photosynthesis and essentially removed from the cycle, being buried as fossil deposits of coal, oil, and gas. Relatively low atmospheric CO2 levels were the norm for the past 10 million years, and during the past million years, they averaged about 220 ppm. More recently, the Holocene epoch, starting ~11,700 years ago, has been a period of unusual climatic stability with relatively warm, moist conditions and low atmospheric CO2 levels of between 260 and 280 ppm. During the Holocene, stable conditions facilitated a social revolution with the domestication of crops and livestock, leading to urbanisation and the development of complex technologies. As part of the latter process, immense quantities of sequestered fossil carbon have recently been used as energy sources, resulting in a particularly rapid increase in CO2 emissions after 1950 CE to the current value of 424 ppm, with further rises to >800 ppm predicted by 2100. This is already perturbing the previously stable Holocene climate and threatening future food production and social stability. Today, the global carbon cycle has been shifted such that carbon sequestration is no longer keeping up with recent anthropogenic emissions. In order to address this imbalance, it is important to understand the roles of potential biological carbon sequestration systems and to devise strategies to facilitate net CO2 uptake; for example, via changes in the patterns of land use, such as afforestation, preventing deforestation, and facilitating agriculture–agroforestry transitions. [ABSTRACT FROM AUTHOR]

Premise of research. The fossil record shows that seed plants appeared during the Devonian and started to become dominant in the Mississippian. However, the identity of their closest relatives remains uncertain with three candidates: Stenokoleales, Archeopteridalean progymnosperms, and Aneurophytalean progymnosperms. To clarify the relationships of these groups, it is necessary to document as many Devonian-Mississippian taxa as possible and increase taxon sampling in phylogenetic analyses. In this context, Stauroxylon beckii Galtier 1970 from Mississippian deposits of France is particularly interesting because of its similarities with both seed plants and some of their potential closest relatives. Here, we provide an updated description of Stauroxylon and discuss its affinities using morphoanatomical comparisons and phylogenetic analyses. Methodology. The holotype of S. beckii and a new specimen from the same formation are described using thin sections, cellulose acetate peels, and polished surfaces. The morphoanatomy of the specimens is compared with that of early seed plants and their putative relatives. Stauroxylon is also included in phylogenetic analyses of the radiatopses based on Toledo and colleague's matrix. Pivotal results. Stauroxylon beckii possess a cruciform protostele with protoxylem strands at the tips of the ribs, a central protoxylem strand, and produces second- and third-order axes in perpendicular planes. The new specimen differs by characters interpreted as developmental differences or intraspecific plasticity (organotaxis, secondary growth) and is also assigned to S. beckii. Both comparative approaches and phylogenetic analyses place Stauroxylon within the Aneurophytalean progymnosperms, a group previously only known in the Devonian. The inclusion of Stauroxylon strengthens previously established relationships within the radiatopsids. Stauroxylon also displays structural fingerprints important for leaf and pith evolution. Conclusions. Stauroxylon is interpreted as a Mississippian representative of the Aneurophytales. It provides new information on the relationships and morphoanatomical diversity of early seed plants and their closest relatives. [ABSTRACT FROM AUTHOR]

Bonebeds occurring in exposures of the Burlington and Keokuk Limestones (Mississippian/Osagean) along the Iowa and Illinois border (USA) contain an abundant and diverse collection of chondrichthyan remains that includes teeth, spines, denticles, and coprolites. These remains represent cochliodont, hybodont, petalodont, ctenacanthid, symmoriid, and acanthodian (stem chondrichthyan) taxa. The thickest of these beds, herein referred to as the Burlington–Keokuk bonebed, occurs at the top of the Burlington Limestone and presents a remarkable opportunity to study the assemblage of mid-continent, Middle Mississippian chondrichthyans. Bulk matrix samples of this bonebed were collected from two quarries (Biggsville Quarry, Biggsville, IL, USA, and Nelson Quarry, Mediapolis, IA, USA) and disaggregated. Among the multitude of previously known taxa, several teeth represented a new genus and species of hybodont shark. Herein, we describe these teeth as Columnaodus witzkei (gen. et sp. nov.), a hybodontiform with dental features comparable to unnamed specimens reported from elsewhere. [ABSTRACT FROM AUTHOR]

Sardinia (Italy) represents one of the most comprehensive cross-sections of the Variscan orogen. The metamorphic and structural complexity characterizing its axial zone still presents many unresolved issues in the current state of knowledge. The data presented from the structural study of the entire axial zone of this area have allowed the authors to propose a subdivision into two new structural complexes. In particular, a younger complex is identified as the New Gneiss Complex, containing remnants of an older and higher-grade metamorphic complex defined as the Old Gneiss Complex. The structural and geometric relationships between the two complexes suggest the redefinition of the axial zone of Sardinia as part of the intracontinental East Variscan Shear Zone/medium-temperature Regional Mylonitic Complex. Comparable relationships are also highlighted in many other areas of the Variscan chain (e.g., Morocco, Corsica, Maures Massif, and Argentera Massif). Extending this new structural interpretation to other axial zones of the South European Variscan orogen could provide new hints for reconstructing the collision boundaries between Gondwana and Laurussia in the late Carboniferous to the early Permian periods. [ABSTRACT FROM AUTHOR]

Teeth from the late Mississippian Bangor Limestone, Monteagle Limestone, and Pride Mountain Formation (early to middle Chesterian = late Viséan–early Serpukhovian) of northern Alabama, USA, are designated as Cavusodus whitei, gen. et sp. nov. The species is similar to Cypripediodens cristatus Duffin and Ward, known only from the Eyam Limestone Formation (Mississippian, late Viséan) of Derbyshire, England. Cypripediodens cristatus, the only species of the genus, is distinguished by teeth having an elongate crown, an apical cusp having a nearly circular cross-section, a secondary cusp on the lingual face, and several cristae on the lingual heel. Cavusodus whitei teeth resemble those of Cypripediodens cristatus but differ in lacking the secondary cusp, in having a more labiolingually compressed apical cusp, in possessing more robust lingual cristae, and in possessing a longitudinal groove on the labial face. The genera comprising the Janassidae are reconsidered. It is proposed that only Janassa, Cholodus, and Cypripediodens be retained, in addition to the new genus. [ABSTRACT FROM AUTHOR]

