1. Introduction 4
2. Sampling and Analytical Methods 6
3. Summary of the Geology of Alkali Igneous Complexes in the Nuba Mountains 7
3.1 Regional Setting 7
3.2 Petrographic Summary and Definition of Terms 8
3.3 Geochemical Summary 8
4. Alkali Igneous Complexes, Geology and Age Determinations 11
4.1 Jebel Buram: Quartz Alkali Syenite 11
4.2 Masakin Jebels: Reika Alkali Granite and Jebel Doleibaya Biotite Granite 12
4.3 Jebel Tabaq: Alkali Granite 15
4.4 Jebel Kadugli: Biotite Granite 15
4.5 Moro-Limon Hills: Kororak Quartz Syenite 16
4.6 Jebel Keiga: Alkali Syenite 17
4.7 Jebel Tuna: Foid Syenite 18
4.8 Jebel Ed Dair: Alkali Granite 19
4.9 Jebel Liri: Basement, Biotite Granite 20
4.10 Geochronological Summary 21
5. Discussion 22
6. References 23