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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

MARINE VERTEBRATE REMAINS FROM MIDDLE-LATE DEVONIAN BONE BEDS AT LITTLE HARDWICK CREEK IN VAUGHNS MILL, KENTUCKY AND AT THE EAST LIBERTY QUARRY IN LOGAN COUNTY, OHIO

James, John M. 23 September 2011 (has links)
No description available.
62

Strain in Ordovician and Devonian shales from the Massanutten Synclinorium: implications for fold development and tectonic history

Spears, David B. January 1983 (has links)
Syntectonic chlorite pressure fringes on framboidal pyrites record strain in Ordovician and Devonian shales from the Massanutten synclinorium. Total strains display no systematic relation to minor or major structures. Strain histories are related to the development of minor, rather than regional, structures. A two-component model is proposed for minor folding involving both flexural slip and pure shear. Curved fringes, straight fringe segments separated by sharp curvatures and multiple sets of fringes indicate that increments of pure shear were interspersed with continuous to episodic limb rotations accommodated by flexural slip. Similarities of deformation histories of Ordovician and Devonian shales indicate that in this area cover rocks experienced no penetrative deformation during the Taconic Orogeny. Fold geometries and cleavage fans of major structures are consistent with a ramp-fold origin for the Massanutten Synclinorium/Blue Ridge Anticlinorium fold couple. The deformation sequence is characterized by 1) a significant component of lateral shortening associated with minor folds, cleavage and penetrative strain, 2) amplification of the anticlinorium by asymmetric growth over a subsurface ramp. Rotation of the northwest limb to near-vertical during continued compression and transport resulted in local crenulation of the s₁ fabric. / M.S.
63

Late Devonian (Famennian) brachiopods of the West Range Limestone and the Pilot Shale of Eastern Nevada

Mayer, Paul S. 30 August 1994 (has links)
Graduation date: 1995
64

Paleontology Of Middle And Upper Devonian Formations Of Northwest Ohio: Documenting Earth System Evolution For Scientific And Educational Purposes

Mason, Chad R. 14 August 2019 (has links)
No description available.
65

The Cambrian and Devonian carbonate rocks at Yampai Cliffs, Mohave County, Arizona

Wood, William Hulbert, 1911- January 1955 (has links)
No description available.
66

Late Devonian vertebrates from Siberia: a synchrotron microtomography study of bone bed material

Fortier-Dubois, Étienne January 2016 (has links)
This is an investigation of new vertebrate fossil material from the Late Devonian locality of Ivanovka, Uryup River, Siberia. This bone bed material, circa 375 million years in age, represents a unique opportunity to fill a gap in our understanding of Late Devonian diversity, biogeography, and vertebrate evolution: Siberia, at the time, was an independent continent, and yet its fauna remains virtually unknown in comparison with the other paleocontinents, Euramerica and Gondwana. Using synchrotron microtomographic scanning, a non-destructive technique that has never, to our knowledge, been applied to bone bed material, we obtained 3D image stacks that were then modelled to yield triangle meshes representing the bones in three dimensions. These meshes could then be identified, described, and interpreted. Many of the discovered bones belong to the poorly known genus Megistolepis Obruchev 1955, potentially allowing a radical increase in knowledge regarding this taxon. Other material includes lungfish and possible fragments of limbed tetrapods, though the evidence of the latter is scarce. A discussion of the advantages and disadvantages of synchrotron microtomography for the study of bone bed material concludes the paper.
67

Revisão sistemática e paleobiogeográfica de Trilobitas Phacopida (Homalonotidae e Calmoniidae) do Devoniano das Bacias do Parnaíba e Amazonas, Brasil / not available

