Conodontos del Carbonífero de la Meseta Central y de la Cuenca de Tindouf (Marruecos)

En el presente trabajo se describen y analizan las diferentes asociaciones de conodontos registradas en doszonas de Marruecos, la región de Adarouch (Meseta Central) y la Cuenca de Tindouf. La región de Adarouch selocaliza en la parte noroeste de la Cuenca de AzrouKhenifra,que pertenece a la parte central de la Meseta Occidentalde Marruecos, y donde la sucesión carbonífera aflora en bandas de dirección NESOy está compuesta pordiversas formaciones, de las cuales Tizra, Mouarhaz, Akerhi, Idmarrach y Tirhela fueron muestreadas para conodontos.La Cuenca de Tindouf se localiza al sur de Marruecos y es un gran sinclinal cuyo eje presenta una direcciónaproximada ESENNO,aflorando parte del sinclinal al oeste de Algeria y norte de Mauritania. Su flanco norte esun gran escarpe que forma la cadena montañosa de Djebel Ouarkziz, donde se levantaron varias secciones estratigráficasque componen la sección compuesta de Tinguiz Remz. En esta sección se encuentran representadas formacionescarboníferas de Betaina y Ouarkziz, las cuales fueron muestreadas para conodontos. Entre ambasregiones se tomaron 168 muestras lo que implicó un total de 465,8491 kg de roca para procesar en laboratorio y14,0051 kg de residuo sólido insoluble para ser triado posteriormente, obteniéndose 5921 elementos conodontalesentre la región de Adarouch y la Cuenca de Tindouf.En el conjunto de las formaciones de la región de Adarouch se han identificado hasta 10 géneros, 18 especiesy 9 subespecies de taxones multielementales de conodontos donde Gnathodus bilineatus y Gnathodus girtyi,Lochriea commutata, Idioprioniodus claviger, Idioprioniodus conjunctus, Kladognathus tenuis/complectens y“Gnathodus“ homopunctatus son los taxones más comunes. En menor número se registran Mestognathus,Synclydognathus, Cavusgnathus y Vogelgnathus. Las asociaciones de conodontos más abundantes provienen dela parte superior de la Fm Tizra, donde se registra una fauna indicativa de ambientes relativamente profundos enla plataforma externa y que se caracteriza por la biofacies de Idioprioniodus, definida por el predominio de Idioprioniodusy, de Gnathodus y Lochriea..

Early Serpukhovian conodonts from the Guadiato Area (Córdoba, Spain)

The conodont assemblages of three stratigraphic sections from lower Serpukhovian rocks of the Guadiato Area (southwestern Spain) are composed of fifteen taxa, included in nine genera. Many of them are identified in open nomenclature due to the poor preservation of the specimens, of which most of them are fragmented, the presence of juvenile specimens, and the current controversy in the recognition of some multielement apparatuses. Generally, the faunas are not highly diversified and there is a low abundance of specimens in the horizons that yield conodonts. The assemblages include: Cavusgnathus navicula, Cavusgnathus cf. navicula, Gnathodus girtyi, of which two subspecies were identified, Gnathodus girtyi girtyi and Gnathodus girtyi meischneri, Hindeodontoides? sp., Hindeodus cristula, Idioprioniodus healdi, Idioprioniodus spp., Kladognathus macrodentata?, Kladognathus tenuis-complectens, Lochriea? sp., Mestognathus bipluti, Synclydognathus geminus, Synclydognathus spp. and many unidentifiable fragments

Conodontos del Carbonífero de la Meseta Central y de la Cuenca de Tindouf (Marruecos)

Tesis llevada a cabo para conseguir el grado de Doctor por la Universidad Complutense de Madrid.--2017-06-09.--Sobresaliente Cum laude[ES] En el presente trabajo se describen y analizan las diferentes asociaciones de conodontos registradas en doszonas de Marruecos, la región de Adarouch (Meseta Central) y la Cuenca de Tindouf. La región de Adarouch selocaliza en la parte noroeste de la Cuenca de AzrouKhenifra,que pertenece a la parte central de la Meseta Occidentalde Marruecos, y donde la sucesión carbonífera aflora en bandas de dirección NESOy está compuesta pordiversas formaciones, de las cuales Tizra, Mouarhaz, Akerhi, Idmarrach y Tirhela fueron muestreadas para conodontos.La Cuenca de Tindouf se localiza al sur de Marruecos y es un gran sinclinal cuyo eje presenta una direcciónaproximada ESENNO,aflorando parte del sinclinal al oeste de Algeria y norte de Mauritania. Su flanco norte esun gran escarpe que forma la cadena montañosa de Djebel Ouarkziz, donde se levantaron varias secciones estratigráficasque componen la sección compuesta de Tinguiz Remz. En esta sección se encuentran representadas formacionescarboníferas de Betaina y Ouarkziz, las cuales fueron muestreadas para conodontos. Entre ambasregiones se tomaron 168 muestras lo que implicó un total de 465,8491 kg de roca para procesar en laboratorio y14,0051 kg de residuo sólido insoluble para ser triado posteriormente, obteniéndose 5921 elementos conodontalesentre la región de Adarouch y la Cuenca de Tindouf.En el conjunto de las formaciones de la región de Adarouch se han identificado hasta 10 géneros, 18 especiesy 9 subespecies de taxones multielementales de conodontos donde Gnathodus bilineatus y Gnathodus girtyi,Lochriea commutata, Idioprioniodus claviger, Idioprioniodus conjunctus, Kladognathus tenuis/complectens y“Gnathodus“ homopunctatus son los taxones más comunes. En menor número se registran Mestognathus,Synclydognathus, Cavusgnathus y Vogelgnathus. Las asociaciones de conodontos más abundantes provienen dela parte superior de la Fm Tizra, donde se registra una fauna indicativa de ambientes relativamente profundos enla plataforma externa y que se caracteriza por la biofacies de Idioprioniodus, definida por el predominio de Idioprioniodusy, de Gnathodus y Lochriea...[EN] This Ph.D. Thesis is focused on the different conodont assemblages recovered from the Adarouch region (CentralMeseta) and the Tindouf basin (Morocco). The Adarouch region is situated to the northwest of the AzrouKhenifraBasin, in the central part of the Western Meseta, where the Carboniferous succession crops out in NESWorientedstrips and where the Tizra, Mouarhaz, Akerchi and Tirhela formations were sampled for conodonts. The TindoufBasin is a vast syncline with its major axis oriented ESENNW,situated between southern Morocco and westernAlgeria and to the north of Mauritania. Its northern limb constitutes a major escarpment, the Djebel Ouarkziz mountainrange, in which several stratigraphic sections were studied in the composite section of Tinguiz Remz. In thissection, the Betaina and Ouarkziz formations were studied for conodonts. In both regions, 168 levels where sampledfor conodonts, implying a total of 465.8491 kg of rocks processed in the laboratory and 14.0051 kg of solid insolubleresidue for picking. In total, 5921 conodonts were recovered.Conodonts of the formations of the Adarouch region could be ascribed to 10 different multielemental genera ofwhich 18 species and 9 subspecies were identified. The main and most abundant taxons recorded are, Gnathodusbilineatus y Gnathodus girtyi, Lochriea commutata, Idioprioniodus claviger, Idioprioniodus conjunctus, Kladognathustenuis/complectens and “Gnathodus“ homopunctatus, whereas Mestognathus, Synclydognathus, Cavusgnathusand Vogelgnathus are less common, sometimes constituting a minor component in certain assemblages. Theupper part of the Tizra Fm contains the most abundant assemblage of conodonts representative of relatively deepwaterenvironments in an external platform and where the dominance of Idioprioniodus as well as Gnathodus andLochriea has allowed the recognition of the Idioprioniodus biofacies...Esta Tesis Doctoral ha podido realizarse gracias a la beca/contrato FPU­UCM de la Universidad Complutense de Madrid, entre los años 2005­2009. La investigación se ha llevado a cabo gracias al apoyo económico de los proyectos DGICYT (BTE2003­02065) del Ministerio de Ciencia y Tecnología, CGL2006­03085/BTE y CGL2009­10340/BTE del Ministerio de Educación y Ciencia, y CGL2012­30922BTE del Ministerio de Economía, Industria y Competitividad gestionados por el Instituto de Geociencias de Madrid (CSIC­UCM).Peer reviewe

Note on the earliest occurrences of the calcareous algae Paraepimastopora and Archaeolithophyllum in Mississippian rocks

