18,580 research outputs found

    Additional systematic information on the Early Carboniferous palynoflora from the Ambo Formation, Pongo de Mainique, Peru

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    Palynologic results presented in this contribution come from six productive samples located in the upper part of the Ambo Formation at Pongo de Mainique, Peru. A brief geologic information and an annotated species list (some illustrated) including taxonomic and morphologic remarks for some taxa (genera or species) and their stratigraphic and geographic occurrences outside Peru, are displayed herein. The lectotype of Verrucosisporites nitidus Playford is here designed. The composition of the palynoflora allows correlating to the Cordylosporites magnidictyus Palynozone (late VisĂ©an of the Amazon Basin, Brazil). More information such as the complete and illustrated list of taxa, are part of a recent publication on the palynology of the same unit realised by the same authors.Os dados palinolĂłgicos apresentados nesta contribuição foram obtidos a partir de seis amostras fĂ©rteis procedentes da parte superior da Formação Ambo, na localidade de Pongo de Mainique, Peru. Uma sĂ­ntese das informaçÔes geolĂłgicas e a lista de espĂ©cies registradas, algumas das quais ilustradas, sĂŁo apresentadas, bem como comentĂĄrios morfolĂłgicos e taxonĂŽmicos de alguns tĂĄxons e sua distribuição geogrĂĄfica e estratigrĂĄfica fora do Peru. É designado o lectĂłtipo de Verrucosisporites nitidus Playford. A composição da palinoflora permite correlação com a Palinozona Cordylosporites magnidictyus (Viseano final da bacia do Amazonas, Brasil). A lista completa de tĂĄxons, suas ilustraçÔes e outras informaçÔes adicionais sĂŁo parte de uma publicação recente sobre o tema realizada pelos autores.Fil: Azcuy, Carlos Leopoldo. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de GeologĂ­a; ArgentinaFil: Di Pasquo Lartigue, Maria. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de GeologĂ­a; Argentina. Provincia de Entre RĂ­os. Centro de Investigaciones CientĂ­ficas y Transferencia de TecnologĂ­a a la ProducciĂłn. Universidad AutĂłnoma de Entre RĂ­os. Centro de Investigaciones CientĂ­ficas y Transferencia de TecnologĂ­a a la ProducciĂłn. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Santa Fe. Centro de Investigaciones CientĂ­ficas y Transferencia de TecnologĂ­a a la ProducciĂłn; Argentin

    First palynologic record of the Cretaceous La Yesera Formation (Salta Group), northwestern Argentina

