@article {Hensen01042015, title = {{Strike-slip faults mediate the rise of crustal-derived fluids and mud volcanism in the deep sea}}, journal = {Geology}, volume = {43}, number = {4}, year = {2015}, pages = {339{\textendash}342}, abstract = {We report on newly discovered mud volcanoes located at \~{}4500 m water depth \~{}90 km west of the deformation front of the accretionary wedge of the Gulf of Cadiz, and thus outside of their typical geotectonic environment. Seismic data suggest that fluid flow is mediated by a >400-km-long strike-slip fault marking the transcurrent plate boundary between Africa and Eurasia. Geochemical data (Cl, B, Sr, 87Sr/86Sr, $δ$18O, $δ$D) reveal that fluids originate in oceanic crust older than 140 Ma. On their rise to the surface, these fluids receive strong geochemical signals from recrystallization of Upper Jurassic carbonates and clay-mineral dehydration in younger terrigeneous units. At present, reports of mud volcanoes in similar deep-sea settings are rare, but given that the large area of transform-type plate boundaries has been barely investigated, such pathways of fluid discharge may provide an important, yet unappreciated link between the deeply buried oceanic crust and the deep ocean.}, doi = {10.1130/G36359.1}, url = {http://geology.gsapubs.org/content/43/4/339.abstract}, author = {Hensen, Christian and Scholz, Florian and Nuzzo, Marianne and Valadares, Vasco and Gr{\'a}cia, Eul{\`a}lia and Terrinha, Pedro and Liebetrau, Volker and Kaul, Norbert and Silva, Sonia and Mart{\'\i}nez-Loriente, Sara and Bartolom{\'e}, Rafael and Pi{\~n}ero, Elena and Magalh{\~a}es, Vitor H and Schmidt, Mark and Weise, Stephan M and Cunha, Marina and Hilario, Ana and Perea, Hector and Rovelli, Lorenzo and Lackschewitz, Klas} } @article {Martinez-Loriente2013, title = {{Active deformation in old oceanic lithosphere and significance for earthquake hazard: Seismic imaging of the Coral Patch Ridge area and neighboring abyssal plains (SW Iberian Margin)}}, journal = {Geochemistry, Geophysics, Geosystems}, volume = {14}, number = {7}, year = {2013}, month = {jul}, pages = {2206{\textendash}2231}, abstract = {Recently acquired high-resolution multichannel seismic profiles together with bathymetric and sub-bottom profiler data from the external part of the Gulf of Cadiz (Iberia-Africa plate boundary) reveal active deformation involving old (Mesozoic) oceanic lithosphere. This area is located 180 km offshore the SW Iberian Peninsula and embraces the prominent NE-SW trending Coral Patch Ridge, and part of the surrounding deep Horseshoe and Seine abyssal plains. E-W trending dextral strike-slip faults showing surface deformation of flower-like structures predominate in the Horseshoe Abyssal Plain, whereas NE-SW trending compressive structures prevail in the Coral Patch Ridge and Seine Hills. Although the Coral Patch Ridge region is characterized by subdued seismic activity, the area is not free from seismic hazard. Most of the newly mapped faults correspond to active blind thrusts and strike-slip faults that are able to generate large magnitude earthquakes (Mw 7.2-8.4). This may represent a significant earthquake and tsunami hazard that has been overlooked so far. Key Points New active structures have been mapped in the Coral Patch Ridge area The newly mapped faults are able to generate large magnitude earthquakes (Mw>7) These new structures may represent a significant earthquake and tsunami hazard {\textcopyright}2013. American Geophysical Union. All Rights Reserved.}, keywords = {blind thrusts, fault-bend folds, Iberia-Africa boundary, multichannel seismics, seismic hazard assessment, strike-slip faults}, issn = {15252027}, doi = {10.1002/ggge.20173}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84883575301\&partnerID=tZOtx3y1}, author = {Mart{\'\i}nez-Loriente, Sara and Gr{\'a}cia, Eul{\`a}lia and Bartolom{\'e}, Rafael and Sallares, Valenti and Connors, Christopher and Perea, Hector and Lo Iacono, Claudio and Klaeschen, Dirk and Terrinha, Pedro and Da{\~n}obeitia, Juan Jos{\'e} and Zitellini, Nevio} } @article {Gutscher2009, title = {{Tectonic shortening and gravitational spreading in the Gulf of Cadiz accretionary wedge: Observations from multi-beam bathymetry and seismic profiling}}, journal = {Marine and Petroleum Geology}, volume = {26}, number = {5}, year = {2009}, month = {may}, pages = {647{\textendash}659}, abstract = {The Gulf of Cadiz lies astride the complex plate boundary between Africa and Eurasia west of the Betic-Rif mountain belt. We report on the results of recent bathymetric swathmapping and multi-channel seismic surveys carried out here. The seafloor is marked by contrasting morphological provinces, spanning the SW Iberian and NW Moroccan continental margins, abyssal plains and an elongate, arcuate, accretionary wedge. A wide variety of tectonic and gravitational processes appear to have shaped these structures. Active compressional deformation of the wedge is suggested by folding and thrusting of the frontal sedimentary layers as well as basal duplexing in deeper internal units. There is evidence for simultaneous gravitational spreading occurring upslope. The very shallow mean surface and basal slopes of the accretionary wedge (1{\textdegree} each) indicate a very weak decollement layer, geometrically similar to the Mediterranean Ridge accretionary complex. Locally steep slopes (up to 10{\textdegree}) indicate strongly focused, active deformation and potential gravitational instabilities. The unusual surface morphology of the upper accretionary wedge includes "raft-tectonics" type fissures and abundant sub-circular depressions. Dissolution and/or diapiric processes are proposed to be involved in the formation of these depressions. {\textcopyright} 2008 Elsevier Ltd. All rights reserved.}, keywords = {Accretionary wedge, Decollement, Gravitational spreading, Iberia, Morocco}, issn = {02648172}, doi = {10.1016/j.marpetgeo.2007.11.008}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-67349128699\&partnerID=tZOtx3y1}, author = {Gutscher, Marc-Andr{\'e} and Dominguez, Stephane and Westbrook, Graham K. and Gente, Pascal and Babonneau, Nathalie and Mulder, Thierry and Gonthier, Eliane and Bartolom{\'e}, Rafael and Luis, Joaquim and Rosas, Filipe and Terrinha, Pedro} }