Alkaline Rocks and Carbonatites of the World

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

Umm Shibrik

stripes

Occurrence number: 
155-00-008
Country: 
Sudan
Location: 
Longitude: 36, Latitude: 21.6
Carbonatite: 
No

This circular intrusion consists of an earlier central leucocratic granite which is surrounded by a marginal syenite. Detailed petrography is not available. Palaeomagnetic data are given by Cavanagh (1979).

Age: 
Two samples from the granite plug and one from the inner syenite ring gave a Rb-Sr age of 94±16 Ma which Cavanagh (1979) indicates should be regarded as an approximation because of the few data.
References: 

CAVANAGH, B.J. 1979. Rb-Sr geochronology of some pre-Nubian igneous complexes of central and northeastern Sudan. Ph.D. Thesis, University of Leeds. 239 pp. (unpublished)GASS, I.G. 1955. The geology of the Dunganab area, Anglo-Egyptian Sudan. M.Sc. thesis, University of Leeds. 100 pp. (unpublished)

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