The Experts below are selected from a list of 1053 Experts worldwide ranked by ideXlab platform
Qiulai Wang - One of the best experts on this subject based on the ideXlab platform.
-
conodonts of the genus lochriea near the visean Serpukhovian boundary mississippian at the naqing section guizhou province south china
Palaeoworld, 2018Co-Authors: Tamara I Nemyrovska, Xiangdong Wang, Qiulai Wang, Richard H LaneAbstract:Abstract The First Appearance Datum (FAD) of the conodont Lochriea ziegleri in the lineage Lochriea nodosa–L. ziegleri has been considered the most suitable definition and global correlation-level for a revised base of the Serpukhovian Stage. Abundant specimens of Lochriea are recorded throughout the Late Visean–early Serpukhovian interval in the Naqing section, South China. Among them, the P1 elements, with wide morphological variability, enable confirmation and refinement of main lineages within the genus. Two lineages are proposed: 1) noded Lochriea species, such as L. mononodosa–L. nodosa–L. ziegleri, L. senckenbergica and L. multinodosa, and 2) ridged Lochriea species such as L. monocostata–L. costata–L. cruciformis. The possibility for their phylogenetic relationships is evaluated in this paper.
-
correlation of conodont and ammonoid successions across the visean Serpukhovian boundary a review of occurrences in the south urals cantabrian mountains western ireland and the rhenish mountains
Palaeoworld, 2018Co-Authors: Tamara I Nemyrovska, Qiulai Wang, Dieter KornAbstract:Abstract Lochriea ziegleri is the conodont species that bears the highest potential to be the index for the base of Serpukhovian. Proposed phylogenetic lineages within the genus Lochriea, particularly the lineage L. nodosa–L. ziegleri, can be confirmed by the latest studies of the succession of the respective species in sections of north-western Ireland and the Rhenish Mountains of Germany; in these regions the first occurrence datum (FOD) of L. ziegleri is in the P2a zone or the comparable Neoglyphioceras suerlandense ammonoid zone. In the Cantabrian Mountains and the South Urals, the FODs of L. ziegleri are possibly located within ammonoid zones characterized by the genera Revilloceras and early representatives of Dombarites zones with falcatoid ornament.
-
coupled sedimentary and δ13c records of late mississippian platform to slope successions from south china insight into δ13c chemostratigraphy
Palaeogeography Palaeoclimatology Palaeoecology, 2016Co-Authors: Xiangdong Wang, Jitao Chen, Isabel P Montanez, Yuping Qi, Qiulai WangAbstract:Abstract Variability in stratigraphic accumulation rates and distribution of stratal hiatuses along with strong endemism of index fossils hinder regional to global stratigraphic correlation of the Visean–Serpukhovian (V–S) boundary interval (late Mississippian) and thus geological inferences regarding the onset of the late Paleozoic ice age. Here we integrate high-resolution δ13C time series with detailed sedimentary facies analysis of late Visean–early Serpukhovian (V–S) carbonate platform-to-slope successions from South China to evaluate the influences of local depositional and diagenetic processes on δ13Ccarb and to address the correlation issue. Analysis of 11 sedimentary facies from 5 outcrop sections indicates a restricted platform setting (Yashui section) dominated by bioclastic wacke-packstone to lime mudstone in which paleokarst developed, and contemporaneous carbonate slope settings dominated by thin-bedded lime mudstones intercalated with slumps and calciturbidites. Based on vertical facies assemblages, three depositional units are recognized, recording a significant sea-level drawdown across the V–S boundary. Multiple negative δ13C excursions (> 1‰) can be correlated across the V–S boundary interval in several slope sections (Naqing, Luokun, and Narao sections). Variability in the V–S boundary δ13C record in some sections is interpreted to record truncation physically by submarine erosion by slumps or chemically during karstification. A long-term decrease in δ13C values through the Serpukhovian of the Yashui section likely records local influences on carbon cycling in the restricted platform setting. This negative δ13C trend and associated depositional facies at the Yashui section can be correlated to the Arrow Canyon section, USA, which, together with other coeval global sedimentary and geochemical records, indicate a widespread eustatic drawdown in the late Visean with initial buildup of Gondwanan ice sheets. We conclude that integrated sedimentary facies analysis and δ13C chemostratigraphy can be used for stratigraphic correlation when interpreted within a well-constrained sedimentary and carbon-isotope regional framework.
-
late visean early Serpukhovian conodont succession at the naqing nashui section in guizhou south china
Geological Magazine, 2014Co-Authors: Tamara I Nemyrovska, Barry C. Richards, Xiangdong Wang, Jitao Chen, Zhihao Wang, Richard H Lane, Qiulai WangAbstract:This study reports the conodont succession across the Visean–Serpukhovian (V/S) boundary interval at the Naqing section, South China. Continuous centimetre-scale sampling of the relatively deep-water section in recent years has provided new data for a more detailed biostratigraphy of conodonts across the Visean–Serpukhovian boundary. Three conodont zones were described in ascending order: the Gnathodus bilineatus , Lochriea nodosa and Lochriea ziegleri zones. The first appearance datum (FAD) of L. ziegleri has been moved down to 60.1 m above the base of the Naqing section. The correlation of the conodont succession across the Visean–Serpukhovian boundary in the Naqing section with other sections in Eurasia is discussed.
