Lineaments in the West-Central Hesperic Massif (Portugal and Spain) and their geomorphic and tectonic significance

Resumen

A 1:100,000 scale map of lineaments in the West-Central Hesperic Massif has been obtained from the analysis of a digital elevation model (DEM) at the same scale. Lineaments were then correlated with topographic features in order to establish regional tectonic relationships. The correlation of some of the lineaments with mapped faults, especially those with a supposed Cainozoic origin, and the assumption that other lineaments also represent fault traces, enables a fuller interpretation of the brittle tectonics of the Variscan basement, as well as the identification of new lines of fracture that are potentially active in the context of the present-day stress field. A correlation between lineaments and seismicity is also established in order to understand the distribution of epicenters, and the way in which plate boundary stresses are transmitted to the interior of the massif. This correlation indicates the efficient transmission of stress along lineaments at the Portuguese Margin, which is attributed to a tighter coupling of the plate boundary west of Gibraltar.