The geochemistry of gold-bearing and gold-free pyrite and marcasite from the Getchell gold deposit, Humboldt County, Nevada

Petrographic and geochemical investigations of pyrite and marcasite from the Getchell Carlin-type gold deposit show that elevated concentrations of a characteristic suite of trace metals correlate with ore-stage pyrite morphology. Secondary ion mass spectrometry analyses revealed a significant positive correlation between As and Au in ore-stage Fe-sulfide minerals. High-resolution transmission electron microscopy analyses revealed that gold-bearing Fe-sulfide crystals are arsenic-rich marcasite, rather than pyrite. These analyses failed to identify gold as microinclusions in ore-stage pyrite/marcasite, and support the conclusion that gold is present in solid solution; Analyses reflect the chemistry of fluids responsible for precipitation of the pyrite and marcasite. Near stoichiometric, pre-ore pyrite precipitated from fluids that were not saturated in Hg, Tl, As, Cu, Au and Sb. Ore-stage pyrite textures suggest rapid precipitation from fluids that contained Hg, Tl, As, Cu, Au and Sb. Late-ore stage marcasite indicates that late fluids continued to transport significant As.

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Geoscience

Grantor dc:publisher

University of Nevada, Las Vegas

Year

2001

Author dc:creator

• Weaver, Kelli Diane

Contributors dc:contributor

• Jean S. Cline

Statement dc:rights

• IN COPYRIGHT. For more information about this rights statement, please visit http://rightsstatements.org/vocab/InC/1.0/

Language dc:language

English

Identifier

https://oasis.library.unlv.edu/rtds/1344

OAI identifier oai:identifier

oai:oasis.library.unlv.edu:rtds-2343