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    Thirty-four taxa were documented from six palynologically productive samples of the La Yesera Formation (Brealito and Don Bartolo Members) in the PucarĂĄ locality (Salta Province, northwestern Argentina). In the Brealito Member, aquatic species (mainly freshwater algae) dominate the palynofl ora, while terrestrial species are represented by trilete spores (mainly Anemiaceae) and gymnosperm pollen grains. In the Don Bartolo Member, Classopollis spp. dominate most of the assemblages, trilete Anemiaceae spores constitute half of the total counts in one of the assemblages and a unique angiosperm species (Tricolpites variabilis) was found in two assemblages. Ephedra-type pollen grains (three genera and six species) appear in both members, although in low abundance. The results support previous sedimentology studies that indicate a perennial lake environment at the time of deposition of the Brealito Member, with evidence for dry seasonality in the Don Bartolo Member. The inferred regional paleoclimate is subtropical with arid conditions. Considering the stratigraphic ranges of selected species and the sedimentology data, an Albian/Cenomanian age is suggested for the unit.Trinta e quatro tĂĄxons foram registrados a partir de seis amostras palinolĂłgicas provenientes da Formação La Yesera (membros Brealito e Don Bartolo), na localidade PucarĂĄ, ProvĂ­ncia de Salta, noroeste da Argentina. No Membro Brealito, predominam as espĂ©cies aquĂĄticas, principalmente de algas de ĂĄgua doce; as espĂ©cies terrestres estĂŁo representadas por esporos triletes, principalmente de Anemiaceae e por grĂŁos de pĂłlen de gimnospermas. No Membro Don Bartolo, os grĂŁos de pĂłlen Classopollis spp. dominam a maioria das assembleias, embora numa das amostras, metade das contagens totais Ă© constituĂ­da por esporos triletes de Anemiaceae e, uma Ășnica espĂ©cie de angiospermas (Tricolpites variabilis) foi encontrada em duas assembleias. GrĂŁos de pĂłlen do tipo Ephedra, com trĂȘs gĂȘneros e seis espĂ©cies, aparecem em baixa abundĂąncia em ambos os membros. Estes resultados corroboram estudos sedimentolĂłgicos anteriores e indicam ambiente lacustre perene, no momento da deposição do Membro Brealito, com evidĂȘncia de sazonalidade seca para a Membro Don Bartolo. O paleoclima regional inferido Ă© subtropical ĂĄrido. Considerando os intervalos estratigrĂĄfi cos de espĂ©cies selecionadas e os dados sedimentolĂłgicos, Ă© sugerida idade Albiano/Cenomaniano para a unidade estudada.Fil: Narvaez, Paula Liliana. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Mendoza. Instituto Argentino de NivologĂ­a, GlaciologĂ­a y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de NivologĂ­a, GlaciologĂ­a y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de NivologĂ­a, GlaciologĂ­a y Ciencias Ambientales; ArgentinaFil: Pramparo, Mercedes Beatriz. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Mendoza. Instituto Argentino de NivologĂ­a, GlaciologĂ­a y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de NivologĂ­a, GlaciologĂ­a y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de NivologĂ­a, GlaciologĂ­a y Ciencias Ambientales; ArgentinaFil: Sabino GarcĂ­a, Ignacio Federico. Tecpetrol S. A.; Argentin

    Angiosperm pollen grains from the Cuayuca Formation (Late Eocene to Early Oligocene), Puebla, Mexico

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    Systematic descriptions and illustrations of the best preserved angiosperm pollen grains (Monocotyledonae or Liliopsida: n= 7 and Dicotyledonae or Magnoliopsida: n= 41) recovered from Cuayuca Formation (late Eocene-early Oligocene), Puebla State, Mexico are provided, some of them of chronostratigraphic importance (Aglaoreidia pristina, Armeria, Bombacacidites, Corsinipollenites, Eucommia, Favitricolporites, Intratriporopollenites, Lymingtonia, Magnaperiporites, Malvacipollis spinulosa, Margocolporites aff. vanwijhei, Momipites coryloides, Momipites tenuipolus, Mutisiapollis, Ranunculacidites operculatus, and Thomsonipollis sabinetownensis). Taxa identified from the Cuayuca Formation suggest local semiarid vegetation such as tropical deciduous forest, chaparral, grassland, and arid tropical scrub, in which angiosperms are one of the main representatives. Nevertheless, temperate taxa from Pinus forest and cloud forest were also registered from regional vegetation. It is noticeable that at the present time, such taxa are well represented in the vegetation of the Balsas River Basin, which would suggest the existence of this type of flora in the Cuayuca region since the Oligocene.Fil: Ramirez Arriaga, Elia. Universidad Nacional AutĂłnoma de MĂ©xico. Instituto de GeologĂ­a. Departamento de PaleontologĂ­a; MĂ©xicoFil: Pramparo, Mercedes Beatriz. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Mendoza. Instituto Argentino de NivologĂ­a, GlaciologĂ­a y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de NivologĂ­a, GlaciologĂ­a y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de NivologĂ­a, GlaciologĂ­a y Ciencias Ambientales; ArgentinaFil: MartĂ­nez HernĂĄndez, Enrique. Universidad Nacional AutĂłnoma de MĂ©xico. Instituto de GeologĂ­a. Departamento de PaleontologĂ­a; MĂ©xic

