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| PEREIRA,NATAN S.; MANSO,VALDIR A.V.; MACEDO,RENÊ J.A.; DIAS,JOÃO M.A.; SILVA,ADRIANA M.C.. |
| Located 266 km offshore Brazilian coast, Rocas Reef complex is the only atoll in the South Atlantic. Two scientific expeditions carried out detailed sedimentological studies of the complex. Sand texture was dominant in the sedimentary environment, although other textures such as gravel, sandy gravel and gravelly sand, were also observed. Mean size ranged from fine sand to coarse sand (-1.23 to 2.34ø), with an average value of 0.69ø (sand fraction), which from a geological perspective represents a high-energy environment. The values of mean size varied in the different geomorphologic compartments, a response to variable hydrodynamics on the reef. Sorting ranged from very well sorted to poorly sorted, with a mean value of 0.97ø (moderately sorted). The... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Biogenic particles; Carbonate sediments; Atoll reef; Sedimentological parameters. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652013000100057 |
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| Jorry, Stephan; Camoin, Gilbert F.; Jouet, Gwenael; Le Roy, Pascal; Vella, Claude; Courgeon, Simon; Prat, Sophie; Fontanier, Christophe; Paumard, Victorien; Boulle, Julien; Caline, Bruno; Borgomano, Jean. |
| Isolated carbonate platforms occur throughout the geologic record, from Archean to present. Although the respective roles of tectonics, sediment supply and sea-level changes in the stratigraphical architecture of these systems are relatively well constrained, the details of the nature and controls on the variability of sedimentological patterns between and within individual geomorphologic units on platforms have been barely investigated. This study aims at describing and comparing geomorphological and sedimentological features of surficial sediments and fossil reefs from three isolated carbonate platforms located in the SW Indian Ocean (Glorieuses, Juan de Nova and Europa). These carbonate platforms are relatively small and lack continuous reef margins,... |
| Tipo: Text |
Palavras-chave: Mozambique channel; Carbonate sediments; Fossil reefs; Isolated carbonate platforms. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00292/40329/39074.pdf |
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| Paramo, Jorge; Espinosa, Luisa; Posada, Blanca; Núñez, Samuel; Benavides, Seydi. |
| Se describe la distribución espacial de los sedimentos en la plataforma continental, su granulometría (phi) y composición (contenido de carbonato de calcio, CaCO3) y se tiene en cuenta la localización (profundidad, latitud y longitud) para explicar su origen y distribución y establecer su relación con las áreas más productivas en la región norte del Caribe colombiano. Las muestras de sedimentos se colectaron durante dos cruceros llevados a cabo en diciembre de 2005 y febrero de 2006. Se determinó la granulometría con el método de separación por tamices, se calcularon los valores de tamaño medio de los granos de sedimento (PHI=F). Además se determinó el contenido de carbonato de calcio (CaCO3). Se realizó un análisis de clasificación para caracterizar los... |
| Tipo: Journal Contribution |
Palavras-chave: Sediment composition; Granulometry; Carbonate sediments. |
| Ano: 2011 |
URL: http://hdl.handle.net/1834/4421 |
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