Robert Wyns holds a PhD in structural geology (Université Pierre et Marie Curie) and has been a geologist at the Bureau de Recherches Géologiques et Minières since 1981. He participated in the survey of the geological map of France in the Paris basin and then in the Armorican Massif, before leaving for the Middle East and Saudi Arabia. He has also worked on mining (France, Saudi Arabia) and oil projects (Madagascar) and has participated in numerous research projects. Since 1995, its activity has focused mainly on rock alteration processes and the characterization of their physical properties, through scientific research projects and applications, particularly in support of public policies. He has developed methods for mapping and modelling these properties, particularly in the context of altered basement. It is at the origin of the discovery of the fissured horizon in the deep part of the lateritic profiles and its link with alteration processes. Together with his hydrogeological colleagues, in particular Patrick Lachassagne and Benoît Dewandel, he contributed to the development of the modern concept of the stratiform basement aquifer and its validation in different countries or continents (Europe, South Korea, India, Burkina Faso, Guinea, Madagascar, Guyana, New Caledonia...). In addition to his research and public policy support activities, he has been teaching in several universities and engineering schools for the past twenty years, and leads a training course dedicated to the alteration of rocks and their applications within the BRGM.