Dating an orogeny
Although orogeny involves plate tectonics, the tectonic forces result in a variety of associated phenomena, including magmatization, metamorphism, crustal melting, and crustal thickening.Debate exists about the extent to which erosion modifies the patterns of tectonic deformation (see erosion and tectonics).Thus, the final form of the majority of old orogenic belts is a long arcuate strip of crystalline metamorphic rocks sequentially below younger sediments which are thrust atop them and dip away from the orogenic core.During orogeny, deeply buried rocks may be pushed to the surface.
Sea bottom and near shore material may cover some or all of the orogenic area.
The Basement complex of Nigeria is polycyclic and retains memories of events dating back to about 3000 m. As in other parts of Africa, it suffered its most pronounced deformation and remobilisation during the Pan African Orogeny (about 650-450 m. It is also shown that the basement may have participated in the 1300-900 m. Das Basement Nigerias ist polyzyklisch aufgebaut mit Ereignissen, die bis zu 3000 m. Auch wird gezeigt, da\ das Basement von der Kibarischen Orogenese vor 1300-900 m. Le complexe du soubassement nigérien est polycyclique, et porte la marque d'événements remontant à 3.000 millions d'années.
Dating an orogeny comments