Oceanografia Ambiental

URI Permanente desta comunidade

http://repositorio.ufes.br/handle/10/17530
Programa de Pós-Graduação em Oceanografia Ambiental

Centro: CCHN
Telefone: (27) 3250 1735
URL do programa: https://oceanografia.ufes.br/pt-br/pos-graduacao/PPGOA

Navegar

Navegando Oceanografia Ambiental por Assunto "Abrolhos shelf"

Agora exibindo 1 - 2 de 2
  • Nenhuma Miniatura disponível
    Item
    Faciologia inter-recifal e geomorfologia dos recifes submersos da plataforma interna de Abrolhos, Bahia-Brasil
    (Universidade Federal do Espírito Santo, 2015-09-14) Leite, Marcos Daniel de Almeida; Bastos, Alex Cardoso; Baptista Neto, José Antônio; Quaresma, Valéria da Silva
    The presente study deals with geomorphic and sedimentology heterogeneity along the inner shelf of Abrolhos Shelf, Brazil. A combined analysis of side scan sonar, granulometric measurements and sub-bottom profiling characterized the facies heterogeneity of the study area. The results indicated a terrigenous to mixed supply at the Inner Arc and Abrolhos Channel. Outer Arc is represented by pure carbonate sediments. The seabed morphology were represented by different areas such as pinnacles, bank reefs, rhodoliths, pinnacles associated with rhodoliths, mesofhotic reefs and unconsolidated sediment (without reef structures). Pinnacles showed the highest heterogeneity facies in the study area, represented by all carbonate classes of sediment classification based on Larsonneur, while the Dunham classification were represented by wackstone, packstone and grainstone. Banks reefs for the most part is characterized by an muddy inter-reef facies (calcareous mud – Larsonneur/ wackstone and packstone – Dunham). Mesofhotic reefs are represented by a muddy and sandy inter-reef sedimentology while rhodoliths by gravelly deposits. The unconsolidated sediment were represented by two sedimentation patterns, muddy sediments in the Inner Arc and carbonate sandy (grainstone) at the Abrolhos Channel. Lastly, a facies distribution model is presented to the inner shelf of Abrolhos. Mixed sediments make up the Inner Arc, while Abrolhos Channel presents an extensive range of wackstones and packstones regions at the windward side of Inner Arc, those associated with reef structures (boundstone). Grainstones are near the leeward side of the Outer Arc. The Outer Arc samples are represented by a transition of boundstones (rhodoliths), grainstones (pinnacles) and wackstone/packstone (pinnacles, bank reefs and mesofotic reefs).
  • Nenhuma Miniatura disponível
    Item
    Modelo evolutivo da plataforma de Abrolhos: do paleógeno ao neógeno
    (Universidade Federal do Espírito Santo, 2020-08-31) Duarte, Romero Meyrelles; Quaresma, Valeria da Silva; https://orcid.org/0000-0002-7470-6642; http://lattes.cnpq.br/9423011006200936; https://orcid.org/0000-0002-5841-5167; http://lattes.cnpq.br/8723773038981510; Silva, Cleverson Guizan; https://orcid.org/; http://lattes.cnpq.br/2192755725741120; Rangel, Caio Vinicius Gabrig Turbay; https://orcid.org/0000-0003-0398-3391; http://lattes.cnpq.br/5332804895294756
    As part of the brazilian East Margin Continental Shelf, with distinct morphology from the continental shelf, the Abrolhos Shelf presents great ecological relevance, being the largest rhodoliths bank in the world and presenting the greatest south Atlantic biodiversity. However, the geological history of this shelf is still poorly known. It is known about an important Paleocene-Eocene magmatic event wich installed the Abrolhos Volcanic Complex, whose volcanic features can be seen with geophysical methods. Many volcanic seismic facies are could be indentified at the shelf, like seward dipping reflectors (SDR), lava deltas, lava flows, hyaloclastitic mounds, dikes and sills. In this scenario, from data generated by the oil industry, this research revisited concepts and data to propose an evolutionary model for the mixed sedimentation Abrolhos shelf, wich has started in the late-Eocene and crossed the Late Paleogene and all the Neogene periods as a barrier reef shelf in the northern portion, with an wide lagoon, and as an accretionary offlap shelf at the southern portion, where the siliciclastic influx would reach the slope at the lowstand tracts. After the seismic interpretations was proposed a four stage evolutive model for the mixed sedimentation shelf, starting ate the constitution os the Abrolhos Volcanic Complex, until the Pliocene, demonstrating the installation and evolution of the mixed sedimentation shelf