Biostratigraphie et paléoécologie des peuplements d'ostracodes dans le Domérien du Bassin Lusitanien, Portugal

The Domerian sections from the Lusitanian Basin of São Pedro de Muel, Rabaçal and Tomar have provided us with more than 1100 Ostracods belonging from 18 genus and about 48 species. The faunal diversity and density of the associations decrease in space (from Tomar to Rabaçal and São Pedro de Muel) and time, with favourable environments for the proliferation of Ostracods at the lower part of the sections (Stokesi subzone) and more hostile at the upper part (Ragazzonii subzone). The Monestieri and Nitescens horizons and the Subnodosus subzone are characterized by a typical assemblage of Ostracods. The palaeoecological Ostracod indexes reveal the fluctuations of the oxygenation, temperature, depth and hydrodynamism of the water, on the different sections and on the whole platform. They display a diachronous cooling in the Lower Domerian series. In the upper part of the Middle and in the Upper Domerian, the deeper, less oxygenated and cooler waters prevent the development of the Ostracod faunas

The Sinemurian ammonites of the Lusitanian Basin (Portugal): an example of complex endemic evolution.

29 pagesInternational audienceThis work synthesizes all of the observations since the late nineteenth century of the highly endemic Late Sinemurian (Obtusum Chronozone) ammonite faunas of the Lusitanian Basin. It is based mainly on recent abundant collections from the Penedo da Saudade section near São Pedro de Muel (Leiria, Portugal). This rich material (some eight species and four genera), collected bed by bed, allows us to propose an initial biostratigraphic, palaeobiogeographic, evolutionary and taxonomic synthesis of these mostly endemic faunas. The genus Epophioceroides n. gen. is new and three new species are identifi ed: Epophioceroides apertus n. gen. n. sp., Ptycharietites (Subgen. indet. A) asteroceroides n. sp. and Ptycharietites (Ptycharietites) heterogenus n. sp. So far they have been found at São Pedro de Muel only. The only non-endemic ammonite, Asteroceras sp. indet., collected from the base of the fossiliferous sequence, suggests an age in the Obtusum Chronozone for the subsequent taxa. Most probably faunas belong to the Stellare Subchronozone but taxa from the highest fossiliferous levels may also belong to the Denotatus Subchronozone. The newly collected material requires the morphological range of the genus Ptycharietites to be extended to include late forms that become either clearly evolute (subserpenticone) such as Ptycharietites (Pompeckioceras) cf. onchocephalus or clearly involute (suboxycone) such as Ptycharietites (? Subgen. indet. B) sp. indet. A. In terms of ontogeny, paedomorphosis – a rare “size-based” heterochronic process among the Asteroceratinae subfamily – is shown to be of major importance throughout the evolution of the genus Ptycharietites. In palaeobiogeographic terms all endemic Late Sinemurian (Obtusum Chronozone) ammonite faunas (Ptycharietites and Epophioceroides n. gen.) of the Lusitanian Basin remain poorly understood. While they suggest marked isolation of the Lusitanian Basin and perhaps also constraining environmental conditions during the Obtusum Chronozone, there is nothing to indicate whether other basins of the “Iberia-Newfoundland” conjugate margins experienced the same endemic trend. Nor is it clear whether the Late Sinemurian endemic faunas are closely related to NW European or to W Tethyan (Mediterranean) faunas. However, the earliest ammonite collected from the São Pedro de Muel section (i. e., Asteroceras sp. indet., bed 500b) suggests a possible NW European affi nity

The Pliensbachian ammonites of the Algarve Basin (Portugal) and their palaeobiogeographical significance for the ''Iberia-Newfoundland'' conjugate margins.

16 pagesInternational audienceA review of the Pliensbachian ammonite faunas of the Algarve Basin is given covering their taxonomy, stratigraphy and palaeobiogeography (palaeobiodiversity). This review is based on both an extensive revision of the previously collected and/or published material and on new finds precisely located within the ammonite succession. This new material allows us to clarify the variations within the most abundant species--a new species Reynesocoeloceras elmii nov. sp. is described--and to improve our understanding (palaeobiodiversity, palaeobiogeography and bio- or chrono-stratigraphy) of the two single known Pliensbachian fossiliferous assemblages in the Algarve Basin. The first of these assemblages is relatively diverse and is ascribed to the upper half of the Luridum Subchronozone. The second assemblage is less diversified and probably partly condensed. It is broadly attributed to the upper half of the Stokesi Subchronozone. Despite the newly collected ammonites and extensive prospecting, our knowledge of the Pliensbachian ammonite faunas of the Algarve remains fragmentary. Therefore, it is difficult to propose an incontrovertible extensive palaeobiogeographical interpretation for these faunas, but it seems that Tethyan (Mediterranean) affinities were of major importance whereas there were probably no NW European influences via the Lusitanian Basin

Ammonites from the Apoderoceras beds (Early Pliensbachian) in São Pedro de Muel (Lusitanian Basin, Portugal).

