The Eocambrian (Vendian sensu stricto)

Abstract

Different geologic formations that originated after the Katangan orogeny are here attributed to the Eocambrian, the time of their formation being after 680–650 m.y. and prior to the beginning of the Cambrian period, that is earlier than 570 m.y. The duration of the Eocambrian is thus 100–80 m.y., which is much shorter than that of other principal units in a general scale of the Precambrian. Moreover, unlike other Precambrian eras and suberas, separated by diastrophic cycles, the Eocambrian is marked by a large orogeny only at its beginning, and its boundary with the Cambrian shows no traces of any important tectonic events.