Alkaline Rocks and Carbonatites of the World

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

In Imanal

stripes

Occurrence number: 
105-00-007
Country: 
Mali
Location: 
Longitude: 0.1, Latitude: 20.15
Carbonatite: 
Yes

According to Sauvage and Savard (1985) this complex comprises an early alkaline intrusion which has been cut and strongly fenitized by later carbonatites. The alkaline rocks are predominantly ijolites and urtites with some nepheline syenites and pyroxenites. The carbonatites form not only numerous irregular intrusions and dykes throughout the complex, but are also abundant within the country rocks, particularly to the north. Two types of carbonatite have been distinguished. An early white sovite locally contains large crystals of pyroxene and alkali feldspar with apatite and zircon. There followed a series of dolomitic brown and brecciated carbonatites which sometimes contain abundant pyrochlore and magnetite. The carbonatites fenitize the country rock schists as well as the alkaline rocks and hydrothermal activity associated with this process led to deposition of veins of barite.

References: 

SAUVAGE, J.-F. and SAVARD, R. 1985. Les complexes alcalins sous-saturés à carbonatites de la région d'In Imanal (Sahara malien): une presentation. Journal of African Earth Sciences, 3:143-9.

Map: 
Fig. 3_163 The distribution of alkaline intrusions in the Tadhak Province, which lies to the northwest of the Iforas intrusions. The most northwesterly of the Iforas occurrences (Tessalit, No. 10) is shown. and Fig. 3_165 In Imanal (after Liegeois et al., 1991, Fig. 6B).
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