GEOLOGY & PLANETARY SCIENCE A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z                    HOME ABOUT CATEGORIES SITE MAP COPYRIGHT ADVERTISE CONTACT entire Web this site Great Rift Valley The largest rift valley on Earth: a long depression in Southwest Asia and East Africa caused by the movement of tectonic plates, largely beginning during the Oligocene epoch. In Africa, it extends from Ethiopia southwest 1,200 miles through the lake regions. Many of the early hominid sites are in this valley system. Related category    • GEOLOGY AND PLANETARY SCIENCE Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) BACK TO TOP