Born July 17. 1814, near Laufen; died Apr. 13, 1865, in Wallau. Swiss geologist.
In his work Geological Observations on the Solothurn Jurassic (1838–41), Gressly set forth the principles of the concept of facies, a term he used to denote various petrological types of any deposits and the related changes in the nature of the fauna. By using the data of facies analysis, Gressly for the first time compiled paleogeographic maps. In 1861 he gave a concise ecology of Mediterranean fauna (Recollections of a Naturalist in Southern France) as a basis for establishing the past conditions of life for various fossil marine animals. He termed this type of work “paleontological biology.”