Jamhuri Ya Muungano Wa Tanzania

Tanzania Geothermal Development Company


Eneo la jotoardhi la Manyara

The site is located on the western side of Lake Manyara in the Lake Manyara National Park in Arusha Northern Tanzania.

The field is located in the eastern arm of the East Africa Rift System. The geology of the site is dominated by gneiss basement rocks that are distributed in the field. The basement rocks are associated with NNE- SSW trending lineaments which seem to be a fault due to presence of a well-developed scarp.

Lake Manyara is associated with different minerals including the olive green clays likely to be bentonitic in composition which occur in association with other lacustrine sediments. These bentonites were formed as a result of volcanic ashes alteration when deposited in saline water of Lake Manyara.

Radiocarbon dates from four diatom horizons indicate ages ranging from 12 Ka to 135 Ka suggesting a Mid-Holocene age. Middle Pleistocene ages have been assigned to the ridged oncolites of Lake Manyara. The olive green colored clays in the Manyara basin are known to occur in association with other lake beds including phosphorite deposits, stromatolites, bioturbatedsilty clays, partly silicified marls, conglomerates and olive green colored opal beds.