-
carboniferous conodont biostratigraphy of the dianzishang section zhenning guizhou south china
Geological Magazine, 2014Co-Authors: Qiulai Wang, Wei LinAbstract:A preliminary summary of the lower Visean to uppermost Moscovian (Carboniferous) conodont succession and biostratigraphy of the Dianzishang section in Zhenning, Guizhou, South China is presented. Eleven conodont zones, in ascending order, can be recognized: Gnathodus praebilineatus , Gnathodus bilineatus , Lochriea ziegleri , Declinognathodus noduliferus , Neognathodus symmetricus , ‘ Streptognathodus ’ expansus (primitive form), ‘ Streptognathodus ’ expansus , Mesogondolella donbassica – Mesogondolella clarki , Idiognathodus podolskensis , Swadelina fauna and Idiognathodus swadei zones. The first occurrences of Lochriea ziegleri at the base of the Serpukhovian Stage, Declinognathodus noduliferus noduliferus at the base of the Bashkirian Stage and ‘ Streptognathodus ’ expansus at the base of the Moscovian Stage are recognized. The definitions of these stage boundaries, as well as that of the base of the Kasimovian Stage are discussed. Correlations with the Naqing section in South China, Russian and North American sections, as well as other important sections in the world, are considered.
Ian D. Somerville - One of the best experts on this subject based on the ideXlab platform.
-
foraminifers of the visean Serpukhovian boundary interval in western palaeotethys a review
Lethaia, 2019Co-Authors: Pedro Cózar, Daniel Vachard, Markus Aretz, Ian D. SomervilleAbstract:A detailed revision of foraminiferal zonal schemes in sections throughout Europe and North Africa for the Visean–Serpukhovian boundary interval suggests that several foraminiferal taxa might have the potential to form reliable markers throughout the Palaeotethys. This would support the currently investigated boundary definition based on the First Appearance Datum of the conodont Lochriea ziegleri. However, correlation of these foraminiferal markers in the Western Palaeotethys region has encountered several problems, partly arising from taxonomic issues, but mainly because of apparent discrepancies between the First Occurrence Data (FOD). Analysis of the available foraminiferal data has revealed that some taxa show marked delays in their FODs, due to the timing of westward dispersal within the Palaeotethys, emanating from a probable source in eastern Russia. As a result of this investigation, two dispersal routes have been identified, a northern branch and a southern branch. In general, the displacements within the southern branch occurred more rapidly than in the northern branch. In addition to different dispersal routes, separation of the main foraminiferal markers in stratigraphical sections from different regions can result from isolation of shallow‐water facies of the inner platform from those of relatively deeper‐water settings in the outer platform, the latter showing more consistent foraminiferal FODs. The differences in palaeobathymetry and associated energy levels have enabled two foraminiferal zonal schemes to be distinguished for the Visean–Serpukhovian boundary interval in the Western Palaeotethys, one for the inner platform and a second one for the outer platform.
-
Palaeobiogeographic context in the development of shallow-water late Viséan-early Bashkirian benthic foraminifers and calcareous algae in the Cantabrian Mountains (Spain)
Palaeogeography Palaeoclimatology Palaeoecology, 2018Co-Authors: Pedro Cózar, Ian D. Somerville, Silvia Blanco-ferrera, Javier Sanz-lópezAbstract:Abstract The late Visean to early Bashkirian shallow-water carbonate Valdediezma Platform in the Picos de Europa Province of the Cantabrian Zone, has been subdivided into eight microbiotic intervals by means of similarity clusters (using the Morisita coefficient). The most complete Visean-Bashkirian interval is represented in the Valdediezma Valley – Jitu l'Escarandi –road to Tresviso, where only the Steshevian to lower part of the Protvian (middle Serpukhovian) is missing. This interval is better represented in the Pompedrei Bridge to La Hermida composite section, and also in the deeper water section at Vegas de Sotres. These intervals contain a succession from the Mikhailovian (upper Visean) up to the Krasnopolyanian (lower Bashkirian). The assemblages of the Valdediezma Limestone show, comparatively, low similarity indices with the neighbouring basins in the collisional front in the western extremity of the Palaeotethys during the progression of the Variscan Orogeny. In this mobile belt, two domains are recognized; a western domain composed of outcrops in south-western Spain and in the Moroccan Meseta, and an eastern domain comprising basins located in southern France. Some basins, such as the Betic Cordillera, initially had more influence from the western domain, but later, during the late Serpukhovian, it is considered as being part of the eastern domain. The Valdediezma Platform foraminiferal and algal content is coincident with its location as an isolated platform, surrounded by deep-water seas, and with higher similarities with the eastern domain. Regional tectonic events are recognized from the late Visean onward, and they are mostly masked by the overprint of latest Pennsylvanian events. Facies changes are commonly observed, particularly at the base of the intervals, suggesting that facies control is the most important factor controlling the assemblages. It is considered that eustatic sea-level changes exerted a certain control on the assemblages.
