Aspectos sedimentológicos do talude continental setentrional do Rio Grande do Norte, NE do Brasil

Sedimentological aspects of northern continental slope of Rio Grande do Norte, NE of Brazil. The continental slopes of north and northeast regions of Brazil lack data and knowledge and they represent an ecosystem of economic and environmental importance. The aim of this study is to assess the sedime...

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Detalhes bibliográficos
Autores: Almeida, Narelle Maia de, Vital, Helenice, Eichler, Patricia Pinheiro Beck
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2017
País:Brasil
Recursos:Universidade Federal do Ceará (UFC)
Repositorio:Repositório Institucional da Universidade Federal do Ceará (UFC)
Idioma:portugués
OAI Identifier:oai:repositorio.ufc.br:riufc/64127
Acesso em linha:http://www.repositorio.ufc.br/handle/riufc/64127
Access Level:acceso abierto
Palavra-chave:Granulometria
Siliciclásticos
Bioclásticos
Ambientes profundos
Grain size
Siliciclastic
Bioclastic
Deep environments
Descrição
Resumo:Sedimentological aspects of northern continental slope of Rio Grande do Norte, NE of Brazil. The continental slopes of north and northeast regions of Brazil lack data and knowledge and they represent an ecosystem of economic and environmental importance. The aim of this study is to assess the sedimentology of the continental slope of Potiguar Basin, NE Brazil. The samples were collected with box-corer and were analyzed for grain size, calcium carbonate content and organic matter content. Scanning electron microscopy and X-ray diffraction analysis were also conducted to know the sedimentary constituents of the samples. The sedimentary cover presents a grain size decreases as the depth increases, and it is represented by four sedimentary facies: silty, sandy silt, silty sand and sand with gravel. Calcium carbonate contents is moderated to high (37-93.2 %) and the content of organic matter is low (4.6-14.5 %). It is a mixed continental slope because the sediments are composed by siliciclastics and bioclasts. Quartz and Clay minerals are the main siliciclastics. Accessory minerals are Ilmenite, Zircon, Titanite, Muscovite, Biotite, Glauconite, Staurolite, Cordierite, Siderite, Rutile, Magnetite, Tourmaline, Pyrite, Monazite and Barite. Bioclasts are represented by bryozoans, sponges, foraminifera, annelid (Polychaeta tubes), nematodes, mollusks and diatoms. The presence of stable minerals (Zircon, Tourmaline and Rutile) indicates the contributions of Açu and Apodi rivers through their incised valleys and submarine canyons in the sedimentation of study area.