stripes
Singeir is a 15 km diameter ring complex with the smaller 6x4 km intrusion of Kurbei lying immediately to the northeast. The larger complex consists of arcuate intrusions of sodic amphibole granite with stringers, particularly in the inner parts, of biotite-hornblende granite. Between the sheets of peralkaline granite are areas of intimately mixed intrusive and basement rocks. There are numerous aplitic and micro-granitic dykes within the complex that are mainly tangential. The basement acidic and hornblende gneisses are metamorphosed for several hundred metres from the contact. Kurbei consists of the same amphibole peralkaline granite. Swarms of peralkaline rhyolitic, rhyodacitic and kersantitic dykes surround the complex.
BARTH, H. and MEINHOLD, K.-D. 1979. Mineral prospecting in the Bayuda Desert. Part 1, Volume A. Investigation of mineral potential. Technical Report Sudanese-German Exploration Project. Hannover (Bundesanstalt fur Geowissenschaften und Rohstoffe). 336 pp. (unpublished) BARTH, H., BESANG, C., LENZ, H. and MEINHOLD, K.-D. 1983. Results of petrological investigations and Rb/Sr age determinations on the non-orogenic igneous ring-complexes in the Bayuda Desert, Sudan. Geologisches Jahrbuch, 51: 1-34.