-
problems correlating the late brigantian arnsbergian western european substages within northern england
Geological Journal, 2016Co-Authors: Pedro Cózar, Ian D. SomervilleAbstract:A detailed study of foraminiferal assemblages recorded in limestones from northern England in the Stainmore Trough and Alston Block permits their assignment to different European substages than in previous studies. Comparisons with foraminiferal assemblages, mostly from Russia, allow the biozonations to be correlated with the Visean, Serpukhovian and Bashkirian international stages, as well as with the Russian (and Ukrainian) substages for the Serpukhovian (Tarussian, Steshevian, Protvian and Zapaltyubian). The Scar Limestone and Five Yard Limestone Members are assigned to the Tarussian and, thus, represent the lowermost part of the formal Serpukhovian Stage. This new correlation coincides closely with the first occurrence of the conodont Lochriea ziegleri from levels equivalent to the Single Post Limestone that could potentially form the revised base for the Serpukhovian. The Three Yard Limestone Member is correlated with the base of the Steshevian substage which also includes the Four Fathom Limestone Member, Great Limestone Member and Little Limestone. The base of the Protvian is considered to lie within the Crag Limestone, whereas the Rookhope Shell Band contains foraminiferal assemblages more typical of the Zapaltyubian in the Ukraine and Chernyshevkian in the Urals. Assemblages of the Upper Fell Top Limestone and Grindstone/Botany Limestones contain foraminiferal species that have been used for the recognition of the Bashkirian elsewhere. There is no other fossil group which allows the calibration of those foraminiferal assemblages, because ammonoids are virtually absent in the shallow-water cyclothemic successions and conodonts have not been studied in detail in this region. The Mid-Carboniferous boundary and the Voznessenian substage might be reasonably located below the Upper Fell Top Limestone. Copyright © 2015 John Wiley & Sons, Ltd.
-
foraminiferal biostratigraphy across the visean Serpukhovian boundary in the vegas de sotres section cantabrian mountains spain
Journal of Foraminiferal Research, 2016Co-Authors: Pedro Cózar, Ian D. Somerville, Javier Sanzlopez, Silvia BlancoferreraAbstract:A continuous succession of the upper part of the Alba Formation is recorded in the Vegas de Sotres section in the Cantabrian Mountains, northern Spain. This section contains slightly shallower-water facies than elsewhere and as a result is particularly rich in foraminifers. Characterization of the late Visean to Serpukhovian interval in coeval deeper water settings is accomplished by means of integrating conodont, ammonoid and foraminiferal data. The foraminiferal assemblages recorded in units 1–4 of the Alba Formation enabled correlation with the Russian substages in the Moscow Basin, Urals and Donets Basin. The upper part of the Canalon Member (unit 1) is correlated with the Venevian, the lower part of unit 2 is correlated with the Tarusian, and the Steshevian is recognized in the middle and upper part of unit 2. Most of unit 3 is correlated with the Protvian and is equivalent to the E2a ammonoid zone. The youngest Millaro Member (unit 4) contains undiagnostic foraminifers and lies within the Gnathodus truyolsi Conodont Zone equivalent to the E2b/E2c ammonoid zones. The base of the Serpukhovian is defined on the first occurrence of the conodont Lochriea ziegleri . Slightly below this horizon are recorded Neoarchaediscus parvus, N . aff. N . postrugosus, Biseriella paramoderata, Asteroarchaediscus rugosus, Howchinia hemisphaerica and Rectoendothyra latiformis . At the Visean/Serpukhovian (V/S) boundary, species of Tubispirodiscus are recorded and just above, the presence of Asteroarchaediscus baschkiricus is confirmed. The late Serpukhovian is characterized by the occurrence of diverse Eostaffella pseudostruvei, E . sp. cf. E. postmosquensis, Eostaffellina “ protvae ”, Eost. actuosa and Plectostaffella varvariensis . Two new genera and four new species are described: Janischewskina gibshmanae n. sp., Endostaffellopsis umbilicata n. gen. n. sp., Vachardites spinosus n. gen. n. sp., V. priscelloides n. gen. n. sp.
-
potential foraminiferal markers for the visean Serpukhovian and Serpukhovian bashkirian boundaries a case study from central morocco
Journal of Paleontology, 2011Co-Authors: Pedro Cózar, Sergio Rodríguez, Ian D. Somerville, Ismail Said, Daniel Vachard, Paula Medinavarea, Mostafa BerkhliAbstract:The Carboniferous succession in Adarouch (Central Morocco, north of the Atlas Transform Fault) contains thick carbonate beds including upper Visean, Serpukhovian and basal Bashkirian rocks. Foraminifers enable precise recognition of the Visean/Serpukhovian (V/S), early/late Serpukhovian (eS/lS) and Serpukhovian/Bashkirian (S/B) boundaries. Insolentitheca horrida, Loeblichia ukrainica, “Millerella” spp. and Endostaffella? sp. 2 are regarded as regionally useful indices to the V/S boundary, whereas Eostaffellina spp., Eostaffella pseudostruvei and some evolved species of Archaediscus exhibit greater reliability for worldwide correlation of this level. Similarly, the eS/lS boundary is marked locally by Brenckleina rugosa, Eosigmoilina sp., and Monotaxinoides spp. and globally by Loeblichia minima, Bradyina cribrostomata, Plectostaffella spp., Eostaffellina “protvae” and “Turrispiroides”, and the S/B boundary is marked locally by Globivalulina bulloides and globally by Seminovella elegantula, and Novella?. Occurrences of these taxa in Morocco allow correlations with the Moscow Basin, the Urals, the Donetz Basin and North America. The Moroccan assemblages share few taxa in common with Saharan basins south of the Atlas Transform Fault. Correlations with western European basins are difficult because of the paucity in the latter of foraminiferal-bearing carbonate strata.