During the Carboniferous Period, the Qinghai-Tibetan Plateau and its surrounding areas were located in quite different paleogeographic positions with various sedimentary and biological types. It is important to systematically compile and summarize the Carboniferous strata and biotas of the Qinghai-Tibetan Plateau and its surrounding areas, to establish an integrated stratigraphic framework for correlation, and to reconstruct the paleogeography for correctly understanding the breakup of the Gondwana Continent and the evolution of the Paleo-Tethys Ocean in the Late Paleozoic. The Carboniferous of the Qinghai-Tibetan Plateau and its surrounding areas can be subdivided into the Gondwanan, Cimmerian, and Tethyan types. The Gondwanan-type Carboniferous are distributed in the North Himalayan, Kangmar-Lhunze, and Zanda-Zumba regions of the South Tibet Subprovince and northern India-Pakistan Area, where only the Mississippian is developed and the biota is of Gondwanan affinity. The Cimmerian-type Carboniferous, which are found in the Baoshan, Tengchong, Coqen-Xainza, Lhasa-Zayu, Nagqu-Biru, and South Qiangtang regions, as well as Shan-Thai and South Afghanistan-Pamir areas, also represent only the Mississippian strata, but their biota is characterized by mixed characters of European, South China, Australian, and North American types. The Tethyan-type Carboniferous are distributed in the Tanggula Mountains, Hoh Xil-Bayanhar, Chamdo-Hengduanshan, Tiekelike, West Kunlun, Karakorum, East Kunlun-Central Qinling, and Qilian regions, where the Carboniferous succession is well developed, and the biota is of warm-water Tethyan affinity. The biostratigraphical correlation of the Gond-wanan-type and Cimmerian-type Carboniferous is based mainly on conodonts and additionally on brachiopods and rugose corals. The Mississippian of the Tethyan-type Carboniferous is correlated mainly by using rugose corals and brachiopods, whereas in the Pennsylvanian foraminifera (fusuline) and conodonts are regarded as primary fossil groups, subordinated by rugose corals and brachiopods. Adhering to the International standard chronostratigraphy of the Carboniferous, we have reconstructed a framework of the litho- and biostratigraphic subdivision and correlation of the Qinghai-Tibetan Plateau and its surrounding areas. Further studies should focus on isotope geochronology, geochemistry, paleoclimates, and paleoenvironments of the Carboniferous in the Qinghai-Tibetan Plateau and its surrounding areas. [ABSTRACT FROM AUTHOR]

Many massive sulfide deposits have been discovered in the Upper Paleozoic rift-related volcaniclastic sequence in South China, among which the Yushui copper deposit is the most important due to its high grade. The deposit has been variably attributed as SEDEX (sedimentary exhalative) or MVT (Mississippi valley type). The Yushui copper deposit in Guangdong (South China) contains stratiform bornite-chalcopyrite orebodies (102.1 kt Cu @ 3.5%, 186.6 kt Pb @ 4.29%, 117.6 kt Zn @ 2.91%, and 339 t Ag @ 112 g/t) developed along the contact between Upper Carboniferous dolostone and Lower Carboniferous pebbly quartz sandstone, which indicates a shallow marine deposition environment. The Yushui deposit comprises an upper massive sulfide orebody and a lower stockwork orebody with intense alteration. In this study, we newly identified Carboniferous tuffs and syn-volcanic faults in the footwall, and exhalites in the hanging-wall. Hematite from the Cu ores yielded a U-Pb age of 320 ± 15 Ma (MSWD = 2.1, n = 57), and hydrothermal dolomite yielded a Sm-Nd isochron age of 308.1 ± 4.6 Ma (n = 7; MSWD = 0.94), which constrains the timing of mineralization at Yushui. These ages are coeval with the Carboniferous host rocks. Combining the evidence from the geological features (syn-volcanic faults, volcanic rocks, exhalites) and hematite trace element compositions, we suggest that the Yushui is a shallow marine VMS (volcanogenic massive sulfide) deposit. The Sr-Nd isotope composition of hydrothermal dolomite (εNd ~−12) indicates that the ore-forming materials were originated from the crustal basement. The Yushui copper deposit was likely formed during the Late Carboniferous continental back-arc extension in eastern South China. The regional extension may have caused enhanced heat flow, which promoted fluid convection in the basement rocks. In addition, we suggest that volcanic rocks and disseminated chalcopyrite-pyrite mineralization in the Lower Carboniferous quartz sandstone and exhalites are good indicators for regional VMS prospecting. [ABSTRACT FROM AUTHOR]

Plain Language Summary: Nearly synchronous global changes in geomagnetic polarity give both a detailed irregular pacing to geological time and provide a glimpse into heat transfer processes across the core—mantle boundary which drives the Earth's geodynamo. Although the Late Carboniferous is characterized by some well‐studied reversals, details of the tempo of polarity changes in the Early Carboniferous are unknown. This work addresses this by providing a detailed record of polarity changes over a ∼2 million year interval at around 334.5–332.5 million years ago‐from the Trowbarrow Quarry section in NW England. We demonstrate that these limestones likely preserve magnetization from close to their time of formation and record at least 31 polarity reversals. These observations support the idea that the Earth's dynamo was in a hyperactive reversing state similar to those sustained for tens of Myr in the Late Jurassic, parts of the Cambrian and the Late Ediacaran. It further corroborates a ∼200 Myr cyclicity in paleomagnetic field behavior since the Precambrian, potentially linked to variable core heat flow forced by mantle convection. The pattern of geomagnetic polarity changes during the Early Carboniferous (Mississippian) is not known in detail. This information sparsity is addressed by determining a magnetostratigraphy from the late Asbian (late Visean at ∼333 Ma) in Trowbarrow Quarry, UK. This is the stratotype section of the late Asbian and has a detailed foraminiferal zonation based on the same set of paleomagnetic samples, establishing a detailed biostratigraphy. The 195 m‐thick section was sampled at an average spacing of 1.1 m, yielding a detailed magnetostratigraphy comprising nine major magnetozone couplets, and seven submagnetozones. The section dataset has a 78% bias to normal polarity determined from 177 sampling levels. The magnetization is carried by a mixture of hematite and detrital magnetite, with 68% of specimens dominated by hematite magnetizations. The primary magnetization passes a fold test showing its age was prior to the latest Carboniferous. The hematite is inferred to be largely of detrital, eolian origin, although some reddened levels are associated with emergent surfaces, suggesting that a small fraction of hematite is associated with platform emergence. The Mississippian age magnetization is partly overprinted with Kiaman Superchron‐age and Brunhes‐age magnetizations. Using the duration of the section based on astrochronology indicates a reversal frequency of 15.7 ± 0.75 Myr−1, indicating that the geodynamo was in a hyperactive reversing state between 335 and 333 Ma. Key Points: A 195 m section, representing ∼2 Myr, yields a magnetostratigraphy comprizing nine major magnetozone couplets and seven submagnetozonesPrimary magnetizations are predominantly carried by hematite with lesser important detrital magnetite. Data pass regional fold testsA reversal frequency of 15.7 ± 0.75 Myr−1 is calculated, suggesting that the geodynamo was in a hyperactive state at ∼333 Ma [ABSTRACT FROM AUTHOR]

