Alkaline Rocks and Carbonatites of the World

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Djounhane (Idounyan)

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Occurrence number: 
105-00-019
Country: 
Mali
Location: 
Longitude: 1.1, Latitude: 18.47

Situated immediately west of Kidal-Tibeljeljeline (No. 105-00-020) Djounhane is an almost perfectly circular complex 15 km in diameter which is revealed strikingly on satellite photographs (Ba et al., 1985, Fig. 3; Liégeois and Black, 1984). The first phase is a coarse peralkaline to peraluminous granite which forms an outer ring-dyke that has weathered to an annular ridge. This rock consists of perthite, quartz, aegirine-hedenbergite and sodic and calcic-sodic amphiboles which passes into a rock with biotite and calcic amphibole. This is intruded by a heterogeneous hastingsite-biotite granite which in turn is cut by an inner plug of fine-grained biotite-chlorite granite.

Age: 
Probably contemporaneous with Kidal-Tibeljeljeline (No. 105-00-020).
References: 
BA, H., BLACK, R., BENZIANE, B., DIOMBANA, D., HASCOET-FENDER, J., BONIN, B., FABRE, J. and LIÉGEOIS, J.P. 1985. La province des complexes annulaires alcalins sursaturés de l'Adrar des Iforas, Mali. Journal of African Earth Sciences, 3: 123-42.LIÉGEOIS, J.-P. and BLACK, R. 1984. Petrographie et geochronologie Rb-Sr de la transition calco-alcaline-alcaline fini-panafricaine dans l'Adrar des Iforas (Mali): accretion crustale au Precambrien superieur. In. J. Klerkx and J. Michot (eds), Geologie africaine - African Geology. 115-25.
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