1,721,015 research outputs found
CARABAS : a database for carbonates body geometries
No full textRebelle Michel, Friedenberg R., Boichard R., Leroy E., Szambelanczyk J., Van buchem Frans S. P. CARABAS : a database for carbonates body geometries. In: Géologie Méditerranéenne. Tome 28, numéro 1-2, 2001. Anatomy of Carbonate Bodies / Anatomie des corps carbonates. International Meeting / Colloque international. Marseille, 9-12 mai 2001, France, sous la direction de Marc Floquet, Jérôme Hennuy et Jean-Pierre Masse. pp. 149-154
Évolution paléo-environnementale et écologique au Barrémien-Aptien du sous-bassin de Galve (Espagne)
No full textEmbry Jean-Christophe, Vennin Emmanuelle, Van buchem Frans S. P., Pierre Catherine, Schroeder Rolf, Aurell Marcos. Évolution paléo-environnementale et écologique au Barrémien-Aptien du sous-bassin de Galve (Espagne). In: Documents des Laboratoires de Géologie, Lyon, n°156, 2002. STRATI 2002. 3ème congrès français de stratigraphie. Lyon, 8-10 juillet 2002. pp. 104-105
Correlation of messinian carbonate platforms
No full textEsteban M., Clauzon Georges, Cornée Jean-Jacques, Cunningham K., Ferrandini Jean, Franseen E., Görür Naci, Guieu Gérard, Grasso M., Hôffling R., Meyers N., Muller J., Pedley Martyn, Plaziat J.-Cl., Suballyuva A., Suc Jean-Pierre, Valleri G., Van buchem Frans S. P. Correlation of messinian carbonate platforms. In: Géologie Méditerranéenne. Tome 21, numéro 1-2, 1994. Récifs et plates-formes carbonatées miocènes de Méditerranée / Miocene reefs and carbonate platforms of the Mediterranean. Interim colloquium R.C.M.N.S. (Marseille 3-6 mai 1994) sous la direction de Jean-Paul Saint-Martin et Jean-Jacques Cornée. pp. 159-163
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Chronostratigraphy and depositional environments of the Neogene sedimentary section in the Red Sea basin
No full textThe stratigraphy of sedimentary rocks within the Red Sea basin is the key to understanding its geological evolution over the past 30 million years. This dissertation addresses three poorly known aspects of the Red Sea basin stratigraphy: (1) the age of evaporitic units, (2) the age and origin of the shallow seismic S-reflector, and (3) the type and origin of carbonate platforms along its margins.
Due to a lack of fossils, the ages of the main salt layer (Mansiyah Formation) and layered evaporites (Ghawwas Formation) were previously uncertain, ranging between 14 and 5 Ma. This study determined their ages using Sr isotope stratigraphy. Results show that the Mansiyah thick salt layer precipitated rapidly between 14 and 13.2 Ma, while the overlying layered Ghawwas anhydrites between 13.2 and 6 Ma. Furthermore, the timing of salt deposition aligns with the onset of ultra-slow seafloor spreading, suggesting that salt saturation may have been triggered by the hydration of the newly exhumed mantle alongside evaporitic conditions.
Reflection seismic data, calibrated by deepwater well core data, were interpreted based on modern salt tectonics knowledge. The S-reflector is identified as a widespread angular unconformity that flattened salt diapirs and truncated tilted layers throughout the basin. Sr isotopes from a deepwater well core date the unconformity at 6 Ma. The unconformity is attributed to subaerial erosion resulting from the desiccation of the Red Sea basin during the Messinian salinity crisis. This desiccation ended with seawater breakthrough from the Gulf of Aden, forming a deep canyon through the Bab el Mandab strait.
This study covers litho- and biofacies examinations of the Miocene carbonate outcrops along the eastern margin of the Red Sea. Three types of carbonate platforms associated with major rift faults were identified: (1) low-relief ramps during the Aquitanian, (2) delta-top platforms, and (3) fringing reef during the Burdigalian. Well and seismic data reveal that after the Messinian desiccation, thick aggradational reef platforms developed along the eastern margin and were rafted seaward by gliding over the salt layer
Mechanical Characterization of the Hith and Arab Anhydrites in Saudi Arabia
No full textThe Upper Jurassic Hith and Arab formations are primarily composed of evaporites and carbonates. They represent both an important reservoir as well as regional seal for major hydrocarbon accumulations over large parts of the Arabian Peninsula, including Ghawar field, the world's largest oil field.
Recently, the Hith formation has gained attention as a potential seal for CO2 sequestration. Understanding its sealing capacity requires – amongst various other tasks – evaluating its rock mechanical and petrophysical properties, as well as its chemical reactivity under in situ temperature and pressure conditions.
In Eastern Saudi Arabia, at the Ghawar field, the Upper Jurassic section lies buried beneath approximately 2 km of overburden. Near Riyadh, however, Jurassic rocks are closer to the surface and even crop out at an escarpment just south of the city. An 84 mm diameter hole was drilled in this area, continuously coring 200 m through the Jurassic formations, with a recovery rate of 99%.
Current experimental work on this core involves regularly spaced core plugging for porosity and permeability measurements and a comprehensive analysis using Epslog’s Wombat™ device. The Wombat™ performs scratch testing, VP, VS, and XRF measurements, and high-resolution camera image analysis. Wireline data, including gamma-ray, sonic, density, and neutron logs, were also acquired. This unique dataset allows for the evaluation of mechanical variability and stratigraphy as a function of facies as well as lithological and compositional variations.
The aim of this research is to conduct a rock mechanical characterization of the Hith and Arab formations and infer their impact on sealing potential for CO2 storage. These results will be compared to published data from a comprehensive literature review on anhydrites and evaporites. This study is part of a larger initiative to investigate the relevance, impact, and risks of these processes for carbon capture and storage (CCS) developments in Saudi Arabia and beyond.
Results revealed that the Hith and Arab B and C anhydrites are strong formations with average UCS values of 94 MPa, 96 MPa, and 100 MPa. In contrast, the Arab A and B carbonates have lower UCS values of approximately 66 MPa and 76 MPa. A common trend observed is an increase in UCS values with depth across all formations. The higher strength of anhydrites is evident in the facies classification, with UCS values ranging from 91 MPa to 115 MPa for anhydrite facies, and 76 MPa and 66 MPa for gypsum and carbonates/shales. These experimental results highlight that rock strength is significantly influenced by its composition
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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