Controversy has swirled around the provenance of the copper oxhide ingots. Lead isotope analysis (LIA) suggests that the late LBA ingots (that is, after 1250 BC) are composed of Cypriot copper, specifically copper from the Apilki mine and its surrounding area. The Gelidonya ingots' ratios are consistent with Cypriot ores while the Uluburun ingots fall on the periphery of the Cypriot isotopic field. On the other hand, Late Minoan I ingots found on Crete have Paleozoic lead isotope ratios and are more consistent with ore sources in Afghanistan, Iran, or Central Asia. The controversy settles on the validity of LIA. Paul Budd argues that LBA copper is the product of such extensive mixing and recycling that LIA, which works best for metals from a single ore deposit, is unfeasible.
Some scholars worry that the 1250 BC date is too limiting. They note that Cyprus was smelting copper on a large scale in the early LBA and had the potential to export the metal to Crete and other places at this time. Furthermore, copper ore is more plentiful on Cyprus than on Sardinia and far more plentiful than on Crete. Archaeologists have discovered numerous Cypriot exports to Sardinia including metalworking tools and prestige metal objects.
Due to the heavy corrosion of tin oxhide ingots and the limited data for lead isotopic studies of tin, the provenance of the tin ingots has been uncertain. The fact that scholars have been unable to pinpoint Bronze Age tin ore deposits compounds this problem.