On Thu, 26 Aug 1999 [log in to unmask] wrote:
>
> Turquoise in the Americas, Scientific American, FEb. 1992, p. 84 has a great
> article on how Western US turquoise ended up in Aztec Masks from the Spanish
> explorations of the 1500 that were traded throughout Europe.
>
This article (by Harbottle and Weigand) is not to be relied upon. Their
reconstructions of prehistroic trade in turquoise were based upon trace
element analyses of turquoise sources in the American southwest and of a
smallish sample of artifacts. The underlying data were never published,
and those of us who are somewhat knowledgeable about archaeometric
approaches to tracing inorganic materials to source are extremely
sceptical - everything that we know about the geology and geochemistry of
copper deposits suggests that chemical variation within individual copper
deposits is likely to be great (a potential problem not addressed by the
authors of the study, who seem to have run only a couple of samples from
each source). The only viable way of approaching this is through lead
isotope analysis - Suzanne Young of Harvard has for some years been
systematically studying southwestern turquoise deposit by this method, but
her work is far from complete yet.
----------------------
David Killick
Associate Professor, Department of Anthropology,
University of Arizona, Tucson, AZ 85721-0030.
Phones: office (520)621-8685; laboratory 621-7986; fax 621-2088
[log in to unmask]
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|