Project objectives are refinement of stratigraphy, structure, and magmatic-hydrothermal evolution of the Tonopah, Goldfield, and Comstock Lode districts, and determination of the sources of hydrothermal mineral components. Results are expected to include refined geologic and tectonic maps of important districts in the Walker Lane, reduced uncertainty in sources of elements in ore deposits, improved precious metal deposit models, and refined provincial and local scale exploration concepts for concealed, high-grade, gold-silver deposits.
Science Issue and Relevance
Large, exposed mineral resources have sustained economies and stabilized social order worldwide for centuries. Future mineral supplies will be obtained from concealed resources, which must be higher grade for unsubsidized extraction. Lithospheric-scale (crust and upper mantle) investigations of large, high-grade metal deposits are fundamental to identifying concealed resources with sufficient unit value to mine with existing technology. Determination of sources of igneous host rocks and components of hydrothermal minerals in such world-class gold-silver-copper (Au-Ag-Cu) deposits as Tonopah, Goldfield and Comstock Lode, Nevada, is a basic requirement for understanding the magmatic and hydrothermal processes that form these deposits, and for predicting the location of similar, concealed deposits.
Project results are expected to include refined geologic and tectonic maps of important districts in the Walker Lane, reduced uncertainty in sources of elements in ore deposits, improved precious metal deposit models, and refined provincial and local scale exploration concepts for concealed, high-grade, gold-silver deposits.
Methodology to Address Issue
During previous research in the Southern Walker Lane, a systematic investigation was begun of the sources of igneous and hydrothermal mineral components in three significant, subduction-related, Au-Ag-Cu districts in Miocene volcanic fields in western Nevada and eastern California (Goldfield and Tonopah, NV, Bodie Hills, CA-NV). This investigation employed multiple methods including mapping of volcanic stratigraphy, geochronology, and geochemical and isotopic analyses. Although studies were completed in the Bodie Hills, they were not completed in the Goldfield and Tonopah districts. The Comstock Lode Au-Ag district was added to the current investigation because of its world-class size and grade, and the existence of significant legacy data. Our objectives are refinement of stratigraphy, structure, and magmatic-hydrothermal evolution of the Tonopah, Goldfield, and Comstock Lode districts, and determination of the sources of hydrothermal mineral components.
Below are other science projects associated with this project.
Magmatic-Tectonic History and Component Sources of Major Precious Metal Deposits in the Southern Walker Lane
Below are data or web applications associated with this project.
Fluid Inclusion Noble Gas Data From Goldfield and Tonopah Epithermal Au-Ag Deposits
Below are publications associated with this project.
Petrology of volcanic rocks associated with silver-gold (Ag-Au) epithermal deposits in the Tonopah, Divide, and Goldfield Mining Districts, Nevada
Petrographic, geochemical, and geochronologic data for cenozoic volcanic rocks of the Tonopah, Divide, and Goldfield Mining Districts, Nevada
Noble gas data from Goldfield and Tonopah epithermal Au-Ag deposits, ancestral Cascades Arc, USA: Evidence for a primitive mantle volatile source
Below are partners associated with this project.
- Overview
Project objectives are refinement of stratigraphy, structure, and magmatic-hydrothermal evolution of the Tonopah, Goldfield, and Comstock Lode districts, and determination of the sources of hydrothermal mineral components. Results are expected to include refined geologic and tectonic maps of important districts in the Walker Lane, reduced uncertainty in sources of elements in ore deposits, improved precious metal deposit models, and refined provincial and local scale exploration concepts for concealed, high-grade, gold-silver deposits.
Science Issue and Relevance
Large, exposed mineral resources have sustained economies and stabilized social order worldwide for centuries. Future mineral supplies will be obtained from concealed resources, which must be higher grade for unsubsidized extraction. Lithospheric-scale (crust and upper mantle) investigations of large, high-grade metal deposits are fundamental to identifying concealed resources with sufficient unit value to mine with existing technology. Determination of sources of igneous host rocks and components of hydrothermal minerals in such world-class gold-silver-copper (Au-Ag-Cu) deposits as Tonopah, Goldfield and Comstock Lode, Nevada, is a basic requirement for understanding the magmatic and hydrothermal processes that form these deposits, and for predicting the location of similar, concealed deposits.
