in trouble for at least a decade. They have endured disease, decline in moose population - their main source of food - and inbreeding on top of all that. I was hoping that the past two winters where the lakes had frozen over would allow others to join the gene pool there. Maybe some left the island instead or maybe they've just died off. I haven't read any of the literature (scientific) in some time but it's not good news either way. I know a few researchers who studied there and iare still "in the loop" about that population, I'll have to call and have a chat with them soon.

Miners Left a Pollution Trail in the Great Lakes 6000 Years Ago


Now, new research suggests that Isle Royale’s mining boom peaked about 6000 years ago and left a legacy of aquatic pollution. The high levels of copper, lead, and potassium in sediments from a cove on the island point to a long and intense period of indigenous mining. Researchers presented these results, published recently in the journal The Holocene, in a poster session on 16 December at the 2014 American Geophysical Union Fall Meeting.


European explorers first noticed evidence for indigenous copper mines back in the 1800s. In some places, miners had dug down more than 20 meters into bedrock—an impressive feat considering their limited tools. However, without a way to date the pits directly, the timing of these mining activities could only be loosely constrained by the ages of copper artifacts found across the Great Lakes region. Archaeologists have dated many objects associated with the so-called Old Copper Complex, but the objects span thousands of years.



tools and spearpoints found

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https://eos.org/articles/miners-left-pollution-trail-great-lakes-6000-years-ago



The purity of the copper


Old World Copper
Most European copper was smelted out of copper ores starting about 4460 Be. These ores often had only a concentration of 15% copper in them, and had many trace element contaminants, such as lead (Ref. 19). Buried hoards of bronze are usually composed of broken axeheads, miscellaneous broken pieces, and lumps, recycling the valuable metal. Henderson's book (Ref. 19) reports a German study that did 12,000 [!] chemical analyses of copper-containing artifacts, with the aim of identifying "workshops". They were not able to do this, but noted that "hoards which often contain low impurity metal in SouthhEastern England and Northern France may be linked to the occurrence of copper ingots, which also had low impurities." Barber (Ref28) says that "ingot (or 'cake') fragments are a common feature of founder's hoards of the late Bronze Age, and often comprise pure, unalloyed copper." Barber (Ref.25) says only one mining site in the British Isles (Great Orme) shows evidence of activity after the early Bronze Age. Burgess (Ref 16) says of the British Isles Bronze Age, "the remarkable thing is that metallurgy seems to have started in the south-east, apparently as early as anywhere in Britain, [though] the southeast has no local ores".

The Miners of Michigan Copper
It is estimated that half a billion pounds (Ref. 1 ) of copper were mined in tens of thousands of pits on Isle Royale and the Keweenaw Peninsula of Michigan by ancient miners over a period of a thousand years. Carbon dating of wood timbers in the pits has dated the mining to start about 2450 BC and end abruptly at 1200 Be. Officially, no one knows where the Michigan copper went. All the "ancient copper culture" tools that have been found could have been manufactured from just one of the large boulders. A placard in London's British Museum Bronze Age axe exhibit says: "from about 2500 BC, the use of copper, formerly limited to parts of Southern Europe, suddenly swept through the rest of the Continent". No one seems to know where the copper in Europe came from.

Indian legends tell the mining was done by fair-haired "marine men". Along with wooden tools, and stone hammers, a walrus-skin bag has been found (Ref. 1 ). A huge copper boulder was found in the bottom of a deep pit raised up on solid oak timbers, still preserved in the anaerobic conditions for more than 3,000 years. Some habitation sites and garden beds have been found and studied (various ref). It is thought that most of the miners retired to Aztalan (near Madison, Wisconsin) and other locations to the south at the onset of the hard winters on Lake Superior. The mining appears to have ended overnight, as though they had left for the day, and never came back. A petroglyph of one of their sailing ships has been found (


http://www.rocksandrows.com/copper-trade-2.php