Abstract
The analysis of the brittle tectonic deformation on all scales in one area of the eastern Iberian Chain (Mosqueruela, Teruel) allows us to define a fracture pattern characterized by three main sets: NNE to NE, ENE and E to ESE. Brittle structures (stylolites, tension gashes, brittle-ductile shear zones and faults) show a poliphase Alpine tectonics. From the analysis of fault populations two compressive (wrench regime) phases and a multidirectional extension regime have been inferred. Their chronological evolution is the fol1owing: 1) ENE compression; 2) ESE compression; 3) nearly multidirectional NNE extension. The study of fractures using a number of methodologies at macro-, meso- and microstructural scales allows us to suggest a model of stress distribution and relationships between different structures in sorne areas. The detailed fracture mapping on a hectometric scale shows the distribution and strike variations of fractures. These changes have been interpreted as stress deflection phenomena due to major structures which, in many cases, were identified. Examples of stress deflections have been analyzed both for strike-slip and normal fault sets.
Highlights
The analysis of the brittle tectonic deformation on all scales in one area of the eastern Iberian Chain (Mosqueruela, Teruel) allows us to define a fracture pattern characterized by three main sets: NNE to NE, ENE and E to ESE
The study of fractures using a number of methodologies at macro, meso- and microstructural scales allows us to suggest a model of stress distribution and relationships between different structures in sorne areas
The detailed fracture mapping on a hectometric scale shows the distribution and strike variations of fractures. These changes have been interpreted as stress deflection phenomena due to major structures which, in many cases, were identified
Summary
Los métodos de análisis poblacional de fallas permiten la determinación de estados de esfuerzo tectónicos locales. Algunos investigadores explican las distintas direcciones de esfuerzo observadas en algunas regiones por la influencia de fallas de mayor escala sobre las trayectorias del campo primario de esfuerzos (Guiraud y Seguret, 1984; Guimera, 1988; Casas, 1992). La proliferación de modelos y ejemplos de estructuras secundarias a diversas escalas mueve a muchos geólogos al escepticismo acerca del valor que pueden tener las micro y mesoestructuras frágiles como indicadores para la reconstrucción de paleocampos de esfuerzos primarios. Normalmente, si las condiciones de observación son buenas, estas últimas aparecen en las fotografías aéreas como débiles entramados de líneas entre los espacios dejados por las fracturas cartográficas.
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