    On the taxonomic resolution of pollen and spore records of Earth’s vegetation

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    Premise of research. Pollen and spores (sporomorphs) are a valuable record of plant life and have provided information on subjects ranging from the nature and timing of evolutionary events to the relationship between vegetation and climate. However, sporomorphs can be morphologically similar at the species, genus, or family level. Studies of extinct plant groups in pre-Quaternary time often include dispersed sporomorph taxa whose parent plant is known only to the class level. Consequently, sporomorph records of vegetation suffer from limited taxonomic resolution and typically record information about plant life at a taxonomic rank above species.Methodology. In this article, we review the causes of low taxonomic resolution, highlight examples where this has hampered the study of vegetation, and discuss the strategies researchers have developed to overcome the low taxonomic resolution of the sporomorph record. Based on this review, we offer our views on how greater taxonomic precision might be attained in future work. Pivotal results. Low taxonomic resolution results from a combination of several factors, including inadequate reference collections, the absence of sporomorphs in situ in fossilized reproductive structures, and damage following fossilization. A primary cause is the difficulty of accurately describing the very small morphological differences between species using descriptive terminology, which results in palynologists classifying sporomorphs conservatively at the genus or family level to ensure that classifications are reproducible between samples and between researchers. Conclusions. In our view, the most promising approach to the problem of low taxonomic resolution is a combination of high-resolution imaging and computational image analysis. In particular, we encourage palynologists to explore the utility of microscopy techniques that aim to recover morphological information from below the diffraction limit of light and to employ computational image analyses to consistently quantify small morphological differences between species

    Palaeoecological and possible evolutionary effects of early Namurian (Serpukhovian, Carboniferous) glacioeustatic cyclicity

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    Early Namurian (Serpukhovian, Carboniferous), sedimentary cycles in the Throckley and Rowlands Gill boreholes, near Newcastle upon Tyne, UK, consist of fossiliferous limestones overlain by (usually unfossiliferous) black mudstone, followed by sandstones and often by thin coal seams. Sedimentological and regional geological evidence suggests that the largest are high-amplitude cycles, probably of glacioeustatic origin. 13C (bulk organic matter) delineates marine and non-marine conditions because of the large difference between terrestrial and marine 13C, and indicates that full marine salinity was only intermittent and resulted from glacioeustatic marine transgression superimposed on a background of inundation by freshwater from large rivers, which killed off the marine biota. Palynology suggests that plant groups, including ferns and putative pteridosperms, were affected by changing sea level, and that there is a theoretical possibility of connection between cyclicity and the first appearance of walchiacean conifer-like monosaccate pollen such as Potonieisporites. Long-term terrestrial and marine increasing 13C (organic) may reflect the onset of major glaciation in Gondwana, as there is evidence to suggest that the two are coeval, but no specific mechanism can be suggested to link the trends

    Palynologic processing in Antarctica

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    Hiddenocysta matsuokae gen. nov. et sp. nov. from the Holocene of Vancouver Island, British Columbia, Canada

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    A new dinoflagellate cyst genus and species are described here as Hiddenocysta gen. nov. and Hiddenocysta matsuokae sp. nov. from Holocene sediments in a core from the west coast of Vancouver Island (British Columbia, Canada). The genus Hiddenocysta encompasses spherical to ovoid skolochorate cysts, characterized by a gonyaulacoid plate pattern and a 2P precingular archeopyle. The species H. matsuokae is characterized by a granular wall and slender trifurcate processes with heavily perforated process bases. Two end members are described here based on process morphology and number of processes (formas 1 and 2). Cyst wall chemistry is analyzed using micro-Fourier transform infrared (FTIR) spectroscopy and reveals a unique dinosporin composition consistent with a gonyaulacoid autotrophic feeding strategy

    Nueva informaciĂłn palinolĂłgica sobre la FormaciĂłn Poti (Viseano superior) en el arroyo Roncador, Cuenca ParnaĂ­ba, noreste de Brasil