The Rheic Ocean closure stratigraphic record in southern Mexico is largely exposed in the Paleozoic Acatlán Complex. One of the most distinctive characteristics of the Acatlán Complex is the presence of high-pressure rocks, interpreted as remnants of the Rheic Ocean and the adjacent continental margin of Gondwana, which were subducted and then exhumed to the surface. Despite its importance in reconstructing the dynamics of the westernmost Rheic Ocean closure, the timing and mechanisms of exhumation of these high-pressure rocks remain debated. Some authors have tentatively interpreted the late Paleozoic, fluvial to marine succession of the Patlanoaya Group in southern Mexico as the sedimentary response to the exhumation of high-pressure rocks of the Acatlán Complex. Therefore, these sedimentary rocks may be particularly helpful in understanding the timing and evolution of high-pressure rocks exhumation during the Rheic Ocean closure. In this work, the tectono-sedimentary evolution of the continental deposits of the Patlanoaya Group was reconstructed, integrating sedimentologic, petrographic, and U-Pb detrital geochronological data to test the different scenarios proposed for the exhumation of the Acatlán Complex high-pressure rocks. Our data suggest that the lower Patlanoaya Group was deposited in an Early Mississippian basin with a two-stage evolution: a phase characterized by debris flow deposits derived from small-scale reliefs composed of low-grade metamorphic rocks and a subsequent phase marked by an NNE-trending fluvial system deposits sourced from low-metamorphic grade rocks of a mylonitic zone. Therefore, the lower Patlanoaya Group deposition was controlled by a major NNE-trending mylonitic shear zone associated with the development of a supradetachment basin linked to the progressive exhumation of high-pressure rocks during an Early Mississippian major extensional event. This work highlights the importance of sedimentary deposits in reconstructing the late Paleozoic history of the Acatlán Complex during the Rheic Ocean closure and the final stage of the Pangea assembly. [ABSTRACT FROM AUTHOR]

The Nord-Pas-de-Calais Coalfield is formed by an almost continuous succession of upper Carboniferous deposits, from which an extremely diverse macroflora has historically been described. Recent evidence has highlighted a clear pattern of changing species diversity, showing some differences from what is seen in other coalfields of Variscan Euramerica. We further study this significant macroflora, focusing on the biostratigraphical changes and their palaeoecological implications. Clustering and ordination analyses have indicated key floral discontinuities that enable the standard regional macrofloral biozones to be recognized in the Nord-Pas-de-Calais Coalfield. By combining these results with the previous diversity studies, six distinct phases in the evolution of the coal swamp vegetation in north-eastern France can be identified: (1) an initial invasion of peat substrate vegetation in the earliest Langsettian; (2) a rapid diversification of the clastic substrate vegetation in the early-middle Langsettian; (3) a more gradual diversification of the vegetation of both clastic and peat substrates during the late Langsettian to middle Duckmantian glacial phase C3; (4) the appearance of more characteristically late Westphalian, but less diverse floras during the late Duckmantian to early Bolsovian C3-C4 interglacial phase; (5) a marked increase in species diversity in the middle-late Bolsovian, coinciding with the onset of the C4 glacial phase; and (6) a marked reduction in species diversity, and the appearance of new medullosaleans and marattialeans in the Asturian, possibly linked to climate change. The evidence clearly shows how this palaeotropical swamp vegetation was responding to climate change and orogenic landscape changes during Westphalian times. [ABSTRACT FROM AUTHOR]

Gas produced water is originated from formation associated water produced during oil and gas production operations, which is characterized by numerous types, high mineralization and complex pollution components. Through sampling, testing and analyzing gas produced water in the Eastern Sichuan area, it is found that the carboniferous formation is rich in mineral resources, such as strontium (up to 814 mg/L), bromine (up to 717 mg/L), which is much higher than the content in the brine of Qaidam Basin salt lakes or seawater. And currently, China's strontium ore and bromine are in a situation of high import demand and supply shortage. By clarifying the strontium and bromine recovery techniques and evaluating the preliminary economic feasibility of potential mining, it is found that there are significant prospects of development and utilization. This study aims to provide scientific basis for the extraction of strontium and bromine resources in gas produced water in the Eastern Sichuan area and to establish the foundation for better sustainable development and resource utilization of oil and gas fields. [ABSTRACT FROM AUTHOR]

Problems Statement and Purpose. The colouration (when pigment is distributed more or less uniformly within skeletal substance) and colour patterns (when pigment is concentrated or arranged in bands, lines, spots, patches, etc.) of fossil brachiopod shells is poorly understood, since its preservation in the fossil record requires the coincidence of several, sometimes random, taphonomic factors. However, the study of the original colouration of fossil invertebrates is of great palaeoecological and taphonomic importance (e.g., to study of the evolution of vision, the development of predator-prey relationships). Records of Palaeozoic brachiopod shells with preserved colouration are quite rare and the shell colouration and colour patterns are currently known for only 15 genera. Data and Methods. Studied isolated valves of the lingulid brachiopods Lingularia mytiloides from the lower Moscovian Kamensk Formation of Luhansk Region (Ukraine) show a preserved colour pattern on the outer surface, represented mainly by light concentric bands. Studied remains are represented by small, 8-10 mm long and 6-7 mm wide, moderately convex ventral thinshelled valves with elongate elliptical outlines, a rounded anterior margin, subparallel lateral margins and a small, pointed umbo. Valve surface is covered with thin concentric growth lines and weakly developed rugae. Results and Discussion. The studied specimens were divided into two groups based on shell colouration features, which may reflect some details of the colouration and colour patterns. However, these differences may be taphonomic artefacts. It is quite possible that the colour bands on the surface of the valves are evidence of sulphide oxidation, but even so, they likely still reflect the original colour patterns. Environmental conditions were important factors for the preservation of the colouration on the shells of the studied lingulid brachiopods. Among these conditions, the most important were slow sedimentation, absence of agents of mechanical and chemical destruction, such as high-energy water activity, encrustation by epibionts, etc., dysaerobic conditions, and rapid burial apparently accompanied by the activity of bacterial communities. The studied colour patterns on the shells of Lingularia mytiloides are similar to those on other fossil lingulids. The adaptive significance of this colouration for the studied lingulids, which lived infaunally, remains unclear and cannot be resolved with the available material. [ABSTRACT FROM AUTHOR]

