Montalbán de Córdoba, Spain
Montalbán de Córdoba, Spain

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Alvarez-Vazquez C.,Centro Paleobotanico | Wagner R.H.,Centro Paleobotanico
Atlantic Geology | Year: 2017

As part of a larger project to revise the systematics of lower Westphalian floras of Nova Scotia and New Brunswick, the sphenopsid taxa are presently reviewed. We recognize 15 species, of which one, Annularia stopesiae, is new. Detailed synonymy lists allow a refinement of the stratigraphic and geographic ranges of these species. Scant attention has been paid previously to Canadian species in the European literature. For example, Annularia latifolia was described later from Europe as Annularia jongmansii. The identical composition of Westphalian floras from Canada and western Europe is striking. © Atlantic Geology 2017.

Nemyrovska T.I.,Ukrainian Academy of Sciences | Wagner R.H.,Centro Paleobotanico | Winkler Prins C.F.,NCB Naturalis | Montanez I.,University of California at Davis
Scripta Geologica | Year: 2011

Two different tectono-stratigraphic domains are recognised in the Cantabrian Mountains, Asturian-Leonese (Cantabrian Zone) and Palentian (Palentian Zone). The area under investigation belongs to the southern part of the Palentian Domain and attention is focused on the Upper Viséan to lowermost Bashkirian limestones at the village of La Lastra in northern Palencia. A new geological map of the Palentian Zone is accompanied by a more detailed map centred on La Lastra. The Barcaliente Limestone Formation (Serpukhovian to lowermost Bashkirian) occurs in the overturned limb of a recumbent anticline which constitutes the head of a south-verging major thrust unit, the Carrionas Thrust Sheet (Palentian Zone). It shows here a shallowing trend in the Serpukhovian. After a transgressive phase near the mid-Carboniferous boundary, the lower Bashkirian again shows shallowing culminating in a palaeokarst at the base of the overlying Perapertú Formation. The conodont faunas present a continuous succession across the Mississippian-Pennsylvanian boundary, most similar to the ones found at Aksu (Hissar Range, Uzbekistan).

Upper Barruelian, "Saberian," and Stephanian B (Kasimovianlower Gzhelian) strata in northwestern Spain represent a strongly subsiding alluvial plain connected to the Paleotethys and adjacent to a mountainous hinterland. The rocks have been deformed into steeply dipping, often isoclinal synclines delimited by foreland-directed thrust faults; a steep basin margin with paleovalleys occurs on the hinterland side. One of these tectonic outliers is the La Magdalena Coalfield, of "Saberian" age, where the quantification of a substantial floral record (140 taxa) from 85 localities in 1200 m of strata allows us to observe changes in floral composition through time matched with broad changes in sedimentary facies corresponding to increased remoteness from a receding basin margin. Within the context of a humid environment, a predominantly fluvial facies changed upward and in time into more generalized semi-lacustrine and peat-forming facies. Although pteridosperms and marattialean tree ferns (pecopterids) are dominant throughout, a proportional increase in tree ferns is observed for the higher part of the succession where calamitaceans become less common and lycopsids more noticeable. These floral changes reflect wetter sedimentary conditions, conducive to the production of coals (high ash) of limited lateral extent. © 2011 SEPM (Society for Sedimentary Geology).

Wagner R.F.,Centro Paleobotanico | Winkler Prins C.F.,NCB Naturalis
Newsletters on Stratigraphy | Year: 2016

The history of Pennsylvanian chronostratigraphic units is analysed, starting with the West European stages and substages as discussed in the international congresses of Carboniferous Stratigraphy (from 1927 onwards) and, later (from 1952), by the IUGS Subcommission on Carboniferous Stratigraphy (SCCS). An increasingly more international approach led to a "global" stratigraphic subdivision which can be applied only to the palaeoequatorial belt, not to the high palaeolatitudinal areas of Gondwana and Angaraland. The current emphasis on purely biostratigraphic criteria is criticised as a throwback to usage prior to the definition of stratotypes for chronostratigraphic units. The "global" scheme makes official use of East European stratigraphic units which are correlated with West European and North American regional units. Problems with these correlations are discussed. Reasons are given to prefer a correlation which approximates the Namurian-Westphalian boundary to that between Bashkirian and Moscovian stages. Reliance on the correlation of major cyclothems is regarded as subject to the absence of major gaps in the succession, which cannot always be guaranteed. Problems of continuity are generally present in carbonate successions. Basinal successions of mixed terrestrial and carbonate facies are preferred for effective stratotypes of chronostratigraphic units with adequate biostratigraphic support. Correlations in the currently recommended "global" chart (by SCCS) are corrected in Fig. 18 of the present paper. © 2016 Gebrüder Borntraeger, Stuttgart, Germany.