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    Se presenta el resultado del anålisis palinológico de seis muestras de superficie de la Formación Poti expuesta en el arroyo Roncador (Jerumenha, Piauí), noreste de Brasil. Esta unidad sobreyace en discordancia a la Formación Longå (Famenniano superior-Tournaisiano) y sobre ella se dispone en discordancia la Formación Piaui (Pennsylvaniano inferior). Lutitas carbonosas y limolitas brindaron una diversa asociación de palinomorfos bien preservados, compuesta por 95 especies: 58 especies autóctonas de esporas y 5 de algas, y 9 especies de esporas y 23 especies de microplancton retrabajados principalmente de depósitos del Devónico. Se describen tres nuevas especies (Verrucosisporites iannuzzii, V. roncadorense, V. souzai). Se documenta el primer registro de 24 especies para el Mississippiano de Brasil y 7 especies para América del Sur. Entre las especies con valor estratigråfico registradas en la sección aquí estudiada Anapiculatisporites amplus, A. concinnus, Foveosporites pellucidus, Grandispora maculosa, Reticulatisporites magnidictyus, Verrucosisporites morulatus, Waltzispora polita, junto con otras no registradas previamente en la Formación Poti (Apiculiretusispora microseta, Densosporites spinosus, Knoxisporites ruhlandi, Punctatisporites subvaricosus, Retusotriletes mirabilis, Tricidarisporites phippsae), confirman una edad Viseano tardío y su correlación con la Zona R. magnidictyus (Mag) Melo y Loboziak. La comparación mundial del presente conjunto palinológico indica una gran afinidad con palinofloras coetåneas distribuidas en paleolatitudes similares en América del Sur, Norte de África y Australia (Reino Paracas). Las características sedimentológicas (e.g., areniscas con estratificación cruzada sigmoidal y ondulitas) y paleontológicas (e.g., restos de plantas y abundante materia orgånica terrestre) de la sección indican que la depositación ocurrió en un ambiente de estuario de baja profundidad.This contribution presents the results of the palynological analysis of six surface samples of the Poti Formation cropping out at the Roncador creek (Jerumenha, Piauí), northeastern Brazil. This unit unconformable overlies the upper Famennian-Tournaisian Longå Formation and it is unconformable overlain by the lower Pennsylvanian Piaui Formation. Carbonaceous shales and siltstones yielded a diverse assemblage of well-preserved palynomorphs, composed of 95 species: 58 indigenous spore, and 5 algal species, and 9 reworked spore and 23 reworked microplankton species mostly from Devonian strata. Three new species are described (Verrucosisporites iannuzzii, V. roncadorense, V. souzai). First records for the Mississippian of Brazil (24 species) and South America (7 species) are also documented. Several age diagnostic species recorded in the Poti Formation (Anapiculatisporites amplus, A. concinnus, Foveosporites pellucidus, Grandispora maculosa, Reticulatisporites magnidictyus, Verrucosisporites morulatus and Waltzispora polita), completed with others not previously documented in subsurface deposits of this unit (Apiculiretusispora microseta, Densosporites spinosus, Knoxisporites ruhlandi, Punctatisporites subvaricosus, Retusotriletes mirabilis and Tricidarisporites phippsae), confirms a late Visean age and its correlation to the R. magnidictyus Melo and Loboziak Zone. Worldwide comparison of the Roncador association indicates greater affinity with coeval palynofloras with similar paleolatitudinal position in South America, North Africa and Australia (Paracas Realm). Sedimentologic (e.g., sandstones with sigmoidal cross and wave ripples beddings) and paleontological features (e.g., plant remains and abundant terrestrial organic matter) along this section document a shallow estuarine depositional environment.Fil: Di Pasquo Lartigue, Maria. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; ArgentinaFil: Iannuzzi, R.. Universidade Federal do Rio Grande do Sul; Brasi

    Application of palynological techniques for correlation of coal seams in the Lower Lignite Creek area, Nenana Coal Field

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    This study concerns spores and pollen in the coals of the lower Lignite Creek area in the Nenana Coal Field, which is operated by Usibelli Mining Company. The seams studied are part of the Suntrana Formation which contains a large portion of the coal reserves of Nenana coal. These coals are mid-Miocene in age and are separated from each other by cyclic sandstone, clay and silt deposits, which reflect alternating periods of coal forming swamps and depositing streams. A preliminary study of the mega and micro botanical fossils of this area was made in 1969 by Wolfe and Leopold (Wahrhaftig et al, 1969). Palynological investigation was done on 26 samples of the Suntrana Formation and evidence from this and fossil leaves indicate that the formation should be placed in the Seldovian stage.Introduction -- Sampling -- Maceration procedures -- Interpretation -- References -- Appendix
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