1,188 research outputs found

    Identification of the Early Permian (Autunian) in the subsurface of the Ebro Basin, NE Spain, and its paleogeographic consequences

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    The Early Permian (Autunian) has not been identifi ed up to now in the subsurface of the Tertiary Ebro Basin because of the scarcity of oil well boreholes reaching the Variscan basement and the systematic attribution of a Carboniferous age, without any paleontological data, to the unmetamorfosed siliciclastic sediments found at the base of some of them, clearly above the Early Paleozoic basement. Grey and black shale samples recovered from cores preserved in the REPSOL-YPF archives of the Caspe-1 oil well between meters 1.437 and 1.449 have yielded palynological assemblages dominated by Vittatina costabilis, Potonieisporites novicus, Potonieisporites sp., and other poorly preserved elements. This association has an Early Permian (Autunian) age and closely resembles other fi ndings in the Iberian Ranges, the Pyrenees and the southern margin of the Iberian Massif, shading new light on the early stages of the extensional events taking place in central and NE parts of the Iberian Microplate just after the main compressive phases of the Variscan orogeny. [ABSTRACT] El Pérmico Inferior (Autuniense) no había sido identifi cado hasta ahora en el subsuelo de la Cuenca Terciaria del Ebro dada la escasez de pozos de petróleo que alcanzasen el basamento varisco de la zona y la sistemática atribución de una edad Carbonífero, sin dato paleontológico alguno, a los sedimentos siliciclásticos no metamórfi cos encontrados en la base de algunos de ellos, claramente sobre el basamento del Paleozoico Inferior. Se recuperaron muestras de lutitas grises y negras de testigos conservados en los archivos de REPSOL-YPF del sondeo Caspe-1, entre los metros 1.437 y 1.449, que han proporcionado una asociación de palinomorfos compuesta por Vittatina costabilis, Potonieisporites novicus, Potonieisporites sp., y otros elementos peor conservados. Esta asociación tiene una edad Pérmico Inferior (Autuniense) y tiene gran similitud con otras descritas en la Cordillera Ibérica, los Pirineos y el borde S del Macizo Ibérico, arrojando nueva luz sobre los primeros eventos extensivos que tuvieron lugar en el centro y NE de la Microplaca Ibérica inmediatamente después de las principales fases de compresión de la orogenia Varisca

    Paleobotanical and palynological evidence for the age of the Matzitzi Formation, Mexico

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    This study addresses some of the stratigraphical problems of the Matzitzi Formation of Puebla and Oaxaca States in Mexico. The age assignment for this unit is controversial although most researchers today accept a Leonardian age (Kungurian, 279.3–272.3 Ma) based on the presence of the gigantopterid Lonesomia mexicana Weber. However, after re-examination of the holotype and two paratypes, the absence of diagnostic taxonomic characters prevents the assignment of this fossil type species to the gigantopterid group. Excluding the presence of gigantopterids in this formation, the macroflora seems to be Permian in age. Samples were collected for palynological analysis to determine the age of the formation. Studied palynological assemblages seem to be reworked and are represented by 18 fossil taxa assigned to the following genera: Calamospora, Deltoidospora, Densosporites, Granulatisporites, Laevigatosporites, Latipulvinites, Lophotriletes, Platysaccus, Punctatosporites, Raistrickia, Schopfipollenites, Thymospora, Triquitrites, Verrucosisporites, and Vesicaspora. Described palynomorphs are likely Late Pennsylvanian according to the presence of Latipulvinites kosankii and Thymospora thiessenii. The biostratigraphic and geochronologic age disparities should be solved in the future

    New palynological data in Muschelkalk facies of the Catalan Coastal Ranges (NE of the Iberian Peninsula)

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    The Middle Triassic (Ladinian) deposits of the Catalan Basin (Spain) are essentially represented by extensive marine carbonate platforms developed in a rift tectonic setting. During the Ladinian, a regional sea-level drop led to a significant paleogeographic reorganisation of the depocentres of eastern Iberia producing a relevant shift in the distribution of the sedimentary environments. To better calibrate the age of the correlative conformity and the associated depositional facies, a new palynological study was carried out in two localities in Tarragona province (Spain). The palynological assemblages suggest a Longobardian–Cordevolian age (Middle–Late Triassic transition) for the materials deposited below and above the correlative conformity. This study allows a refined biostratigraphic and sedimentary correlation between the carbonate sediments in the Catalan Basin and those in the Iberian Ranges and adjacent basins of the Tethys region

    Paleobotanical and palynological evidence for the age of the Matzitzi Formation, Mexico

    Get PDF
    This study addresses some of the stratigraphical problems of the Matzitzi Formation of Puebla and Oaxaca States in Mexico. The age assignment for this unit is controversial although most researchers today accept a Leonardian age (Kungurian, 279.3–272.3 Ma) based on the presence of the gigantopterid Lonesomia mexicana Weber. However, after re-examination of the holotype and two paratypes, the absence of diagnostic taxonomic characters prevents the assignment of this fossil type species to the gigantopterid group. Excluding the presence of gigantopterids in this formation, the macroflora seems to be Permian in age. Samples were collected for palynological analysis to determine the age of the formation. Studied palynological assemblages seem to be reworked and are represented by 18 fossil taxa assigned to the following genera: Calamospora, Deltoidospora, Densosporites, Granulatisporites, Laevigatosporites, Latipulvinites, Lophotriletes, Platysaccus, Punctatosporites, Raistrickia, Schopfipollenites, Thymospora, Triquitrites, Verrucosisporites, and Vesicaspora. Described palynomorphs are likely Late Pennsylvanian according to the presence of Latipulvinites kosankii and Thymospora thiessenii. The biostratigraphic and geochronologic age disparities should be solved in the future