Project results are expected to include refined geologic and tectonic maps of important districts in the Walker Lane, reduced uncertainty in sources of elements in ore deposits, improved precious metal deposit models, and refined provincial and local scale exploration concepts for concealed, high-grade, gold-silver deposits.
Methodology to Address Issue
During previous research in the Southern Walker Lane, a systematic investigation was begun of the sources of igneous and hydrothermal mineral components in three significant, subduction-related, Au-Ag-Cu districts in Miocene volcanic fields in western Nevada and eastern California (Goldfield and Tonopah, NV, Bodie Hills, CA-NV). This investigation employed multiple methods including mapping of volcanic stratigraphy, geochronology, and geochemical and isotopic analyses. Although studies were completed in the Bodie Hills, they were not completed in the Goldfield and Tonopah districts. The Comstock Lode Au-Ag district was added to the current investigation because of its world-class size and grade, and the existence of significant legacy data. Our objectives are refinement of stratigraphy, structure, and magmatic-hydrothermal evolution of the Tonopah, Goldfield, and Comstock Lode districts, and determination of the sources of hydrothermal mineral components.
- Science
Below are other science projects associated with this project.
Magmatic-Tectonic History and Component Sources of Major Precious Metal Deposits in the Southern Walker Lane
We conducted linked investigations to address the magmatic-hydrothermal evolution, post-mineralization structural histories, and sources of host rocks and hydrothermal mineral components of three significant, subduction-related, Au-Ag districts in the Walker Lane structural zone in the western Great Basin. - Data
Below are data or web applications associated with this project.
Fluid Inclusion Noble Gas Data From Goldfield and Tonopah Epithermal Au-Ag Deposits
Twenty-five ore and gangue mineral separates from the Miocene-age Goldfield and Tonopah epithermal Au-Ag deposits in southwestern Nevada were analyzed to determine the helium, neon, and argon (He, Ne, and Ar) isotopic compositions contained in fluid inclusions. Four mineral separates from the Butte Main Stage vein deposit and two from the Bingham pyrite-enargite vein deposits were also analyzed. F - Publications
Below are publications associated with this project.
Petrology of volcanic rocks associated with silver-gold (Ag-Au) epithermal deposits in the Tonopah, Divide, and Goldfield Mining Districts, Nevada
Miocene calc-alkaline volcanic rocks, part of the southern segment of the ancestral Cascades magmatic arc, are spatially, temporally, and likely genetically associated with precious metal epithermal deposits in the Tonopah, Divide, and Goldfield Districts of west-central Nevada. In the Tonopah mining district, volcanic rocks include the Mizpah Trachyte, Fraction Tuff, and Oddie Rhyolite; in the DiAuthorsEdward A. du Bray, David John, Joseph Colgan, Peter G. Vikre, Michael A. Cosca, Leah E. MorganPetrographic, geochemical, and geochronologic data for cenozoic volcanic rocks of the Tonopah, Divide, and Goldfield Mining Districts, Nevada
The purpose of this report is to summarize geochemical, petrographic, and geochronologic data for samples, principally those of unmineralized Tertiary volcanic rocks, from the Tonopah, Divide, and Goldfield mining districts of west-central Nevada (fig. 1). Much of the data presented here for the Tonopah and Divide districts are for samples collected by Bonham and Garside (1979) during geologic mapAuthorsEdward A. du Bray, David John, Peter G. Vikre, Joseph Colgan, Michael A. Cosca, Leah E. Morgan, Robert J. Fleck, Wayne R. Premo, Christopher S. Holm-DenomaNoble gas data from Goldfield and Tonopah epithermal Au-Ag deposits, ancestral Cascades Arc, USA: Evidence for a primitive mantle volatile source
The He, Ne, and Ar isotopic composition of fluid inclusions in ore and gangue minerals were analyzed to determine the source of volatiles in the high-grade Goldfield and Tonopah epithermal Au-Ag deposits in southwestern Nevada, USA. Ar and Ne are mainly atmospheric, whereas He has only a minor atmospheric component. Corrected 3He/4He ratios (with atmospheric He removed) range widely from 0.05 to 3AuthorsAndrew H. Manning, Albert H. Hofstra - Partners
Below are partners associated with this project.