Iberian roofing slate as a Global Heritage Stone Province Resource

The Iberian Peninsula is, nowadays, the main producer of roofing slate of the world. Most of the outcrops are located in the NW of the Iberian Peninsula, in the regions of Galicia, Leon, and in Portugal. The technique of working and roofing with slate was brought from Flanders by King Felipe II by the second half of the XVI century. The most representative building from this period is the Monastery of El Escorial, N Madrid. However, the Spanish slate industry remained incipient until the 1960s, when Galicia and Leon suffered an accelerated industrialization process which greatly enhanced the volume of production. Additionally, the Portuguese slate industry was well developed by the second half of the XIX century. Most of the Portuguese production was exported, mainly to the United Kingdom. By the second half of the XX century, the Spanish, and in a lesser extent, the Portuguese roofing slate spread all over Europe, forcing most of the existing European quarries to close. Nowadays, different varieties of roofing slates are quarried, mainly in Spain, being used indistinctly in new residential construction and for restoration of historical buildings. The main importing countries are France, Germany and the United Kingdom. This work presents an overview of the history and main varieties of the Iberian roofing slate, in order to propose its inclusion as a Global Heritage Stone Province.