The upper Stephanian fern Sphenopteris hadrophylla Knight, described originally in an unpublished thesis on the Sabero Coalfield in León, NW Spain, is now validly introduced on the basis of new, more complete, material collected from the La Magdalena Coalfield in León. This includes sporangiate pinnae interpreted as possibly attributable to Discopteris Stur. A holotype and paratypes are designated from this material. The more fragmentary specimens from Sabero are recorded also. Additional specimens from Villablino (León), El Bierzo (León), Ciñera-Matallana (León), and the Narragansett Basin in New England (U.S.A.) are referred to and partly illustrated, thus demonstrating the wider distribution of the species. Comparisons are made with several species of Stephanian age known from Europe and North America.

Pendleton J.L.,University of Sheffield | Cleal C.J.,National Museum Wales | Falcon-Lang H.J.,Royal Holloway, University of London | Falcon-Lang H.J.,University of Munster | And 2 more authors.
Review of Palaeobotany and Palynology | Year: 2012

The Bristol Coalfield of southwest Britain, although intensively studied in the early history of palaeobotany, has received little attention for 75. years. Here we review the palaeobotany of the mid-Bolsovian to Cantabrian (Moscovian) Warwickshire Group of the Bristol Coalfield, which comprises, from base to top, the Winterbourne, Pennant Sandstone and Grovesend formations. Based on an investigation of all available adpression and sandstone-cast plant assemblages in a facies context, we develop a new system of biostratigraphical zonation and elucidate palaeoecology. Our key findings are: (1) Using the new biozonation we identify a stratigraphical gap encompassing the early to mid-Asturian, occurring between the mid- and late Bolsovian Pennant Sandstone and the late Asturian Grovesend formations. This tectonic-induced stratigraphical gap most likely relates to the Leonian Phase of the Variscan uplift and can be correlated with contemporaneous hiatuses in the South Wales and other European coalfields. (2) We recognise a diverse patchwork of plant communities as follows: Peat mires of the Bolsovian Winterbourne and Pennant Sandstone formations were dominated by lepidodendrids and ferns, but were replaced by tree-fern and fern-dominated mires in the late Asturian Grovesend Formation. Clastic swamps fringed these mires and were characterised by a diversity of pteridosperm, calamitaleans and ferns. Riparian communities associated with the coarse-grained deposits of large-scale braided fluvial systems that vertically alternate with the coals/shales, variously comprised . Sigillaria, calamitaleans and cordaitaleans, with pockets of pteridosperms and calamitaleans surrounding channel abandonments. In addition, large cordaitaleans were common in drier interfluve and/or hinterland areas. Switching between stable mire communities and disturbed fluvial communities either reflects autocyclic channel switching or allocyclic alternations driven by climate change. © 2012 Elsevier B.V.

Wagner R.H.,Centro Paleobotanico | Alvarez-Vazquez C.,Centro Paleobotanico
Scripta Geologica | Year: 2010

An analysis of Alethopteris virginiana Fontaine & White from the lower Dunkard in the Appalachians of North America shows that three different taxa are likely to be represented in the initial illustration. The specific epithet 'virginiana' ought to be restricted to a form comparable to Callipteridium costei (Zeiller) Wagner, whereas the two other taxa are referred to pecopterid ferns. A neotype is proposed for Callipteridium virginianum (Fontaine & White) comb. nov. on the basis of topotypes. Zeiller's illustration of 'Alethopteris' costei is reproduced for comparison. On the other hand, a full description and illustration are provided for Alethopteris leonensis Wagner, a species which had been identified previously with Alethopteris virginiana, apparently in error. An associated Holcospermum 'seed' is also illustrated. Comparisons include the rather similar Alethopteris bohemica Franke, 1912, which is also illustrated with an associated 'seed'. The age of the lower Dunkard flora is determined as (early?) Autunian. The relative position of the Upper Pennsylvanian (upper Conemaugh, Monongahela, Dunkard) of eastern North America is depicted in a chart showing the full succession of substages in the West European chronostratigraphic classification of the Pennsylvanian Subsystem, as well as the corresponding megafloral zones.

