@article {Vazquez2008, title = {{Cenozoic deformational structures on the Galicia Bank Region (NW Iberian continental margin)}}, journal = {Marine Geology}, volume = {249}, number = {1-2}, year = {2008}, month = {mar}, pages = {128{\textendash}149}, abstract = {An analysis of Cenozoic tectonics was carried out on the Galicia Bank Region by means of 750~km of single-channel and 155~km of multi-channel vertical seismic profiles and multibeam bathymetry. This work forms part of a general study aimed at determining the geological risk in the wreck area of the Prestige oil tanker. Several structures affecting the post-rift sedimentary units were identified: I) Faults inherited from the Lower Cretaceous propagating rift (reactivated and non-reactivated), including reactivated normal (N-S, NW-SE) and transfer (NE-SW) faults; and II) Structures resulting from compressive episodes in the Paleogene to Upper Miocene and the Upper Miocene to the Present, including a) neotectonic normal faults decoupled from the basement structure, b) folds and flexures and c) reverse faults (NE-SW to ENE-SWS) related to the Bay of Biscay subduction, that are the most striking regional structures. The characterization of structural style, sedimentary post-rift unit deformation and morphological trends were used to carry out a detailed study of the morphostructure of the Galicia Bank Region. Six morphostructural provinces were differentiated, from E to W: 1) the Galicia Interior Basin related to a main graben; 2) the Transitional Zone, which is a horst and graben territory; 3) the Galicia Bank Main Horst; 4) the Half-Graben Domain; 5) the Deep Galicia Margin, whose structure shows rotated blocks; and 6) the Northwestern Flank, characterized by reverse faults. The Transitional Zone and the Galicia Bank provinces are assumed to be the two morphostructural provinces of the Galicia Bank marginal platform. The origin of the Cenozoic deformation must have been related to reactivation processes during the Pyrenean orogeny. We propose that the fault pattern observed in the study area is related to the phase of renewed Mesozoic fault activity. Polyphase extension in the rifting stage and Cenozoic movements have produced an extensional interference pattern that is evident in the physiography. The decouplage between basement tectonics and upper sedimentary unit tectonics suggests the presence of a viscous layer. A thrust-related main antiform related to the Bay of Biscay subduction is proposed to explain the origin of the Galicia Bank morphology. {\textcopyright} 2007 Elsevier B.V. All rights reserved.}, keywords = {Cenozoic, fault reactivation, Galicia Bank, morphostructure, physiography, tectonics}, issn = {00253227}, doi = {10.1016/j.margeo.2007.09.014}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-39549103245\&partnerID=tZOtx3y1}, author = {V{\'a}zquez, J.T. and Medialdea, T. and Ercilla, G. and Somoza, L. and Estrada, F. and Fern{\'a}ndez Puga, M.C. and Gallart, J. and Gr{\`a}cia, E. and Maestro, A. and Sayago, M.} } @article {Hernandez-Molina2008, title = {{Recent sedimentary processes in the Prestige site area (Galicia Bank, NW Iberian Margin) evidenced by high-resolution marine geophysical methods}}, journal = {Marine Geology}, volume = {249}, number = {1-2}, year = {2008}, month = {mar}, pages = {21{\textendash}45}, abstract = {An echo-character analysis of the oil tanker Prestige wreck area was undertaken using high-resolution marine geophysical methods (TOPAS and airgun seismic-reflection profiles, multibeam echosounder and TOBI sidescan sonar). Integration and comparison of the results using all these methods is presented given some practical applications for indirect near-surface and seafloor interpretations. Ten different echo types were identified and grouped into four main classes: I) distinct; II) indistinct; III) irregular and IV) hyperbolic. Echo-character distribution enabled us to determine recent sedimentary processes in the area. Two major depositional systems can be found through the identification of these sedimentary processes: a) a slope depositional system (SDS) located in the eastern and central area, where mass-movement processes are dominant and b) a turbiditic Main Channel depositional system (TDS) located in the western area where channel-related processes are dominant. Both of these interact over the half-graben structure of the southwestern sector of the Galicia Bank, where the Prestige wreck is located. Within the SDS, erosive and depositional mass-movement processes characterised a complex depositional system. Erosive processes occur on the fault scarp, channels head, inter-lobe channels and distal part of the sedimentary lobes. Moreover, depositional processes take place on the top of the fault scarp, sedimentary wedges, sedimentary lobes, and on the west flank of the Main Channel. Both depositional systems interact, but the SDS should be more active during fault-scarp reactivation periods, through relief rejuvenation and new exposed deposits. Microearthquake activity would favour the available materials, being weathered, eroded and transported by mass-movements. In such a situation, the TDS acts as the main collector of eroded sediment derived from the fault scarp throughout the SDS being responsible for its evacuation into the Iberian Abyssal Plain. However, outside of fault reactivation periods, the SDS is less active (such as during the present situation). {\textcopyright} 2007 Elsevier B.V. All rights reserved.}, keywords = {echo-character analysis, Galicia Bank, high-resolution seismic profiles, sedimentary process, swath bathymetry, TOBI sidescan sonar}, issn = {00253227}, doi = {10.1016/j.margeo.2007.09.011}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-39549115454\&partnerID=tZOtx3y1}, author = {Hern{\'a}ndez-Molina, F.J. and Llave, E. and Ercilla, G. and Maestro, A. and Medialdea, T. and Ferrin, A. and Somoza, L. and Gr{\`a}cia, E. and Masson, D.G. and Garc{\'\i}a, M. and Vizcaino, A. and Le{\'o}n, R.} }