    New palynological data in Muschelkalk facies of the Catalan Coastal Ranges (NE of the Iberian Peninsula)

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    The Middle Triassic (Ladinian) deposits of the Catalan Basin (Spain) are essentially represented by extensive marine carbonate platforms developed in a rift tectonic setting. During the Ladinian, a regional sea-level drop led to a significant paleogeographic reorganisation of the depocentres of eastern Iberia producing a relevant shift in the distribution of the sedimentary environments. To better calibrate the age of the correlative conformity and the associated depositional facies, a new palynological study was carried out in two localities in Tarragona province (Spain). The palynological assemblages suggest a Longobardian–Cordevolian age (Middle–Late Triassic transition) for the materials deposited below and above the correlative conformity. This study allows a refined biostratigraphic and sedimentary correlation between the carbonate sediments in the Catalan Basin and those in the Iberian Ranges and adjacent basins of the Tethys region

    State of the art of Triassic palynostratigraphical knowledge of the Cantabrian Mountains (N Spain)

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    The present-day Cantabrian Mountains (North Spain) represent the western continuation of the Pyrenean-Cantabrian Orogen, which arose from a Cenozoic collision between the Iberian and Eurasian plates. The early Alpine sedimentary record of the Cantabrian basin is represented by the latest Carboniferous-Permian and Triassic rocks, mostly of continental origin. A lack of palaeontological data has led, until recently, to erroneous interpretations of the stratigraphic position of this sedimentary record. Within the framework of the Triassic sedimentary record in northern Spain, the precise age of six samples was determined and they were grouped into four palynological assemblages according to their taxonomic composition. The study of these assemblages includes a review of all the Triassic assemblages published to date as regards the Cantabrian Mountains, thereby optimising our Triassic palynostratigraphical knowledge of this area enabling comparisons with other Triassic assemblages of Central and SW Europe

    State of the art of Triassic palynostratigraphical knowledge of the Cantabrian Mountains (N Spain)

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    The present-day Cantabrian Mountains (North Spain) represent the western continuation of the Pyrenean-Cantabrian Orogen, which arose from a Cenozoic collision between the Iberian and Eurasian plates. The early Alpine sedimentary record of the Cantabrian basin is represented by the latest Carboniferous-Permian and Triassic rocks, mostly of continental origin. A lack of palaeontological data has led, until recently, to erroneous interpretations of the stratigraphic position of this sedimentary record. Within the framework of the Triassic sedimentary record in northern Spain, the precise age of six samples was determined and they were grouped into four palynological assemblages according to their taxonomic composition. The study of these assemblages includes a review of all the Triassic assemblages published to date as regards the Cantabrian Mountains, thereby optimising our Triassic palynostratigraphical knowledge of this area enabling comparisons with other Triassic assemblages of Central and SW Europe

    Synthesis, antioxidant properties and neuroprotection of α-phenyl-tert-butylnitrone derived HomoBisNitrones in in vitro and in vivo ischemia models

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    We herein report the synthesis, antioxidant power and neuroprotective properties of nine homo-bis-nitrones HBNs1–9 as alpha-phenyl-N-tert-butylnitrone (PBN) analogues for stroke therapy. In vitro neuroprotection studies of HBNs1–9 against Oligomycin A/Rotenone and in an oxygen-glucose-deprivation model of ischemia in human neuroblastoma cell cultures, indicate that (1Z,1′Z)-1,1′-(1,3-phenylene)bis(N-benzylmethanimine oxide) (HBN6) is a potent neuroprotective agent that prevents the decrease in neuronal metabolic activity (EC = 1.24 ± 0.39 μM) as well as necrotic and apoptotic cell death. HBN6 shows strong hydroxyl radical scavenger power (81%), and capacity to decrease superoxide production in human neuroblastoma cell cultures (maximal activity = 95.8 ± 3.6%), values significantly superior to the neuroprotective and antioxidant properties of the parent PBN. The higher neuroprotective ability of HBN6 has been rationalized by means of Density Functional Theory calculations. Calculated physicochemical and ADME properties confirmed HBN6 as a hit-agent showing suitable drug-like properties. Finally, the contribution of HBN6 to brain damage prevention was confirmed in a permanent MCAO setting by assessing infarct volume outcome 48 h after stroke in drug administered experimental animals, which provides evidence of a significant reduction of the brain lesion size and strongly suggests that HBN6 is a potential neuroprotective agent against stroke.We would like to thank Soledad Martinez Montero for the excellent technical assistance. This work was supported by grants from the Spanish Ministry of Economy and Competitiveness (SAF2015-65586-R to JMC; CTQ2016- 78205-P and CTQ2016-81797-REDC to IF, and NEUROCENTRO-CM S2017/BMD3760 to RMM and DNG), and Camilo José Cela University (UCJC-2018-04) to MJOG. DDI thanks the University of Alcalá and Spanish Ministry of Science, Innovation and Universities for pre-doctoral FPU grants. BCG thanks the Spanish Ministr
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