Abstract

GARCIA-RODRIGUEZ, Manuel; GOMEZ-HERAS, Miguel; FORT, Rafael  and  ALVAREZ DE BUERGO, Mónica. Thermal control of weathering of hardened surfaces on granitic rocks (Pedriza de Manzanares, Spain). Bol. Soc. Geol. Mex [online]. 2015, vol.67, n.3, pp.533-544. ISSN 1405-3322.

Pedriza de Manzanares is part of the Guadarrama National Park in the Spanish Central System. It is characterized by a labyrinthine landscape composed of alternating blocks and large walls of granite. Case-hardened crusts of millimetric thickness covering most of these rock surfaces control the surface alteration and favor the development and distribution of micro-reliefs on the walls. Some variables such as temperature, sclerometric index and micro-relief morphology are analyzed in this paper in order to explain the destructive process of alteration that favors the formation of irregularities on the granite surface. On the other hand, the paper establishes the relation between the first stage of case-hardening in sub-edaphic conditions, which is associated with the alteration front, and the thickness of such crusts and regolith erosion. These results can be applied to other granitic regions with similar characteristics all over the world.

Keywords : Case-hardening; granite weathering; Pedriza de Manzanares; Guadarrama National Park.