Svetlana Nikolaeva - One of the best experts on this subject based on the ideXlab platform.
-
an evaluation of biostratigraphic markers across multiple geological sections in the search for the gssp of the base of the Serpukhovian stage mississippian
Palaeoworld, 2020Co-Authors: E I Kulagina, Svetlana Nikolaeva, Alexander S Alekseev, Yury Gatovsky, Galina Yu Ponomareva, Nilyufer B GibshmanAbstract:Abstract This paper aims to evaluate potential biostratigraphic markers for the Visean–Serpukhovian boundary in sections of Europe and Asia, to help identify the base of the global Serpukhovian Stage, which is a high priority task for Carboniferous biostratigraphy. Sections in the Serpukhovian stratotype area in the Moscow Basin contain a gap at the base of the Tarusian Regional Substage (basal in the classical Serpukhovian), so the traditional boundary defined in these sections cannot be precisely correlated with other successions worldwide. The IUGS Task Group to establish a GSSP close to the traditional Visean–Serpukhovian boundary focused on the search for a new boundary marker, primarily on the first appearance datum (FAD) of the conodont Lochriea ziegleri in the lineage Lochriea nodosa to Lochriea ziegleri, considering it to be a suitable biostratigraphic event. The FOD (first occurrence datum) of L. ziegleri has been recognized in many successions worldwide, although only in a few sections the supposed evolutionary lineage of L. ziegleri was inferred. There are serious impediments to the FAD of L. ziegleri being universally accepted as the boundary marker. This paper presents a review of the FOD levels of L. ziegleri documented so far from multiple sections along with other correlatable markers (foraminifers and ammonoids) that can serve as additional points of reference in sections where a conodont record is poor or absent. The reviewed sections are Naqing Section (South China), Verkhnyaya Kardailovka and Kugarchi sections (South Urals, Russia), Mariinsky Log and Ladeinaya Mountain Sections (western slope of the Middle Urals, Russia), Novogurovsky Section (Moscow Basin, Russia), Vegas de Sotres Section (Cantabrian Mountains, Spain), Lugasnaghta Section (County Leitrim, Ireland), Wenne River Bank Section (Germany), and Milivojevica Kamenjar Section (Družetic, NW Serbia). We also included a compilation of data from sections of North England and southern Scotland. In this paper, we will mainly focus on newly described sections, while the discussion of most previously described sections was summarized by Nikolaeva et al. (2001, 2002, 2005, 2009b) and other publications, so they are only briefly mentioned in this review. It should be added that there is no such a thing as a perfect GSSP section, as each section has certain disadvantages, either lithological, paleontological, or both, so it is important to hear and discuss all the different opinions to develop the optimum strategy for future research. In addition, we analyze published records from several sites in North England and southern Scotland. We discuss the first appearances of the ammonoid genera Cravenoceras, Edmooroceras, Lyrogoniatites, Dombarites, and Platygoniatites, the foraminifers Neoarchaediscus postrugosus, Hemidiscopsis muradymica, H. hemisphaerica, species of Janischewskina and Monotaxinoides, Eostaffella pseudostruvei group, Eostaffellina decurta, and Endothyranopsis plana. We publish here for the first time the useful accounts of foraminifers and conodonts from the Mariinsky Log Section and Ladeinaya Mountain Section (Middle Urals, Russia), and re-figure several important type specimens from Europe and the Urals.
-
new late visean and early Serpukhovian ammonoids in the verkhnyaya kardailovka section eastern slope of the south urals
Paleontological Journal, 2017Co-Authors: Svetlana Nikolaeva, V A KonovalovaAbstract:New Late Visean and Early Serpukhovian ammonoids are described from the Verkhnyaya Kardailovka section (South Urals, Bashkortostan). The ammonoid assemblages allow the recognition of the Hypergoniatites−Ferganoceras Genozone and a correlation with the synchronous zonations of North Africa, Spain, and China. The new species Ferganoceras constrictum sp. nov., Dombarites clemens sp. nov., and Hypergoniatites kardailovkensis sp. nov. are described.
-
new visean and Serpukhovian ammonoids from the verkhnyaya kardailovka section eastern slope of the south urals
Paleontological Journal, 2013Co-Authors: Svetlana NikolaevaAbstract:Visean and Early Serpukhovian ammonoids from the Verkhnyaya Kardailovka section (South Urals, Bashkortostan) are discussed. The ammonoid assemblages include taxa that have not been previously recorded from this region and are probably connected with the open shelf settings of the eastern subregion of the South Urals. For the first time in the South Urals, we were able to recognize the succession of the ammonoid genozones Goniatites → Hypergoniatites-Ferganoceras → Uralopronorites-Cravenoceras within the same section that can be correlated with the synchronous zonations of Western Europe, North Africa, and North America. New records allow interpretation of the evolution of the family Goniatitidae in the Ural Paleocean in the terminal Visean. Two new species, Goniatites altus sp. nov. and Platygoniatites integer sp. nov. are described.
