Geology, alteration, and geochemistry of the McGinness Hills area, Lander County, Nevada
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Authors
Wendall, Daniel E.
Issue Date
1985
Type
Thesis
Language
en_US
Keywords
Hydrothermal Systems , Mcginness Hills , Quartz + Kaolinite + Alunite Alteration Of Andesite , Hot-spring Systems , Quartz + Adularia Alteration Of Rhyolite Ash-flow Tuff , Andesite , Porphyry Mo System , Sinter Terraces , Au , Ag , Hg , Sb , Base Metals , Au Enrichment , Ag Enrichment , As Enrichment , Hg Enrichment , Silica Stages , Precious-metal Values , Late Banded Quartz/chalcedony + Adularia Veins , Geochemical Anomalies , Geochemical Alteration , Geochemical Deformation , Co2 , H2s , Mackay Theses and Dissertations Grant Collection
Alternative Title
Abstract
Two distinct hydrothermal systems have been active in McGinness Hills: an older (35 m.y.) system characterized by quartz + kaolinite i alunite alteration of andesite, and a younger (2.7 m.y.) hot-spring system that produced quartz + adularia alteration of rhyolite ash-flow tuff and andesite. The older system is characterized by elevated F and scattered Mo and W anomalies, suggesting that this terrane may overlie a porphyry Mo system. The younger system formed sinter terraces and deposited Au, Ag, Hg, and Sb within 300 feet of the surface with low values of associated base metals. Au enrichment occurs above Ag, As and Hg enrichment; Sb is concentrated within the sinter. Three distinct silica stages are recognized. The highest precious-metal values are associated with late banded quartz/chalcedony + adularia veins. The patterns of geochemical anomalies, alteration, and deformation may be related to the loss of CO2 and H2S from the fluid during boiling.
Description
Thesis Number: 1976.
Online access for this thesis was created in part with support from the Institute of Museum and Library Services (IMLS) administered by the Nevada State Library, Archives and Public Records through the Library Services and Technology Act (LSTA). To obtain a high quality image or document please contact the DeLaMare Library at https://unr.libanswers.com/ or call: 775-784-6945.
Online access for this thesis was created in part with support from the Institute of Museum and Library Services (IMLS) administered by the Nevada State Library, Archives and Public Records through the Library Services and Technology Act (LSTA). To obtain a high quality image or document please contact the DeLaMare Library at https://unr.libanswers.com/ or call: 775-784-6945.
Citation
Publisher
University of Nevada, Reno
License
In Copyright(All Rights Reserved)