Andean orogeny Andean orogeny The Andean orogeny () is an ongoing process of orogeny that began in the Early Jurassic and is responsible for the rise of the Andes mountains. The orogeny is driven by a reactivation of a long-lived subduction system along the western margin of South America. On a continental scale the Cretaceous (90 Ma) and Oligocene (30 Ma) were periods of re-arrangements in the orogeny. Locally the details of the nature of the orogeny varies depending on the segment and the geological period considered. Subduction orogeny has been occurring in what is now western South America since the break-up
Antler orogeny due to sea-level rise in the Cambrian rather than displacement from an ocean basin. The sedimentary effects of the Antler orogeny are well known and well described in many published reports, but the exact nature of that event and the driving force remain unsettled. Among the unanswered questions are these: what aspect of plate tectonics was involved; what effect did the Alamo impact event have; why did marine basins appear in the area of general uplift; why did the western facies assemblage, and not the eastern assemblage, include bedded chert, basaltic bodies, barite deposits, and sulfide deposits. Antler orogeny The