Lake Magadi

Lake Magadi

Location

Rift Valley

Coordinates

152 3616 / 1.867S 36.267E / -1.867; 36.267Coordinates: 152 3616 / 1.867S 36.267E / -1.867; 36.267

Basin countries

Kenya

Surface area

100 km

Lake Magadi is the southernmost lake in the Kenya Rift Valley, lying in a catchment of faulted volcanic rocks, north east of Lake Eyasi. During the dry season, it is 80% covered by soda and is well known for its wading birds, including flamingos.

Lake Magadi is a saline, alkaline lake, approximately 100 square kilometers in size, that lies in a graben. The lake is an example of a “saline pan”. The lake water, which is a dense sodium carbonate brine, precipitates vast quantities of the mineral trona (sodium sesquicarbonate). In places, the salt is up to 40 m thick. The lake is recharged mainly by saline hot springs (temperatures up to 86C) that discharge into alkaline “lagoons” around the lake margins, there being little surface runoff in this arid region. Most hot springs lie along the northwestern and southern shorelines of the lake. During the rainy season a thin (

Lake Magadi was not always so saline. Several thousand years ago (during the late Pleistocene to mid-Holocene) the Magadi basin held a freshwater lake with many fish, whose remains are preserved in the High Magadi Beds, a series of lacustrine and volcaniclastic sediments preserved in various locations around the present shoreline. Evidence also exists for several older Pleistocene precursor lakes that were much larger than present Lake Magadi. At times, Lake Magadi and Lake Natron were united as a single larger lake.

Lake Magadi is also well known for its extensive deposits of siliceous chert. There are many varieties including bedded cherts that formed in the lake and intrusive dike-like bodies that penetrated through overlying sediments while the silica was soft. Most famous is “Magadi-type chert”, which formed from a sodium silicate mineral precursor magadiite that was discovered at Lake Magadi during the 1960s.

Magadi township lies on the lake’s east shore, and is home to the Magadi Soda factory, owned by Tata India since December 2005. This factory produces soda ash, which has a range of industrial uses.

The lake is featured in Fernando Meirelles’s film The Constant Gardener, which is based on the book of the same name by John le Carr, although in the film the shots are supposed to be at Lake Turkana.

A causeway that crosses the lake provides access to the area west of the lake (Nguruman Escarpment). There is no tourist accommodation at Magadi townsite.

References

Baker, B.H. 1958. Geology of the Magadi area. Report of the Geological Survey of Kenya, 42, 81 pp.

Behr, H.J. 2002. Magadiite and Magadi chert: a critical analysis of the silica sediments in the Lake Magadi Basin, Kenya. SEPM Special Publication 73, p. 257-273.

Eugster, H.P. 1970. Chemistry and origin of the brines from Lake Magadi, Kenya. Mineralogical Society of America Special Paper, No. 3, p. 215-235.

Eugster, H.P. 1980. Lake Magadi, Kenya, and its Pleistocene precursors. In Nissenbaum, A. (Editor) Hypersaline brines and evaporitic environments. Elsevier, Amsterdam, pp. 195-232.

Jones, B.F., Eugster, H.P., and Rettig, S.L. 1977. Hydrochemistry of the Lake Magadi basin, Kenya. Geochimica et Cosmochimica Acta, v. 41, p. 53-72.

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Lakes of Kenya

Lakes

Baringo  Bogoria  Chew Bahir  Elmenteita  Kamnarok  Logipi  Magadi  Naivasha  Nakuru  Turkana  Victoria

Categories: Lakes of Kenya | Lakes of the Great Rift Valley | Saline lakes