Lithospheric structuration onshore-offshore of the Sergipe-Alagoas passive margin, NE Brazil, based on wide-angle seismic data
Type | Article | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Date | 2018-12 | ||||||||||||
Language | English | ||||||||||||
Author(s) | Pinheiro Joao Marcelo1, Schnurle Philippe![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
||||||||||||
Affiliation(s) | 1 : IFREMER, REM GM, Ctr Brest, F-29280 Plouzane, France. 2 : Inst Politecn Lisboa, ISEL, R Conselheiro Emidio Navarro, P-1959007 Lisbon, Portugal. 3 : Univ Lisbon, Fac Ciencias, Inst Dom Luiz, Ed C1,Piso 1, P-1749016 Lisbon, Portugal. 4 : Univ Brasilia, Inst Geociencias, Campus Darcy Ribeiro, BR-70910900 Brasilia, DF, Brazil. 5 : Petrobras SA, Cenpes Res Ctr, Rio De Janeiro, Brazil. 6 : Univ Bretagne Occidentale, Lab Geosci Ocean, UMR6538, Pl Nicolas Copernic, F-29280 Plouzane, France. 7 : Univ Nantes, Geolittomer, LETG UMR 6554, CNRS,Inst Geog & Amenagement Reg, Campus Tertre,BP 81227, F-44312 Nantes 3, France. |
||||||||||||
Source | Journal Of South American Earth Sciences (0895-9811) (Pergamon-elsevier Science Ltd), 2018-12 , Vol. 88 , P. 649-672 | ||||||||||||
DOI | 10.1016/j.jsames.2018.09.015 | ||||||||||||
WOS© Times Cited | 3 | ||||||||||||
Keyword(s) | South Atlantic ocean, NE Brazil, Sergipe-Alagoas basin, Passive margins, Wide-angle refraction seismics, Crustal structure, Tectonic inheritance | ||||||||||||
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. |
||||||||||||
Full Text |
|