The Mississippian records of the calcareous algal genera Paraepimastopora and Archaeolithophyllum are re-evaluated, as these genera are usually considered to first occur or are confined to Pennsylvanian and Permian rocks. Most specimens of Paraepimastopora in Mississippian rocks have been documented in open nomenclature. Revision of the taxonomic characters permits to assign them to three species: Paraepimastopora cf. kansasensis (JOHNSON) ROUX, Paraepimastopora cf. noetschensis KRAINER & VACHARD, and Paraepimastopora sp. nov. cf. Paraepimatopora sp. A sensu GROVES. These species, although possibly first occurring from the Tournaisian-Viséan boundary, are widespread in the late Viséan in many western Palaeotethyan basins. Revision of the taxonomic characters for Archaeolithophyllum suggests that the single species recorded in Mississippian rocks is Archaeolithophyllum lamellosum WRAY, a taxon rarely recorded in western Palaeotethyan basins, although now first recorded in Ireland and Scotland during the late Brigantian. Subsequently, the species is present in the Serpukhovian (late Mississippian) of France, Spain and Poland. In the Bashkirian (early Pennsylvanian) the genus diversified with several species recorded, and with a notable increase in the abundance of specimens elsewhere. [RESUMEN] Se analizan los registros del Mississippiense pertenecientes a especimenes de los géneros de algas calcáreas Paraepimastopora y Archaeolithophyllum, debido a que, habitualmente, estos géneros son considerados y descritos en rocas del Pensilvaniense y Pérmico. La mayor parte de los ejemplares de Paraepimastopora en rocas del Mississippiense se han citado en nomenclatura abierta. La revisión de los caracteres taxonómicos permite reagrupar los ejemplares en Paraepimastopora cf. kansasensis (JOHNSON) ROUX, Paraepimastopora cf. noetschensis KRAINER & VACHARD, y Paraepimastopora sp. nov. cf. Paraepimastopora sp. A sensu GROVES. Estas especies que, posiblemente aparecen desde el límite Tournasiense-Viseense, pero sólo están bien representados en el Viseense superior de muchas cuencas del Palaeotethys occidental. La revisión de los caracteres taxonómicos de Archaeolithophyllum sugiere que la única especie registrada en el Mississippiense es Archaeolithophyllum lamellosum WRAY, raras veces se cita en cuencas del Paleotethys occidental, considerándose sus primeros registros en el Brigantiense superior de Irlanda y Escocia. Con posterioridad se ha encontrado la especie en el Serpujoviense de Francia, España y Polonia. En el Bashkiriense (Pennsylvaniense inferior), el género se diversificó en varias especies y con un notable aumento en el número de ejemplares en numerosas cuencas

Conodontos del Serpujoviense inferior del Área del Guadiato (Córdoba, España)

Se describen las asociaciones de conodontos de tres secciones estratigráficas de materiales del Serpujoviense inferior en el Área del Guadiato (Suroeste de España). Se han identificado quince taxones pertenecientes a nueve géneros, muchos en nomenclatura abierta debido a varios factores tales como, la preservación de los especimenes, de los cuales, la mayoría están fragmentados, la presencia de especímenes juveniles, y a la controversia existente en el reconocimiento de los aparatos multielementales. En general, las faunas no son muy diversas y la abundancia de ejemplares es baja. Las asociaciones incluyen: Cavusgnathus navicula, Cavusgnathus cf. navicula, Gnathodus girtyi, del que se identificaron dos subespecies, Gnathodus girtyi girtyi y Gnathodus girtyi meischneri, Hindeodontoides? sp., Hindeodus cristula, Idioprioniodus healdi, Idioprioniodus spp., Kladognathus macrodentata?, Kladognathus tenuis-complectens, Lochriea? sp., Mestognathus bipluti, Synclydognathus geminus, Synclydognathus spp. y elementos no identificados

New genera of late Viséan metaspondil dasycladales from the Fuenteobejuna section (Mississippian of the Guadiato Valley, southwestern Spain)

