Thrust–wrench interference tectonics in the Gulf of Cadiz (Africa–Iberia plate boundary in the North-East Atlantic): Insights from analog models

In the Gulf of Cadiz key segment of the Africa-Iberia plate boundary (North-East Atlantic ocean), three main different modes of tectonic interference between a recently identified wrench system (SWIM) and the Gulf of Cadiz Accretionary Wedge (GCAW) were tested through analog sand-box modeling: a) An...

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Bibliographic Details
Published in:Marine Geology
Main Authors: Duarte, João C., Rosas, Filipe M., Terrinha, Pedro, Gutscher, Marc-André, Malavieille, Jacques, Silva, Sónia, Matias, Luis
Format: Article in Journal/Newspaper
Language:English
Published: Elsevier 2011
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Online Access:https://oceanrep.geomar.de/id/eprint/27143/
https://oceanrep.geomar.de/id/eprint/27143/1/1-s2.0-S0025322711002027-main.pdf
https://doi.org/10.1016/j.margeo.2011.09.014
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Summary:In the Gulf of Cadiz key segment of the Africa-Iberia plate boundary (North-East Atlantic ocean), three main different modes of tectonic interference between a recently identified wrench system (SWIM) and the Gulf of Cadiz Accretionary Wedge (GCAW) were tested through analog sand-box modeling: a) An active accretionary wedge on top of a pre-existent inactive basement fault; b) An active strike-slip fault cutting a previously formed, inactive, accretionary wedge; and c) Simultaneous activity of both the accretionary wedge and the strike-slip fault. The results we obtained and the comparison with the natural deformation pattern favor a tectonic evolution comprising two main steps: i) the formation of the Gulf of Cadiz Accretionary Wedge on top of inactive, Tethyan-related, basement faults (Middle Miocene to similar to 1.8 Ma); ii) subsequent reactivation of these basement faults with dextral strike-slip motion (similar to 1.8 Ma to present) simultaneously with continued tectonic accretion in the GCAW. These results exclude the possibility of ongoing active SWIM wrench system cross-cutting an inactive GCAW structure. Our results also support a new interpretation of the SWIM wrench system as fundamentally resulting from strike-slip reactivation of an old (Tethyan-related) plate boundary