-
the carboniferous carbonates of the dombar hills western kazakhstan and the problem of the visean Serpukhovian boundary
Palaeoworld, 2009Co-Authors: Svetlana Nikolaeva, Lemuza Z Akhmetshina, Vera A Konovalova, Vladimir F Korobkov, Gulnara F ZainakaevaAbstract:Abstract The Upper Visean–Serpukhovian ammonoid-rich carbonates in the Dombar Hills (Aktobe Region, western Kazakhstan) provide an excellent opportunity to calibrate the ammonoid and conodont zonations around the base of the Serpukhovian Stage, and are important for interregional correlation. A section in the Dombar Hills spanning the Visean–Serpukhovian boundary is measured and its fossil content is analyzed. Two ammonoid genozones (Hypergoniatites-Ferganoceras and Uralopronorites-Cravenoceras) and two conodont zones (Lochriea nodosa and Lochriea ziegleri) are recognized. The section displays a contact between the Hypergoniatites-Ferganoceras and Uralopronorites-Cravenoceras ammonoid genozones in a continuous succession and an evolutionarily early appearance of the genus Cravenoceras. The base of the Serpukhovian Stage is drawn at the level of the first appearance datum (FAD) of the conodont Lochriea ziegleri, which, as in the Verkhnyaya Kardailovka section (potential GSSP candidate, South Urals, Russia) enters within the Hypergoniatites-Ferganoceras ammonoid Genozone.
-
paleontology and microfacies of the Serpukhovian in the verkhnyaya kardailovka section south urals russia potential candidate for the gssp for the visean Serpukhovian boundary
Newsletters on Stratigraphy, 2009Co-Authors: Svetlana Nikolaeva, E I Kulagina, Vladimir N Pazukhin, N N Kochetova, V A KonovalovaAbstract:A uniquely complete carbonate sequence spanning a large portion of the Visean and the entire Ser- pukhovian is exposed on the Ural River, opposite the village of Verkhnyaya Kardailovka (South Urals, Bashkortostan, Russia). The Upper Visean and Serpukhovian beds in this section are composed of deep- water carbonates containing ammonoids, conodonts, ostracodes and foraminifers. The section is well-sampled, measured, its lithology is now described, and a sedimentary environment near the seaward end of a carbonate platform and deep shelf is suggested. Abundant fossils allow the recognition of four successive ammonoid and four successive conodont zones, which allow reliable correlations of the regional Serpukhovian stages outside the South Urals, although the type section of the Serpukhovian in the Moscow Basin is in the shallow-water facies. The base of the Serpukhovian in the Moscow Basin and in the South Urals is defined by the first ap- pearance datum (FAD) of the conodont Lochriea ziegleri. This level coincides with the base of the Koso- gorskian in the Urals, correlates with the entry of the foraminifer "Millerella" tortula near the base of the Taru- sian in the Moscow Basin and is close to the earliest occurrences of Dombarites paratectus and Cravenoceras at the base of the Uralopronorites-Cravenoceras Genozone and of the latter genus at the base of the British E1 Zone. Because of its accessibility, abundant fossils, and its well studied lithology, the Verkhnyaya Kar- dailovka Section is an excellent candidate for the GSSP of the Visean-Serpukhovian boundary.
Pedro Cózar - One of the best experts on this subject based on the ideXlab platform.
-
foraminifers of the visean Serpukhovian boundary interval in western palaeotethys a review
Lethaia, 2019Co-Authors: Pedro Cózar, Daniel Vachard, Markus Aretz, Ian D. SomervilleAbstract:A detailed revision of foraminiferal zonal schemes in sections throughout Europe and North Africa for the Visean–Serpukhovian boundary interval suggests that several foraminiferal taxa might have the potential to form reliable markers throughout the Palaeotethys. This would support the currently investigated boundary definition based on the First Appearance Datum of the conodont Lochriea ziegleri. However, correlation of these foraminiferal markers in the Western Palaeotethys region has encountered several problems, partly arising from taxonomic issues, but mainly because of apparent discrepancies between the First Occurrence Data (FOD). Analysis of the available foraminiferal data has revealed that some taxa show marked delays in their FODs, due to the timing of westward dispersal within the Palaeotethys, emanating from a probable source in eastern Russia. As a result of this investigation, two dispersal routes have been identified, a northern branch and a southern branch. In general, the displacements within the southern branch occurred more rapidly than in the northern branch. In addition to different dispersal routes, separation of the main foraminiferal markers in stratigraphical sections from different regions can result from isolation of shallow‐water facies of the inner platform from those of relatively deeper‐water settings in the outer platform, the latter showing more consistent foraminiferal FODs. The differences in palaeobathymetry and associated energy levels have enabled two foraminiferal zonal schemes to be distinguished for the Visean–Serpukhovian boundary interval in the Western Palaeotethys, one for the inner platform and a second one for the outer platform.
