Re: dating methods

On Wed, 29 Nov 2006 17:36:49 +0100, "Micha Shepher" <m.
shepher@xxxxxxxxx> wrote:

Can someone answer this question:

1. Is there a reliable dating system for precious metals?

You may be able to date the age of the deposit if the precious metal
contains impurities. In case of gold it will be impossible if it was
nugget gold which is pure. In case of bronze it works if the bronze
hasn't been recycled, but that was commonly the case.

Dating the age of the deposit from which the ore came will help in
identifying the provenance, but not the artifact.

You cannot date the time when the precious metal was formed into a
weapon or other artifact.

2. If the location where the artifact was found is unknown, is it possible
at all to date it?

You can date ceramics independent of their location of manufacture by
thermoluminescence. You can also check the geochemical signature of
the clay from which it was formed, and sometimes it is possible to
find out where it came from. Sometimes a certain clay with a peculiar
assemblage of lithic debris is quite well known throughout a region,
say the Western Mediterranean, but only by pure chance one day they
find out where it was made. (In the present context I remember a
source which was eventually identified on the Eolian islands.) All
this was a pretty difficult task 15 years ago, but it has become
easier now that a very large data base is available which has been
worked out since.

3. How accurate can such a dating system be?

Very good question. Depends on the method, on the amount of
radioactive isotopes in the sample, and a bunch of other things.
Interpreting isotopic ages is not so easy.

4. Can it be applied without damaging the artifact?

Thermoluminescence I think yes, but not 100% sure. Methods based on
isotopes: no.

Hayabusa
.