Neste estudo são apresentados os dados obtidos de microfósseis, foraminíferos e radiolários, em dois poços 1-MAS-12 e 1-MAS-16, nas formações Ilha de Santana e Travosas, do Grupo Humberto de Campos, Bacia Pará-Maranhão. Com base no estudo de foraminíferos constatou-se a idade Turoniana-Maastrichtiana, para os depósitos analisados. Dos foraminíferos planctônicos, os mais abundantes foram Archeoglobigerina blowi e Heterohelix globulosa. Dentre as formas bentônicas, a mais presente foi Gavelinella pertusa. Dos radiolários foram reconhecidos Histiastrum latum, Orbiculiforma sp., Pseudoaulophacus sp. e Dictyomitra multicostata. Observou-se o predomínio das formas planctônicas em relação às bentônicas, sendo os picos de abundância de foraminíferos e radiolários indicativos de alta produtividade orgânica e eventos de ressurgência. / The data presented here were obtained from foraminifera and radiolaria microfossils present in two wells: 1-MAS-12 and 1-MAS-16, inside at Ilha de Santana e Travosas formation, Humberto de Campos Group, Pará-Maranhão Basin. It was possible to infere, from the analysed samples, the Turonian-Maastrichtian age of the deposits. Among the planktonic foraminifera, the more abundant were Archeoglobigerina blowi e Heterohelix globulosa. Among the bentonic, it was the Gavelinella pertusa. Of the radiolaria were recognized Histiastrum latum, Orbiculiforma sp., Pseudoautophacus sp. e Dictyomitra multicostata. It was observed that the planktonic forms were prevalent over the bentonic. The foraminífera and radiolaria abundance peaks are indicative of high organic productivity and upwelling events.

A Bacia de Campos está limitada pelo Alto de Vitória ao Norte e pelo Alto de Florianópolis ao sul, possuindo uma área de aproximadamente 100.000 km2. Sua seção rifte é composta pela porção basal a mediana do Grupo Lagoa Feia, e inclui a principal rocha geradora da bacia, reconhecidamente rica em matéria orgânica, sendo a maior produtora de hidrocarbonetos do Brasil, e rochas reservatório carbonáticas. O presente estudo foca sua análise no intervalo rifte, onde foi realizada uma interpretação e mapeamento sistemático de linhas sísmicas 2D em uma área chave da bacia. Esta análise é baseada em adaptações de modelos já existentes de evolução de bacias rifte, e nos conceitos de estratigrafia de sequências aplicados à sismoestratigrafia. Através da interpretação e mapeamento das seções sísmicas, foi possível elaborar um modelo evolutivo para a fase inicial da Bacia de Campos, com a elaboração de uma carta cronoestratigráfica e estabelecimento dos tratos de sistemas que distinguem as diferentes fases de evolução dos meio-grábens reconhecidos. O resultado foi a delimitação de três tratos de sistemas tectônicos, que permitiram uma compreensão detalhada da complexa evolução e desenvolvimento das calhas da Bacia de Campos durante a fase rifte. / The Campos Basin is limited northward by the Vitória High and southward by the Florianópolis High, with an area of approximately 100,000 km2. The rift section in the Campos Basin comprises the basal and median portions of the Lagoa Feia Group, and includes the main source rocks in the basin, which is known to be rich in organic matter and is the best hydrocarbon producer in Brazil, as well as carbonate reservoir rocks. The present study focuses its analysis on the rift section, where a systematic mapping and interpretation of 2D seismic lines in a key area of the basin was carried out. This analysis is based on adaptations of existing evolution models for rift basins, and the concepts of sequence stratigraphy applied to seismic stratigraphy. Through the interpretation and mapping of seismic sections, it was possible to propose an evolution model for the initial phase of the Campos Basin, with the construction of a chronostratigraphic chart and the establishment of systems tracts that distinguish different stages on the evolution of the recognized half-grabens. The result was the delimitation of three tectonic systems tracts that allowed the detailed understanding of the complex evolution and trough development of the Campos Basin during the rift phase.

