Alkaline Rocks and Carbonatites of the World

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

Tiguesmat El Akhdar

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Occurrence number: 
107-00-003
Country: 
Mauritania
Location: 
Longitude: -8.18, Latitude: 24.85
Carbonatite: 
No

The Tiguesmat peralkaline granite intrusion is approximately 10x10 km; a smaller peralkaline granite is located 15 km to the southeast. The rock is variably fine- to coarse-grained and consists of quartz, microcline perthite, with a little aegirine, riebeckite and biotite; there is accessory fluorite, astrophyllite, titanite and allanite.

Age: 
A Rb-Sr three point whole-rock isochron defined an age of 1912±47 Ma (Bessoles, 1977; Cahen et al., 1984)
References: 

BESSOLES, B. 1977. Géologie de l'Afrique: Le craton ouest Africain. Mémoires du Bureau de Recherches Géologiques et Minières, 88: 1-403.CAHEN, L., SNELLING, N.J., DELHAL, J. and VAIL, J.R. 1984. The geochronology and evolution of Africa. Clarendon Press, Oxford. 512 pp.CARTE GEOLOGIQUE de la dorsale regueibat et de ses bordures sedimentaires (Partie orientale). Republique Islamique de Mauritanie. 1974. Nations Unies. MAU-69-504. 1:500,000.

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