Discovery of the African rift valleys: early work on the Gregory Rift Valley and volcanoes in Northern Tanzania
2008. "Discovery of the African rift valleys: early work on the Gregory Rift Valley and volcanoes in Northern Tanzania", The Gregory Rift Valley and Neogene—Recent Volcanoes of Northern Tanzania, J. B. Dawson
Download citation file:
The Austrian geomorphologist Eduard Suess was the first to recognize the importance of the African rift valleys. However, Suess never visited Africa, and he would never have been able to make his perceptive recognition of this aspect of the geomorphology of the African continent had it not been for earlier field explorers.
The discovery of the African rift valleys can be traced back to the middle part of the nineteenth century. At the time, little was known about the interior of much of Africa, partly because, due to uplift of the continental rim, easy access to much of the interior of Central Africa was precluded by major cataract systems near the mouths of many of the larger rivers (Congo, Niger, Zambesi).
The mainspring for the exploration of East Africa came from a largely unacknowledged source, the missionary community on the East African coast. In 1846, the Church Missionary Society of London established a mission station at Kisuludini in the Rabai Hills on the mainland across from Mombasa Island. The mission was started by Johann Krapf, who was soon joined by Johann Erhardt and Johann Rebmann. All three were Lutherans, trained at Basel; apparently the Society had difficulties recruiting British missionaries for the arduous mission life in East Africa (Oliver 1952). In addition to their pastoral duties, the missionaries travelled inland in attempts to find suitable sites for further mission stations and, during these journeys, they made observations on the geographical features they encountered. It was on such journeys that Rebmann
Figures & Tables
The structure and volcanic activity of the northern Tanzania sector of the Gregory Rift Valley have hitherto been described less than those in Ethiopia and Kenya. This book focuses on northern Tanzania where, although the volcanic area is smaller than those to the north, there are major features such as Kilimanjaro, the highest mountain on the African continent, Ngorongoro, one of the largest calderas on Earth, and Oldoinyo Lengai, the world’s only active carbonatite volcano. Following an account of the discovery and early exploration of the Rift Valley, there are descriptions of the individual volcanoes. These are set within the context of the regional geology and geophysics of the rift valley and in relation to the structural evolution of the rift and its associated sedimentary basins which include Olduvai, an important site in the history of human evolution. The volume concludes with a discussion of the volcanism in relation to the plume-related African Superswell.