Replacement of uraninite by bornite via coupled dissolution-reprecipitation: Evidence from texture and microstructure

dc.contributor.authorMacmillan, E.
dc.contributor.authorCiobanu, C.
dc.contributor.authorEhrig, K.
dc.contributor.authorCook, N.
dc.contributor.authorPring, A.
dc.date.issued2016
dc.description.abstractThe occurrence and nature of rhythmically intergrown crystals of uraninite and bornite from the Olympic Dam iron oxide-copper-gold (IOCG)-U-Ag deposit, South Australia, is reported. Distinct zones within primary, euhedral uraninite crystals have been replaced by bornite and minor fluorite leaving a skeleton of uraninite, infilled with these minerals. The partially replaced uraninite crystals are always closely associated with locally abundant bornite and fluorite. The textural features of the intergrowth are consistent with partial replacement of uraninite by bornite via a coupled dissolution-reprecipitation reaction driven by a F-rich and Cu-Fe-sulfide-bearing hydrothermal fluid rather than a form of oscillatory growth or exsolution from a U–Cu–Fe–S solid solution. The crystallographic relationship between the parent uraninite and the daughter bornite and fluorite were explored by electron backscattered diffraction, as all three minerals share common crystal structural features, despite their chemical diversity. Generally speaking, the crystallographic orientation of the uraninite parent is initially inherited by the replacing bornite, but later the orientation of the bornite changes.
dc.description.statementofresponsibilityEdeltraud Macmillan, Cristiana L. Ciobanu, Kathy Ehrig, Nigel J. Cook, Allan Pring
dc.identifier.citationCanadian Mineralogist: crystallography, geochemistry, mineralogy, petrology, mineral deposits, 2016; 54(6):1369-1383
dc.identifier.doi10.3749/canmin.1600031
dc.identifier.issn0008-4476
dc.identifier.issn1499-1276
dc.identifier.orcidCook, N. [0000-0002-7470-3935]
dc.identifier.urihttp://hdl.handle.net/2440/107371
dc.language.isoen
dc.publisherMineralogical Association of Canada
dc.rights© The Mineralogical Association of Canada (MAC)
dc.source.urihttps://doi.org/10.3749/canmin.1600031
dc.subjectUraninite; Cu-Fe-sulfide minerals; Olympic Dam; epitaxial replacement; coupled dissolution-reprecipitation reaction
dc.titleReplacement of uraninite by bornite via coupled dissolution-reprecipitation: Evidence from texture and microstructure
dc.typeJournal article
pubs.publication-statusPublished

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