Nickel-gold ore of the mackinaw mine, Snohomish County, Washington

Economic Geology
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Abstract

The Mackinaw mine ore is of an unusual or unique type, consisting chiefly of niccolite, maucherite, pentlandite, chalcopyrite, cubanite, and magnetite in an altered peridotite. Valleriite, gold and sphalerite are minor primary minerals; chalcocite and violarite or bravoite are supergene minerals. Pyrrhotite and pyrite are absent. From the textural relations it is inferred that a complex copper-nickel-iron sulfide was deposited early. On cooling, the sulfide unmixed into two different complex sulfides, one of which in turn unmixed into chalcopyrite and cubanite, the other into chalcopyrite and pentlandite. The latter exsolution relationship has not been previously reported. Valleriite either exsolved from, or replaced, chalcopyrite. Late solutions altered the niccolite to maucherite, and introduced gold and magnetite. The gold is almost always with maucherite. © 1958 Society of Economic Geologists, Inc.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Nickel-gold ore of the mackinaw mine, Snohomish County, Washington
Series title Economic Geology
DOI 10.2113/gsecongeo.53.4.426
Volume 53
Issue 1
Year Published 1958
Language English
Publisher Elsevier
Description 22 p.
First page 426
Last page 447
Country United States
State Washington
County Snohomish County
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