A reconsideration of Pan African orogenic cycle in the Anti-Atlas Mountains, Morocco

For over 50 years the Pan African orogeny has been recognized as a Neoproterozoic tectonothermal episode affecting West Africa 800–550Ma. As such, the Pan African events are similar to the Appalachian orogenic cycle extending from ~1100 to 250Ma and the Cordilleran orogenic cycle of 350Ma to the present. A significant difference is that the Appalachian orogenic cycle has long been recognized as consisting of separate Grenville, Taconic, Acadian and Alleghenian orogenies. Similarly, the Cordilleran orogenic cycle consists of distinct Antler, Sonoma, Nevadan, Sevier, Laramide and ongoing Cascadian-Andean orogenies. Failure to distinguish individual tectonic events in the Anti-Atlas Mountains has been attributable to the dearth of radiometric dates in this region. Since 2000, precision geochronologic dating in the Anti-Atlas Mountains, Morocco, has provided a means by which it is now appropriate to designate a Pan African orogenic cycle consisting of separate distinct orogenic events. We herein propose the following distinct orogenic events in the Anti-Atlas Mountains of Morocco: Iriri-Tichibanine orogeny (760–700Ma), Bou Azzer orogeny (680–640Ma) and the WACadomian orogeny (620–555Ma).