Michigan Copper in the Mediterranean
(Isle Royale and Keweenaw Peninsula, c. 2400BC-1200 BC)
the smelting of (roasted) ores. We therefore can eliminate the conclusion that the ingots consist of as-smelted raw copper from a smelting furnace. Most of the ore available on Cyprus is of chalcopyritic composition, and relics of sulfides are quite difficult to completely remove, yet this mixed sulfide does not occur in the copper ingots.”
The Hauptman study concludes that “from a chemical point of view, the purity of the ingots is extraordinary in comparison with other sorts of copper from Wadi Arabah (high lead), from the Caucasus (high arsenic), from Oman (high arsenic and nickel). The ingots are made of pure copper, and all the ingots show a homogeneous composition. From our metallographic investigations, we are able to exclude a conscious purification or even a refining process to produce the ingots. We see few indications that bronze scrap could have been added, due to the very low tin concentration, and would not include gas bubbles and slag inclusions. The ingots provide an explanation for the previously vexing question of how an ingot of a metal as ductile as copper could have been broken up into small pieces such as those excavated by the hundreds in Sardinia. Two characteristics of the Uluburun ingots stand out – the presence of a substantial degree of porosity, and a high concentration of copper oxide inclusions, which made it brittle. Simply dropping the ingots onto a hard surface would easily shatter the ingots.”
A 32 page 1995 study by Budd et al (Ref.55), reviewed all the work to date, and says “all the oxhide ingots are composed of essentially pure copper… No meaningful conclusions on provenance can currently be drawn from a consideration of trace element data for oxhide ingots, ores, and artifacts on Cyprus or Sardinia … It is no surprise that the only oxhide ingot mold ever found, at Ras Ibn Hani, Syria, in 1983 was surrounded by droplets bearing the same isotope signature as the vast majority of the oxhide ingots. The 1989 (Ref.35) Gale report concludes that the Aghia Triadha ingots on Crete “are certainly not made of Cypriot copper”, and the copper source could not be identified. Dickinson, author of the Aegean Bronze Age (Ref. 1 ) “From outside the Aegean came … oxhide ingots. These have all, when tested, proved to be non-Aegean metal.”
Where did the copper go?
Enormous orders for bronze weapons are recorded on excavated Bronze Age clay tablets, for swords in the tens of thousands. The Roman soldier is said to have worn up to 48 pounds of bronze in his uniform. Armies throughout the ancient world were equipped with bronze weapons. Statues and musical instruments, chariots, furniture and vases were made of copper and bronze. Even rooms were lined with copper and bronze. After the bronze Colossus of Rhodes was destroyed in an earthquake in 226 B.c., it was sold to a merchant, who used almost 1,000 camels to ship the pieces to Syria (Ref.l3). “From only 5% of the Karum Kanesh tablets, we already know of 110 donkey loads carrying 15 tons of tin into Anatolia, enough to produce (at 5-7% tin content) 200 to 300 tons of bronze.”(Ref.23).
A variety of cultural groups were involved in the mining, shipping, and trading of copper, among them the Egyptians, the Megalithic peoples of the western coast of Europe, the Atlanteans, and the Minoans. The Minoans have the reputation of controlling the copper…