Estratigrafia sísmica do Cenozóico na plataforma continental algarvia: interpre...

• Author(s): Lopes, Fernando C. ; Cunha, P. Proença
• Date: 2000
• Persistent ID: http://hdl.handle.net/10316/15200
• Origin: Estudo Geral - Universidade de Coimbra
• Subject(s): Algarve; Plataforma continental; Cenozóico; Estratigrafia sísmica; Tectónica; Análise de bacias
• Document Type: Article
• Language: Portuguese

Description

The interpretation of 64 seismic reflection profiles in the Algarve continental platform (36º 20'-37º 00' paralels and 7º 20'-8º 40' meridians) calibrated with five petroleum exploration wells, with the identification of the geometric relations between six Cenozoic seismic units (B to G) and tectonic structures, allowed the construction of sucessive time-isopach maps (twt/s) and detailed interpretation of the geologic evolution. Two major tectonic structures were identified: a) the Portimão-Monchique fracture zone (striking N-S); b) an off-shore NW-SE fault zone, probably the S. Marcos-Quarteira fault. This accident separates two tectonic domains: the western domain (with N-S and E-W predominant structures and, secondarily, NW-SE and NE-SW) and the eastern domain (dominated by WSW-ENE, NW-SE, NE-SW, NNE-SSW and NNW-SSE structures). A persistent halokinetic activity had two major moments: a) sin-C unit; b) sin- and post-E unit. An increasing flexuration of the margin was identified, with spacial and temporal variation of the subsidence. The tectonic regime is considered as generally compressive, but the interpretation of the successíve stress-fields is rendered dificult by the existence of tectonic sub-domains and evaporitic structures.