Alkaline Rocks and Carbonatites of the World

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Tumbine (Milange)

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Occurrence number: 
114-00-011
Country: 
Mozambique
Location: 
Longitude: 35.8, Latitude: -16.08

The almost circular intrusion of Tumbine has a diameter of 8 km and is expressed as the mountain of Serra Tumbine, which rises to 1542 m above a peneplain. The core of the intrusion consists of nepheline syenites which are surrounded by a ring of syenite. A sample of syenite described by Coelho (1959a) consists of perthite, biotite, aegirine-augite, with more sodic rims, riebeckite, scapolite and titanite. A second specimen has a gneissose fabric and consists of perthite, aegirine-augite, hornblende, biotite and a little riebeckite and apatite. Analyses of these two rocks indicate 7% and 14% normative nepheline, but quartz has been found in syenites close to the margins. A carbonatite is shown immediately southwest of Tumbine on Fig. 4.11.1 of Cilek (1989), but this may be an error.

Economic: 
Possible bauxite accumulations have been investigated but prove to be uneconomic (Cilek, 1989).
References: 
CILEK, V.G. 1989. Industrial minerals of Mozambique. Geological Survey, Prague. 326 pp.COELHO, A.V.P. 1959a. Reconhecimentos petrográficos sumários dos maciços da Lupata, Morrumbala, Chiperone-Derre e Milange. Boletim. Serviços de Geologia e Minas, Província de Moçambique, 26: 1-47.
Location: 
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith