thumbnail

Are modern geothermal waters in northwest Nevada forming epithermal gold deposits?

By: , and 

Links

  • The Publications Warehouse does not have links to digital versions of this publication at this time
  • Download citation as: RIS | Dublin Core

Abstract

Hydrothermal systems currently are active near some gold deposits in northwestern Nevada. Possible links of these modern systems to gold mineralization were evaluated by chemically and isotopically analyzing water samples from the Brady, Dixie Valley, Humboldt House, San Emidio-Empire, Soda Lake, and Wabuska geothermal areas. In addition, quartz veins from Humboldt House and the adjacent Florida Canyon Mine were analyzed to compare ore and gangue phases with those predicted to form from proximal hydrothermal fluids.

Nearly all water samples are alkali-chloride-type. Total dissolved solids range from 800 to 3900 mg/L, and pH varies from 5.6 to 7.8. Geochemical modeling with SOLVEQ, WATCH, and CHILLER predict the precipitation of silica in all systems during cooling. Anhydrite, calcite, barite, pyrite, base-metal sulfides, and alumino-silicates are variably saturated at calculated reservoir temperatures and also precipitate during boiling/cooling of some fluids. Measured dissolved gold concentrations are low (<0.2μg/L), but are generally consistent with contents predicted by equilibrium of sampled solutions with elemental gold at reservoir temperatures.  Although the modern geothermal waters can precipitate ore minerals, the low gold and other ore metal concentrations require very large fluid volumes to form a deposit of economic interest.

Additional publication details

Publication type Conference Paper
Publication Subtype Conference Paper
Title Are modern geothermal waters in northwest Nevada forming epithermal gold deposits?
Year Published 2010
Language English
Publisher Geological Society of Nevada
Contributing office(s) Crustal Geophysics and Geochemistry Science Center
Description 12 p.
Larger Work Type Book
Larger Work Subtype Conference publication
Larger Work Title Geological Society of Nevada Symposium, Great Basin Evolution and Metallogeny 2010
First page 833
Last page 844