A região de General Salgado (Formação Adamantina, Bacia Bauru) mostra-se como uma região extremamente rica em fósseis de vertebrados. Essa riqueza evidencia-se na presença de diversos registros de Crocodilianos do Cretáceo. Entre eles, encontra-se um esqueleto articulado, composto por partes do crânio e um pó-crânio praticamente completo. Os caracteres que alocam o exemplar à família Baurusuchidae são: o quadrado altamente verticalizado, com a presença de uma concavidade na sua superfície lateral, a conformação da mandíbula, a presença de uma depressão longitudinal na porção anterior do jugal e a expansão descendente da aba lateral do esquamosal. A presente descrição de pós-crânio é a primeira realizada para um táxon da família extinta Baurusuchidae. Já foi noticiada a existência de material pós-craniano deste clado extinto de Crocodyliformes, porém nenhum exemplar foi realmente descrito até o presente momento. Esse material fóssil parece pertencer a novo táxon, devido à sua conformação peculiar do jugal, do processo retro-articular e da expansão descendente da aba lateral do esquamosal. Os caracteres levantados foram empregados para definir a posição filogenética e taxonômica do exemplar no grupo dos Notosuchia, e pretende-se, com isso, contribuir para a compreensão da diversidade dos mesmos. / The area of General Salgado (Adamantina Formation, Bauru Basin) is extremely rich in vertebrate fossils. This richeness is evident with the presence of several records of Cretaceous crocodiliforms. Among them, an articulated skeleton of a new Baurusuchidae was found, composed by parts of the cranium and a practically complete post-cranium. Characters that place the specimen in the family Baurusuchidae are: the highly verticalized quadrate, with the presence of a cavity in its lateral surface; the configuration of the jaw; the presence of a longitudinal depression in the first portion of the jugal; and the descendent expansion of the lateral edge of the esquamosal. The present postcranial description is the first one provided for taxon of the extinct family Baurusuchidae. This fossil material appears to belong to a new taxon, due to the peculiar configuration of its jugal, of the retro-articular process, and of the descendent expansion of the lateral edge of the esquamosal. The gathered caracters were used to define the filogenetic and taxonomic position of the specimen in Notosuchia. With this filogenetic analysis, it is expected to contribute with the comprehension of the diversity of the group.

No presente trabalho o gênero fóssil Bauruemys elegans é redescrito. Sua anatomia craniana e pós-craniana foi analisada em detalhes com base em novos exemplares coletados deste fóssil. Bauruemys elegans é um quelônio do Cretáceo Superior da Bacia Bauru, encontrado no Município de Pirapozinho, interior do estado de São Paulo e descrito originalmente por Suárez em 1969 como “Podocnemis elegans”. Os materiais analisados foram comparados com a osteologia de representantes atuais dos clados Chelidae, Pelomedusidae e Podocnemididae, bem como com descrições de outros táxons disponíveis na literatura. As relações filogenéticas de Bauruemys elegans dentro do clado Podocnemidinura foram analisadas através da análise de parcimônia envolvendo 19 táxons e 56 caracteres. Nesta análise Bauruemys elegans constitui, de fato, um gênero distinto entre os podocnemidídeos, corroborando propostas já descritas na literatura. A análise também revelou que, através dos caracteres osteológicos, Bauruemys elegans possui afinidades filogenéticas próximas aos podocnemidídeos atuais, posicionando-se como grupo-irmão do clado formado pelo fóssil Cambaremys langertoni e pela Família Podocnemididae. / In this study, the fossil Bauruemys elegans is redescribed. Its cranial and postcranial anatomy was analysed in detail based on new specimens collected. Bauruemys elegans is a chelonian from Upper Cretaceous of the Bauru Basin founded in the municipality of Pirapozinho, São Paulo state and was originally described by Suarez (1969) as Podocnemis elegans. The specimens analysed was compared with some extant representatives of Chelidae, Pelomedusidae and Podocnemididae families and descriptions avaliable on the literature. The phylogenetic affinities of the Bauruemys elegans within Podocnemidinura was evaluated through a parsimony analysis envolving 19 taxa and 56 characters. The results of phylogenetic analysis shows that Bauruemys elegans is, in fact, a distinct genus within the clade Podocnemididae. This corroborated anterior hypothesis proposed. Adittionally, this analysis using osteological characters, indicate Bauruemys elegans as the sister group of Cambaremys langertoni and Podocnemididae.

