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| Titel |
Deep structure of the Santos Basin-São Paulo Plateau System, SE Brazil |
| VerfasserIn |
Mikael Evain, Alexandra Afilhado, Caesar Rigoti, Afonso Loureiro, Daniela Alves, Frauke Klingelhoefer, Philippe Schnurle, Aurelie Feld, Reinhardt Fuck, José Soares, Marcus Vinicius de Lima, Carlos Corela, Luis Matias, Massinissa Benabdellouahed, Agnès Baltzer, Marina Rabineau, Adriano Viana, Maryline Moulin, Daniel Aslanian |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250110295
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| Publikation (Nr.) |
 EGU/EGU2015-10276.pdf |
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| Zusammenfassung |
| The structure and nature of the crust underlying the Santos Basin-São Paulo Plateau System (SSPS), in the SE Brazilian margin, is discussed based on five wide-angle seismic profiles acquired during the SanBa experiment in 2011. Velocity models allow us to precisely divide the SSPS in six domains from unthinned continental crust (Domain CC) to normal oceanic crust (Domain OC). A seventh domain (Domain D), a triangular shape region in the SE of the SSPS, is discussed by [Klingelhoefer et al., GJI, 2014]. Beneath the continental shelf, a ~100 km wide necking zone (Domain N) is imaged where continental crust thins abruptly from ~40 km to less than 15 km. Toward the ocean, most of the SSPS (Domain A and C) shows velocity ranges, velocity gradients and a Moho interface characteristic of thinned continental crust. The central domain (Domain B) has, however, a very heterogeneous structure. While its southwestern part still exhibits extremely thinned (7 km) continental crust, its northeastern part depicts a 2-4 km thick upper layer (6.0-6.5 km/s) overlying an anomalous velocity layer (7.0-7.8 km/s) and no evidence of a Moho interface. This structure is interpreted as atypical oceanic crust, exhumed lower crust or upper continental crust intruded by mafic material, overlying either altered mantle in the first two cases or intruded lower continental crust in the last case. The v-shaped structuration in this central domain confirms an initial episode of rifting within the SSPS oblique to the general opening direction of the South Atlantic central segment. |
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