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

Chapter 6
Principles of Stable Isotope Ratio Analysis
After a review of the pertinent archaeological and historical evidence, it becomes
evident that a detailed program of source discrimination using isotope ratio analyses is in
order, so as to trace the source of the raw material of ivory. Analyses conducted by van
der Merwe et al. (1990) using 13 C/ 12 C, 15 N/ 14 N, and 87 Sr/ 86 Sr isotope ratios in the bone
collagen of modern African elephants demonstrated the efficacy of this method for
provenancing elephant bone and ivory. Furthermore, recent research by White et al.
(1998) testified to the utilization of 18 O/ 16 O to distinguish between populations. Thus a
detailed analysis of the elephant and hippopotamus ivory from the Uluburun shipwreck
was carried out by determining the isotope ratios of 13 C/ 12 C, 15 N/ 14 N, 18 O/ 16 O, and
87 Sr/ 86 Sr. δ 13 C and δ 15 N will be measured from the collagen component of the ivory and
bone samples, if preserved, whereas δ 13 C and δ 18 O was measured from the apatite
(inorganic component of ivory and bone). An ashed sample will be used to analyze the
87 Sr/ 86 Sr ratio. All measurements were made with a Finnigan MAT Delta plus XL mass
spectrometer or by ICP-MS (Inductively Coupled Plasma Mass Spectrometry). The ivory
samples may be provenanced by comparing the strontium isotope ratio values obtained
with published geological data on the regions under study (namely, Syria, Palestine,
Egypt, Sudan, and Libya). The carbon, nitrogen, and oxygen isotope ratios are useful in
reconstructing the environment of the animal, and therefore help to narrow down the
possibilities.
Isotope ratio analysis has been utilized in archaeological bone chemistry studies
to reconstruct the diet and health of ancient populations, palaeoclimate, as well as to
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