Heat flow across the East African Plateau

Four new heat flow measurements from western Tanzania are combined with existing data from non-rifted areas of East Africa to determine if there is a broad heat flow anomaly associated with the East African Plateau. Three of the new data sites lie in the Kibaran Belt and yield heat flows of 60, 68, and 74 mW m^-2. The fourth new site is in the interior of the Tanzania Craton and gives a heat flow of 33 mW m^-2. The ensemble of heat flow data from the interior of East Africa, when compared to the global distribution of heat flow in tectonically undisturbed Precambrian terrains of similar age, indicates that heat flow from the center of the Plateau is not elevated. This finding suggests that if the lithosphere beneath the interior of the Plateau lithosphere has been thermally perturbed, as proposed previously by many investigators, then the thermal anomaly must be of insufficient magnitude and/or has not existed for an adequate length of time to affect surface heat flow.