First palynological data from the upper Carboniferous in the Oriental Pyrenees (Argestues, Lleida, Spain)

Este trabajo muestra la primera asociación palinológica del Pensilvaniense tardío de los Pirineos Orientales (N Península Ibérica). La evidencia proviene de la Unidad Gris (UG) de la sección Rio Pallarols (Argestues, España). La GU se distingue principalmente por sus características litológicas y parcialmente por su contenido paleobotánico. Esta unidad fue primeramente atribuida al Estefaniense B-C por su contenido macroflorístico pero, hasta la fecha, ninguna evidencia palinológica ha contrastado dicha asignación. Para confirmar dicha edad, se obtuvo una muestra con contenido palinológico en la base de esta sección. La composición taxonómica de la asociación es característica de una flora Autuniense s.l. Esta asociación podría ser asignada al Estefaniense (Kasimoviense-Gzheliense) por comparación con las escalas palinoestratigráficas clásicas descritas para los depósitos carboníferos de Europa occidental. Esta nueva evidencia es coherente con las dataciones radiométricas llevadas a cabo en niveles equivalentes, las cuales sugieren una edad Kasimoviense - Gzheliense (307,4 ± 1,4 Ma – 302,6 ± 2,6 Ma)This paper shows the first palynological assemblage from the Late Pennsylvanian of Oriental Pyrenees (N Iberian Peninsula). Evidence comes from the Grey Unit (GU) from Rio Pallarols section (Argestues, Spain). The GU is distinguished mainly by its lithological characteristics and partly by its paleobotanical content. This unit was initially attributed the Stephanian B-C according to its macrofloristic content, but to date, no palynological evidence has confirmed such assignation. To confirm that age, a sample with palynological content was obtained at the base of this section. The taxonomic composition of the assemblage is characteristic of an Autunian s.l. flora. This assemblage could be assigned to Stephanian age (Kasimovian-Gzhelian) by comparison with classic palynostratigraphic scales from the Carboniferous deposits of Western Europe. This new evidence is consistent with the radiometric dating carried out at equivalent levels, which suggest a Kasimovian – Gzhelian age (307.4 ± 1.4 Ma - 302.6 ± 2.6 Ma

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

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

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

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

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

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

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

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

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)

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

Palynostratigraphy of the Middle Triassic (Anisian) Eslida Formation, SE Iberian Ranges, Spain

The Triassic record in the SE Iberian Ranges starts with two tecto-sedimentary units of continental origin in Buntsandstein facies: and Cañizar and Eslida Formations. The Eslida Formation always lies conformably on top of the Cañizar Formation and it grades upwards into overlying coastal mud flats, traditionally assigned to the Röt facies. In the past, accurate dating of the Eslida Formation was problematic because of its continental character, absence of datable fossil remains, and lithological similarities with Middle–Upper Permian rocks. Macroflora and fossilised vertebrate footprints in the Eslida Formation indicate an Anisian age (Middle Triassic). In this work, we date the Eslida Formation on the basis of a palynological assemblage. The precise dating of the Eslida Formation is essential in order to establish stratigraphical correlations with other units in the Iberian Ranges and to obtain palaeogeographical considerations on the rapid subsidence represented by the sedimentary record of this unit in the new NNE–SSE Middle Triassic rift developed in eastern Iberia.This research was supported by projects CGL2014-52699P (Spanish Ministry), CSIC Research Groups: Sistemas Sedimentarios y Variabilidad Climática (642853) and Procesos de Formación Mineral, and UCM-BSCH-GR58/08 Projects Análisis de Cuencas (910429) and Paleoclimas (910198).Peer reviewe

The Artinskian Warming Event: an Euramerican change in climate and the terrestrial biota during the early Permian

One of the most significant climate changes in the history of Earth happened during the late Palaeozoic, with the melting of the Gondwanan ice sheets and a progressive warming that profoundly changed the composition of the global terrestrial biota. Nevertheless, there is a lack of studies on mid-late Cisuralian central Pangaea (presentday Europe and North Africa). We have comprehensively revised the well-constrained tetrapod ichnofauna, macroflora, and microflora from the late Cisuralian of the Southern Alps and compared it to other Cisuralian assemblages from Europe and North Africa. The results show a dramatic increase in both diversity and relative abundance of drought-tolerant forms during the Artinskian, at about 287 Ma. This biotic replacement is sudden, conspicuous, widespread and time-equivalent to the biotic replacement observed at the low palaeolatitudes of western Pangaea (present-day western USA) and to a major increase of pCO2 and Na2O values in Euramerican successions. This is possibly related to the eruption of the Tarim Large Igneous Province of NW China and Panjal Traps of NW India that may have caused the final melting of the Gondwanan ice sheets. Consequently, this substantial faunal and floral change is probably driven by a global climatic event (Artinskian Warming Event, AWE) that increased temperature and aridity at the low palaeolatitudes of Pangaea, enhancing the apparent abundance and diversity of drought-tolerant taxa. Further studies are needed to better constrain the timing of this event and verify its full extent, in both the continental and marine realms, as well as to investigate its relationship with contemporary eruptions