Alkaline Rocks and Carbonatites of the World

Setup during HiTech AlkCarb: an online database of alkaline rock and carbonatite occurrences

Lake Simbi Crater

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Occurrence number: 
085-00-045
Country: 
Kenya
Region: 
Homa Bay district
Location: 
Longitude: 34.63, Latitude: -0.37
Carbonatite: 
No

This explosion crater (maar) is located 15 km east of Homa Mountain and comprises a low-angle, 5-20 m high ring of talus around a lake. The outward dipping sediments are heavily altered now consisting of clays and gravels but some are recognisably pyroclastic. Amongst the rock fragments have been found one of bronzite pyroxenite with an olivine melilitite rim. The latter consists of fresh euhedral melilitite laths, olivine, magnetite and perovskite. Fragments of feldspathic micro-ijolite, aegirine-K-feldspar fenite and biotite alvikite have also been found.

References: 

LE BAS, M.J. 1977. Carbonatite-nephelinite volcanism: an African case history. John Wiley, London. 347 pp.

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith