Abstract
An investigation on the effects of a strong theological contrast in the deformation of layered anisotropic rocks is presented. The study focuses on the geometric and kinematic analysis of complex structures developed within and adjacent to a thin marble-metapsammite multilayer unit from the Cap de Creus tectonometamorphic belt (NE Spain). Zones of high ductile strain localise in the marble layers, which exhibit complex folds, whereas metapsammites show mostly brittle (boudinage) structures. These structures strongly contrast with coeval retrogressive discrete shear zones developed in the surrounding migmatitic schists. The extreme strain partitioning is due to the theological contrast between different lithological layers. In addition, the specific orientation of this multilayer unit induces a reversal of local kinematics with regard to bulk kinematics. Consequently, caution should be exercised when interpreting regional tectonics in highly partitioned domains associated with rheological heterogeneities. (C) 2009 Elsevier Ltd. All rights reserved.
| Original language | English |
|---|---|
| Pages (from-to) | 498-511 |
| Number of pages | 14 |
| Journal | Journal of Structural Geology |
| Volume | 31 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - May 2009 |
Bibliographical note
This work was funded by the Spanish Ministry of Education and Science (Project CGL2007-66857-C02-01). We thank Lina M. Castaño for support in both field and laboratory work and the referees, Florian Fusseis and Neil Mancktelow for their constructive reviews.Keywords
- Boudin
- Fold
- Fracture
- Multilayer rheology
- Shear zone
- Strain partitioning
- Cap-de-Creus
- high-strain zone
- Eastern Pyrenees
- shear zones
- viscous transition
- rock masses
- folds
- boudinage
- flow
- magmatism