Tracing the Source of the Elephant And Hippopotamus Ivory from ...

North Africa
Now moving north another dearth of published strontium isotope values is seen.
Whatever strontium values are available as outlined below have been culled from
research either not directly discussing the region, or concerned primarily with very
specific geological formations. From the Great Sand Sea in western Egypt the 87 Sr/ 86 Sr
values for the local sandstone range from 0.70910 to 0.71053 (n = 5; plotted in Figure 47
as open orange squares) (Schaaf et al. 2002: 570). The local sandstone was sampled
from the area where the arrow in Figure 63 indicates “LDG strewn field.” Nevertheless,
these values are only useful if ‘desert’ elephants should be represented in the Uluburun
samples. However, the local sandstone (marked “LDG field”) was plotted, in Figure 64,
against sandstone samples from the BP and Oasis crators (data from Abate et al. 1999)
and Precambrian granitic rocks from northeast Africa west of the Nile (data from Pegram
et al. 1976; Schandelmeier and Darbyshire et al. 1984; Harms et al. 1990). From this
graph a value of 0.70625 to greater than 0.7140 is estimated for the Precambrian granitic
rocks.
Küster and Liégeois (2001) sampled many types of geology along the Nile in the
Bayuda Desert, located north of Khartoum (see Figure 65 for location). Unfortunately
the strontium isotope values (Table 7) have an extremely large range and as a result prove
virtually useless.
Returning full circle to the topic of the strontium budget of the eastern
Mediterranean, the strontium isotope signature for Saharan dust is discussed by Grousset
et al. (1998), but in the context of the Atlantic off the coast of northwest Africa. It seems
that 87 Sr/ 86 Sr ratios increase with decreasing grain size in carbonate-free sediments
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