Copper deposits lead isotope fields

Figure 9 shows the results of the lead isotope analyses of these objects compared with the lead isotope composition of the objects from Kastri on Syros and Chalandriani. On the basis of our measurements of the amount of variation in lead isotopic composition found for other copper ore deposits, we have estimated approximate bounds for at least five different copper ore sources from which Trojan copper must have been derived. As yet, there is not enough lead isotope data on the Anatolian copper ore deposits to be able to directly link the estimated lead isotope fields with particular copper occurrences. However, because the lead isotope composition is, to a first approximation, controlled by the geological age of the ore deposit, these five different ore sources, of widely different lead isotope compositions, must have been formed at quite different times. 

These associations are, at present, only tentative and assume a roughly single-stage lead isotope evolution, with negligible contamination of the copper ore deposits by lead derived from older country rocks. Nevertheless, this approach should be used as a basis for further field exploration of the areas in question. The mines and ore deposits in north and northwestern Turkey have recently been explored by a team from the Max Planck Institute for Nuclear Physics in Heidelberg (42, 59), and we hope that there will soon be more information available for the lead isotope fingerprints of Anatolian ore sources. Information available so far proves only that Troy did not get copper from its hinterland and does not identify its source. 

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