Meira, Felipe van Enck 02 September 2016 (has links)
O conhecimento acerca dos invertebrados devonianos no Brasil teve início em fins do século XIX e a primeira metade do século XX, período no qual foram feitas expedições pioneiras às principais bacias paleozoicas do país - as bacias do Paraná, Parnaíba e Amazonas. Desta fase também resultaram importantes trabalhos científicos (e.g., Clarke, 1913), usados ainda hoje como referência em estudos. Dentre os trilobitas, os grupos mais representativos são os Homalonotidae e os Calmoniidae, cuja importância como ferramentas em questões paleoambientais e paleobiogeográficas vem sendo constatada a partir de recentes revisões sistemáticas em fósseis da Bacia do Paraná. Estes estudos também têm demonstrado que muitas das variações nos fósseis, interpretadas por pesquisadores anteriores como taxonômicas, decorrem de alterações tafonômicas, que podem levar a classificações errôneas. Neste contexto, o presente trabalho teve como objetivos revisar a sistemática dos trilobitas Phacopida (Homalonotidae e Calmoniidae) nas bacias do Parnaíba e Amazonas, incluindo, na primeira localidade, a nova ocorrência de São João Vermelho, no município de João Costa (PI), investigar, sempre que pertinente, a implicação das alterações tafonômicas na sistemática desses fósseis, identificando fatores diagenéticos/intempéricos que podem interferir nos caracteres morfológicos e discutir as implicações paleobiogeográficas dos Homalonotidae e Calmoniidae do Devoniano das bacias do Amazonas e Parnaíba, em relação a outras localidades adjacentes à estas bacias. Resultados das pesquisas mostram que a localidade de São João Vermelho é bastante promissora do ponto de vista paleontológico, pois consiste em uma nova localidade para o táxon M. tuberculatus, o qual também é documentado nas duas subbacias da Bacia do Paraná - Alto Garças e Apucarana, indicando que esta espécie apresenta alto grau de cosmopolitanismo. A análise de exemplares de Burmeisteria (Homalonotidae) desta localidade sugere que as diferenças nas espécies deste gênero no Brasil são mais sutis do que imaginado. Na Bacia do Amazonas, os Phacopida estão representados especialmente por Calmoniidae do gênero Malvinella, também presentes na Bolívia. As relações paleobiogeográficas entre as bacias paleozoicas brasileiras e a Bolívia, durante o Eo e Mesodevoniano, teriam sido mais estreitas do que se imaginava. A principal rota de migração para a Bacia do Parnaíba teria sido através da Bacia do Paraná, conforme constatado pela presença de M. tuberculatus. Já a migração para a Bacia do Amazonas teria se dado a sudoeste desta bacia, já que Malvinella ocorre apenas nesta bacia e na Bolívia / The knowledge on Brazilian Devonian invertebrates started by the end of the 19th century and the first half of the 20th century, period which pioneering expeditions were made to the main Paleozoic basins of the country - Paraná, Parnaíba and Amazon basins. Important scientific contributions also resulted from this fase (e.g. Clarke, 1913), still used today as reference in studies. Among trilobites, the most representative groups are the Homalonotidae and Calmoniidae, whose importance in paleoenvironmental and paleobiogeographical questions have been noted from recent systematic revisions in Paraná Basin fossils. These studies also have demonstrated that many variations in fossils, interpreted by previous researchers as taxonomic, are due to taphonomic alterations, which can lead to erroneous classifications. In this context, the current study aimed to review the systematics of Phacopida trilobites (Homalonotidae and Calmoniidae) from the Parnaíba and Amazon basins, including, in the former locality, the new occurrence of São João Vermelho, in the João Costa municipality (PI); to investigate, whenever relevant, .the implication of the taphonomic alterations in the systematics of these fossils, identifying diagenetic/weathering factors which can interfere in the morphological features; and to discuss the paleobiogeographic implications of the Homalonotidae and Calmoniidae from the Devonian of the Parnaíba and Amazon basins, in relation to other localities adjacent to these basins. Study results show that the locality of São João Vermelho is paleontologically promising, as it consists of a new place for the M. tuberculatus taxon, which is also documented in the both Paraná Basin subbasins - Alto Garças and Apucarana, indicating that this species is highly cosmopolitan. The analysis of Burmeisteria (Homalonotidae) exemplars from this locality suggests that differences between the species of this genus in Brazil are slighter than thought. In the Amazon Basin, Phacopida trilobites are especially represented by the Calmoniidae genus Malvinella, also present in Bolivia. The paleobiogeographic relations between the Paleozoic Brazilian basins and Bolivia, during Early and Middle Devonian, would have been closer than thought. The main migration route to the Parnaíba Basin would have been through the Paraná Basin, as found by the presence of M. tuberculatus. The migration to the Amazon Basin, in turn, would have occurred southwestward this basin, as Malvinella occurs only in this locality and in Bolivia.
68

Paleontologia dos Discinidae (Brachiopoda: Linguliformea) da sucessão devoniana da Bacia do Paraná, Estado do Paraná, Brasil: Revisão sistemática, distribuição geográfica e estratigráfica.

