| Abstract: | An asthenospheric, diapir-type continental rift-valley model is developed. This model seems to satisfy the gravity anomalies observed over some of the rifts of East Africa without necessitating the assumption of excessively thick sections of low-density sediments or exceedingly low-density volcanics in the valleys. It is suggested that frequently observed large-amplitude Bouguer anomaly minima coinciding with some rift valleys are partially caused by hot creep of material from the lower crust into the mantle material in the rift zone. |
