Axial longitudinal flow in volcaniclastic materials of the Late-Carboniferous-Permian Cadí basin (Southern Pyrenees) determined from Anisotropy of Magnetic Susceptibility

Simón-Muzás Ana (Universidad de Zaragoza) ; Casas-Sainz, Antonio (Universidad de Zaragoza) ; Soto, Ruth ; Gisbert Aguilar, Josep (Universidad de Zaragoza) ; Román-Berdiel, Teresa (Universidad de Zaragoza) ; Oliva-Urcia, Belén ; Pueyo, Emilio L. ; Beamud, Elisabeth

Resumen: The aim of this work is the application of the anisotropy of magnetic susceptibility (AMS) to the study of volcanic materials from the Late Carboniferous-Permian Cadí basin (southern Pyrenees) in order to (i) explore the limits of this technique in ancient volcanic materials that have undergone strong chemical alteration and a complex tectonic evolution and (ii) provide new insights on the deposition of volcanic materials in this tectonically controlled sedimentary basin. To establish a comparison with the petrofabric of rocks, AMS was complemented with observations and orientation analyses at the outcrop scale, in oriented polished blocks and in thin sections under the microscope. High resolution sampling (620 specimens from 56 sites located in five transects along a sequence 150 m thick) allowed to characterize the volcaniclastic and lava flow series. The AMS results show a fairly constant average magnetic lineation oriented WNW-ESE (in situ and tilt-corrected) and two secondary maxima (N-S to NE-SW in some areas). The magnetic mineralogy analyses indicate the contribution of paramagnetic and ferromagnetic (magnetite, Tc 580 °C) phases to susceptibility. The magnetic fabric has a close relationship with the spatial distribution and orientation of the mineral and grain components of the studied rocks, mainly controlled by depositional processes, with a negligible contribution of the tectonic imprint. Therefore, the magnetic lineation (i.e. K1 axes) can be reliably used as a paleoflow indicator. Nevertheless, it was not possible to establish a clear correspondence between lithological and magnetic fabric types. The results obtained indicate that the AMS approach represents a powerful tool to infer the paleoflow pattern in ancient volcanic and volcaniclastic rocks, even under a priori unfavourable conditions.

Idioma: Inglés

DOI: 10.1016/j.jvolgeores.2021.107443

Año: 2022

Publicado en: JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH 421 (2022), 107443 [22 pp]
ISSN: 0377-0273

Factor impacto JCR: 2.9 (2022)

Categ. JCR: GEOSCIENCES, MULTIDISCIPLINARY rank: 88 / 202 = 0.436 (2022) - Q2 - T2

Factor impacto CITESCORE: 6.2 - Earth and Planetary Sciences (Q1)

Factor impacto SCIMAGO: 1.107 - Geophysics (Q1) - Geochemistry and Petrology (Q1)

Financiación: info:eu-repo/grantAgreement/ES/MCIU/CGL2017-84901-C2-2-P
Financiación: info:eu-repo/grantAgreement/ES/MCIU/FPU19-02353
Financiación: info:eu-repo/grantAgreement/ES/MCIN/AEI/10.13039/501100011033
Financiación: info:eu-repo/grantAgreement/ES/MICINN/PID2020-108753GB-C22
Financiación: info:eu-repo/grantAgreement/ES/MICINN/PID2020-114273GB-C22

Tipo y forma: Article (Published version)

Área (Departamento): Área Petrología y Geoquímica (Dpto. Ciencias de la Tierra)
Área (Departamento): Área Geodinámica Interna (Dpto. Ciencias de la Tierra)