24 pagesInternational audienceThe lowermost Portuguese Pliensbachian is characterized by the association of Apoderoceras dunrobinense Spath, Tragophylloceras numismale (Quenstedt) and Vicininodiceras aff. mouterdei Donovan. This ammonite fauna indicates the lower part of the Jamesoni Chronozone (lower to middle Taylori Subchronozone). Thanks to the numerous specimens collected, the ontogeny and variability of A. dunrobinense Spath, could also be investigated. The paleogeographical distribution of these ammonites underlines the close connections between the Lusitanian Basin and the Euroboreal seas during the Early Pliensbachian

Atlas des fossiles caractéristiques du Lias portugais III a) Domérien (Ammonites).

45 pagesInternational audienceCe fascicule est le troisième de l'Atlas des fossiles caractéristiques du Lias portugais; il fait suite au fascicule I consacré aux faunes du Lias Inférieur (Hettangien-Sinémurien) et au fascicule II dédié aux faunes de la première partie du Lias Moyen (Carixien). Le fascicule III est consacré à la deuxième partie du Lias Moyen, le sous-étage Domérien. Contrairement aux publications précédentes, le présent travail se restreint aux seules ammonites. Une cinquantaine d'espèces sont brièvement décrites et figurées. Les autres taxons (nautiles, bélemnites, brachiopodes, lamellibranches...) feront l'objet d'un prochain fascicule. Le but de l'Atlas des fossiles caractéristiques du Portugal vise à faire connaître à tous ceux qui s'intéressent à la géologie du Portugal, les principales faunes liasiques. Il est notamment conçu pour fournir un support largement illustré pour les études de terrain. Cette compilation offre une image représentative des macrofaunes d'invertébrés portugais et dans le cas des faunes d'ammonites, elle est même exhaustive et peut être utilisée par les spécialistes notamment dans les domaines de la biostratigraphie et de la paléobiogéographie

The toponyms of the Atlantic islands from the Community of Portuguese Speaking Counties (CPLP) in the history of Palaeontology

PTDC.FER-HFC.30666O recurso a topónimos locais é de uso frequente na descrição científica de novas espécies. Numa perspetiva histórica da taxonomia paleontológica, estes enriquecem substancialmente a nomenclatura existente e permitem contextualizações geográficas mais efetivas. Desde meados do século XIX, os Açores, Madeira e Cabo Verde foram visitados por muitos naturalistas, os quais descreveram floras e faunas atuais e fósseis, usando frequentemente a toponímia local. Daí resultou, sobretudo, a descrição de mais de 60 novos táxones de invertebrados fósseis (ou “subfósseis”) do Cretácico Inferior ao Holocénico, para além de quatro vegetais, um cocolitoforídeo e um icnofóssíl, a partir de topónimos das ilhas atlânticas da Macaronésia da CPLP (Comunidade dos Países de Língua Portuguesa). Os mais utilizados foram Porto Santo (Madeira) (9), Madeira (6), Açores (6), Santa Maria (Açores) (5) e Cabo Verde (6), mas outros existem ligados a designações locais, como povoações e geoformas. Dado que muitos outros topónimos também têm servido para espécies atuais dos mesmos arquipélagos, incluindo São Tomé e Príncipe, e que as associações paleontológicas dos depósitos destas ilhas ainda carecem, em grande medida, de estudos aprofundados, é natural que parte destes táxones ainda venham a ser encontrados em novas jazidas, enriquecendo a presente lista. É interessante notar, também, que alguns dos nomes adotados não cumprem as regras do ICNZ (International Code of Zoological Nomenclature - Código Internacional de Nomenclatura Zoológica), necessitando de futura revisão.publishersversionpublishe

The jurassic of the peniche peninsula (Portugal): Scientific, educational and science popularization relevance

The Peniche Peninsula shows the most continuous carbonate sedimentary succession of the Jurassic in Portugal. In this paper, supported by several important scientific arguments from the different domains of Sedimentary Geology, we highlight this locality as a focal point to understand the Early Jurassic time interval. Among several other themes we emphasize the definition of the Toarcian GSSP, the discussion around the Early Toarcian oceanic anoxic event and the organic-rich deposition occurred in the Sinemurian- Pliensbachian of the Peniche Peninsula section. These key geological themes have been the focus of significant educational/scientific outreach, involving Geology promotion activities directed towards different audiences, on a local and international scale

El Jurásico de la Península de Peniche (Portugal): relevancia científica, educativa y divulgativa

