The Shipping of Michigan Copper across the Atlantic in the Bronze Age (Isle Royale and Keweenaw Peninsula, c. 2400BC-1200 BC) Summary Recent scientific literature has come to the conclusion that the major source of the copper that swept through the European Bronze Age after 2500 BC is unknown. However, these studies claim that the 10 tons of copper oxhide ingots recovered from the late Bronze Age (1300 BC) Uluburun shipwreck off the coast of Turkey was “extraordinarily pure” (more than 99.5% pure), and that it was not the product of smelting from ore. The oxhides are all brittle “blister copper”,...