Crystallographic preferred orientations and microstructure of a Variscan marble mylonite in the Ossa-Morena Zone (SW Iberia)
The mylonitic marbles of the Cherneca shear zone, a Variscan sinistral strike-slip structure developed in the Ossa-Morena Zone (SW Iberia) related to the emplacement of the Santa Olalla Igneous Complex, were studied in detail. Different mylonites (from protomylonites to ultramylonites) were analyzed...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2007 |
| País: | España |
| Institución: | Universidad Complutense de Madrid (UCM) |
| Repositorio: | Docta Complutense |
| Idioma: | inglés |
| OAI Identifier: | oai:docta.ucm.es:20.500.14352/49726 |
| Acceso en línea: | https://hdl.handle.net/20.500.14352/49726 |
| Access Level: | acceso abierto |
| Palabra clave: | 551.24 548 Crystallographic preferred orientation Texture Microstructure Mylonite Shear bands Variscan Orogeny Cristalografía (Geología) Geodinámica 2507 Geofísica |
| Sumario: | The mylonitic marbles of the Cherneca shear zone, a Variscan sinistral strike-slip structure developed in the Ossa-Morena Zone (SW Iberia) related to the emplacement of the Santa Olalla Igneous Complex, were studied in detail. Different mylonites (from protomylonites to ultramylonites) were analyzed by Electron Back-Scattering Diffraction (EBSD) in order to determine the crystallographic preferred orientation (CPO) of calcite. The CPOs show very good agreement with experimental torsion work giving suitable interpretations of the operative slip systems and strain quantifications, thus the obtained natural CPOs validate the experimental approaches. A wide range of observed textures and microstructures are mainly controlled by the amount of shear strain, the presence of secondary phases, and the development of antithetic subsidiary shears. The effect of secondary phases and the nucleation of antithetic shear bands on texture development are discussed. |
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