000162099 001__ 162099
000162099 005__ 20251017144603.0
000162099 0247_ $$2doi$$a10.1016/j.jsg.2025.105495
000162099 0248_ $$2sideral$$a144692
000162099 037__ $$aART-2025-144692
000162099 041__ $$aeng
000162099 100__ $$0(orcid)0000-0003-1563-6434$$aOliva-Urcia, B.$$uUniversidad de Zaragoza
000162099 245__ $$aDeformation and magnetic fabrics in isoclinal folds of the Variscan Pyrenees
000162099 260__ $$c2025
000162099 5060_ $$aAccess copy available to the general public$$fUnrestricted
000162099 5203_ $$aMagnetic 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 (kmin 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 kmin 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.
000162099 536__ $$9info:eu-repo/grantAgreement/ES/DGA/E32-20R$$9info:eu-repo/grantAgreement/ES/MICINN/CGL2017-90632-REDT$$9info:eu-repo/grantAgreement/ES/MICINN/PID2019-108753GB-C22
000162099 540__ $$9info:eu-repo/semantics/openAccess$$aby-nc$$uhttps://creativecommons.org/licenses/by-nc/4.0/deed.es
000162099 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion
000162099 700__ $$0(orcid)0000-0002-9743-8695$$aRomán-Berdiel, T.$$uUniversidad de Zaragoza
000162099 700__ $$aClariana, P.
000162099 700__ $$0(orcid)0000-0002-1929-8850$$aSoto, R.
000162099 700__ $$0(orcid)0000-0002-5159-8140$$aIzquierdo-Llavall, E.
000162099 700__ $$0(orcid)0000-0003-3652-3527$$aCasas-Sainz, A.$$uUniversidad de Zaragoza
000162099 7102_ $$12000$$2428$$aUniversidad de Zaragoza$$bDpto. Ciencias de la Tierra$$cÁrea Geodinámica Interna
000162099 773__ $$g199 (2025), 105495 [23 pp.]$$pJ. struct. geol.$$tJournal of Structural Geology$$x0191-8141
000162099 8564_ $$s1853768$$uhttps://zaguan.unizar.es/record/162099/files/texto_completo.pdf$$yVersión publicada
000162099 8564_ $$s2537557$$uhttps://zaguan.unizar.es/record/162099/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada
000162099 909CO $$ooai:zaguan.unizar.es:162099$$particulos$$pdriver
000162099 951__ $$a2025-10-17-14:14:41
000162099 980__ $$aARTICLE