Gold-Silver Mining Districts, Alteration Zones, and Paleolandforms in the Miocene Bodie Hills Volcanic Field, California and Nevada Scientific Investigations Report 2015–5012 U.S. Department of the Interior U.S. Geological Survey Cover. Photograph showing ore bins at head of aerial tramway from the Sarita Mine to the Masonic mill, Masonic Mining District. Gold-Silver Mining Districts, Alteration Zones, and Paleolandforms in the Miocene Bodie Hills Volcanic Field, California and Nevada By Peter G. Vikre, David A. John, Edward A. du Bray, and Robert J. Fleck Scientific Investigations Report 2015 –5012 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior SALLY JEWELL, Secretary U.S. Geological Survey Suzette M. Kimball, Acting Director U.S. Geological Survey, Reston, Virginia: 2015 For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment—visit http://www.usgs.gov/ or call 1–888–ASK–USGS. For an overview of USGS information products, including maps, imagery, and publications, visit http://www.usgs.gov/pubprod/. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner. Suggested citation: Vikre, P.G., John, D.A., du Bray, E.A., and Fleck, R.J., 2015, Gold-silver mining districts, alteration zones, and paleolandforms in the Miocene Bodie Hills volcanic field, California and Nevada: U.S. Geological Survey Scientific Investigations Report 2015–5012, 160 p., http://dx.doi.org/10.3133/sir20155012. ISSN 2328-0328 (online) iii Contents Abstract ...........................................................................................................................................................1 Introduction.....................................................................................................................................................3 Bodie Hills Volcanic Field ...........................................................................................................................11 Methods.........................................................................................................................................................12 Masonic Mining District .............................................................................................................................13 Location ................................................................................................................................................13 History and Production ......................................................................................................................13 Stratigraphy .........................................................................................................................................13 Structure...............................................................................................................................................17 Forms of Gold-Silver-Copper Deposits ............................................................................................17 Breccias and Vein Deposits in High-Angle, Subplanar Fault Zones .................................17 Mineral and Rock Compositions of Breccias and Vein Deposits ......................................18 Clastic and Hydrothermal Sedimentary Deposits ................................................................22 Interpretation of Clastic and Hydrothermal Sedimentary Deposits ..................................22 Mineral and Rock Compositions of Clastic and Hydrothermal Sedimentary Deposits .................................................................................................23 Other Minerals and Forms of Mineralization ........................................................................25 Wall-Rock Alteration ..........................................................................................................................25 Sulfur Isotope Compositions and Equilibrium Temperatures .............................................27 Aster Imagery .............................................................................................................................28 Short Wave Infrared (SWIR) Spectra .....................................................................................28 Host Rock and Alteration Mineral Ages .........................................................................................28 Red Wash-East Walker River Alteration Zone ........................................................................................28 Location ................................................................................................................................................28 Definition ..............................................................................................................................................28 History and Production ......................................................................................................................30 Stratigraphy .........................................................................................................................................30 Structure...............................................................................................................................................30 Hydrothermal Alteration ....................................................................................................................30 Minor Elements in Rocks ..........................................................................................................31 Sulfur Isotope Composition ......................................................................................................31 ASTER Imagery ..........................................................................................................................31 SWIR Spectra .............................................................................................................................31 Hydrothermal Mineral Ages ..............................................................................................................31 East Brawley Peak Alteration Zone ..........................................................................................................33 Location ................................................................................................................................................33 Definition ..............................................................................................................................................33 History and Production ......................................................................................................................33 Stratigraphy .........................................................................................................................................33 Structure...............................................................................................................................................33 iv Hydrothermal Alteration ....................................................................................................................35 Minor Elements in Rocks ..........................................................................................................35 ASTER Imagery ..........................................................................................................................35 SWIR Spectra .............................................................................................................................35 Fluid Inclusion Microthermometry and Composition ....................................................................35 Hydrothermal Mineral Ages ..............................................................................................................36 Sawtooth Ridge Alteration Zone ...............................................................................................................36 Location ................................................................................................................................................36 Definition ..............................................................................................................................................36 History and Production ......................................................................................................................36 Stratigraphy .........................................................................................................................................36 Structure...............................................................................................................................................36 Hydrothermal Alteration ....................................................................................................................36 Sulfur Isotope Composition ......................................................................................................38 ASTER Imagery ..........................................................................................................................38 SWIR Spectra .............................................................................................................................38 Hydrothermal Mineral Age ................................................................................................................38 Aurora Canyon Alteration Zone .................................................................................................................38 Location ................................................................................................................................................38 Definition ..............................................................................................................................................38 History and Production ......................................................................................................................38 Stratigraphy .........................................................................................................................................38 Structure...............................................................................................................................................40 Hydrothermal Alteration ....................................................................................................................40 Minor Elements in Rocks ..........................................................................................................40 ASTER Imagery ..........................................................................................................................40 SWIR Spectra .............................................................................................................................40 Hydrothermal Mineral Age ................................................................................................................40 Potato Peak Alteration Zone ......................................................................................................................41 Location ................................................................................................................................................41 Definition ..............................................................................................................................................41 History and Production ......................................................................................................................41 Stratigraphy .........................................................................................................................................41 Structure...............................................................................................................................................41 Hydrothermal Alteration ....................................................................................................................41 Minor Elements in Rocks ..........................................................................................................41 Sulfur Isotope Compositions ....................................................................................................43 ASTER Imagery ..........................................................................................................................43 SWIR Spectra .............................................................................................................................43 Hydrothermal Mineral Age ................................................................................................................43 Aurora Mining District.................................................................................................................................43 Location ................................................................................................................................................43 History and Production ......................................................................................................................43 Stratigraphy .........................................................................................................................................46 Structure...............................................................................................................................................46 v Forms of Gold-Silver Mineralization ................................................................................................47 Veins and Vein Zones ................................................................................................................47 Ore Bodies...................................................................................................................................48 Juniata-Prospectus Vein Minerals .........................................................................................49 Mineral Compositions in Silver Hill and Middle Hill Veins ..................................................50 Minor Elements in Rocks ..........................................................................................................50 Fluid Inclusion Microthermometry and Compositions .........................................................50 Sulfur Isotope Compositions of Vein Minerals ......................................................................53 Wall-Rock Alteration ..........................................................................................................................54 ASTER Imagery ..........................................................................................................................54 SWIR Spectra .............................................................................................................................54 Hydrothermal Mineral Ages ..............................................................................................................54 Four Corners Alteration Zone.....................................................................................................................54 Location ................................................................................................................................................54 Definition ..............................................................................................................................................54 History and Production ......................................................................................................................56 Stratigraphy .........................................................................................................................................56 Structure...............................................................................................................................................56 Hydrothermal Alteration ....................................................................................................................56 ASTER Imagery ..........................................................................................................................56 SWIR Spectra .............................................................................................................................56 Hydrothermal Mineral Ages ..............................................................................................................56 Paramount-Bald Peak Alteration Zone ....................................................................................................56 Location ................................................................................................................................................56 Definition ..............................................................................................................................................56 History and Production ......................................................................................................................60 Stratigraphy .........................................................................................................................................60 Structure...............................................................................................................................................60 Hydrothermal Alteration ....................................................................................................................64 Paramount Mine Area ...............................................................................................................64 Minor Elements in Rocks ..........................................................................................................64 Atastra Creek Area ....................................................................................................................65 Bald Peak Area...........................................................................................................................65 Sulfur Isotope Compositions ....................................................................................................69 ASTER Imagery ..........................................................................................................................69 SWIR Spectra .............................................................................................................................69 Hydrothermal Mineral Ages ..............................................................................................................69 Cinnabar Canyon-US 395 Alteration Zone ...............................................................................................70 Location ................................................................................................................................................70 Definition ..............................................................................................................................................70 History and Production ......................................................................................................................70 Stratigraphy .........................................................................................................................................70 Structure...............................................................................................................................................70 Forms of Mercury and Sulfur Mineralization .................................................................................71 vi Hydrothermal Alteration ....................................................................................................................71 Minor Elements in Rocks ..........................................................................................................75 Sulfur Isotope Compositions ....................................................................................................76 ASTER Imagery ..........................................................................................................................76 SWIR Spectra .............................................................................................................................76 XRD Mineralogy .........................................................................................................................76 Hydrothermal Mineral Ages ..............................................................................................................76 Bodie Mining District...................................................................................................................................77 Location ................................................................................................................................................77 History and Production ......................................................................................................................77 Stratigraphy .........................................................................................................................................80 Structure...............................................................................................................................................81 Forms of Silver-Gold Deposits ..........................................................................................................81 Incline Series Veins ...................................................................................................................84 Burgess Series Veins ................................................................................................................88 