Tectónica colisional alpina y estructura sísmica de la corteza entre el Pirineo y la Cordillera Cantábrica
- D. Pedreira 1
- J.A. Pulgar 1
- J. Gallart
- D. Córdoba
- J. Díaz
- R. Carbonell
- J.J. Dañobeitia
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1
Universidad de Oviedo
info
ISSN: 1576-5172
Année de publication: 2000
Titre de la publication: V Congreso Geológico de España (Alicante, 10-14 julio 2000)
Número: 1
Pages: 79-82
Type: Article
D'autres publications dans: Geotemas (Madrid)
Résumé
The crustal structure of the transition zone between the Pyrenees and the Cantabrian Mountains was investigated from a set of seismic refraction / wide angle reflection profiles acquired in 1997. An E-W profile of 540 km shows important variations in crustal thickness and velocity distribution from the Cantabrian Mountains to the Western Pyrenees. A continuous Alpine crustal root is observed, with Moho depths of 46-48 km, except for the Western part of the Basque Cantabrian Basin, where the Moho is located at about 40 km. Another outstanding feature is the inferred presence of a discontinuous layer of 6.40-6.90 km s~’ at midcrustal depths beneath the Cantabrian Mountains and the Eastern Basque-Cantabrian Basin. Some geological and geophysical constraints suggest that it can represent a wedge of the lower crust of the Cantabrian Margin indenting the Iberian crust during the Alpine compression. This indentation was conditioned and/or affected by some NE-SW structures and this explains its discontinuous presence along the profile. The anomalously low velocity for this lower crustal material could be a consequence of its intense deformation during the collision and crustal indentation