Review of the Stone Heritage of the City of Oviedo, Asturias

Abstract The city of Oviedo, the capital of the autonomous community of Asturias, has a rich history that dates back to the late Roman Empire (4th century AD). The societies and cultures that left their mark over the centuries have contributed to a diverse architectural heritage, entirely constructed with stones sourced from local quarries. The most representative lithotypes are Piedramuelle limestone and Laspra dolostone. These rocks were quarried from the mid-High Middle Ages until the early 20th century. Piedramuelle limestone is a bioclastic limestone, in which two facies can be differentiated based on grain size: the yellow coarse-grained variety (Piedramuelle CG) and the reddish fine-grained variety (Piedramuelle FG). In contrast, Laspra dolostone has a microcrystalline texture, composed of more than 95% dolomite, with small amounts of quartz and clay. Both lithotypes are frequently found together in the architectural heritage. Piedramuelle, being massive and compact, was used for ashlars and the structural elements of buildings, while Laspra, which is easy to carve but fragile, was employed for interior ornamentation. The deterioration of the studied lithotypes is mainly caused by the interaction between their physical properties and the temperate-cold, humid regional climate, further intensified by urban conditions and historical coal pollution. These rocks are prominently represented in the architectural heritage of Oviedo, forming key components of the buildings in the historic center, some of which are recognized as World Heritage Sites by UNESCO (UNESCO World Heritage List #312). These lithotypes have not only served as essential materials in the construction of Oviedo’s architectural heritage but have also influenced and shaped the city’s character.