The Peniche Peninsula shows the most continuous carbonate sedimentary succession of the Jurassic in Portugal. In this paper, supported by several important scientific arguments from the different domains of Sedimentary Geology, we highlight this locality as a focal point to understand the Early Jurassic time interval. Among several other themes we emphasize the definition of the Toarcian GSSP, the discussion around the Early Toarcian oceanic anoxic event and the organic-rich deposition occurred in the Sinemurian- Pliensbachian of the Peniche Peninsula section. These key geological themes have been the focus of significant educational/scientific outreach, involving Geology promotion activities directed towards different audiences, on a local and international scale.La Península de Peniche, situada en la Cuenca Lusitánica, muestra la sucesión carbonática sedimentaria más continua del Jurásico Inferior de Portugal. En ella ha quedado registrada la evolución y los principales cambios paleoambientales ocurridos en el Margen Occidental ibérico durante este intervalo.Investigaciones recientes sobre varias peculiaridades científicas relacionadas con diferentes aspectos de la Geología Sedimentaria han convertido esta localidad en un punto clave para entender este intervalo de tiempo del Jurásico Inferior. Esto se debe principalmente a: i) la definición de la Ponta do Trovão como el GSSP (Global Boundary Stratotype Section and Point) de la base del Piso Toarciense; ii) la discusión sobre el Evento Anóxico Oceánico del Toarciense y su correlación con una extinción en masa de 2º orden y, iii) la sedimentación rica en materia orgánica que tuvo lugar durante la parte superior del Sinemuriense y el Pliensbachiense. Además, se hace hincapié en las características sedimentarias únicas de gran parte de los depósitos del Toarciense relacionadas con un episodio notable y singular de la sedimentación dentro del contexto de la Cuenca Lusitánica. Estos temas geológicos claves han atraído a numerosos equipos de investigadores de diferentes partes del mundo. La sección de Peniche ha sido el objeto de importantes y significativas actividades de divulgación científica y educativa por su interés científico global, el excelente conocimiento estratigráfico de dicha sección, así como por su accesibilidad y extraordinario valor paisajístico. También ha sido el foco de atención para realizar acciones de promoción de la Geología dirigidas a diferentes públicos a escala local e internacional. Dichas actividades han consistido en clases de campo.para estudiantes de nivel primario, secundario y universitario, programas de capacitación de diferentes carreras profesionales (principalmente maestros de escuelas secundarias y geólogos del petróleo), reuniones de campo internacionales e iniciativas dirigidas a la comprensión pública de la Ciencia, como por ejemplo, excursiones de campo, conferencias, talleres, mesas redondas y exposiciones de fotografía. Todo ello pone de manifiesto la necesidad y el beneficio que tiene el transmitir a la sociedad los avances científicos en Geología.Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEFundação para a Ciência e Tecnologia (FCT)pu

Formal proposal for the Global Boundary Stratotype Section and Point (GSSP) of the Toarcian Stage, at the base of the Polymorphum Zone in the Peniche section (Portugal)

The Global Stratotype Section and Point (GSSP) for the base of Toarcian Stage is proposed at the base of micritic limestone bed 15e at Ponta do Trovão (Peniche, Lusitanian Basin, Portugal), 80km north of Lisbon, with the mass occurrence of the ammonite genus Dactylioceras (subgenus Eodactylites). The Pliensbachian/Toarcian boundary (PLB/TOA) is comprised in a continuous section forming over 450m of carbonate-rich sediments. Tectonics, synsedimentary disturbance, metamorphism or significant diagenesis do not significantly affect this area. At the PLB/TOA, no vertical facies changes, stratigraphical gaps or hiatuses have been recorded. The base of the Toarcian Stage is marked in the bed 15e by the first occurrence of D. (E.) simplex, co-occurring with D. (E.) pseudocommune and D. (E.) polymorphum. The ammonite association of D. (Eodactylites) ssp. and other species e.g. Protogrammoceras (Paltarpites) cf. paltum, Lioceratoides aff. ballinense and Tiltoniceras aff. capillatum is particularly significant for the boundary definition and correlation with sections in different basins. Ammonites of the PLB/TOA are taxa characteristic of both the Mediterranean and Northwest European provinces that allow reliable, global correlations. The PLB/TOA is also characterized by other biostratigraphical markers (brachiopods, calcareous nannofossils, ostracods and benthic foraminifers) and by high resolution stable carbon and oxygen isotopes, 87Sr/86Sr that show distinctive changes just above the PLB/TOA, thus providing additional, powerful tools for global correlations. The PBL-TOA lies at the end of a second (and third) order cycle of sea-level change, and the top of bed 15e is interpreted as a sequence boundary. Cyclostratigraphy analysis is available for the Lower Toarcian of Ponta do Trovão. Detailed correlations with the Almonacid de la Cuba section (Iberian Range, Spain) provides complementary data of the ammonite succession in the Northwest European Hawskerense and Paltum Subzones, and magnetostratigraphical data that allow supraregional correlations. The proposal was voted by the Toarcian Working Group in June, 2012, and by the International Subcommission on Jurassic Stratigraphy in September, 2012, approved by the ICS in November, 2014, and ratified by the IUGS in December, 2014