Estudio petrográfico de la alteración en la arenisca del monasterio de Rueda (Sástago, Zaragoza). Primeros resultados

Abstract

A petrographical study about macroporosity, profiles of deterioration and treatment, has been taken out over seventeen samples from Rueda cloister. These samples have been taken from different placés from the monastery. They are all lithic sandstone with more than 50% of carbonated rock fragments, grain size between 0.4 and 0.9 mm and porosity under 14%. Five kind of deterioration processes have been found: microfissures parallels to the rock surface, cracks and microchannels perpendiculars to the sürfàte, salt precipitation onto or under the surface, black crusts and biological crusts. Several samples have evidences of ancient treatment; this treatment can be: lime mortar, whitewash, some kind of organic compound red-brownish isotrope and gypsum. At last, four kind of profiles of deterioration have been describe according to these results an d to the evolution of macroporosity