No presente trabalho materiais de microvertebrados coletados no sítio fossilifero de Pirapozinho são descritos. Estão presentes nesta camada materiais fósseis de peixes, quelônios e dentes de dinossauro e crocodilo. Diversos estudos anteriores descreveram e posicionaram filogeneticamente o exemplar mais comum encontrado na localidade, o quelônio fóssil Bauruemys elegans, porém não existem trabalhos sistemáticos voltados para a descrição dos fragmentos presentes no afloramento. Para classificar taxonomicamente os materiais encontrados, foram empregados os materiais depositados em coleções científicas e a informação disponível na literatura. Grande parte do material triado corresponde a fragmentos que não puderam ser utilizados para descrição, pois apresentam considerável desgaste, provavelmente devido ao teor da camada que indica se tratarem de materiais oriundos de eventos de transporte hidráulico, hipótese levantada devido ao empacotamento, abrasão e completa dissociação e desarticulação que se encontram os materiais / In this work microvertebrate materials from Pirapozinho fossiliferous site were colected and described. In this strata are present fóssil material of fish, turtles and teeth of dinosaur and crocodile. Several previous works described and placed phylogenetically the most common specimenfound in this locality, the fóssil turtle Bauruemys elegans, however there are no systematic work focused on the fragments descriptions present in the locality. To classify taxonomically the materials found, were used the materials deposited in scientific collections and in information available in literature. Most of the material screened corresponds to fragments that could not be used for description, because they show considerable wear, probably due to the content of the strata that indicates that these material are related to events of hydraulic transport, hypothesis due to packaging, abrasion and complete dissociation and disarticulation ofthe materials

A Formação Crato, localizada na bacia do Araripe, Nordeste do Brasil, contém um dos registros fossíferos vegetais mais importantes do Cretáceo Inferior. Estes fósseis apresentam excelente estado de preservação, no geral, com pouca fragmentação, órgãos em conexão e estruturas epidérmicas e anatômicas delicadamente substituídas por óxidos de ferro. Como acontecia globalmente, as gimnospermas eram o grupo vegetal dominante na paleoflora eocretácea da Formação Crato, ocorrendo na forma de Bennettitales, Coniferales e Gnetales. As Bennettitales foram um componente aparentemente raro, estando representado pelas espécies Otozamites sp. e Zamites sp. Dentre as Coniferales, encontram-se as famílias Araucariaceae e Cheirolepidiaceae, as Araucariaceae registradas nas espécies Araucarites vulcanoi Duarte e Araucarites kunzmanni sp. nov.; as Cheirolepidiaceae, o grupo mais diverso, estão representadas pelas espécies Brachyphyllum obesum Heer, Brachyphyllum ponsi sp. nov., Brachyphyllum araripense sp. nov., Tomaxellia aff. T. biforme Archangelsky, Toxamellia aff. T. degiustoi e Pseudofrenelopsis sp. As Gnetales ocorrem na forma das espécies Limaephyton cratense gen. et sp. nov., Limaephyton duartei gen. et sp. nov. e Limaephytophyllum mohrium gen. et sp. nov. Características morfológicas, epidérmicas e anatômicas presentes nos macrofitofósseis da Formação Crato, evidenciam adaptações a um ambiente de baixa umidade. Esta flora se desenvolveu dentro da Região Equatorial, numa área intracontinental sob condições climáticas áridas e semi-áridas. / Crato Formation, located in the Araripe Basin, Northeastern Brazil, bears one of the most important Lower Cretaceous fóssil plant Record. The fossils have an excellent preservation, usually low fragmentated, with attached organs and epidermic and anatomic features delicatedly replaced by iron oxides. As it happens worldwide, gymnosperms were the dominant group in the Lower Cretaceous Crato Formation paleoflora, existing as Bennettitales, Coniferales e Gnetales. Bennettitales were an apparently scarce component, represented by the species Otozamites sp. and Zamites sp. Between the Coniferales, are the families Araucariaceae and Cheirolepidiaceae, the Araucariaceae recorded by the species Araucarites vulcanoi Duarte and Araucarites kunzmanni sp. nov.; Cheirolepidiaceae, the most diverse group, is registered by species Brachyphyllum obesum Heer, Brachyphyllum ponsi sp. nov., Brachyphyllum araripense sp. nov., Tomaxellia aff. T. biforme Archangelsky, Toxamellia aff. T. degiustoi e Pseudofrenelopsis sp. As Gnetales are documented by the species Limaephyton duartei gen. et sp. nov. and Limaephytophyllum mohrium gen. et sp. nov. Morphologic, epidermic and anatomic features founded in the plant fossils from Crato Formation, evidence low moisture environment adaptations. That flora was developed in the Equatorial Region, in an intracontinental area with arid to semi-arid climatic conditions.

