%0 Journal Article
%A Díaz García, Florentino
%A Martínez Catalán, José Ramón
%A Arenas Martín, Ricardo
%A González Cuadra, Pablo
%T Structural and kinematic analysis of the Corredoiras detachment:evidence for early Variscan synconvergent extensionin the Ordenes Complex, NW Spain
%D 1999
%@ 1437-3254
%U https://hdl.handle.net/20.500.14352/59199
%X An important detachment is described in theallochthonous Ordenes Complex, in the NW IberianMassif, and its meaning is related to the kinematics ofcontemporaneous convergent structures. The CorredoirasDetachment (CD) separates a hangingwall unit,characterised by a medium-pressure metamorphicgradient, from a footwall high-pressure and hightemperatureunit and an underlying ophiolitic unit. Anassociated ductile shear zone, nearly 2000 m thick,developed in the lower part of the hangingwall unit,where the Corredoiras Orthogneiss, a Lower Ordovicianmetagranite, was progressively transformed intoaugengneisses, mylonitic and ultramylonitic gneisses.The attitude of the stretching and mineral lineation inthe mylonites varies due to late refolding at map scale,but the sense of movement can be estimated, beingroughly top to the SE. According to crosscutting relationships,the CD developed subsequent to thethrusting of the high-pressure/high-temperature unitonto the ophiolitic unit, and prior to younger extensionaldetachments, upright folding and strike-sliptectonics. The geometric relationships of the CD withthe previous structures in the footwall unit, the subtractivecharacter of the metamorphic gap between itshangingwall and footwall, and the available isotopicdata suggest that the CD is an early Variscan, ductileextensional detachment, the movement of which wasroughly simultaneous with the onset of thrusting of theallochthonous complexes over their relative autochthon.
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