Revista Brasileira de Geofísica
versión impresa ISSN 0102-261X
BAPTISTA NETO, José Antônio; SILVA, Cleverson Guizan; DIAS, Gilberto Tavares de Macedo y FONSECA, Estefan Monteiro da. Distribuição sedimentar da Lagoa Rodrigo de Freitas através de sísmica de alta resolução. Rev. Bras. Geof. [online]. 2011, vol.29, n.1, pp.187-195. ISSN 0102-261X. http://dx.doi.org/10.1590/S0102-261X2011000100013.
The Rodrigo de Freitas Lagoon (Rio de Janeiro State) sediments and bottom characteristics were analyzed using high-resolution (10 kHz) sub-bottom profiles associated with particle size analyses of 44 bottom sediment samples. Four types of echo-characters were identified revealing the strong relation with the particle size distribution and bottom morphology. In areas of acoustic penetration, the basement delineates buried sugar-loaf hills and infilled-valley features. The total sediment thickness can reach as much as 16 meters along the paleovalleys, which are aligned in a NE-SW direction, parallel to the regional basement orientation observed on the coastal massifs. There is a predominance of organic rich muddy sediments, infilling the paleovalleys which are the main sites of shallow gas occurrences within the lagoonal sediments.
Palabras clave : shallow seismic; Rodrigo de Freitas Lagoon; sedimentary processes.