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Título
3D Analysis of an Ordovician igneous ensemble: A complex magmatic structure hidden in a polydeformed allochthonous Variscan unit
Autor(es)
Materia
Ring dikes
Pluton geometry
Recumbent folds
Allochthonous complexes
Iberian Massif
Clasificación UNESCO
2506 Geología
Fecha de publicación
2009
Editor
Elsevier
Citación
Díez Fernández, R. & Martínez Catalán, J.R. (2009). 3D Analysis of an Ordovician igneous ensemble: A complex magmatic structure hidden in a polydeformed allochthonous Variscan unit. Journal of Structural Geology, 31(3), 222-236. https://doi.org/10.1016/j.jsg.2008.11.017
Resumen
[EN]The basal units of the allochthonous complexes of NW Iberia represent a fragment of the external edge of
Gondwana subducted and subsequently exhumed during the Variscan collision. The structural analysis
carried out in orthogneissic massifs of the southern part of one of these, the Malpica–Tui Unit, reveals the
generation of recumbent folds and associated axial planar foliation during their exhumation. These folds
nucleated in irregular igneous bodies that were initially deformed during the subduction event and show
east to southeast vergence. Down-plunge projection of surface data and a series of regularly spaced
cross-sections have been used to build 3D models of the two main bodies of orthogneiss, of calc-alkaline
and peralkaline compositions respectively. The first is presently a lens-shaped body folded in a recumbent
syncline, whereas the peralkaline gneiss, also affected by a train of asymmetric recumbent folds in
the south, exhibits in the north a fold-like structure which is interpreted as inherited from its primary
geometry, that of a ring dike pluton.
URI
ISSN
0191-8141
DOI
10.1016/j.jsg.2008.11.017
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