Desert rivers - Climatic Change in Deserts - page 179

Figure 10.10. Blue Nile paleochannels, central Sudan. (After Williams, 2009b .)
The first attempt at luminescence dating of White Nile alluvium was on sediment
cores collected from a 6 m deep trench dug near the village of Esh Shawal, 300 km
upstream from the Blue and White Nile confluence at Khartoum ( Figure 10.5 ). The
luminescence ages revealed that White Nile alluvium dated back to at least 240 ka
(Williams et al., 2003 ), consistent with independent but similar estimates for the
inception of Lake Victoria in the Ugandan headwaters (Talbot and Williams, 2009 ;
Williams and Talbot, 2009 ).
A series of sinuous Blue Nile paleochannels are very clearly visible on air photo-
graphs of the north-west Gezira ( Figure 10.11 ). They continue towards the White Nile
and disappear beneath the dunes located between Jebel Aulia in the north and Naima