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Information Circular 10. Copper and Nickel Resources in the Duluth Complex, Northeastern Minnesota
Bonnichsen, Bill (Minnesota Geological Survey, 1974)
 

Title 
Information Circular 10. Copper and Nickel Resources in the Duluth Complex, Northeastern Minnesota

Author(s)

Issue Date
1974

Publisher
Minnesota Geological Survey

Type
Map, Report

Abstract
The Ely-Hoyt Lakes region, in northeastern Minnesota, contains very large quantities of disseminated copper and nickel sulfides that are potentially minable. The principal sulfides are pyrrhotite, chalcopyrite, cubanite, and pentlandite, and the average copper-nickel ratio in the sulfide concentrations is approximately 3:1. The sulfides are associated with the northwestern margin of the Duluth Complex, a large mafic igneous pluton of Late Precambrian age, and occur principally within the basal zone of the intrusion. A conservative estimate of the metal resources in the Ely-Hoyt Lakes region, based on assay data available from 24 drill holes, and a cutoff grade, or lower mining limit, of 0.5 percent combined copper and nickel indicates 13.8 million tons of copper and 4.6 million tons of nickel having a gross value of $27 billion. Although the copper and nickel deposits in the Ely-Hoyt Lakes region are marginal economically, they constitute one of the United States' principal metal resources.

Appears in Collection(s)

Series/Report Number
Information Circular
10

Suggested Citation
Bonnichsen, Bill. (1974). Information Circular 10. Copper and Nickel Resources in the Duluth Complex, Northeastern Minnesota. Minnesota Geological Survey. Retrieved from the University of Minnesota Digital Conservancy, http://purl.umn.edu/59299.


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