Fábricas constrictivas de ejes-c de cuarzo en arcosas deformadas por disolución por presión
- F.J. Fernández 1
- D. Brown 2
- J. Álvarez-Marrón 2
- A. Pérez-Estaún 2
- R. Menéndez-Duarte 1
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1
Universidad de Oviedo
info
- 2 Instituto de Ciencias de la Tierra “Jaume Aimera” (CSIC)
ISSN: 1576-5172
Año de publicación: 2004
Título del ejemplar: IV Congreso Geológico de España (Zaragoza, 12-15 julio, 2004)
Número: 6
Páginas: 37-40
Tipo: Artículo
Otras publicaciones en: Geotemas (Madrid)
Resumen
Arkosic sandstone interlayered within calcite mylonites at the base o f the southern Urals accretionary prism preserves their original sedimentary microstructure and presents only a weak shape and crystallographic preferred orientation (SPO and CPO, respectively). SPOs of XZ-sections show fabrics mainly formed by pressure solution, where quartz and feldspar grains have a characteristic bimodal shape and the mean axial ratio of the finite strain is c. 2. The unusual pattern described by the quartz c-axes fabrics formed during the acquisition o f their SPOs is characterised by girdles normal to Y At the light o f our results, and accordingly with the deformation conditions o f the calcite mylonites, the quartz c-axis preferred orientation may be formed by pressure solution under constrictional strain, and not as usually occurs by intracrystalline plasticity.