The Hadim Nappe has a relatively complete succession from the Middle(?)--Upper Devonian to Upper Cretaceous in the Taurides. The Bademli section is one of thewell exposed sections of theHadim Nappe that is selected for detailed biostratigraphic investigations. It includes a continuous Viséan stratigraphic succession. In the Bademli section, rich and diverse Early--Middle Viséan foraminiferal assemblages were recovered, most of which were reported for the first time in Turkey. Four first occurrence biozones, which approximately correspond to the Zones MFZ10 to MFZ13 of the Belgium stratotype section, are identified based on the foraminiferal analysis of the Lower-Middle Viséan strata of the Bademli section that are Ammarchaediscus-Glomodiscus first occurrence zone, Uralodiscus rotundus first occurrence zone, Pojarkovella first occurrence zone and Endothyranopsis (Reitlingeropsis) intermedia - Endothyranopsis mosquensis first occurrence zone. [ABSTRACT FROM AUTHOR]

Three species assigned to the same nominal genus of Paleozoic xenacanthiform shark have been combined with the name Orthacanthus gracilis (Chondrichthyes, Xenacanthiformes, Orthacanthidae). Orthacanthus gracilis (Giebel, 1848), which was originally combined as Chilodus gracilis Giebel, 1848, is the senior synonym; it has priority over both Orthacanthus gracilis (Newberry, 1857), which was originally combined as Diplodus gracilis Newberry, 1857, and Orthacanthus gracilis Newberry, 1875a. Proposed species-group replacement names are Orthacanthus lintonensis nom. nov. for O. gracilis (Newberry, 1857) and Orthacanthus adamas nom. nov. for O. gracilis Newberry, 1875a. Chilodus gracilis Giebel, 1848 is designated as the type species of Chilodus Giebel, 1848; this species becomes the type species for Giebelodus Whitley, 1940, which is a replacement name for Chilodus Giebel, 1848 (preoccupied by Chilodus Müller & Troschel, 1844, Actinopterygii). Giebelodus Whitley, 1940 is a junior subjective synonym of Orthacanthus Agassiz, 1843. [ABSTRACT FROM AUTHOR]

Introduction: The Sierra Santa Teresa is located 20 km southeast of Hermosillo in the central region of Sonora state, Mexico. The sedimentary strata mainly correspond to limestone, mudstone, wackestone and packstone texture, from the upper Paleozoic. The biota is represented by crinoids of the morphospecies Baryschyr anosus, Cyclocaudex insaturatus, Floricyclus angustimargo, Cyclocion distictus, Lamprosterigma erathense, Preptopremnum rugosum in association with algae, fusulinid foraminifera, coralline sponges (Chaetetes sp.), solitary corals (Lophophyllidium sp., Fomichevella sp.), fenestellid bryozoans (Archimedes stoyanowi), and brachiopods (Antiquatonia sp.). Objective: The principal aim of this study is to analyze the biotic composition in the Sierra Santa Teresa and its paleoecological and paleogeographical considerations. Methods: In this study we synthetize information about the principal taxa collected in outcrops of the Carboniferous of the Sierra, Santa Teresa. Results: The distribution of the biota, and particularly the crinoid morphospecies, allowed paleobiogeographical correlations to be made with other Mississippian-Pennsylvanian localities of Mexico and different regions of the United States of America in Texas, Colorado, Illinois and Oklahoma, which were located in the southwestern of the North American Craton. Conclusions: It is considered that the paleoenvironment inferred based on the paleontological records of the Sierra Santa Teresa were shallow seas that allowed the development of communities of crinoids, as well as other invertebrates such as coralline sponges, solitary corals, fenestellid bryozoans and brachiopods, with a range stratigraphic from the Middle-Upper Mississippian (Chesterian) to the Middle Pennsylvanian (Desmoinesian). [ABSTRACT FROM AUTHOR]

The paper presents new finds of fossil fauna and flora at the rediscovered locality Krsmol "Deep gorge" ("Hluboká rokle") of the Ploužnice Horizon (Semily Formation, Krkonoše Piedmont Basin). Several metres thick reddish to grey tuffaceous siltstones of this lacustrine horizon contain 10 centimetres thick layer of grey, hard, siltstones with good fissility, containing one to two thin layers enriched in isolated osteological fragments of vertebrates at the base. Scales and teeth of actinopterygians, scales and fragments of the pectoral girdle of acanthodians are common, and teeth of chondrichthyans can be occasionally found. Rare scales of actinopterygians, isolated insect wings and sporadic plant remains are also present in the overlying reddish-purple siltstone. The newly found fauna in Krsmol extends the existing knowledge based on the old collections and coincides in species with the findings at other sites of the Ploužnice Horizon. From the biostratigraphic point of view, the findings of scales of actinopterygian fish Sphaerolepis kounoviensis, which is an important representative of the biozone corresponding to the uppermost Carboniferous shark teeth and especially the wings of the insect Sysciophlebia rubida of the family Spiloblattinidae are significant, on the basis of which the strata can be classified as Stefan B/C (Kasimovian/Gzhelian) similarly to the strata at other sites of the Ploužnice Horizon. [ABSTRACT FROM AUTHOR]

