Perte-du-Rhône . North of Bellegarde-sur-Valserine

Bellegarde-sur-Valserine

Bellegarde-sur-Valserine is a commune in the Ain department in eastern France.-Geography:Bellegarde is located at the confluence of the Valserine and the Rhône....

 there is a sixty metre deep fault into which the Rhone used to disappear during the dry season. In 1948 the Génissiat Dam was built south of Bellegarde and the perte du Rhône was transformed in a reservoir twenty three kilometre long from Génissiat to the Swiss border. A similar feature called pertes de la Valserine

River Valserine

The river Valserine is a tributary of the Rhone that flows for from the Col de la Faucille in the Jura Mountains to its confluence with the Rhone at Bellegarde-sur-Valserine...

still exits in the same area.

In 1854 Eugène Renevier

Eugène Renevier

Eugène Renevier Swiss geologist, was born at Lausanne, Switzerland, as a descendant of a noble family.In 1857 he became professor of geology and paleontology in the University of Lausanne...

 professor of geology and paleontology in the University of Lausanne, with François Jules Pictet de la Rive

François Jules Pictet de la Rive

François Jules Pictet de la Rive was a Swiss zoologist and palaeontologist.He was born in Geneva. He graduated B. Sc. at Geneva in 1829, and pursued his studies for a short time at Paris, where under the influence of Georges Cuvier, de Blainville and others, he worked at natural history and...

wrote Fossiles du terrain aptien de la Perte-du-Rhone.