Alkaline Rocks and Carbonatites of the World

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Rishiwa (Rishua)

stripes

Occurrence number: 
122-00-018
Country: 
Nigeria
Location: 
Longitude: 8.33, Latitude: 10.3

This complex has not been mapped in detail. Photogeological interpretation (Turner, 1979) indicates two overlapping oval centres of which the southern one probably consists of arfvedsonite granites and the northern one of the same rocks but with a partial, outer, earlier (?) intrusion of riebeckite-annite granite which on the western side contains an area comprising a net-veined assemblage of acid and basic rocks (Kinnaird, 1981). The fullest account is that of Raeburn et al. (1927) who identified molybdenite and allanite in granite.

References: 
KINNAIRD, J.A. 1981. Geology of the Nigerian anorogenic ring complexes. Geological map, scale 1:500 000. St. Andrews University Younger Granite Research Group.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