New finds of fossil assemblages of brachiopods, mollusks, crinoids, arthropods and fishes, as well as terrestrial plants from a part of the Dyakove Group, which corresponds to the coal-bearing Mandrykyne Formation and the lower part of the Mospyne Formation and is exposed in the southern part of the Luhansk Region, were studied. For the first time, a brachiopod assemblage consisting of species of the genera Crurithyris, Tiramnia, Alphachoristites, Lissochonetes were identified in these rocks. In addition, phyllocarids and impressions of terrestrial plants of the genera Halonia, Calamites, Pinnularia, Paripteris, Eusphenopteris, Artisia and Cordaites were found in the Dyakove Group for the first time. Bivalves and gastropods in the studied collection are represented by the genera Phestia, Palaeoneilo, Nuculavus, Solenomorpha, Sanguinolites, Posidoniella, ?Euchondria, ?Nodospira, Euphemites, Retispira, Glabrocingulum, Rhineoderma, Angyomphalus, and Naticopsis. Cephalopods are represented by the species of the genera Gzheloceras, ?Pseudogzheloceras, Melvilloceras, Retites, Gastrioceras and ?Owenoceras. In addition to the above groups, the rocks also contain the crinoids Platyplateium, Platycrinites, ?Unilineatocrinus and Bicostulatocrinus as well as fragments of fin spines of acanthodians Gyracanthidae indet. and isolated unidentified fish scales. [ABSTRACT FROM AUTHOR]

Explanations for major catastrophes in the history of life commonly focus on their time-spans. Less biotic crises are worth attention as well, however, which requires their investigation in a longer-lasting context. The present study relates the Taghanic (Givetian) and mid-Carboniferous (Serpukhovian) biotic crises to some long-term changes in their environmental developments. The trends in these developments are interpreted on the basis of changes of the global sea level, the global average temperatures, the total surface area of exposed land, the total number of lithospheric plates, and the concentration of atmospheric oxygen. It is found that the Taghanic and mid-Carboniferous biotic crises can be related directly or indirectly to some long-term environmental changes.

Abstract The pattern of geomagnetic polarity changes during the Early Carboniferous (Mississippian) is not known in detail. This information sparsity is addressed by determining a magnetostratigraphy from the late Asbian (late Visean at ∼333 Ma) in Trowbarrow Quarry, UK. This is the stratotype section of the late Asbian and has a detailed foraminiferal zonation based on the same set of paleomagnetic samples, establishing a detailed biostratigraphy. The 195 m‐thick section was sampled at an average spacing of 1.1 m, yielding a detailed magnetostratigraphy comprising nine major magnetozone couplets, and seven submagnetozones. The section dataset has a 78% bias to normal polarity determined from 177 sampling levels. The magnetization is carried by a mixture of hematite and detrital magnetite, with 68% of specimens dominated by hematite magnetizations. The primary magnetization passes a fold test showing its age was prior to the latest Carboniferous. The hematite is inferred to be largely of detrital, eolian origin, although some reddened levels are associated with emergent surfaces, suggesting that a small fraction of hematite is associated with platform emergence. The Mississippian age magnetization is partly overprinted with Kiaman Superchron‐age and Brunhes‐age magnetizations. Using the duration of the section based on astrochronology indicates a reversal frequency of 15.7 ± 0.75 Myr−1, indicating that the geodynamo was in a hyperactive reversing state between 335 and 333 Ma.

This work presents an in-depth examination of the Carboniferous volcanic reservoir within the CH471 well area, situated in the central portion of the Hongche fault zone on the northwestern margin of the Junggar Basin. Leveraging seismic data and well connection comparisons, we scrutinize the tectonic evolution model and elucidate the impact of the nappe structure of the Hongche fault zone on the volcanic reservoir. The study has obtained the following understanding: after the formation of Carboniferous volcanic rocks, affected by the Hongche fault structure, a series of structural superpositions from extension to extrusion and finally thrust occurred, resulting in a northwestward tilt of the volcanic rock mass, and a large number of cracks were generated inside the rock mass. At the same time, the top was uplifted and affected by weathering and leaching to form a weathering crust, eventually forming a reservoir. The northern part is located in the edge area of the eruption center, and the rock mass has good stratification. The rock strata have certain constraints on the reservoir distribution, and the reservoir is inclined along the rock mass. The southern part is close to the eruption center and features large volcanic breccia accumulation bodies with strong internal heterogeneity. The reservoir developed mainly in the superposition of the range of control of the weathering crust and dense fracture development, and the rock mass morphology does not control the area. Structure is the key to forming a volcanic rock reservoir, mainly reflected in the following aspects. First, tectonic activity is accompanied by fracture development, and fractures are densely developed in areas with strong activity, which can effectively improve the physical properties of volcanic reservoirs. Second, tectonic activity leads to the strata uplift and weathering denudation, forming a weathering crust. Within the range of control of weathering and leaching, the physical properties of volcanic rocks are improved, and it is easier to form high-quality reservoirs. Third, the distribution of volcanic rock masses is controlled by tectonic activity, which affects the reservoir controlled by the dominant lithology.

The GSSP for the Kasimovian Stage has not been fixed or defined. Several conodont species: Swadelina subexcelsa (Alekseev et Goreva, 2001), Idiognathodus turbatus (Rosscoe et Barrick, 2009) or Idiognathodus sagittalis (Kozitskaya, 1978) and Idiognathodus heckeli (Rosscoe et Barrick, 2013) were proposed and discussed by the Task Group as potential index taxa for the boundary definition. This paper describes the distribution of all potential conodont markers and refines the levels of their appearance in the key sections in the type region of the Kasimovian, considering revision of the previously obtained and new data. The traditional lower boundary of the Kasimovian Stage in the Moscow Basin coincides with the level of FAD of the conodont Swadelina subexcelsa. This species could be traced across large distances, including different continents and could be proposed as a good marker for the Moscovian-Kasimovian boundary. The first occurrences of other species as Idiognathodus sagittalis,I. turbatus and I. heckeli are fixed at the base of the middle member of the Neverovo Formation of the Khamovnikian Substage, i.e. much higher than the base of the Kasimovian that was established for the Carboniferous of Russia. The levels of the appearance of this species have a high potential for the global correlation, but it is not good solution for the definition of the Global Kasimovian Boundary. [ABSTRACT FROM AUTHOR]

