Geometría, distribución de desplazamientos análisis de curvatura en poblaciones de fallasejemplos de fallas a pequeña escala en la Fm. Barrios (sinclinal de Villazón-Reigada, Asturias)

Abstract

The non metamorphosed Ordovician quartzites that outcrop in the Cantabrian Mountains (Variscan belt of NW Iberia) are commonly intensely faulted depicting complex arrays of different fault sets. The analysis of two meter-scale contiguous arrays of faults, developed on a single bedding surface with complete exposure, shows different geometrical characteristics regarding the population statistics of single fault displacements and lengths. Detailed mapping allowed the identification of 144 individual faults in one array and 220 in the other array. The dataset consists of more than 7000 individual displacement measurements. Both fault populations contain single faults that show diifferent kinds of displacement profiles. Displacement/Length values are consistent with published values, although the correlation between both parameters is not very strong. In contrast, cumulative length and cumulative displacement log-log plots reflect different characteristics for both arrays. On one hand, one of the arrays displays a length population that suggests the presence of two different groups of faults whereas the displacement population does not reflect such a division. On the other hand, the second array displays an opposite behaviour. It is interpreted that both arrays represent different modes of development of a single fault population.