Comniskey, Jeanninny Carla 24 March 2011 (has links)
Made available in DSpace on 2017-07-21T18:13:48Z (GMT). No. of bitstreams: 1 Jeanninny Comniskey.pdf: 5522788 bytes, checksum: 549fd8a645e09159673d8bc21ef5872b (MD5) Previous issue date: 2011-03-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The present paper is about branchiopods discinids that occur from the Devonian succession in the state of Paraná, Brazil. The following themes were discussed: systematic review, basic taphonomic analysis and a geographic distribution and stratigraphic. The fieldworks were developed with the intuition of collecting material with stratigraphic control. It was recorded four species of discinids: Orbiculoidea baini, Orbiculoidea bodenbenderi, Orbiculoidea excentrica e Gigadiscina collis. The discinids occur from the Neopraguiano until at least Eogivetiano. The stratigraphic and geographic distribution varies with the species. Considering about the extinction of the group, along with its collapse of the malvinokaffric fauna is also presented. The transference from Orbiculoidea collis taxon to Gigadiscina collis and its maintenance of the others species with originals descriptions added to new data are also presented. / O presente trabalho trata dos braquiópodes discinídeos ocorrentes na sucessão devoniana do estado do Paraná, Brasil. Foram abordados os seguintes temas: revisão sistemática, análise tafonômica básica e distribuição geográfica e estratigráfica. Trabalhos de campo foram desenvolvidos no intuito de se coletar material com controle estratigráfico preciso. Registrou-se quatro espécies de discinídeos quais sejam: Orbiculoidea baini, Orbiculoidea bodenbenderi, Orbiculoidea excentrica e Gigadiscina collis. Os discinídeos ocorrem desde o Neopraguiano até pelo menos o Eogivetiano. A distribuição geográfica e estratigráfica varia de acordo com a espécie. Considerações sobre a extinção do grupo, juntamente com o colapso da fauna malvinocáfrica é ainda apresentado. A transferência do táxon Orbiculoidea collis para Gigadiscina collis e a manutenção das demais espécies com descrições originais adicionadas de novos dados são também apresentadas.
69

CARACTERIZAÇÃO PALEOAMBIENTAL E CORRELAÇÃO ESTRATIGRÁFICA DE AFLORAMENTOS DEVONIANOS DA REGIÃO NORDESTE DO ESTADO DO PARANÁ, BRASIL