The microfloral assemblages of Mississippian carbonate outcrops close to Fuenteobejuna, southwestern Spain, are analysed and the occurrence of new genera and species of Diploporaceae dasyclad algae can be highlighted. Two new taxa are described, Guadiatella delicata n. gen. n. sp., and Borladella alternons n. gen. n. sp. Both taxa are new monospecific genera without equivalence in the Mississippian. They occur in upper Visean rocks, in the Asbian and Brigantian substages. The genus Japhetella is here considered as an invalid genus.Dirección General de Investigaciones Científicas y TecnológicasDepto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEpu

Palaeobiogeographical constraints on the distribution of foraminifers and rugose corals in the Carboniferous Tindouf Basin, South Morocco

The northern flank of the Tindouf Syncline in southern Morocco exhibits a continuous, well exposed Carboniferous succession with limestones of Late Asbian to Early Bashkirian age containing rich and diverse foraminiferal and rugose coral assemblages. Analysis of these assemblages provides new data on the relatively poorly known Saharan basins. The palaeobiogeographical relationship of the Tindouf Basin with other Palaeotethyan basins is complex. Although there is a predominance of cosmopolitan taxa for the Palaeotethys, it is recognized that there was an influence of basins from NW Europe, such as the UK and Ireland. Some taxa are recorded in both NW Europe and Tindouf without any characteristic contributions from intermediate basins in northern Morocco. The neighbouring Béchar Basin in Algeria presents distinct assemblages. The bulk of the data analyzed suggest that this sector of the western Palaeotethys can be subdivided into four palaeobiogeographical subprovinces: the Atlantic Subprovince (UK, Ireland, N France and Belgium), the Mediterranean Subprovince (Pyrenees, Montagne Noire, Betic Cordillera, Rif (N Morocco) and Balearic Islands), and the Saharan Subprovince (Béchar, Reggan, Ahnet-Mouydir and Tindouf). In between, mobile belts of mixed faunal assemblage characteristics are observed (e.g., SW Spain and Central Meseta) forming the West peri-Gondwanan Subprovince. Analysis of the Tindouf Basin faunas shows that, as in other Saharan basins, there is a high diversity and abundance of foraminiferal taxa, with a higher proportion of survivors and longer stratigraphic ranges; these features also are mirrored by rugose corals. This emphasizes the longevity of the carbonate platform in a tropical setting, where periodic transgressions introduced new assemblages, and oceanic currents are interpreted as one of the main controlling factors for the distribution of the taxa in these subprovinces. Moreover, not only were water temperatures on the platform higher, but also tectonic stability greater. It is considered that the effects of the first phases of the Gondwanan glaciation were minimal on the Tindouf faunas

The Tindouf Basin, a marine refuge during the Serpukhovian (Carboniferous) mass extinction in the northwestern Gondwana platform

Several macrofaunas and microfossils of the Carboniferous Saharan basins have longer stratigraphic ranges than those of other basins in the western Palaeotethys realm, particularly in the Tindouf Basin (Morocco–Algeria). Foraminifers are particularly abundant and diverse in the Serpukhovian and basal Bashkirian compared to coeval basins, and some taxa have longer ranges than in the neighbouring Reggan and Béchar basins, although this effect is more marked compared to the western Palaeotethyan assemblages in Europe. Several rugose coral species are recorded from the early Bashkirian that previously were considered to have disappeared in the Serpukhovian. The Tindouf Basin, as one of the most western Saharan basins in North Africa, shows the greatest stratigraphic ranges of taxa which diminish eastwards. Evidence for a mass extinction event during the Serpukhovian in the Tindouf Basin has not been clearly recognized, although a possible influence of glaciation is observed in the faunal diversity. Eustatic sea-level changes were experienced in Tindouf with the cyclic pattern of sedimentation, but warm water ocean currents from the palaeoequator were able to maintain tropical conditions on the platform. Tectonics in the area, led to emerging land masses and barriers, and created a partly isolated basin in this sector of the western part of the Sahara Platform in northern Gondwana. The combination of those factors controlled the environmental conditions in the area, allowing the persistence of the fauna for longer stratigraphic ranges than its equivalent counterparts in the western Palaeotethys

Potential foraminiferal markers for the Visean-Serpukhovian and Serpukhovian-Bashkirian boundaries- A case-study from Central Morocco

Potential foraminiferal markers for the Visean-Serpukhovian and Serpukhovian-Bashkirian boundaries- A case-study from Central MoroccoThe 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?. Ocurrences 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