Alkaline Rocks and Carbonatites of the World

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Mba Namboe (Sabon Gari)

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Occurrence number: 
029-00-021
Country: 
Cameroon
Location: 
Longitude: 11.2, Latitude: 6.35

This is an approximately circular, 7 km diameter intrusion consisting of a leucocratic microgranite with a little epidote and a peralkaline granite of perthite, riebeckite and aegirine with some fluorite and epidote.

Age: 
Cantagrel et al. (1978) report a K-Ar age of 48.5(1 Ma and a Rb-Sr whole rock isochron combining data from Mba Namboe with Mayo Darle (No. 19) gave 63.3(1.3 Ma (Lasserre, 1978).
References: 
CANTAGREL, J.-M., JAMOND, C. and LASSERE, M. 1978. Le magmatisme alcalin de la ligne du Cameroun au Tertiaire inférieur: données géochronologiques K/Ar. Bulletin de la Société Géologique de France Compte Rendu Sommaire des Seances, 20: 300-3.LASSERRE, M. 1978. Mise au point sur les granitoides dits "ultimes" du Cameroun: gisement, pétrographie et géochronologie. Bulletin du Bureau de Recherches Géologiques et Minières. Paris, IV: 143-59.
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