Myszynski Junior, Lucinei José 28 August 2018 (has links)
Submitted by Angela Maria de Oliveira (amolivei@uepg.br) on 2018-12-03T10:10:14Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) LUCINEI JOSE MYSZYNSKI JUNIOR .pdf: 10056837 bytes, checksum: dc11b5f87f23c4fe76985b934ad83518 (MD5) / Made available in DSpace on 2018-12-03T10:10:14Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) LUCINEI JOSE MYSZYNSKI JUNIOR .pdf: 10056837 bytes, checksum: dc11b5f87f23c4fe76985b934ad83518 (MD5) Previous issue date: 2018-08-28 / Este trabalho tem por objetivo a correlação estratigráfica em escala regional e o reconhecimento e intepretação dos eventos paleoambientais que originaram as concentrações fossilíferas identificadas na região nordeste da área aflorante da Bacia Sedimentar do Paraná, no estado homônimo. Nas áreas entre os municípios de Arapoti, Jaguariaíva, Piraí do Sul e Ventania, foram identificados mais de 42 pontos de rochas aflorantes que vão do Siluriano ao Carbonífero, naqueles onde a qualidade da exposição rochosa permitiu foram realizadas coletas sistemáticas de material fóssil de acordo com protocolo tafonômico paleoautoecológico proposto na literatura. Ainda em campo, aspectos como o posicionamento do fóssil em relação ao acamamento, graus de articulação/desarticulação, fragmentação e estruturas sedimentares foram observados. Tais informações permitiram uma análise tafonômica mais segura e consequentemente uma interpretação paleoambiental mais fidedigna. Todo o material fóssil coletado foi encaminhado ao Laboratório de Paleontologia e Estratigrafia da Universidade Estadual de Ponta Grossa, onde encontra-se depositado. Foi realizada sua limpeza, numeração, classificação taxonômica, catalogação e fotografação. Análises integradas resultaram na proposição de duas novas seções colunares para a região: a Seção CEEP e a Seção Mutuca (cada uma composta por vários afloramentos). A partir da interpretação das informações litológicas e do agrupamento de diferentes feições sedimentológicas foram identificadas litofácies para cada uma das seções, que, por sua vez, auxiliaram na reconstrução paleoambiental. O agrupamento de diferentes atributos tafonômicos observados nos fósseis e a observação das estruturas sedimentares permitiram o reconhecimento de três tafofácies distintas em cada uma das seções, representando ambientes e processos sedimentares distintos. A correlação estratigráfica com áreas já descritas em outros trabalhos foi realizada a partir da identificação em campo das feições características de cada um dos andares do período Devoniano e também a partir da datação dos depósitos pela presença de conteúdo palinológico. As análises tafonômicas, a paleofauna presente, a interpretação dos paleoambientes, a correlação com as áreas adjacentes já descritas por outros autores e os resultados palinológicos, permitem correlacionar as duas seções como representantes dos momentos iniciais do Devoniano, com rochas cujas idades vão do Neo-Praguiano ao Neo-Emsiano. / This work aims at the stratigraphic correlation in a regional scale and the recognition and interpretation of the paleoenvironmental events that originated the fossiliferous concentrations identified in the northeast region of the Paraná Sedimentary Basin in the homonymous state. In the areas among the municipalities of Arapoti, Jaguariaíva Piraí do Sul and Ventania, more than 42 outcrops were identified, in those where the quality of the rocky exposure allowed, a systematic collection of fossil material was carried out according to the paleoautoecological taphonomic protocol proposed by the literature. Still in the field, aspects such as the positioning of the fossil in relation to the bedding plane, degrees of articulation/disarticulation, fragmentation, and sedimentary structures were observed, such information allowed for a safer taphonomic analysis and consequently a more reliable paleoenvironmental interpretation. All the collected fossil material was sent to the Laboratory of Paleontology and Stratigraphy of the UEPG, where it is deposited. Its cleaning, numbering, taxonomic classification, cataloging and photographing has beem done. Field explorations identified 42 rocky outcrops ranging from the Silurian to the Carboniferous, integrated analyzes resulted in the proposition of two new conlunary sections for the region, the CEEP Section and the Mutuca Section, each composed of several outcrops. From the interpretation of the lithological information and the grouping of different features, lithofacies were identifieded for each of the sections, which, in turn, helped in the paleoenvironmental reconstruction. The grouping of different taphonomic attributes observed in the fossils and the observation of the sedimentary structures allowed the recognition of three distinct taphofacies in each of the sections, representing different specific sedimentary environments and processes. The stratigraphic correlation with areas already described in other works was made from the identification in the field of characteristic features in each of the age of the Devonian period and also from the dating of the deposits by the presence of palynological content. Tafonomic analyzes paleofauna present, interpretation of paleoenvironments, correlation with adjacent areas already described by other authors and the palinological results, allow to correlate the two sections as representatives of the initial moments of the Devonian, with rocks ranging from Neo-Praguian to NeoEmsian.
70

Foraminifery spodního devonu pražského souvrství / Early Devonian Foraminifera from the Prague Formation

Vaněčková, Anna January 2012 (has links)
Lower Devonian foraminifera are known from only a few localities globally and thus are not much investigated. The taxonomy, as well as further use of this group is insufficiently known. One of the main areas of research of foraminifera is the Barrandian area in the Czech Republic. This thesis follows previous studies of this territory but focuses particulary on the Prag formation, which has proven to be rich in foraminifera communities. Taxonomic studies were conducted at two Lower Devonian sites, namely the Na Stydlých vodách quarry and the Požáry quarry. The study showed that foraminifera communities described from the Na Stydlých vodách quarry were dominated by the following genera: Hyperammina, Colonammina and Tolypammina. The highest abundance was recorded at the transition of dvorecko-prokopské limestones and řeporyje limestones and in dvorecko-prokopské limestones. At the Požáry quarry, the communities were dominated by tubular genera of Tolypammina, Hyperammina and Bathysiphon and spherical genera of Lagenammina and Colonammina. The abbundance of Colonammina is unusually high, the genus has been described rarely from other parts of the world so far.

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