Alkaline Rocks and Carbonatites of the World

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

Erbairi

stripes

Occurrence number: 
155-00-012
Country: 
Sudan
Location: 
Longitude: 36.33, Latitude: 21.28
Carbonatite: 
No

An approximately circular intrusion of quartz syenite 3 km in diameter, but little petrography is known.

Age: 
A whole rock K-Ar determination on syenite gave 147 Ma (Vail, 1976). A Rb-Sr study of four samples gave inconclusive results, because of probable weathering, but reference lines through the data of 138 Ma and 98 Ma suggest emplacement during the Cretaceous (Cavanagh, 1979).
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 (unpublished)GASS, I.G. 1955.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 (unpublished)VAIL, J.R. 1976. Location and geochronology of igneous ring-complexes and related rocks in north-east Africa. Geologisches Jahrbuch, B20: 97-114.

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