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Kinematic analysis of the southern Iberian shear zone and tectonic evolution of the Acebuches metabasites (SW Variscan Iberian Massif)
Author(s) -
Díaz Azpiroz Manuel,
Fernández Carlos
Publication year - 2005
Publication title -
tectonics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.465
H-Index - 134
eISSN - 1944-9194
pISSN - 0278-7407
DOI - 10.1029/2004tc001682
Subject(s) - geology , shear zone , lineation , massif , shear (geology) , seismology , fibrous joint , simple shear , tectonics , accretionary wedge , petrology , paleontology , subduction , medicine , anatomy
The Acebuches metabasites constitute a slice of oceanic crust located at the Variscan suture between the Ossa Morena and the South Portuguese zones (Iberian Massif). The emplacement of the metabasites onto the accretionary prism was associated with the activity of the southern Iberian shear zone. Careful measurements of the fabrics and structures related to this shear zone show consistent kinematic criteria pointing to the presence of a simple shear component, with an oblique predominantly left‐lateral sense of displacement. The data are consistent with existing models of triclinic or oblique shear zones considering coeval simple shear and pure shear components. These models provide a satisfactory explanation of the observed spatial variations in the foliation, lineation and fold hinge data. The kinematics of other shear deformations, older and younger than the southern Iberian shear zone, have also been established. These results offer new insights into the tectonic evolution of this suture of the Variscan belt, and show how complex transpressional strains can arise during oblique crustal deformation associated with the motions of tectonic plates.