Bioclastic Carbonate Lacustrine Facies Models in the Campos Basin (Lower Cretaceous), Brazil

• Autores: Maria Dolores de Carvalho, Uyara Mundim Praça, Augusto Carlos da Silva Telles, Ricardo Jorge Jahnert, Jeferson Luiz Dias
• Localización: Lake basins through space and time / coord. por Elizabeth H. Gierlowski-Kordesch, K. Kelts, 2000, ISBN 0891810528, págs. 245-255
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • The Campos Basin is one of the sedimentary basins on the Brazilian continental margin, located offshore of the State of Rio de [anciroIfiigure 1). The basin has an area of 100,000 km-, with its eastern limit in the oceanat 3000 m water depth with only 500 km2 onshore. Its structural limits are the Vitoria structural high to the north, Cabo Frio structural high to the south, and Campos fault (hinge line) to the west (bounding only on Cretaceous rocks). To the east, the basin theoretically extends to great salt diapirs (of Permian age) presently located between 3500 and 4000 m of water depth.

    The Campos Basin originated in the Lower Cretaceousbreak-up of Gondwana, as part of a rift valley system(Guardado et al., 1988). Stratigraphy of the basin is subdivided, from bottom to top, into the following formations:Cabiunas, Lagoa Feia, Macae, Campos and Embore. This lithostratigraphic sequence reflects its tectonicevolution and is more than 4 km thick. The LagoaFeia Formation lies unconformably over the volcanicrocks of the Cabiunas Formation (Figure 2), dated by KArmethods as between 125 and 130 m.y. The Lagoa Feia. Formation is the oldest sedimentary sequence of the basin and was deposited as a rift-related alluvial-lacustrinecomplex. At the upper part of the formation, there are thick molluscan shell deposits, known as the Coquinas sequence, which are important oil reservoirs int he Campos Basin, and are the object of the present study.