[log in to unmask] wrote:
> ...There are several suspicious
> indices - besides the already discussed - which made me to
> separate these very small slag cakes from common smithing waste
> (which is present on the site too):
> 1. relatively low content of FeO + Fe2O3 (most often 30 + 3%, but
> once only 10%! - see table of chemical composition I attached) while
> smithing slags are here commonly of cca 40% - 45% Fe oxides
Without having seen the specimen or the exact mineralogical compositions and
structures ("Telephon-Diagnose"):
One characteristic feature of "smithing slags" is the EXTREMELY wide range of
composition - due to different activities in the same hearth - despite the
fact that its "normal" composition varies about that of faylithic slags.
> 2. indices of cca 1 cm wide projections from the edge of slag cakes
> (towards a taphole?)
In seemingly rare cases (i.e. Elisenhof) smithing slags may end in a
protrusion (up to several cms length) which can be explained as (secondary)
filling of a blow hole (tuyere) from below with slag.
> 3. other indices of non - ferous metallurgy on the site: 5 finds of
> stone moulds for casting of small objects (jewels, crucifixes etc.).
> In general, does it exist some evidence of small capacity furnaces
> for non - ferrous smelting and refining? I only know portable
> "Probieroefen" (for little bit other purposes).
Independent from the capacity of the furnace, there exists evidence of use of
small scale (Cu-alloy-) melting crucibles (with slagged surfaces) at various
periods.
Until this moment, the whole complex seems to fit best into Chris Salters
remark, suggesting different activities in the same workshop. Nearby even the
founding of bells may have taken place, eventually.
What I find less satisfying - and would need some explication - is the rather
low total of most analyses of the annexed table, except that of a (slag
contaminated) copper-tin-bronze.
Ingo Keesmann
__________________________________________________________
Arbeitsgruppe Archaeometallurgie
Institut fuer Geowissenschaften
Johannes Gutenberg-Universitaet Mainz
D-55099 Mainz (Germany)
Telefon (+49) 6131 39 3 0181
Telefax (+49) 6131 39 2 3070
[log in to unmask]
http://www.uni-mainz.de/FB/Geo/Geologie/archaeo/
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|