stripes
This 12x8 km complex includes both intrusive and extrusive rocks and displays an east to west progression of intrusive centres. The extrusive rocks include trachytic and rhyolitic tuffs, breccias and lavas. Clasts of basement rocks are abundant in the pyroclastic rocks and some tuffs may be ignimbrites. The intrusive series commences in the east with a syenite which is followed by a number of peralkaline syenites and granites. The syenite contains fayalite, biotite and diopsidic pyroxene. The peralkaline granites include a sodic amphibole, partly replaced by aegirine, while accessories include fluorite, zircon, possible astrophyllite and late 'deuteric' albite.
CURTIS, P. and BRINKMANN, K. 1985. The geology of younger intrusive alkali complexes in the southwestern Nuba Mountains, Sudan. Geologisches Jahrbuch, 63: 3-41.
