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Lead is present in the Chalcolithic slags from Timna (0.6% - ~some %), containing Pb in metallic ansd oxidic form. These slags are results of copper smelting. Iron ores that was added in this period to copper ores as flux contain a lot of Pb. Copper ores with remnants of sulphides also contain Pb (galena). Even in copper ingots found in the Central Negev amount of Pb was relatively high (up to 3%). Almost all the Pb is concentrated in sulphidic inclusions. See B. Rothenberg (1990), Hauptmann et al. (1992 Archeomaterials), Segal et al. in proceedings of the conference "Metal in antiquity" that'll be published I think before summer. Best wishes Irina. At 09:53 3/29/99 +0200, you wrote: >Does prehistoric copper slag ever contain lead in appreciable quantities? I don't know any quantitative analyses of copper slag that could be used to answer this question. On the face of it common sense says that lead would only be added to already smelted metal, but some copper ores have a lot of natural lead and could be a problem. > >I am asking because I thought I was going to have some ore samples analysed for lead isotopes, but suddenly the laboratory realized that nobody knew how much lead there would be in them and samples with a lot of lead would be bad for the mass spectrometer. As a non-scientist I am a bit out of my depth, and I would be grateful for help. Have bulk analyses of that kind been made of copper slag? If so please give references. What other arguments should be considered. I would like to present the laboratory with as neutral and objective information as I can - obviously I am not interested in dirtying up their machine. I think basically the geologists, some of whom may view the archaeological project with a bit of suspicion anyway, do not know much about prehistoric copper slag and suddenly got an idea. > >David Liversage, Morlenesvej 26, DK-2840 Holte, Denmark > > Dr. Irina Segal Geochemistry Department The Geological Survey of Israel 30 Malkhe Israel Street Jerusalem 95501, Israel %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%