Orogeny process whereby new mountains and other land-forms were thrust up, or else there would eventually be no land; he suggested that marine fossils in mountainsides must once have been at the sea-floor. Orogeny was used by Amanz Gressly (1840) and Jules Thurmann (1854) as "orogenic" in terms of the creation of mountain elevations, as the term "mountain building" was still used to describe the processes. Elie de Beaumont (1852) used the evocative "Jaws of a Vise" theory to explain orogeny, but was more concerned with the height rather than the implicit structures created by and contained in orogenic belts. His
Colorado orogeny Colorado orogeny The Colorado orogeny, or Colorado orogen, was an orogeny in Colorado and surrounding areas which was a part of the development of the ancestral Rockies. The Colorado orogeny, formerly called the Colorado province, is a >500-km-wide belt of oceanic arc rock (1.78–1.65 Ga) that extends southward into New Mexico and composes a major part of the Proterozoic provinces of southwestern United States. This transcontinental collisional event occurred during the Paleoproterozoic (Statherian Period). The Wyoming sector of the Colorado orogeny was formerly called the Medicine Bow orogeny. The eastern sector extends into the High Plains and is called the