TY - JOUR
T1 - Thrust-wrench interference tectonics in the Gulf of Cadiz (Africa-Iberia plate boundary in the North-East Atlantic): Insights from analog models
AU - Duarte, Joao Casal
AU - Rosas, Filipe
AU - Terrinha, Pedro
AU - Gutscher, Marc-Andre
AU - Malavielle, Jacques
AU - Silva, Sonia
AU - Matias, Luis
PY - 2011
Y1 - 2011
N2 - In the Gulf of Cadiz key segment of the Africaa??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 1.8 Ma); ii) subsequent reactivation
of these basement faults with dextral strike-slip motion ( 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.
AB - In the Gulf of Cadiz key segment of the Africaa??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 1.8 Ma); ii) subsequent reactivation
of these basement faults with dextral strike-slip motion ( 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.
UR - http://www.elsevier.com/locate/margeo
U2 - 10.1016/j.margeo.2011.09.014
DO - 10.1016/j.margeo.2011.09.014
M3 - Article
VL - 289
SP - 135
EP - 149
JO - Marine Geology
JF - Marine Geology
SN - 0025-3227
IS - 1-4
ER -