-
Palaeobiogeographic context in the development of shallow-water late Viséan-early Bashkirian benthic foraminifers and calcareous algae in the Cantabrian Mountains (Spain)
Palaeogeography Palaeoclimatology Palaeoecology, 2018Co-Authors: Pedro Cózar, Ian D. Somerville, Silvia Blanco-ferrera, Javier Sanz-lópezAbstract:Abstract The late Visean to early Bashkirian shallow-water carbonate Valdediezma Platform in the Picos de Europa Province of the Cantabrian Zone, has been subdivided into eight microbiotic intervals by means of similarity clusters (using the Morisita coefficient). The most complete Visean-Bashkirian interval is represented in the Valdediezma Valley – Jitu l'Escarandi –road to Tresviso, where only the Steshevian to lower part of the Protvian (middle Serpukhovian) is missing. This interval is better represented in the Pompedrei Bridge to La Hermida composite section, and also in the deeper water section at Vegas de Sotres. These intervals contain a succession from the Mikhailovian (upper Visean) up to the Krasnopolyanian (lower Bashkirian). The assemblages of the Valdediezma Limestone show, comparatively, low similarity indices with the neighbouring basins in the collisional front in the western extremity of the Palaeotethys during the progression of the Variscan Orogeny. In this mobile belt, two domains are recognized; a western domain composed of outcrops in south-western Spain and in the Moroccan Meseta, and an eastern domain comprising basins located in southern France. Some basins, such as the Betic Cordillera, initially had more influence from the western domain, but later, during the late Serpukhovian, it is considered as being part of the eastern domain. The Valdediezma Platform foraminiferal and algal content is coincident with its location as an isolated platform, surrounded by deep-water seas, and with higher similarities with the eastern domain. Regional tectonic events are recognized from the late Visean onward, and they are mostly masked by the overprint of latest Pennsylvanian events. Facies changes are commonly observed, particularly at the base of the intervals, suggesting that facies control is the most important factor controlling the assemblages. It is considered that eustatic sea-level changes exerted a certain control on the assemblages.
-
new data on the late visean late Serpukhovian foraminifers of northern alborz iran biostratigraphic implications
Revue de Micropaléontologie, 2017Co-Authors: Keyvan Zandkarimi, Pedro Cózar, Daniel Vachard, Bahram Najafian, Bahauddin Hamdi, Hossein MosaddeghAbstract:Abstract The Upper Visean–Upper Serpukhovian deposits of northern Alborz (Iran) consist of thin-bedded, fine sandstone and siltstone, marly and ooidal limestone and marly shale. Rich and diverse foraminiferal assemblages have been analyzed in two sections (Dozdehban and Naserabad). Five biozones and most foraminifers are first described from Upper Visean–Upper Serpukhovian deposits of Iran. The Late Visean of the area is subdivided into a Neoarchaediscus Zone and a Howchinia gibba–Archaediscus / Paraarchaediscus at angulatus-tenuis stage- Neoarchaediscus akchimensis Zone correlated to the Upper Mikhailovian–Venevian and Early to Late Brigantian substages of the Russian Platform and Western Europe. The Early Serpukhovian corresponds to the Biseriella parva – Climacammina Zone, and the Late Serpukhovian includes the Turrispiroides multivolutus – Brenckleina – Eostaffellina protvae zone that correlate to the Tarusian–Steshevian and Protvian substages of the Russian Platform, respectively. Furthermore, the upper beds in the Naserabad section contain the Plectostaffella – Globivalvulina kamensis ? Zone, which is dated as Zapaltyubian?, lastest Serpukhovian.
-
problems correlating the late brigantian arnsbergian western european substages within northern england
Geological Journal, 2016Co-Authors: Pedro Cózar, Ian D. SomervilleAbstract:A detailed study of foraminiferal assemblages recorded in limestones from northern England in the Stainmore Trough and Alston Block permits their assignment to different European substages than in previous studies. Comparisons with foraminiferal assemblages, mostly from Russia, allow the biozonations to be correlated with the Visean, Serpukhovian and Bashkirian international stages, as well as with the Russian (and Ukrainian) substages for the Serpukhovian (Tarussian, Steshevian, Protvian and Zapaltyubian). The Scar Limestone and Five Yard Limestone Members are assigned to the Tarussian and, thus, represent the lowermost part of the formal Serpukhovian Stage. This new correlation coincides closely with the first occurrence of the conodont Lochriea ziegleri from levels equivalent to the Single Post Limestone that could potentially form the revised base for the Serpukhovian. The Three Yard Limestone Member is correlated with the base of the Steshevian substage which also includes the Four Fathom Limestone Member, Great Limestone Member and Little Limestone. The base of the Protvian is considered to lie within the Crag Limestone, whereas the Rookhope Shell Band contains foraminiferal assemblages more typical of the Zapaltyubian in the Ukraine and Chernyshevkian in the Urals. Assemblages of the Upper Fell Top Limestone and Grindstone/Botany Limestones contain foraminiferal species that have been used for the recognition of the Bashkirian elsewhere. There is no other fossil group which allows the calibration of those foraminiferal assemblages, because ammonoids are virtually absent in the shallow-water cyclothemic successions and conodonts have not been studied in detail in this region. The Mid-Carboniferous boundary and the Voznessenian substage might be reasonably located below the Upper Fell Top Limestone. Copyright © 2015 John Wiley & Sons, Ltd.