Polyneopteran clade of insects is very diverse and has a remarkable fossil history starting in the Late Palaeozoic. Representatives of Dictyoptera comprise roaches, termites and mantids and their stem group relatives like the common Palaeozoic and Mesozoic roachoids, a group well known for its problematic taxonomy. In this study, two new taxa are described based on forewing venation well displaying convexity or concavity of the veins due to preservation in spherosideritic concretions. A new paoliid, Stephanopsis testai sp. nov. (Blattinopsidae), from Moscovian deposits at Mazon Creek (Illinois, U.S.A.), supplements Stephanopsis mirandus found at the same locality, which mainly differs in the branching patterns of MP and anal veins. A new stem dictyopteran, Sosnowiecia dareki gen. nov. et sp. nov. (?Mesorthopteridae), from Langsettian deposits at Sosnowiec-Klimontów (Lower Silesia, Poland) is problematic in terms of taxonomy as it has a mosaic of characters characteristic of Paoliida, Eoblattida and Grylloblattida, but retains affinities with roachoid insects, such as Miroblatta sp. Hence, these two new species increase the diversity of Carboniferous polyneopteran insects, but reveals the problem of depending only on alar characters in taxonomy. [ABSTRACT FROM AUTHOR]

Concretions are an interesting mode of preservation that can occasionally yield fossils with soft tissues. To properly interpret these fossils, an understanding of their fossilization is required. Probabilistic models are useful tools to identify variations between different Konservat-Lagerstätten that are separated spatially and temporally. However, the application of probabilistic modeling has been limited to Early Paleozoic Konservat-Lagerstätten preserved in shales. In this paper, the patterns of preservation of three concretionary Konservat-Lagerstätten—the Carboniferous Mazon Creek (USA) and Montceau-les-Mines (France), and the Silurian Herefordshire Lagerstätte (UK)—are analyzed using a statistical approach. It is demonstrated that the degree of biotic involvement, i.e., the degree to which a carcass dictates its own preservation, is connected to internal organ conditional probabilities—the probabilities of finding an internal organ associated with another structure such as biomineralized, sclerotized, cuticularized, or cellular body walls. In concretions that are externally forced with little biological mediation (e.g., Herefordshire), all internal organ conditional probabilities are uniform. As biological mediation in concretion formation becomes more pronounced, heterogeneities in conditional probabilities are introduced (e.g., Montceau-les-Mines and Mazon Creek). The three concretionary sites were also compared with previously investigated Konservat-Lagerstätten preserving fossils in shales to demonstrate how the developed probability framework aids in understanding the broad-scale functioning of preservation in Konservat-Lagerstätten. [ABSTRACT FROM AUTHOR]

The Jebel Begaa region of the eastern Anti-Atlas in SE Morocco yielded a single, very well-preserved goniatite that is closely related to Helicocyclus divergens Riley, 1996 from the lower Viséan (Chadian) of northern England. Both are placed in a new genus, Tectocyclus n. gen., with the Moroccan T. herbigi n. sp. as the type species. Characteristic are its subtriangular suture elements, which distinguish it strongly from Helicocyclus gracillimus Schindewolf, 1951, which is revised based on the re-examination of its types. The type-species of Helicocyclus is characterized by wide, bell-shaped lateral lobes, unlike as in described helicocyclids from the upper Tournaisian and Viséan of North Africa, Russia, and Central Asia. These are assigned, partly with reservation, to Serpenticyclus n. gen., with the oldest species, Helicocyclus fuscus Korn, Bockwinkel, Ebbighausen, and Klug, 2003, as the type-species. All three genera form the Helicocyclinae n. subfam., which first appeared in North Africa, migrated at the end of the Tournaisian across the Variscan Sea to the southern shelf of Laurussia, to Central Asia, and to the Urals seaway, where it survived into Arundian levels of the Viséan. [ABSTRACT FROM AUTHOR]

The Oaxacan Complex Carboniferous-Permian sedimentary cover in southern México records provenance shifts through time, reflecting the collision between Gondwana and Laurentia to amalgamate Pangea. The integration of petrological analysis and LA-ICP-MS U-Pb zircon geochronology from Santiago, Ixtaltepec and Yododeñe formations compared with adjacent terranes suggests that: (1) during the Early Mississippian, the Santiago Formation received sediments mainly from local sources such as the Oaxacan Complex and Tiñu Formation, with minor contributions from adjacent peri-Gondwana sources. The magmatic activity may have started during this time (~359–346 Ma) (2) during the Late Mississippian (Ixtaltepec Formation), detrital zircon grains of Ediacaran-Cambrian age are dominant, derived from sediments either related to the Pan-African/Brasiliano orogeny or the opening of the Iapetus Ocean; (3) during the Late Mississippian-Middle Pennsylvanian, intercalated marine volcaniclastic sandstone (Ixtaltepec Formation) provides the first record of Carboniferous arc-related volcanism reported in southern Mexico, dated between 330 and 308 Ma; (4) the early Permian Yododeñe Formation records the exhumation and erosion of the sedimentary cover during the final stage of Pangea assembly. Rhyodacitic subvolcanic sills and lavas dated at ~282–270 Ma are present throughout the succession. Volcanism and ca. 360–308 Ma detrital zircon grains could be associated with a Carboniferous magmatic arc formed by subduction of the Rheic oceanic plate beneath Gondwana. Slightly younger detrital zircon and subvolcanic rocks dated at ~300–270 Ma are linked to a western Pangea arc developed in response to the subduction of the Paleo-Pacific Ocean following Pangea assembly. Our results suggest that the Carboniferous-Permian units were deposited in a peri-arc basin, sharing sediment provenance with the Maya and Coahuila blocks, the Sierra de Juárez Complex, and northwestern South America. [ABSTRACT FROM AUTHOR]

Coal balls, in which fossil plants are preserved in permineralized peat deposits, have widely been described from coal deposits representing the tropical forest of the Carboniferous. Coal ball preparation techniques have evolved over the past century, with the cellulose acetate peel method becoming the standard in the 1950s. While coal ball research is not as active as it has been in the past, large collections of coal balls and their respective peels still form a large part of many museum and university collections. This contribution aims to review coal ball preparation methods, curation, and the digital archiving of peels to create a cohesive guide for researchers working with coal balls and other petrified plant material. The physical and digital curation of cellulose acetate peels and other types of coal ball specimens is critical for long‐term preservation and accessibility. Physical curation involves embedding coal balls in media to slow pyrite deterioration. Digital curation creates high‐resolution scans of peels, which can be shared and accessed online. Cellulose acetate peels and their digital curation are a valuable and accessible technique for the analysis of coal balls, and physical and digital curation ensures long‐term preservation. [ABSTRACT FROM AUTHOR]

