103 research outputs found
Palynofacies classification of the depositional elements of confined turbidite systems : Examples from the Gres d'Annot, SE France
Acknowledgements We thank BG Brasil for financial support for this project and permission to publish. BG Group is a wholly owned subsidiary of Royal Dutch Shell. McArthur is grateful to the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) for the scholarship 049/2012. The Agência Nacional do Petróleo (ANP) are thanked for supporting this project. Massimo Zecchin is thanked for handling this paper and Roberto Tinterri is thanked for his constructive review, in addition to an anonymous reviewer.Peer reviewedPostprin
Tectonic and stratigraphic evolution based on seismic sequence stratigraphy: Central rift section of the campos basin, offshore brazil
The rift section of the Brazilian basins represent the sedimentary record associated with the first stages of Gondwana break‐up in the Early Cretaceous phase (Berriasian to Aptian). The rift succession of the Campos Basin constitutes one of the main petroleum systems of Brazil’s marginal basins. This interval contains the main source rock and important reservoirs in the Lagoa Feia Group deposits. The Lagoa Feia Group is characterized by siliciclastic, carbonate and evaporite sediments deposited during the rift and post‐rift phases. Despite the economic relevance, little is known in stratigraphic terms regarding this rift interval. To date, most studies of the Lagoa Feia Group have adopted a lithostratigraphic approach, while this study proposes a tectonostrati-graphic framework for the deep‐rift succession of the Campos Basin (Lagoa Feia Group), using the fundamentals of seismic sequence stratigraphy. This work also aims to establish a methodological and practical procedure for the stratigraphic analysis of rift basins, using seismic data and seismofacies, and focusing on tectonicstratigraphic analysis. The dataset comprised 2D seismic lines, core and lithological logs from exploration wells. Three seismic facies were identified based on reflector patterns and lithologic data from well cores, providing an improved subdivision of the pre‐, syn‐ and post‐rift stages. The syn‐rift stage was further subdivided based on the geometric patterns of the reflectors. Tectonics was the main controlling factor in the sedimentary succession, and the pattern and geometry of the seismic reflectors of the syn‐rift interval in the Campos Basin allowed the identification of three tectonic systems tracts: (i) a Rift Initiation Systems Tract; (ii) a High Tectonic Activity Systems Tract and (iii) a Low Tectonic Activity Systems Tract
Arquitetura estratigráfica dos depósitos fluviais albianos da base da Formação São Mateus no norte da Bacia do Espírito Santo
The alluvial deposits from the São Mateus Formation (Albian of the Espírito Santo Basin) consist of important reservoirs. However, there are few studies detailing the stratigraphy of this stratigraphic range. Consequently, this paper presents a study at the high-resolution stratigraphic subdivision of the basal section consists predominantly of alluvial deposits. Against the difficulties presented for the stratigraphic correlation of these deposits, the strategy of correlation was the subdivide of the succession alluvial in stratigraphic cycles. This method is based on the variation in the ratio between the rates of creation of accommodation and supply sediment (A: S) that directly controls the degree of amalgamation of sandstone bodies of the fluvial channels. Therefore, six cycles were defined composed internally for systems tracts of high and low accommodation. These cycles reflect the structuring of the amalgamation disposition of the fluvial channels with the deposits external to the channels through the ratio between the accommodation rate (A) and the sedimentary influx rate (S) forming cycles.Os depósitos aluviais da Formação São Mateus (Albiano da Bacia do Espírito Santo, Brasil) consistem em importantes reservatórios. Entretanto, existem poucos trabalhos detalhando a estratigrafia deste intervalo estratigráfico. Em decorrência disso, este trabalho teve por objetivo estabelecer um fatiamento estratigráfico de alta resolução da seção basal desta unidade, a qual é constituída por depósitos fluviais. Diante das dificuldades apresentadas para a correlação estratigráfica desses depósitos, a estratégia de correlação utilizada foi a subdivisão da sucessão aluvial em ciclos estratigráficos. Este método se baseia na variação na razão entre as taxas de criação de acomodação e suprimento sedimentar (A:S) que diretamente controla o grau de amalgamação dos corpos arenosos de canais fluviais. Com isso, foram definidos seis ciclos compostos internamente por tratos de sistemas de alta e baixa acomodação. Esses ciclos refletem a estruturação do arranjo da amalgamação dos canais fluviais com os depósitos externos aos canais através da razão entre a taxa de acomodação (A) e a taxa de influxo sedimentar (S) formando ciclos
Does fixed-angle plate osteosynthesis solve the problems of a fractured proximal humerus?: A prospective series of 87 patients
Background and purpose There is considerable controversy about the treatment of complex, displaced proximal humeral fractures. Various types of head-preserving osteosynthesis have been suggested. This prospective case series was designed to evaluate the perioperative and early postoperative complications associated with fixed-angle implants and to record outcome after bone healing
Roles of Acetone and Diacetone Alcohol in Coordination and Dissociation Reactions of Uranyl Complexes
Strongly coupled binuclear uranium-oxo complexes from uranyl oxo rearrangement and reductive silylation
The most common motif in uranium chemistry is the d0f0 uranyl ion [UO2]21 in which the oxo groups are rigorously linear and inert. Alternative geometries, such as the cis-uranyl, have been identified theoretically and implicated in oxo-atom transfer reactions that are relevant to environmental speciation and nuclear waste remediation. Single electron reduction is now known to impart greater oxo-group reactivity, but with retention of the linear OUO motif, and reactions of the oxo groups to form new covalent bonds remain rare. Here, we describe the synthesis, structure, reactivity and magnetic properties of a binuclear uranium–oxo complex. Formed through a combination of reduction and oxo-silylation and migration from a trans to a cis position, the new butterfly-shaped Si–OUO2UO–Si molecule shows remarkably strong UV–UV coupling and chemical inertness, suggesting that this rearranged uranium oxo motif might exist for other actinide species in the environment, and have relevance to the aggregation of actinide oxide clusters.JRC.E.6-Actinides researc
- …