-
foraminiferal biostratigraphy across the visean Serpukhovian boundary in the vegas de sotres section cantabrian mountains spain
Journal of Foraminiferal Research, 2016Co-Authors: Pedro Cózar, Ian D. Somerville, Javier Sanzlopez, Silvia BlancoferreraAbstract:A continuous succession of the upper part of the Alba Formation is recorded in the Vegas de Sotres section in the Cantabrian Mountains, northern Spain. This section contains slightly shallower-water facies than elsewhere and as a result is particularly rich in foraminifers. Characterization of the late Visean to Serpukhovian interval in coeval deeper water settings is accomplished by means of integrating conodont, ammonoid and foraminiferal data. The foraminiferal assemblages recorded in units 1–4 of the Alba Formation enabled correlation with the Russian substages in the Moscow Basin, Urals and Donets Basin. The upper part of the Canalon Member (unit 1) is correlated with the Venevian, the lower part of unit 2 is correlated with the Tarusian, and the Steshevian is recognized in the middle and upper part of unit 2. Most of unit 3 is correlated with the Protvian and is equivalent to the E2a ammonoid zone. The youngest Millaro Member (unit 4) contains undiagnostic foraminifers and lies within the Gnathodus truyolsi Conodont Zone equivalent to the E2b/E2c ammonoid zones. The base of the Serpukhovian is defined on the first occurrence of the conodont Lochriea ziegleri . Slightly below this horizon are recorded Neoarchaediscus parvus, N . aff. N . postrugosus, Biseriella paramoderata, Asteroarchaediscus rugosus, Howchinia hemisphaerica and Rectoendothyra latiformis . At the Visean/Serpukhovian (V/S) boundary, species of Tubispirodiscus are recorded and just above, the presence of Asteroarchaediscus baschkiricus is confirmed. The late Serpukhovian is characterized by the occurrence of diverse Eostaffella pseudostruvei, E . sp. cf. E. postmosquensis, Eostaffellina “ protvae ”, Eost. actuosa and Plectostaffella varvariensis . Two new genera and four new species are described: Janischewskina gibshmanae n. sp., Endostaffellopsis umbilicata n. gen. n. sp., Vachardites spinosus n. gen. n. sp., V. priscelloides n. gen. n. sp.
Cózar Pedro - One of the best experts on this subject based on the ideXlab platform.
-
Development of a Mississippian¿Lower Pennsylvanian isolated carbonate platform within the basinal griotte facies of the Cantabrian Mountains, NW Spain
'Springer Science and Business Media LLC', 2021Co-Authors: Cózar Pedro, Silvia Blanco-ferrera, Javier Sanz-lópezAbstract:The Valdediezma platform consists of upper Tournaisian to lower Bashkirian (Carboniferous) shallow-water carbonates deposited in the core of the Picos de Europa Province (Cantabrian Mountains, northwest Spain). Although faulted in several thrust sheets, it is the only preserved platform developed in the Mississippian starved basins of the southern branch of the Variscan Orogen that is characterised also by pelagic sedimentation. This unusual platform provides an exceptional opportunity to study the lateral variation from the platform to the typical condensed griotte limestones developed in a starved basin, the origin of such a platform in a particularly unfavourable setting for carbonate accumulation, as well as the nucleation of the subsequent widespread Pennsylvanian carbonate platforms of the Cantabrian Mountains. Sixteen carbonate microfacies are differentiated in the Valdediezma Limestone, from shallow-water to slope to basinal environments. The carbonate production is related to the submarine topography and the rapid rates of microbial mound growth and accumulation, particularly from the upper Viséan to the lower Serpukhovian. A high-elevation platform and steep southern margin occurred during the deposition of condensed cephalopod-bearing limestones in the basin. A higher rate of carbonate accumulation is recognised from the upper Serpukhovian and younger, with similar thicknesses in shallow- and deeper water settings. The thickest part of the succession was coeval with the larger subsidence resulting from the migration of the Variscan deformation at the margin of the foreland basin of the Cantabrian Zone. The migration of deformation along the foreland uplifted the Valdediezma platform from the lower Bashkirian and caused its partial erosion. The Pennsylvanian carbonate platform developed on an exhumed Mississippian platform. Tectonic overloading due to the emplacement of nearby thrust sheets caused the subsidence and burial of the Valdediezma platform in the upper Moscovian.Early comments and improvement of the English by G. Sevastopulo, I.D. Somerville, M.W. Hounslow and G. Della Porta are acknowledged. We thank two anonymous reviewers for their constructive comments. Thanks to the collaboration of the Picos de Europa National Park, field works were possible
-
Irish Serpukhovian revisited
'Wiley', 2021Co-Authors: Cózar Pedro, Somerville I.d.Abstract:In this study of Mississippian rocks in Ireland, it is now recognized, based on faunal evidence, that several upper Viséan limestone formations which were previously excluded from the Serpukhovian now belong, in part, to the lower two substages of the Serpukhovian. A reassessment of previous foraminiferal determinations, together with new foraminiferal data, has confirmed that rocks equivalent to the Tarusian and Steshevian substages are present in several sections. In the Slievenaglasha Formation and Magowna Formation (County Clare) and Deer Park Formation (County Meath), Tarusian and Steshevian foraminiferal assemblages are thus recorded. In the Clogrenan Formation (County Carlow), Carganamuck Limestone Formation (County Armagh) and Rockdale Limestone Formation (County Tyrone), Tarusian foraminiferal assemblages are recorded in the upper beds of thick limestone successions. Key foraminiferal and algal taxa characterize each assemblage, which have been correlated with equivalent Serpukhovian strata in the north of England and Scotland. A three-stage evolution is recognized in archaediscid foraminifers: from Neoarchaediscus gregorii, followed by Neoarchaediscus postrugosus form 1, and N. postrugosus form 2, with Neoarchaediscus postrugosus form 1 used to define the base of the Serpukhovian. The recognition of Tarusian and Steshevian foraminiferal assemblages implies that areas of shallow-water platform carbonate sedimentation in Ireland during the upper Viséan (Brigantian) persisted into the Early Serpukhovian.Ministry of Ciencia, Investigación y Universidades (projectCGL2016-78738BTE