Palaeophonus arctusMatthew, 1895, from the late Carboniferous Fern Ledges of Nova Scotia, Canada, and Palaeophonus lightbodyiKjellesvig-Waering, 1954, from the Silurian of Ludford Lane in England, are problematic names proposed for fossil scorpions (Arachnida: Scorpiones). Matthew's name has been widely overlooked in the literature, but features in online resources such as the Paleobiology Database, where it currently extends the stratigraphic range of the genus PalaeophonusThorell & Lindström, 1884 from the Silurian into the Carboniferous. The fossil on which it is based cannot be interpreted with confidence as a scorpion. Kjellesvig-Waering's name is based on an isolated pedipalp chela, which lacks characters justifying its placement in Palaeophonus or any other Palaeozoic scorpion genus. Both names are treated here as nomina dubia. We also take the opportunity to synonymize AllopalaeophonusKjellesvig-Waering, 1986 with Palaeophonus. These two mid-Silurian genera are currently placed in separate infraorders, but the holotype of Allopalaeophonus caledonicus (Hunter, 1886) is very similar in habitus to the type species of Palaeophonus: Palaeophonus nunciusThorell & Lindström, 1884. The single character currently separating the genera, mesosomal sternite shape, is unconvincing. [ABSTRACT FROM AUTHOR]

Nearly 100 million tons of reserves have been explored in the Well 471 area of the Hongche Fault zone. The Carboniferous volcanic rock reservoir is the main oil-bearing reservoir in the well CH471 area and is the main target of exploration and development. The characteristics of the Carboniferous volcanic rock reservoir are studied through core, thin section, physical property, logging, and other data, and its main controlling factors are analyzed in combination with actual means of production. The lithologies of the volcanic reservoir in the study area are mainly volcanic breccia, andesite, and basalt. The matrix physical properties of volcanic rock reservoirs are medium-porosity and ultralow-permeability, among which volcanic breccia has the best physical properties. The reservoir space mainly comprises primary pores, secondary dissolution pores, and fractures, resulting in a dual medium pore-fracture-type reservoir. Combined with production data analysis, the lateral distribution of oil and gas is controlled by lithology and lithofacies, with explosive volcanic breccia being the best, followed by the basalt and andesite of overflow facies, which are vertically affected by weathering and leaching and distributed within 50~300 m from the top of the Carboniferous system. The area with densely developed fractures was conducive to developing high-quality reservoirs. The tectonic movement promoted the formation of weathering and controlled the development of faults. Based on a comprehensive analysis, it is believed that the formation of Carboniferous volcanic oil and gas reservoirs in the study area was controlled and influenced by the lithology, lithofacies, weathering, leaching, faults (fractures), and tectonics. [ABSTRACT FROM AUTHOR]

• Devonian-Carboniferous sedimentation and paleoenvironments along the Iberian Pyrite Belt are analysed. • Several stratigraphic hiatuses are identified and confirmed in the Neves-Corvo region. • Palynostratigraphy is an important tool to define the age of the black shales hosting the mineralization. • IPB bioevents related to the major extinction event and environment changes are documented in the Devonian-Carboniferous Boundary. • Improvement of the stratigraphy of the IPB and geological knowledge. Based on drill hole sampling and sedimentary rock dating by palynology, the present research focuses on the palynostratigraphic events established in the key geological section of Guedelhinha–Lançadoiras–Algaré located in the Portuguese Neves–Corvo mine region, Iberian Pyrite Belt. The age data allow detailing the lithostratigraphic sequence and further understanding the complex structural setting, representing an important contribution to the geological knowledge of this sector located to the immediate WNW of the Neves–Corvo VMS deposit. The combination of the studied events allows the reconstruction of the Devonian-Carboniferous sedimentation and paleoenvironments along the Iberian Pyrite Belt. Several stratigraphic hiatuses identified in the Neves–Corvo region by the palynological record are confirmed, mainly occurring from the mid Frasnian to mid Famennian, from the early and mid Strunian, and from the early to late Tournaisian, which were mainly coincident with the worldwide extinction events, in particular during Frasnian–Famennian and Late Devonian times. Extensional tectonics and related gravitational faults, local uplift mechanisms and intense volcanic activity could also explain the lack of palynological data and sedimentary hiatus. In this research, the importance of the late Strunian times in the Iberian Pyrite Belt (Miospore Biozone LN of the Neves Formation) is highlighted, confirming the contemporaneity of felsic volcanism, hydrothermalism, sulphide mineralization precipitation and black shale anoxic sedimentation. [ABSTRACT FROM AUTHOR]

This paper presents geochemical data for 171 core samples of the Carboniferous coal-bearing series and the Miocene cove from the central part of the Upper Silesian Coal Basin. Major oxide concentrations (Al2O3, SiO2, Fe2O3, P2O5, K2O, MgO, CaO, Na2O, K2O, MnO, TiO2, and Cr2O3) were obtained using XRF. Trace and major elements (Mo, Cu, Pb, Zn, Ni, Co, U, Cr, V, Mn, As, Th, Sr, Cd, Sb, Bi, Ba, Ti, W, Zr, Ce, Nb, Ta, Be Sc) were analysed ICP-MS. The main goals of this study were to demonstrate the distribution, as well as the stratigraphical variability, of the selected elements and to determine whether chemostratigraphy tools could be effectively applied to analyze Carboniferous and Miocene deposits of the USCB. Geochemical studies have shown showed different geochemical features of the samples from the Carboniferous and the Miocene. The diversity is mainly expressed in the enrichment of Miocene sediments in Ca and Sr related to biogenic carbonate material. It was also stated that the concentrations of trace elements associated with the detrital fraction, such as Zn, Cr, Co, Ba, Ti, Zr, Nb, and Sc show slightly higher values in Carboniferous sediments. On the basis of the content of Ti, Zr, and Nb, as well as ratios such as Th/U, Zr/Th, Ti/Zr, and TiO2/K2O, units with different inputs of the terrigenous fraction can be identified in both Carboniferous and Miocene formations. The paper shows that chemostratigraphy can be used as a stratigraphic and correlation tool for the Carboniferous and the Miocene deposits of the USCB. [ABSTRACT FROM AUTHOR]

