Structural Map of the Galicia Margin

Abstract

All available seismic data have been used to establish a new structural map of the Galicia passive margin. The northsouth syn-rift normal faults that bound the tilted fault blocks are interrupted and/or slightly offset by a discrete pattern of transverse faults oriented N55°-N70° and N115°-N135°.

Cenozoic deformational structures on the Galicia Bank Region (NW Iberian continental margin)

“…In the seismic reflection profiles, this bulge appears as anticline folds affecting post-rift sedimentary units which are related to the basement horsts. The trending of this bulge does not coincide with the direction of the extensional blocks, but it is similar to the Mesozoic transfer fault system defined in this area (Thommeret and Boillot, 1988;Boillot et al, 1989) and parallel to the Cenozoic subduction of the Bay of Biscay oceanic crust.…”

“…Another province, the Transitional Zone, is faulted by both systems (Pérez-Gussinyé et al, 2003;Reston, 2005). The NE-SW faults worked as a transfer system during both extension events (Thommeret and Boillot, 1988;Boillot et al, 1989). Faulting of these systems has been proposed by Reston (2005) as a consequence of progressive extensional evolution; the second system of high-angle normal faults was fractured when the fault dip of the first system decreased by rotation.…”

“…3). Two families of faults have been described in this area (Thommeret and Boillot, 1988;Boillot et al, 1989): the first one is a set of NW-SE to N-S normal faults, and the second one is a set of NE-SW transfer faults, although they also show a normal component.…”

“…In spite of the wide space between seismic lines, mapping of these structural features was also done using the general GEBCO bathymetry, the new corridors of multibeam bathymetry obtained together with the seismic lines (Fig. 3), and previous works from the literature (Thommeret and Boillot, 1988;Boillot et al, 1989;Murillas et al, 1990;Pérez-Gussinyé et al, 2003).…”

Continent–ocean-transitions: Review, and a new tectono-magmatic model of the Vøring Plateau, NE Atlantic

“…The southeast Flemish Cap margin (east of Newfoundland) and the Galicia Bank margin (west of Spain) may be considered as a typical conjugate non-volcanic margin pair. Whereas the southeast Flemish Cap margin is narrow with a steep continental slope which probably corresponds to a major detachment fault (Parson et al, 1985;Sibuet, 1992), the Galicia Bank margin is wider and displays a system of margin-parallel tilted faults blocks that gently deepen oceanward (Thommeret et al, 1988). A strong subhorizontal reflector beneath the tilted fault blocks of the Galicia Bank margin has been interpreted as an important detachment fault (e.g.…”