Análisis de la dirección de extensión Mesozoica en el norte de la placa Ibérica a partir de datos de la anisotropía de la susceptibilidad magnética(ASM)
- R. Soto 1
- Antonio María Casas Sáinz 2
- Juan José Villalaín Santamaría 2
- Andrés Gil Imaz 2
- G. Fernández González 1
- P. del Río 3
- Manuel Calvo Rathert 1
- Tania Mochales 4
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1
Universidad de Burgos
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2
Universidad de Zaragoza
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3
Universidad de Cádiz
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4
Instituto Geológico y Minero de España
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ISSN: 1576-5172
Year of publication: 2008
Issue Title: VII Congreso Geológico de España
Issue: 10
Pages: 1211-1214
Type: Article
More publications in: Geotemas (Madrid)
Abstract
We present the results of anisotropy of magnetic susceptibility (AMS) analyses carried out in weakly deformed Triassic red beds, Jurassic and Lower Cretaceous limestones, sandstones and shales from several inverted Mesozoic basins located near the northern Iberian plate margin (Santander, Cabuérniga, Polientes, Bilbao and Aralar basins in the Basque-Cantabrian basin, and the Cameros basin in the NW of the Iberian Chain). A well-defined magnetic lineation of tectonic origin is found in most sites, interpreted as the stretching direction resulting from the extensional deformation characterising this period. Both the Triassic and Lower Cretaceous rifting events are characterised by the same NE-SW extensional direction in the main subsidence areas indicating the activity of the same NW-SE master faults during these events. Conversely, during Jurassic and Aptian times a lower activity of NW-SE faults, together with more important extension along a NW-SE direction can be inferred from AMS analysis. This work points out the suitability of AMS data analyses in establishing basin histories and geodynamic reconstructions even in subsequently inverted basins, provided that no important compressional deformation occurs.