Wagner R.H.,Centro Paleobotanico | Alvarez-Vazquez C.,Centro Paleobotanico
Proceedings of the Yorkshire Geological Society | Year: 2016

Pecopteris miltonii, a middle Westphalian fern originally described from Yorkshire, England, is redescribed and figured here from roof shales of the Barnsley Seam, the level from which it was first recorded. This material is regarded as complementary to the holotype, a fertile specimen showing limited morphological variation and almost lacking venation. Pinna shape of the holotype, including terminals, and the shape and dimensions of pinnules, match that of the material in hand. An analysis of the literature shows that only a limited number of specimens recorded with the miltonii epithet may be regarded as properly assigned. This includes a magnificent specimen figured from Lower Silesia by Stur. Although the species is apparently rare, it is fairly widespread, from North America to central Europe (Bohemia, Lower Silesia). The taxonomic position of Pecopteris miltonii is discussed with reference to the genera Lobatopteris and Crenulopteris, and its synonymy with Pecopteris aspidioides is proposed. A full analysis of Pecopteris miltonii and its synonymy serves to delimit this classical species, which has been often misidentified.

Wagner R.H.,Centro Paleobotanico | Alvarez-Vazquez C.,Centro Paleobotanico
Review of Palaeobotany and Palynology | Year: 2010

A general review is presented of the Carboniferous floral records in the Iberian Peninsula in the context of the geological history and distribution of the different basins. Mississippian floras are found in Sierra Morena, where major strike-slip faults brought in terranes of diverse provenance. Lower Pennsylvanian floras are represented in the Peñarroya-Belmez-Espiel (Córdoba) and Villanueva del Río y Minas (Sevilla) coalfields of SW Spain (also strike-slip controlled), at La Camocha, near Gijón (Asturias), and in other parts of northern Spain. Middle Pennsylvanian is represented near Oporto, but more completely in the Central Asturian Coalfield, as well as other, more limited localities in NW Spain and the Pyrenees. Upper Pennsylvanian (Stephanian Stage-Cantabrian to Stephanian B substages) floras are splendidly represented in NW Spain. Uppermost Pennsylvanian (Stephanian C-Autunian) floras are present in the strike-slip controlled Douro and Buçaco basins of North Portugal, the Pyrenees, Central Spain (Ciudad Real, Guadalajara, Zaragoza), and SW Spain (Guadalcanal and Valdeviar in Sevilla province). A complete succession of megafloral zones is presented. This includes a new Annularia spicata Zone at the top of the Pennsylvanian (equivalent to middle to upper Autunian which has been often attributed to the Lower Permian). The information is summarised in charts compiled from a selection of the most significant species. A number of floral elements are illustrated including the zonal indices. Brief taxonomic comments are provided in the Appendix. © 2010 Elsevier B.V.

Wagner R.H.,Centro Paleobotanico
Review of Palaeobotany and Palynology | Year: 2012

Records of plant megafossils in the Devonian of the Iberian Peninsula refer to sparse drifted remains in marine strata, apart from unidentifiable debris, and misidentified ichnofossils. The age attributions are sometimes questionable. A critical analysis leaves only five localities with incidental Devonian plant megafossils capable of sustaining approximate taxonomic identifications. Another two localities of possible late Devonian age are more likely earliest Carboniferous. The various records are discussed in their geological context, taking into account that the Iberian Massif was constituted from different terranes in Pennsylvanian times. A critical discussion is presented of the reviews published by Montero (2008) and Montero and Diéguez (2010), particularly the latter which adds considerations on floral composition and sedimentary environments which lack a factual basis. A later paper by Cascales-Miñana et al. (2011) is commented on. © 2011 Elsevier B.V.

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