000079366 001__ 79366
000079366 005__ 20220831095643.0
000079366 0247_ $$2doi$$a10.1007/s41513-018-0065-3
000079366 0248_ $$2sideral$$a109069
000079366 037__ $$aART-2018-109069
000079366 041__ $$aeng
000079366 100__ $$aAlvaro, J.J.
000079366 245__ $$aAr-40/Ar-39 chronological constraints on syn- and post-Variscan biotite porphyroblasts from the Iberian Chains, NE Spain
000079366 260__ $$c2018
000079366 5060_ $$aAccess copy available to the general public$$fUnrestricted
000079366 5203_ $$aWe perform a multidisciplinary study of biotite porphyroblasts and veinlet infills hosted in Cambrian strata of the hanging walls from the NW-SE-trending Datos, Jarque and Daroca thrusts (Iberian Chains). Stratigraphic and microstructural crosscutting features indicate that a biotite isograd runs parallel to the southeastern transects of the three thrusts. The metamorphic grade reached in the southeastern edge of the Iberian Chains is clearly distinct from both the Cadomian epizonal metamorphism, exclusively recorded in the Ediacaran-basal Cambrian Paracuellos Group, and the Variscan anchizone metamorphism recorded throughout Cambrian-Devonian strata. During post-Variscan negative inversion tectonics, renewed K-metasomatism along the same thrusts led to crystallisation of geochemically similar biotites in parallel fissures and veins. Ar-40/Ar-39 ages are (i) latest Westphalian-to-Guadalupian (285.82 23.75 Ma) for metamorphic biotite porphyroblasts affected by diffusion loss of Ar, including the Carboniferous-Permian transition within error; and (ii) Early Triassic (246.87 +/- 5.36 Ma) for biotite occlusion in post-Variscan veinlets. The Iberian Chains represent the southeastern prolongation of the Cantabrian and West Asturian-Leonese zones. The latter displays a uniform eastward decrease in metamorphic grade, whereas the Iberian Chains exhibits a heterogeneous distribution of low-grade metamorphic conditions (chlorite zone). The local presence of the biotite isograd is linked to the higher tectonic gradients associated with the Daroca, Jarque and Datos thrusts, quite similar to the metamorphic isogrades recognized both in the northeastern edge of the Demanda Massif and the Novellana-Pola de Allande-Degana Belt of the West Asturian-Leonese Zone. This distribution allows the identification of a broad NW-SE belt of biotite-in isograd-related synkinematic metamorphism, following the western contact of the Narcea Antiform, the Anguiano Thrust and the southeastern edges of the Daroca, Jarque and Datos Thrusts in the Iberian Chains. Based on Variscan structural style and metamorphic grades, the Datos Thrust links with the contact that separates the Cantabrian and West Asturian-Leonese zones of the Iberian Massif.
000079366 536__ $$9info:eu-repo/grantAgreement/ES/MINECO/CGL2017-87631-P$$9info:eu-repo/grantAgreement/ES/MINECO/CGL2013-46169-C2-1-P$$9info:eu-repo/grantAgreement/ES/DGA/E32-17R
000079366 540__ $$9info:eu-repo/semantics/openAccess$$aAll rights reserved$$uhttp://www.europeana.eu/rights/rr-f/
000079366 590__ $$a0.929$$b2018
000079366 591__ $$aGEOLOGY$$b28 / 46 = 0.609$$c2018$$dQ3$$eT2
000079366 592__ $$a0.423$$b2018
000079366 593__ $$aStratigraphy$$c2018$$dQ2
000079366 593__ $$aGeology$$c2018$$dQ2
000079366 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/acceptedVersion
000079366 700__ $$0(orcid)0000-0002-4970-6333$$aBauluz, B.$$uUniversidad de Zaragoza
000079366 700__ $$0(orcid)0000-0001-6110-1081$$aGil-Imaz, A.$$uUniversidad de Zaragoza
000079366 700__ $$aUbide, T.
000079366 7102_ $$12000$$2428$$aUniversidad de Zaragoza$$bDpto. Ciencias de la Tierra$$cÁrea Geodinámica Interna
000079366 7102_ $$12000$$2120$$aUniversidad de Zaragoza$$bDpto. Ciencias de la Tierra$$cÁrea Cristalografía Mineralog.
000079366 773__ $$g44, 4 (2018), 655-670$$pJ. iber. geol.$$tJOURNAL OF IBERIAN GEOLOGY$$x1698-6180
000079366 8564_ $$s1994595$$uhttps://zaguan.unizar.es/record/79366/files/texto_completo.pdf$$yPostprint
000079366 8564_ $$s8683$$uhttps://zaguan.unizar.es/record/79366/files/texto_completo.jpg?subformat=icon$$xicon$$yPostprint
000079366 909CO $$ooai:zaguan.unizar.es:79366$$particulos$$pdriver
000079366 951__ $$a2022-08-31-09:48:24
000079366 980__ $$aARTICLE