10.04.2013 Views

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

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

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

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

fault and is filled with flood-basalt type volcanics <strong>of</strong> Quaternary age. This valley is,<br />

understandably, an active fault zone that is known as <strong>the</strong> "Karasu fault," and extends in a<br />

NE-SW direction. The authors collected eighteen samples for strontium isotope analysis<br />

<strong>from</strong> alkali basalts, quartz tholeiites, and olivine tholeiites, <strong>the</strong> results <strong>of</strong> which are<br />

reproduced in Figure 47 (solid dark-blue diamond). The 87 Sr/ 86 Sr values for <strong>the</strong> basalts<br />

range <strong>from</strong> 0.703353 to 0.704410, whereas <strong>the</strong> quartz-tholeiites are <strong>from</strong> 0.704410 to<br />

0.705490, and <strong>the</strong> olivine tholeiites <strong>from</strong> 0.703490 to 0.704780. The latter two types<br />

have higher 87 Sr/ 86 Sr values due to contamination <strong>of</strong> magmas by crustal materials (Alici<br />

et al. 2001: 124, 129). The second study, by Gale et al. (1981), hails <strong>from</strong> <strong>the</strong> Baër-Bassit<br />

area <strong>of</strong> Syria which lies north <strong>of</strong> Ugarit/Ras Shamra along <strong>the</strong> Levantine coast. The study<br />

is a more specific investigation concentrating primarily on <strong>the</strong> metalliferous sediments<br />

associated with Upper Cretaceous ophiolites. Only four samples were collected, and <strong>the</strong>ir<br />

locations are depicted in Figure 48. See also Figure 49 for a larger geologic map <strong>of</strong> <strong>the</strong><br />

region. The results are reproduced in Figure 47 (solid pink squares).<br />

It is readily apparent that <strong>the</strong> values <strong>from</strong> sou<strong>the</strong>astern Turkey and northwestern<br />

Syria range on opposite ends <strong>of</strong> <strong>the</strong> spectrum <strong>of</strong> typical 87 Sr/ 86 Sr values. The Karasu<br />

Valley has 87 Sr/ 86 Sr values typical <strong>of</strong> <strong>the</strong> basalt geology <strong>of</strong> <strong>the</strong> area, whereas <strong>the</strong> Baër-<br />

Bassit values derive <strong>from</strong> <strong>the</strong> strontium isotope signature <strong>of</strong> <strong>the</strong> Campanian-Maestrichtian<br />

sea, when <strong>the</strong> sediments were formed (Gale et al. 1981: 1299). These two studies only<br />

highlight <strong>the</strong> difficulties inherent in trying to characterize a geologically complex area by<br />

a narrow range <strong>of</strong> 87 Sr/ 86 Sr values. The complicated nature <strong>of</strong> <strong>the</strong> geology requires a<br />

large number <strong>of</strong> site-specific studies in order for a strontium isotope pr<strong>of</strong>ile <strong>of</strong> <strong>the</strong> region<br />

to be developed, and unfortunately such studies are not available at this time.<br />

132

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!