-
New data on the Serpukhovian (Carboniferous) coral assemblages from the northwestern part of the Moscow Basin (Russia)
Società Paleontologica Italiana, 2020Co-Authors: Somerville, Ian D., Rodríguez Sergio, Kossovaya, Olga L., Cózar PedroAbstract:Research in two quarries of the Borovichi area near the Uglovka town (northwestern Moscow Basin) has provided several rugose and tabulate corals that improve the knowledge on the palaeontology of that area. The Zarech’e quarry yielded rare specimens of Syringopora reticulata and Dibunophyllum bipartitum, as well as common specimens of Actinocyathus floriformis, A. borealis and A. crassiconus. The Uglovka quarry provided also Syringopora reticulata, Dibunophyllum bipartitum but different species of colonial rugosans: Actinocyathus sp., Lonsdaleia multiseptata and Schoenophyllum sp. The palaeogeographical distribution of the recorded species indicates a good communication of the Eastern European Basin with western and eastern Palaeotethys during the Serpukhovian. The presence of the genus Schoenophyllum suggests also connection with North America, probably along the northern coast of Laurussia
-
Foraminifers of the Viséan–Serpukhovian boundary interval in Western Palaeotethys: a review
'Wiley', 2019Co-Authors: Cózar Pedro, Vachard Daniel, Aretz Markus, Somerville IanAbstract:A detailed revision of foraminiferal zonal schemes in sections throughout Europe and North Africa for the Viséan–Serpukhovian boundary interval suggests that several foraminiferal taxa might have the potential to form reliable markers throughout the Palaeotethys. This would support the currently investigated boundary definition based on the First Appearance Datum of the conodont Lochriea ziegleri. However, correlation of these foraminiferal markers in the Western Palaeotethys region has encountered several problems, partly arising from taxonomic issues, but mainly because of apparent discrepancies between the First Occurrence Data (FOD). Analysis of the available foraminiferal data has revealed that some taxa show marked delays in their FODs, due to the timing of westward dispersal within the Palaeotethys, emanating from a probable source in eastern Russia. As a result of this investigation, two dispersal routes have been identified, a northern branch and a southern branch. In general, the displacements within the southern branch occurred more rapidly than in the northern branch. In addition to different dispersal routes, separation of the main foraminiferal markers in stratigraphical sections from different regions can result from isolation of shallow‐water facies of the inner platform from those of relatively deeper‐water settings in the outer platform, the latter showing more consistent foraminiferal FODs. The differences in palaeobathymetry and associated energy levels have enabled two foraminiferal zonal schemes to be distinguished for the Viséan–Serpukhovian boundary interval in the Western Palaeotethys, one for the inner platform and a second one for the outer platform.P.C. and I.D.S. are grateful to the financial support of the Spanish Ministerio de Ciencia, Innovación y Universidades (research project CGL2016‐78738).Peer reviewe
-
Palaeobiogeographic context in the development of shallow-water late Viséan-early Bashkirian benthic foraminifers and calcareous algae in the Cantabrian Mountains (Spain)
Elsevier, 2018Co-Authors: Cózar Pedro, Blanco-ferrera Silvia, Somerville Ian, Sanz-lópez JavierAbstract:The late Viséan to early Bashkirian shallow-water carbonate Valdediezma Platform in the Picos de Europa Province of the Cantabrian Zone, has been subdivided into eight microbiotic intervals by means of similarity clusters (using the Morisita coefficient). The most complete Viséan-Bashkirian interval is represented in the Valdediezma Valley – Jitu l'Escarandi –road to Tresviso, where only the Steshevian to lower part of the Protvian (middle Serpukhovian) is missing. This interval is better represented in the Pompedrei Bridge to La Hermida composite section, and also in the deeper water section at Vegas de Sotres. These intervals contain a succession from the Mikhailovian (upper Viséan) up to the Krasnopolyanian (lower Bashkirian). The assemblages of the Valdediezma Limestone show, comparatively, low similarity indices with the neighbouring basins in the collisional front in the western extremity of the Palaeotethys during the progression of the Variscan Orogeny. In this mobile belt, two domains are recognized; a western domain composed of outcrops in south-western Spain and in the Moroccan Meseta, and an eastern domain comprising basins located in southern France. Some basins, such as the Betic Cordillera, initially had more influence from the western domain, but later, during the late Serpukhovian, it is considered as being part of the eastern domain. The Valdediezma Platform foraminiferal and algal content is coincident with its location as an isolated platform, surrounded by deep-water seas, and with higher similarities with the eastern domain. Regional tectonic events are recognized from the late Viséan onward, and they are mostly masked by the overprint of latest Pennsylvanian events. Facies changes are commonly observed, particularly at the base of the intervals, suggesting that facies control is the most important factor controlling the assemblages. It is considered that eustatic sea-level changes exerted a certain control on the assemblages.The authors are grateful to the financial support of the Spanish Ministerio de Economía y Competitividad (research project CGL2016-78738).Peer reviewe