Hydrogen is envisaged to be an important element in the drive to replace hydrocarbons in the energy mix and its geological storage in man-made salt caverns or porous subsurface reservoirs onshore in the United Kingdom is being actively investigated. It has recently been suggested that porous Carboniferous sandstone reservoirs of the partially depleted and abandoned Cousland Field, located c.15 km SE of Edinburgh, could be used for the storage of hydrogen as part of efforts to decarbonise the industrialised and heavily populated central belt of Scotland. The gas field occurs in an onshore surface anticline situated in a culmination along a topographic ridge on the eastern flank of the Midlothian Coalfield. Mapping of outcropping beds led to a well, Cousland-1, being drilled in 1937-39 as part of a national campaign of oil exploration, which discovered natural gas in two thin sands. Despite the initial success, all the subsequent five appraisal wells, drilled between 1939 and 1960, were devoid of commercial hydrocarbons. Despite the disappointing drilling campaign, the field was still developed based on the original Cousland-1 well result and some 0.25 billion standard cubic feet (“scf”) (7.0 million m3) of gas were produced between 1939 and 1965 before the well was plugged and abandoned. This paper draws upon and integrates hitherto unpublished historical records, obtained from the archives of the UK Onshore Geophysical Library, to critically examine the possibility that the Cousland gas field might be re-purposed for hydrogen storage. These studies conclude that it is currently not possible to demonstrate the subsurface configuration, host reservoir distribution or sealing mechanism of the proposed storage container because the information required is not available and may be impossible to obtain. Rather than supporting the case for hydrogen storage, our new evaluation demonstrates that the Cousland field is a poor site that fails to meet the criteria for safe subsurface storage and should not be used for this purpose until and unless the significant challenges can be addressed.

Abstract Concretions are an interesting mode of preservation that can occasionally yield fossils with soft tissues. To properly interpret these fossils, an understanding of their fossilization is required. Probabilistic models are useful tools to identify variations between different Konservat-Lagerstätten that are separated spatially and temporally. However, the application of probabilistic modeling has been limited to Early Paleozoic Konservat-Lagerstätten preserved in shales. In this paper, the patterns of preservation of three concretionary Konservat-Lagerstätten—the Carboniferous Mazon Creek (USA) and Montceau-les-Mines (France), and the Silurian Herefordshire Lagerstätte (UK)—are analyzed using a statistical approach. It is demonstrated that the degree of biotic involvement, i.e., the degree to which a carcass dictates its own preservation, is connected to internal organ conditional probabilities—the probabilities of finding an internal organ associated with another structure such as biomineralized, sclerotized, cuticularized, or cellular body walls. In concretions that are externally forced with little biological mediation (e.g., Herefordshire), all internal organ conditional probabilities are uniform. As biological mediation in concretion formation becomes more pronounced, heterogeneities in conditional probabilities are introduced (e.g., Montceau-les-Mines and Mazon Creek). The three concretionary sites were also compared with previously investigated Konservat-Lagerstätten preserving fossils in shales to demonstrate how the developed probability framework aids in understanding the broad-scale functioning of preservation in Konservat-Lagerstätten.

Various types of source rocks were developed in the Carboniferous trench-arc basin environment on the northeastern margin of the Junggar Basin. In order to implement the efficient hydrocarbon supply area of the main source rocks and guide the oil and gas exploration in this area, researches on the hydrocarbon generation mechanism, potential, evolution process, and hydrocarbon supply characteristics of different types of source rocks were carried out through the combination of geology and geochemistry based on the test data of drilling, organic geochemistry of outcrop source rock samples, and hydrocarbon-generating thermal simulation experiments. The results show that there are three types of source rocks, namely mudstone, tuffaceous mudstone and carbonaceous mudstone in the Carboniferous in the study area. Different source rocks have different parent material composition and activation energy distribution for hydrocarbon generation, and their hydrocarbon generation potential and evolution model have obvious differences. Mudstone generated hydrocarbon rapidly at relatively low maturity stage, tuffaceous mudstone continued to generate hydrocarbon slowly, and carbonaceous mudstone generated hydrocarbon rapidly at relatively higher maturity stage. Later structural transformation, sedimentary filling and geothermal field evolution jointly controlled the thermal evolution process and hydrocarbon supply characteristics of source rocks. Hydrocarbon generation and hydrocarbon loss of source rocks were coupled in time and space, and six hydrocarbon supply models can be divided, i.e., (1) high-efficiency hydrocarbon generation, low hydrocarbon loss, high-efficiency hydrocarbon supply, (2) high-efficiency hydrocarbon generation, relatively high hydrocarbon loss, relatively high-efficiency hydrocarbon supply, (3) relatively high-efficiency hydrocarbon generation, low hydrocarbon loss, relatively high-efficiency hydrocarbon supply, (4) relatively high-efficiency hydrocarbon generation, high hydrocarbon loss, low-efficiency hydrocarbon supply, (5) low-efficiency hydrocarbon generation, high hydrocarbon loss, relatively low-efficiency hydrocarbon supply, and (6) low-efficiency hydrocarbon generation, low hydrocarbon loss, low-efficiency hydrocarbon supply. Among them, the Shibei and Dishuiquan sags are relatively high-efficiency hydrocarbon generation, low hydrocarbon loss and relatively high-efficiency hydrocarbon supply units with material foundation for forming large and medium-sized oil and gas fields, which are the most favorable exploration targets at present.

Bonebeds occurring in exposures of the Burlington and Keokuk Limestones (Mississippian/Osagean) along the Iowa and Illinois border (USA) contain an abundant and diverse collection of chondrichthyan remains that includes teeth, spines, denticles, and coprolites. These remains represent cochliodont, hybodont, petalodont, ctenacanthid, symmoriid, and acanthodian (stem chondrichthyan) taxa. The thickest of these beds, herein referred to as the Burlington–Keokuk bonebed, occurs at the top of the Burlington Limestone and presents a remarkable opportunity to study the assemblage of mid-continent, Middle Mississippian chondrichthyans. Bulk matrix samples of this bonebed were collected from two quarries (Biggsville Quarry, Biggsville, IL, USA, and Nelson Quarry, Mediapolis, IA, USA) and disaggregated. Among the multitude of previously known taxa, several teeth represented a new genus and species of hybodont shark. Herein, we describe these teeth as Columnaodus witzkei (gen. et sp. nov.), a hybodontiform with dental features comparable to unnamed specimens reported from elsewhere.