Abstract

MOREIRA, N.; BURCIO, M.; DIAS, R.  and  COKE, C.. Strain partitioning of Variscan deformation in the Peso da Régua and Vila Nova de Foz Côa region (Centro Iberian Zone autochthon). Comunicações Geológicas [online]. 2010, n.97, pp.147-162. ISSN 1647-581X.

The first and main Variscan deformation phase in Marão-Vila Nova de Foz Côa axis (Centro Iberian Autochthon) induced the formation of wide zones gently folded bounded by coeval narrow bands emphasizing stronger deformation. These bands are associated with a WNW-ESE shear zones with a sinistral kinematics. In the Douro Group Cambrian formation of Peso da Régua and Vila Nova de Foz Côa sectors, is possible to see a clear relationship between the narrow bands emphasizing stronger deformation and the regional sinistral shear zones. This geometry shows an extensive area with strong strain partitioning which emphasize the presence of a regional major structure. Such structural pattern characterizes the axial zone of the flower structure, create by the sinistral transpressive regime in northern sectors of the Centro Iberian autochthon during the Variscan orogeny. This structure is here named Douro Flower Structure. The lateral continuity of this regional structure from Marão to Vila Nova de Foz Côa that was possible to put in evidence by this work is interrupted by NNE-SSE Tardi-Variscan sinistral shear-zones, that are reactivated during the Alpine Orogeny.

Keywords : D₁ Variscan deformation; Centro Iberian Autochthon; WNW-ESE Sinistral Shears; Flower Structure.

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