Deciphering western Mediterranean kinematics using metamorphic porphyroblasts from the Alpujárride Complex (Betic Cordillera)
Identificadores
URI: https://hdl.handle.net/10481/80327Metadatos
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Elsevier
Materia
Alpujarride complex Betic Cordillera Alpine orogeny Foliation intersection axes X-ray computed tomography
Fecha
2023-02Referencia bibliográfica
Ruiz-Fuentes, A., Aerden, D.G.A.M., 2023. Deciphering western Mediterranean kinematics using metamorphic porphyroblasts from the Alpujárride Complex (Betic Cordillera). Journal of Structural Geology 168, 104823.
Patrocinador
FPU grant from the Spanish Ministery of Education and Science, Culture and Sports (FPU17/01874); Spanish government grant CGL2016-80687-R AEI/FEDER; Junta de Andalucía Projects P18-RT-3275 (AGORA), B-RNM-301-UGR18 (PAPEL) and RNM148; Funding for open access charge: Universidad de Granada / CBUAResumen
3D microstructural analysis of porphyroblast inclusion trails using X-ray Computed Tomography is integrated
with analysis of field structures to unravel the Alpine deformation history of the Alpujárride Complex, which
constitutes the partially submerged metamorphic core of the Gibraltar Arc. Prograde metamorphism in the
complex has been traditionally linked to a ’D1’ event witnessed by inclusion trails in garnet porphyroblasts.
Orientation data for these microstructures reveal three age groups with differently oriented axes of inclusion-trail
curvature (known as FIA). The successive development of FIAs trending WNW-ESE, ENE-WSW and NNW-SSE is
shown and correlated with the Paleogene-Neogene relative plate-motion paths of Africa, Iberia and the Alborán
Domain as known from paleomagnetic data. During the late-metamorphic evolution of the Alpujárride Complex,
after garnet growth had ceased, two steeply dipping crenulation cleavages and associated folds with roughly
suborthogonal N–S and E-W trends developed, in addition to two subhorizontal ones. Inclusion trails are also
found to exhibit a general preference for subvertical and subhorizontal orientations, suggesting a protracted
orogenic evolution characterized by multiple stress permutations causing alternations of crustal shortening and
gravitational collapse.