Orientador: Alessandro Batezelli / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociências / Made available in DSpace on 2018-08-25T01:50:06Z (GMT). No. of bitstreams: 1 Pereira_CamilaTavares_M.pdf: 6719830 bytes, checksum: c010edfeb787dd0ffb56ed12b5a56676 (MD5) Previous issue date: 2014 / Resumo: A Formação Marília, que aflora no sudeste do Brasil, é uma sucessão sedimentar caracterizada por estratos sedimentares alternados com paleossolos. As feições pedogenéticas podem ser relacionadas com os fatores climáticos e são utilizadas como ferramenta na interpretação de paleoambientes. Através da descrição macro e microscópica, associada a análise mineralógica e fluorescência de raios-X, foram identificados e caracterizados 20 de perfis de paleossolos da Formação Marília, Maastrichtiano da Bacia Bauru. A intercalação de horizontes C, Ck, Bt, Btk e Gley, possibilitaram a elaboração de um modelo de evolução paleoambiental, onde os dados geoquímicas permitiram tecer considerações paleoclimáticas. As mudanças nos processos de formação destes paleossolos foram impulsionadas principalmente pelas variações de umidade disponível. As estimativas de paleoprecipitação (MAP) obtidas por meio do CIA-K em horizontes Bt e Btk, indicam que a pluviosidade variou de 20-1000 mm/ano. Estas condições climáticas contrastantes resultaram na sobreposição de perfis distintos, sugerindo oscilação entre condições áridas a semiáridas. Estes resultados contribuem para um melhor entendimento paleoambiental do Cretáceo Tardio para a porção sudeste brasileira / Abstract: The Marília Formation is the Maastrichtian sequence of the Bauru Basin and crops out in southeastern Brazil. It is a sedimentary succession characterized by alternating sedimentary strata and paleosols. The pedogenic features can be related to climatic factors and are used as a tool in the interpretation of paleoenvironments. By means of a macro- and microscopic description, associated with mineralogical and x-ray fluorescence analyses, twenty paleosol sections were identified and characterized in the Marília Formation. The characterization of C, Ck, Bt, Btk and Gley horizons and the corresponding geochemical data helped define a paleoenvironmental evolutionary model and make some paleoclimatic considerations. Changes in the processes of formation of these paleosols were mainly triggered by moisture variations. Paleoprecipitation estimates (MAP) obtained by means of CIA-K in Bt and Btk horizons indicate that precipitation varied 20-1000 mm/year. These contrasting climatic conditions caused overlapping of distinct profiles, suggesting oscillation between arid to semi-arid conditions. These results contribute to a better understanding of the Upper Cretaceous paleoenvironment in southeastern Brazil / Mestrado / Geologia e Recursos Naturais / Mestra em Geociências

No description available.

