Perte du Rhône
La Perte-du-Rhône is a sixty-metre-deep geologic fault just upstream of Bellegarde-sur-Valserine in France, into which the Rhone River used to disappear during the dry season.
In 1948 the Génissiat Dam, designed by French architects Albert Laprade and Léon Bazin, was built to the south of Bellegarde. With the construction of the dam, the perte du Rhône was transformed into a reservoir twenty three kilometres long, from Génissiat to the Swiss border. A similar feature called pertes de la Valserine still exists in the same area.
In 1854 Eugène Renevier professor of geology and paleontology in the University of Lausanne, with François Jules Pictet de la Rive wrote Fossiles du terrain aptien de la Perte-du-Rhône.
