Las areniscas de la Catedral de Sigüenza (Guadalajara): estudio petrológico

Abstract

The Cathedral of Siguenza (13rd Century) was built with stony materials, mainly sandstones (arkoses). Three different types of rocks are distinguished: red, green and yellow sandstones with coarse to medium grain-size. Green shades and coarse arkosic sandstones present the higher index of decay. The three facies of study show several pathologies such as grain disgregations, grooves, alveolar erosions, etc. Green arkoses have the worse hydric behaviour of the three studied facies, showing higher water saturation degrees and capillarity coefficients. These facies are more affected directly for humidity-dryness processes. By the other way, durability related with salts and water crystallization into their porous systems is higher than the other facies. On the other hand, red arkoses present the best mechanic and hydric behaviour, so they are the most suitable to be used as substitution materials in future restoration-conservation works. Ancient quarries are located In the Anticlinal of Siguenza (Triassic, Buntsandsteln).