Deformation and magnetic fabrics in isoclinal folds of the Variscan Pyrenees
23 p.
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/403559 |
| Acceso en línea: | http://hdl.handle.net/10261/403559 https://api.elsevier.com/content/abstract/scopus_id/105009415626 |
| Access Level: | acceso abierto |
| Palabra clave: | Variscan Alpine Anisotropy of magnetic susceptibility Isocline folds Limestones Pyrenees |
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oai:digital.csic.es:10261/403559 |
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Deformation and magnetic fabrics in isoclinal folds of the Variscan Pyrenees Oliva-Urcia, Belén Román-Berdiel, T. Clariana, Pilar Soto, Ruth Izquierdo Llavall, Esther Casas-Sainz, Antonio M. Variscan Alpine Anisotropy of magnetic susceptibility Isocline folds Limestones Pyrenees 23 p. [EN] Magnetic fabrics are used as strain markers since they reflect the orientation-distribution of grains in a rock. In this work we analyzed, from the point of view of anisotropy of magnetic susceptibility (at low-temperature and room temperature), Devonian (29 sites) and Ordovician-Silurian (3 sites) sedimentary rocks in the Pyrenean Axial Zone, totalling 611 samples. The main target is to determine the strain in relation to the Variscan (polyphased) and Alpine orogenies in limestones and shales. The magnetic information also derives from thermomagnetic curves, acquisition of the isothermal remanent magnetization (IRM) and coercivity of the remanence analyses, together with hysteresis loops and stepwise thermal demagnetization of induced IRM in 3 axes techniques. The analyses of magnetic properties were complemented with optical microscopy observations and calcimetries. In two of the sample areas (Sen and Llisat valleys), the minimum axes of the magnetic susceptibility ellipsoid (k<inf>min</inf> axes) are mostly perpendicular to bedding whereas in the other two (Zinqueta valley and near Posets peak area), a more developed tectonic fabric is found: the k<inf>min</inf> axes are not completely perpendicular to bedding, and the magnetic susceptibility ellipsoid relates to the foliation plane. Different minerals carry a concordant magnetic fabric with pyrrhotite, magnetite (ferromagnetic s.l.) and phyllosilicates (paramagnetic), and little influence of calcite grains (diamagnetic). The magnetic fabric is interpreted to form at the early stages of the Variscan deformation, prior to the dextral transpression synchronous with granite emplacement that characterizes the late stages of the Variscan Orogeny. However, contact metamorphism and associated fluid circulation can enhance or obliterate the primary magnetic fabric. Field work and thin section preparation was possible thanks to the “Ayuda a la Investigación de la Comarca de Sobrarbe” and National Project CGL 2017-90632-REDT. Project PID 2019-108753 GB-C22, funded by MICIN/AEI/10.3039/501100011033 and by “ERDF A way of making Europe” is also aknowledged. Proyecto del Gobierno de Aragón (E32_20R: Grupo de Investigación Geotransfer). Peer reviewed Elsevier http://hdl.handle.net/10261/403559 https://api.elsevier.com/content/abstract/scopus_id/105009415626 |
| title |
Deformation and magnetic fabrics in isoclinal folds of the Variscan Pyrenees |
| spellingShingle |
Deformation and magnetic fabrics in isoclinal folds of the Variscan Pyrenees Oliva-Urcia, Belén Variscan Alpine Anisotropy of magnetic susceptibility Isocline folds Limestones Pyrenees |
| title_short |
Deformation and magnetic fabrics in isoclinal folds of the Variscan Pyrenees |
| title_full |
Deformation and magnetic fabrics in isoclinal folds of the Variscan Pyrenees |
| title_fullStr |
Deformation and magnetic fabrics in isoclinal folds of the Variscan Pyrenees |
| title_full_unstemmed |
Deformation and magnetic fabrics in isoclinal folds of the Variscan Pyrenees |
| title_sort |
Deformation and magnetic fabrics in isoclinal folds of the Variscan Pyrenees |
| author |
Oliva-Urcia, Belén |
| author_facet |
Oliva-Urcia, Belén Román-Berdiel, T. Clariana, Pilar Soto, Ruth Izquierdo Llavall, Esther Casas-Sainz, Antonio M. |
| author_role |
author |
| author2 |
Román-Berdiel, T. Clariana, Pilar Soto, Ruth Izquierdo Llavall, Esther Casas-Sainz, Antonio M. |
| author2_role |
author author author author author |
| topic |
Variscan Alpine Anisotropy of magnetic susceptibility Isocline folds Limestones Pyrenees |
| topic_facet |
Variscan Alpine Anisotropy of magnetic susceptibility Isocline folds Limestones Pyrenees |
| description |
23 p. |
| publishDate |
2025 |
| format |
article |
| status_str |
publishedVersion |
| url |
http://hdl.handle.net/10261/403559 https://api.elsevier.com/content/abstract/scopus_id/105009415626 |
| eu_rights_str_mv |
openAccess |
| publisher |
Elsevier |
| institution |
Consejo Superior de Investigaciones Científicas (CSIC) |
| collection |
DIGITAL.CSIC. Repositorio Institucional del CSIC |
| reponame_str |
DIGITAL.CSIC. Repositorio Institucional del CSIC |
| instname_str |
Consejo Superior de Investigaciones Científicas (CSIC) |
| _version_ |
1878438833948721152 |
| publishDateSort |
2025 |
| author_browse |
Casas-Sainz, Antonio M. Clariana, Pilar Izquierdo Llavall, Esther Oliva-Urcia, Belén Román-Berdiel, T. Soto, Ruth |
| publisherStr |
Elsevier |
| score |
6,924472 |