Alkaline Rocks and Carbonatites of the World

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Kerku

stripes

Occurrence number: 
122-00-019
Country: 
Nigeria
Location: 
Longitude: 8.33, Latitude: 10.07

Only provisional mapping of this occurrence is available (Raeburn et al., 1927) which, together with photo-interpretation (Turner, 1979), indicates the presence of two overlapping intrusions of which, like Rishiwa (No. 122-00-018) immediately to the north, the more northerly centre appears to be the more complex. The southern intrusion is a granite with sodic amphibole (riebeckite or arfvedsonite?) as the sole mafic mineral, while the northern one is predominantly syenite with in the northeast a further elongate mass of granite. The syenite contains 'hornblende and soda-augite' (Raeburn et al., 1927). In the more northerly granite amphibole substitutes for biotite in some facies.

References: 
RAEBURN, C., BAIN, A.D.N. and RUSS, W. 1927. The tinfields of Zaria and Kano Provinces. Bulletin, Geological Survey of Nigeria, 11: 1-71.TURNER, D.C. 1979. Nigeria: the northern ring complexes. Geological map, scale 1:250,000. St Andrews University Younger Granite Research Group.
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