Tracking the Material History Through the Analysis of Past and Present Alterations and Restorations. Application to Doors and Walls of the Museum Najerillense (La Rioja, Spain)

Abstract. Elements of cultural heritage are living entities with a history that is sometimes marked on its surface by means of different types of alterations (stains, wearing, graffiti, erosion, etc.). The discipline of conservation-restoration aims to preserve the materiality of these elements and presents them to users in a suitable manner; but it is also aware of the historic interest of some of these alterations and, consequently they cannot be just erased without being documented and explained. This is precisely the starting point of the present contribution, where the comparison of decay patterns in different elements of a building —the regional museum of archaeology and ethnography of Najera (La Rioja, Spain)— is explored as a complementary methodology to analyse the material history of the building. As many of these alterations have influence in the three-dimensional geometry of the surfaces and the texture, they can be monitored by means of the products that are generated during the geometric documentation works. The text presents a methodology for the study structured in four stages and draws some conclusions about the potential of this approach.