Is there a "Voisey's Bay-type Ni-Cu sulfide deposit in the Midcontinent rift system in the Lake Superior region?

Schulz, K. J. ; Cannon, W. E. ; Nicholson, S. W. ; Woodruff, L. G.
Organization: Society for Mining, Metallurgy & Exploration
Pages: 6
Publication Date: Jan 1, 1999
The 1.1 Ga Midcontinent rift of North America has many similarities to the geology of the Voisey's Bay region in Labrador and the geology of the Noril'sk region in Siberia. These similarities include the hosting of large volumes of sulfur- undersaturated and trace-element-enriched basalt, having igneous centers characterized by crustal contamination, being characterized by metal depletions in some mafic units (an indication of prior sulfide segregation) and having known occurrences of Ni-Cu sulfide mineralization. These similarities along with new geophysical data and refined models for Ni-Cu sulfide deposits suggest that the Midcontinent rift probably contains undiscovered Cu-Ni [±] PGE sulfide deposits, some of which could be the size and grade of a Voisey's Bay or Noril'sk deposit. In particular, intrusions and related feeder systems that occur in northern Michigan and Wisconsin, as well as to the southwest along the rift margin, deserve serious examination.
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