Recq, M. et al. (1996): Structure sismique de la ride de peridotite a l'ouest du Banc de Galice (ouest Iberie) Seismic structure of the peridotite ridge west of the Galicia Bank, West Iberia
Leg/Site/Hole:
Related Expeditions:
ODP 103
Identifier:
ID:
1996-049272
Type:
georefid
Creator:
Name:
Recq, M.
Affiliation:
Universite de Bretagne Occidentale, Departement des Sciences de la Terre, Brest, France
Role:
author
Name:
Whitmarsh, R. B.
Affiliation:
IFREMER, Plouzane, France
Role:
author
Name:
Sibuet, J. C.
Affiliation:
Role:
author
Name:
White, R. S.
Affiliation:
Role:
author
Name:
Lyness, D.
Affiliation:
Role:
author
Identification:
Title:
Structure sismique de la ride de peridotite a l'ouest du Banc de Galice (ouest Iberie) Seismic structure of the peridotite ridge west of the Galicia Bank, West Iberia
Year:
1996
Source:
Comptes Rendus de l'Academie des Sciences, Serie II. Sciences de la Terre et des Planetes
Publisher:
Gauthier-Villars, Montrouge, France
Volume:
322
Issue:
7
Pages:
571-578
Abstract:
Refraction profiles have been carried out along and across the peridotite ridge at the ocean-continent boundary west of the Galicia margin. Deep sea drilling (ODP Leg 103) shows that the ridge is composed of serpentinized peridotite. The shallow seismic velocity within the ridge is as low as 3.70 km/s, denoting a high grade of serpentinization. Modelling the ridge illustrates its heterogeneity and the large extent of the serpentinization from the crest to 6-8 km below sea floor. A unique downward velocity gradient within the ridge is ruled out. At a depth of 3 km below sea floor, the velocity gradient decreases abruptly through a second order discontinuity bisecting the ridge from west to east. Within a west-dipping transition zone at a depth of roughly 11 km, velocities increase from 7.40 to 7.65 km/s.
Language:
French
Genre:
Serial
Rights:
URL:
Coverage: Geographic coordinates: North:75.0000 West:-80.0000 East:
20.0000 South:0.0000
Keywords: Applied geophysics; Atlantic Ocean; bathymetry; continental crust; continental margin; crust; discontinuities; dredging; drilling; elastic waves; Europe; Galicia Spain; geophysical methods; geophysical surveys; Iberian Peninsula; igneous rocks; Leg 103; Leg 105; mantle; marine methods; metasomatism; models; North Atlantic; Northeast Atlantic; Ocean Drilling Program; ocean floors; oceanic crust; ODP Site 647; offshore; peridotites; plutonic rocks; seismic methods; seismic waves; seismograms; serpentinization; Southern Europe; Spain; surveys; synthetic seismograms; thermal circulation; transition zones; ultramafics; upper mantle; velocity structure;
.