Trace concentrations of silver, antimony, iron, zinc, nickel, cobalt, chromium, lead, and manganese were determined for seven native copper nuggets collected from interior Alaska and for two samples of native copper from the Lake Superior district. The analyzed coppers are remarkably pure, the total trace content of elements determined in this study ranging from 0.0156 to 0.0598 percent.The bulk concentration and variation of analyzed trace metals are similar in the native coppers from Alaska and Lake Superior, an unexpected result which suggests that similar geochemical processes may be involved in the genesis of native copper in greenstones at widely separated localities.Serial samples taken from a drill hole in a large copper nugget show an increase of silver, antimony, and zinc toward the core of the mass, and trace metal variations include minor reversals which suggest cyclic zonation.

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