Geometría del basamento Pirenaico Suroccidental a partir de la exploración sísmica
- R. Toro 1
- A.M. Casas 1
- E. Izquierdo-Llavall 2
- E.L. Pueyo 3
- J. Navas 4
- C. Peropadre 5
- J. Martín 4
- 1 IUCA. Universidad de Zaragoza.
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2
University of Pau and Pays de l'Adour
info
- 3 IGME/Universidad de Zaragoza
- 4 Instituto Geológico y Minero de España (IGME, CSIC)
- 5 Instituto Geológico y Minero de España (IGME)
ISSN: 1576-5172
Year of publication: 2021
Issue Title: X Congreso Geológico de España
Issue: 18
Pages: 565
Type: Article
More publications in: Geotemas (Madrid)
Abstract
The Southwestern Pyrenees (north of Aragón and Navarra) display some key geometric features of the chain; 1) the westward termination of the main outcrop of the Axial Zone, the backbone of the chain where the basement rocks emerge 2) the outcrop of isolated basement units further west (the so-called Basque Massifs) and 3) the lateral variation in crustal geometries, characterized by the underthrusting of the lower Iberian crust beneath the European one, with the upper crust forming an orogenic wedge (Muñoz, 1992; Teixell, 1998, Pedreira et al., 2003). The number, sequence and lateral relationships of the subsurface basement thruss forming this upper crust wedge are com- plex and/or unknown. In this work we show the first 3D model based on geophysics in the region (142 reflection seismic sections in time). To carry out the conversion of time interpretations to depth we consider a seismic velocity model based on sonic logs from several wells (Roncal, Sangüesa-1, Aoiz-1, and Pamplona south). The results obtained have allowed to precisely define the progressive northwards shallowing of the top of the basement (through a sequence of basement thrusts whose surface expression is the Gavarnie Thrust) and the geometry of the main sedimentary units that define the orogenic wedge and the South-Pyrenean orogenic system.