Identificación de fases erosivas en la Pedriza de Manzanares a partir de formas de alteración expuestas

Abstract

Pedriza de Manzanares is the main part of the Sierra de Guadarrama National Park. The area is part also of the Late Paleozoic granites of the Spanish Central Range, intruded during the Variscan orogeny, and uplifted to its present position during Alpine orogeny. Pedriza is a well known area for its granite landforms which attract tourism, educators and rock climbers. The granite defines a landscape with alternance of regolith and fresh granite outcrops with abundant bornhards and boulders. We afford a first approach of this kind of erosion history in the area of Pedriza de Manzanares. The phases of erosion can be reconstructed measuring the position and dimensions of exposed granite underground weathering landforms. We can identify some correlation between variables like taffoni and flared slopes magnitude, regolith-outcrop ratio and taffoni organization in levels. In addition, these levels of taffoni allow us to identify several phases of regolith erosion in different settings and altitudes, and in relation to the geomorphic edaphic processes.