Abstract
The lakes of the Gregory Rift Valley are protected in national parks, reserves and conservation areas. Many of the lakes occur in areas of spectacular landforms located at the base of prominent escarpments. Palaeo-lakes were on average far larger (and deeper) during the Pleistocene. Currently, lakes are mostly relatively small, finger-shaped bodies with a maximum length of a few tens of kilometres. Lake basins have limited catchment and few outlets; rift platforms are tilted outwards so that major rivers flow away from the rift valley. Evaporation exceeds inflow resulting in high levels of alkalinity and salinity. The high sodium content is enhanced due to erosion of the sodium-rich volcanic rocks that characterise the Gregory Rift Valley. Lakes Bogoria , Nakuru, Elmenteita, Manyara and Eyasi are typical in this regard: they are finger-shaped, extremely shallow and markedly alkaline . They have an average pH of 10. Lakes Magadi and Natron are extraordinarily toxic; they contain brines with a pH of 12 that fossilises trees and animals by replacing the wood or bones with sodium carbonate. The alkaline lakes include salt deposits which are a mixture of two naturally occurring compounds of sodium carbonate, trona and natron. The salt deposits of Lake Magadi are quarried for soda ash. Lakes Baringo and Naivasha differ from the alkaline lakes in that they have a more rounded form, occur in basins with larger catchments and are dominated by freshwater. Important vertebrate and hominin fossils have been discovered in the Miocene–Pleistocene sediments of the Tugen Hills , near Lake Baringo . Geysers and hot springs discharge sulphurous brines into some lakes, including Baringo and Manyara. The geysers associated with Lake Bogoria are particularly well known. Many lakes and foreshores sustain significant concentrations of wildlife and they are refuges for more than 400 species of birds. Huge concentrations of flamingoes occur on some of the alkaline lakes.
Photographs not otherwise referenced are by the author.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
References
Baker, B. H. (1958). Geology of the Magadi area (Report 42, 81 p). Geological Survey of Kenya.Â
Baker, B. H. (1987). Outline of the petrology of the Kenyan Rift alkaline province. In J. G. Fitton & B. G. J. Upton (Eds.), Alkaline igneous rocks (Vol. 30, pp. 293–311). London: Geological Society of London Special Publication.
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, 257–273.
Cohen, A. S., Halfpenny, J., Lockley, M., & Michel, E. (1993). Modern vertebrate tracks from Lake Manyara, Tanzania and their paleobiological implications. Paleobiology, 19(4), 433–458.
Dawson, J. B. (2008). The Gregory Rift Valley and neogene-recent volcanoes of northern Tanzania (Vol 33, 102 p).  Geological Society London Memoirs.
Eugster, H. P. (1970). Chemistry and origin of the brines from Lake Magadi, Kenya. Mineralogical Society of America Special Paper, 3, 215–235.
Eugster, H. P. (1980). Lake Magadi, Kenya, and its Pleistocene precursors. In A. Nissenbaum (Ed.), Hypersaline brines and evaporitic environments (pp. 195–232). Amsterdam: Elsevier.
Gaciri, S. J., & Davies, T. C. (1993). The occurrence and geochemistry of fluoride in some natural waters of Kenya. Journal of Hydrology, 143, 393–412.
Hill, A., Curtis, G., & Drake, R. (1986). Sedimentary stratigraphy of the Tugen Hills, Baringo, Kenya. Special Publication Geological Society London, 25, 285–295.
Jirsa, F., Gruber, M., Stojanovic, A., Omondi, S. O., Mader, D., Korner, W., et al. (2013). Major and trace element geochemistry of Lake Bogoria and Lake Nakuru, Kenya, during extreme drought. Chem Erde, 73(3), 275–282.
Jones, B. F., Eugster, H. P., & Rettig, S. L. (1977). Hydrochemistry of the Lake Magadi basin, Kenya. Geochimica et Cosmochimica Acta, 41, 53–72.
Kaufmann, A., Mordeckai, M., Paul, M., Hillaire-Marcel, C., Hollos, G., Boaretto, E., et al. (1990). The 36Cl ages of the brines in the Magadi-Natron basin, East Africa. Geochimica et Cosmochimica Acta, 54, 2827–2833.
McCall, G. J. H. (1967). Geology of the Nakuru-Thomson’s Falls-Lake Hannington area. Explanation to degree sheet 35 (SW quadrant) and 43 (NW quadrant) (Report 78, 122 p). Geological Survey of Kenya.
Nicholson, S. E. (1996). A review of climate dynamics and climate variability in Eastern Africa. In T. C. Johnson & E.O. Odada (Eds.), The Limnology, Climatology and Paleoclimatology of the East Africa Lakes (pp. 25–56). Amsterdam: Gordon and Breach.
Olago, D., Opere, A., & Barongo, J. (2009). Holocene palaeohydrology, groundwater and climate change in the lake basins of the Central Kenya Rift. Hydrological Sciences Journal, 54(4), 765–780.
Renault, R. W. (1993). Zeolitic diagenesis of late Quaternary fluviolacustrine sediments and associated calcrete formation in the Lake Bogoria Basin, Kenya Rift Valley. Sedimentology, 40(2), 271–301.
Renaut, R. W., & Tiercelin, J.-J. (1993). Lake Bogoria, Kenya: Soda, hot springs and about a million flamingos. Geology Today, 9, 56–61.
Renaut, R. W., & Tiercelin, J.-J. (1994). Lake Bogoria, Kenya Rift Valley: a sedimentological overview. In R. W. Renaut & W. M. Last (Eds.), Sedimentology and Geochemistry of Modern and Ancient Saline Lakes (Vol. 50, pp. 101–123). Tulsa: SEPM Special Publication.
Renaut, R. W., & Owen, R. B. (2005). The geysers of Lake Bogoria, Kenya Rift Valley, Africa. GOSA Transactions, 9, 4–18.
Schwartz, H., Renne, P. R., Morgan, L. E., Wildgoose, M. M., Lippert, P. C., Frost, S. R., et al. (2012). Geochronology of the Manyara Beds, northern Tanzania: New tephrostratigraphy, magnetostratigraphy and 40Ar/39Ar ages. Quaternary Geochronology, 7, 48–66.
Street, F. A., & Grove, A. T. (1979). Global maps of lake fluctuations since 30,000 yr BP. Quaternary Research, 12, 83–118.
Vincens, A., & Casanova, J. (1987). Modern background of Natron-Magadi basin (Tanzania-Kenya): Physiography, climate hydrology and vegetation. Science Geology Bulletin (Frankfurt), 40(1–2), 9–21.
Wood, B. (1999). Plio-Pleistocene hominins from the Baringo Region, Kenya. In P. Andrews & P. Banham (Eds.), Late cenozoic environments and hominid evolution: A tribute to Bill Bishop (pp. 113–122). Geological Society of London.
Woolley, A. (2001). Alkaline rocks and carbonatites of the world. Part 3: Africa (372p). Geological Society of London.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
Copyright information
© 2018 Springer International Publishing AG, part of Springer Nature
About this chapter
Cite this chapter
Scoon, R.N. (2018). Lakes of the Gregory Rift Valley: Baringo, Bogoria, Nakuru, Elmenteita, Magadi, Manyara and Eyasi. In: Geology of National Parks of Central/Southern Kenya and Northern Tanzania. Springer, Cham. https://doi.org/10.1007/978-3-319-73785-0_15
Download citation
DOI: https://doi.org/10.1007/978-3-319-73785-0_15
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-319-73784-3
Online ISBN: 978-3-319-73785-0
eBook Packages: Earth and Environmental ScienceEarth and Environmental Science (R0)