Lithospheric structuration onshore-offshore of the Sergipe-Alagoas passive margin, NE Brazil, based on wide-angle seismic data. (December 2018)

• Record Type: Journal Article
• Authors: Morvan, L.; Mazé, J.P.; Pierre, D.; Roudaut-Pitel, M.; Rio, I.; Alves, D.; Barros Junior, P.; Biari, Y.; Corela, C.; Crozon, J.; Duarte, J.L.; Ducatel, C.; Falcão, C.; Fernagu, P.; Le Piver, D.; Mokeddem, Z.; Pelleau, P.; Rigoti, C.; Roest, W.; Roudaut, M.; Pinheiro, J.M.; Schnurle, P.; Evain, M.; Afilhado, A.; Gallais, F.; Klingelhoefer, F.; Loureiro, A.; Fuck, R.; Soares, J.; Cupertino, J.A.; Viana, A.; Rabineau, M.; Baltzer, A.; Benabdellouahed, M.; Dias, N.; Moulin, M.; Aslanian, D.;
• Is Part Of: Journal of South American earth sciences. Volume 88(2018)
• Page Start: 649
• Page End: 672
• Publication Date: 2018-12
• Subjects: South Atlantic ocean -- NE Brazil -- Sergipe-Alagoas basin -- Passive margins -- Wide-angle refraction seismics -- Crustal structure -- Tectonic inheritance; Geology -- Latin America -- Periodicals; Earth sciences -- Latin America -- Periodicals; Geology -- Antarctica -- Periodicals; Earth sciences -- Antarctica -- Periodicals; Geology -- Caribbean Area -- Periodicals; Earth sciences -- Caribbean Area -- Periodicals; Géologie -- Amérique latine -- Périodiques; Sciences de la terre -- Amérique latine -- Périodiques; Géologie -- Antarctique -- Périodiques; Sciences de la terre -- Antarctique -- Périodiques; Géologie -- Caraïbes (Région) -- Périodiques; Sciences de la terre -- Caraïbes (Région) -- Périodiques; Earth sciences; Geology; Antarctica; Caribbean Area; Latin America; Periodicals; 550.5
• DOI: 10.1016/j.jsames.2018.09.015
• Languages: English
• ISSNs: 0895-9811

Abstract

Abstract: The structure and nature of the crust underlying the Camamu-Almada-Jequitinhonha-Sergipe-Alagoas basins System, in the NE Brazilian margin, were investigated based on the interpretation of 12 wide-angle seismic profiles acquired during the SALSA (Sergipe ALagoas Seismic Acquisition) experiment in 2014. In this work, we present two 220-km-long NW-SE combined wide-angle and reflection seismic profiles, SL 01 and SL 02, that have been acquired using 15 ocean-bottom-seismometers along each profile, offshore the southern part of the Sergipe Alagoas Basin (SAB), north of the Vaza-Barris Transfer zone. The SL 02 has a 150-km long inland continuation with 20 land-seismic-stations until the Sergipano Fold Belt (SFB). Wide-angle seismic forward modeling allows us to precisely divide the crust in three domains: beneath the continental shelf, a ∼100 km wide necking zone is imaged where the continental crust thins from ∼35 km on the Unthinned Continental Domain, which displays a three-layered crust structure, to less than 8 km on the Oceanic Crust Domain. In the necking zone, the upper and the middle layers thin dramatically and almost disappear, while the Moho discontinuity shows clear PmPs. The Continental-Oceanic Crust Boundary (COB) is located at ∼80 km from the coastline and is marked by intracrustal seismic reflectors and changes in the seismic velocity, showing a sharp transition. On profile SL02, the oceanic crust is perturbed by a volcanic edifice together with an anomalous velocity zone underneath the area. Highlights: Sergipe Alagoas Basin passive margin modeling. Wide-angle refraction seismic integrated with Multi-Channel reflection seismic data. Location of the Continental- Oceanic crust boundary. Lithospheric structuration and segmentation of Brazil's margin in Central Atlantic.