During the Early Cretaceous a regionally extensive cover of dominantly siliciclastic sediments was deposited across the North African continental margin. Historically, these siliciclastic sediments have been considered to be a relatively homogeneous lithofacies known as the ‘Nubian sandstone’. This lithofacies is generally described as coarse grained, cross-bedded sandstone and is ascribed to a braided fluvial depositional environment. However, there have been few detailed sedimentological studies carried out on these sediments. Furthermore, the stratigraphic relationships between regional Early Cretaceous continental strata in different North African countries has only briefly been described and has only locally been related to equivalent marine deposits. In order to address these problems, this study focuses upon two main approaches. Firstly, outcrop analysis of the Messak Fm (SW Libya) and the Sidi Aïch Fm (C Tunisia) details and contrasts the lithofacies variability of Early Cretaceous siliciclastic sediments in North Africa. Secondly, a unified stratigraphic framework is erected for the Early Cretaceous of Algeria, Tunisia, Libya and Egypt and the palaeogeographic evolution is reconstructed. Detailed sedimentological investigation of the Messak Fm has identified greater variation in lithofacies and depositional processes than was previously recognised. By lithostratigraphic correlation with outcrops in northwest Libya, we show a fluvial system transported sediment northward into a wide fluvio-paralic basin covering western Libya. Several episodes of marine influence culminating in a distinct and regionally correlatable transgressive episode are identified. This is the first time that marine influence has been identified in the Murzuq Basin and increases the maximum known extent of marine transgression in the Early Cretaceous of Libya by 600km. The sedimentology of the Messak Fm is contrasted with the sandstone dominated Sidi Aïch Fm which, although showing similar lithofacies, was deposited in a marginal-shallow marine environment.Building upon previous reviews and new insights from the Messak Fm and Sidi Aïch Fm, a synthesis and reinterpretation of the spatial and temporal heterogeneity of sediments and depositional environments in this region throughout the Early Cretaceous is presented. During the Berriasian-Barremian, the North African platform coastline was dominated by a dry subtropical climate with moderate vegetation. The interior of the platform experienced a Savannah-like semi-arid climate with limited vegetation and palaeosol development but was crossed by extensive fluvial networks draining the equatorial tropics. During the Late Barremian-Early Aptian, simultaneous aridification and marine transgression led to a decreased detrital flux to the marginal basins and widespread deposition of marine carbonates and mudstones. During the Late Aptian-Albian the platform returned to a humid tropical climate. Widespread coarse grained fluvial sediments mark the base of this sequence and palaeosols occur locally. The results of this work have implications for the development and controls of large-scale fluvio-paralic systems and illustrate the fact that, in a limited accommodation epicontinental setting, relative sea-level may be the key control on sedimentation and depositional processes for many hundreds of kilometres inland of the lowstand coastline.

Abstract Dissimilatory microbial sulfate reduction (MSR) The specific objectives of the study were to provide the first measurements of sulfur isotope fractionation associated with acidophilic sulfate reducing-microorganisms, and to examine whether pH influences sulfur fractionation during MSR. The fractionation associated with the strains investigated was comparable to that of neutrophilic strains with similar metabolisms (4-12‰), but varied with pH. Two fractionation regimes were identified: one regime is consistent with fractionation during exponential growth, while the other – not identified previously - is not linked to active sulfate reduction and may result from internal sulfate accumulation. This would represent the first measurement of sulfur fractionation during sulfate uptake, the first step of MSR. Geological processes at the Cretaceous-Paleogene (KPg) boundary The KPg boundary is associated with one of the largest biological extinctions in the history of our planet. Two major geologic events - the Chicxulub bolide impact with evaporite terrane and the eruption of the Deccan continental flood basalts - coincide with the KPg boundary and have been identified as possible triggers for the extinctions, but their relative timing remains unresolved. The objectives of this study were to identify the contribution of these processes to the sulfur burden in the sedimentary environment of two freshwater KPg sections, and to determine their relative timing. The results demonstrate that the peak of Deccan volcanism post-dates the Chicxulub impact and the associated abrupt KPg mass extinction, thus precluding a direct volcanic causal mechanism, but shedding light on the underlying causes for the delayed recovery of ecosystems in the early Paleogene.