Procesos degradativos en antiguas superficies grabadas sobre granitos: Indicadores de magnitud y patrones de estado

Abstract

This paper analyzes the so called, (pilas, gnammas, vasque, etc.), small concavities that retain the water of the rain/ runoff that develops etching processes. Some authors support the beginning of the form already undersoil/ regolith, though all recognize the main development of the form in subaerial environment. The chemical weathering by water increases the size of the pias (pilas, gnamma, vasque), much greater when older is the surface over it develops. Any process that stop the normal evolution (burial, erosion, etc.) can modificate the relative age of the host surface that will be demonstrated younger than in reality is. The size parameters defined by statistic analysis of this measures has a relative chronological value since demonstrate the relationship among evolution of the form and the age of the surface.In this work is presented the analysis of evolution of pias (gnammas, pilas, vasque), of different surfaces developed with a chronology topografically successive to the one which can be assigned also an absolute chronology (by cosmogenic isotopes) that it has been used to know the generation age of the form