Silver Hill Series Veins ..............................................................................................................90 Veins On and Near Queen Bee Hill .........................................................................................91 Wall-Rock Alteration ..........................................................................................................................91 Absolute and Relative Vein and Sinter Ages .........................................................................95 Minor Elements in Veins and Wall Rocks ..............................................................................95 Fluid Inclusion Microthermometry ..........................................................................................97 Oxygen and Hydrogen Isotope Compositions of Vein Minerals and Fluid Inclusion Water ............................................................................................................97 Sulfur Isotope Compositions of Vein Minerals ......................................................................97 ASTER Imagery ..........................................................................................................................98 SWIR Spectra; XRD Analyses ..................................................................................................98 Spring Peak Sinter .......................................................................................................................................98 Location ................................................................................................................................................98 Definition ..............................................................................................................................................98 History and Production ......................................................................................................................98 Stratigraphy .........................................................................................................................................98 Structure.............................................................................................................................................100 Hydrothermal Alteration ..................................................................................................................100 Hydrothermal Mineral Ages ............................................................................................................100 Evolution of Landforms During Assembly and Alteration of the Miocene Bodie Hills Volcanic Field .......................................................................................................................100 Aldrich Station Flora and Fossils in the Bodie Hills ...........................................................100 Eureka Valley Tuff in the Bodie Hills .....................................................................................106 Landforms in Mining Districts and Alteration Zones .........................................................106 Synthesis [Masonic Mining District] ....................................................................................107 Synthesis [Aurora Mining District] .......................................................................................109 Synthesis [Bodie Mining District] .........................................................................................110 Summary......................................................................................................................................................114 Acknowledgments .....................................................................................................................................114 References Cited........................................................................................................................................115 Appendixes .................................................................................................................................................121 vii Figures 1. Map showing locations of mining districts and alteration zones in the Bodie Hills, California and Nevada .................................................................................................................4 2. Geologic map of the southwestern part of the Masonic Mining District, Mono County, California, and Lyon and Mineral Counties, Nevada ...................................14 3. Geologic map of the northeastern part of the Masonic Mining District, Mono County, California, and Mineral County, Nevada .......................................................15 4. Images of volcaniclastic deposits in the Red Wash-East Walker River alteration zone and Masonic Mining District .........................................................................16 5. Images of mineralized fault breccias and veins in the Masonic Mining District .............19 6. Secondary electron images of fault breccia, Masonic Mining District ............................20 7. Secondary electron images of fault breccia, Masonic Mining District ............................21 8. Secondary electron image of quartz+alunite+sulfide vein in granodiorite, Masonic Mining District ............................................................................................................22 9. Image of a dump sample from the Masonic Mining District, Sarita Mine ........................23 10. Images of dump samples from the Masonic Mining District, Sarita Mine .......................24 11. Images of dump samples from the Masonic Mining District, Sarita Mine .......................25 12. Secondary electron images of minerals in very fine-grained brown quartz beds from the Sarita Mine open cut, Masonic Mining District ....................................................26 13. Image of a dump sample from the Masonic Mining District, Sarita Mine ........................27 14. Geologic map of the Red Wash-East Walker River alteration zone, Lyon and Mineral Counties, Nevada, and Mono County, California ....................................................29 15. Advanced Spaceborne Thermal Emission and Reflection Radiometer imagery of the Red Wash-East Walker River alteration zone .............................................................32 16. Geologic map of the East Brawley Peak alteration zone, Mineral County, Nevada, and Mono County, California. ....................................................................................................34 17. Geologic map of the Sawtooth Ridge alteration zone, Mineral County, Nevada, and image of a remnant bowl-shaped thermal vent .............................................................37 18. Geologic map of the Aurora Canyon alteration zone, Mono County, California, and image showing a concentrically exfoliated rhyolite dome ..........................................39 19. Geologic map of the Potato Peak alteration zone, Mono County, California, and image showing landslides developed on altered volcaniclastic strata ............................42 20. Geologic map of the Aurora Mining District, Mineral County, Nevada .............................44 21. Image of a sample from the Aurora Mining District .............................................................49 22. Secondary electron images of an archival vein specimen from the Crocket Mine on Last Chance Hill, Aurora Mining District ...........................................................................51 23. Secondary electron images of an archival vein specimen from the Antelope Mine, Silver Hill, Aurora Mining District ............................................................................................52 24. Secondary electron images of an archival vein specimen from the Antelope Mine, Silver Hill, Aurora Mining District ............................................................................................53 25. Geologic map of the Four Corners alteration zone, Mono County, California ..................55 26. Images of hydrothermal features, Four Corners alteration zone ........................................57 27. Geologic map of the Paramount-Bald Peak alteration zone, Mono County, California, and Mineral County, Nevada, showing sinters, sinter groups, and prospects ................58 28. Geologic map of the Paramount Hg Mine area, Mono County, California, and image showing unoriented, multisized blocks of terrace sinter .........................................61 viii 29. Images of Paramount-Bald Peak alteration zone .................................................................62 30. Images of hydrothermal features in the Paramount-Bald Peak alteration zone .............63 31. Image showing oriented consecutive sections, graphs showing relative element concentrations, and bulk sample element concentrations of sinter from a dismem- bered terrace at the western base of Paramount Mine hill, Paramount-Bald Peak alteration zone .............................................................................................................................66 32. Image showing oriented consecutive sections, graphs showing relative element concentrations, and bulk sample element concentrations of a chalcedonic quartz vein exposed at the upper adit of the Paramount Mine, Paramount-Bald Peak alteration zone .............................................................................................................................67 33. Image showing oriented consecutive sections, graphs showing relative element concentrations, and bulk sample concentrations of sinter from sinter terrace on Atastra Creek, Paramount-Bald Peak alteration zone .........................................................68 34. Geologic map and schematic stratigraphic section of the Cinnabar Canyon-US 395 alteration zone, Mono County, California................................................................................72 35. Images showing volcaniclastic deposits from the Cinnabar Canyon-US 395 alteration zone .............................................................................................................................74 36. Cross section through the Cinnabar Canyon elemental sulfur resource, Cinnabar Canyon-US 395 alteration zone, Mono County, California ..................................75 37. Geologic map of the Bodie Mining District, Mono County, California ...............................78 38. Geologic cross sections of the Bodie Mining District ..........................................................79 39. Images of veins in the Bodie Mining District .........................................................................82 40. Secondary and backscatter electron images of samples representative of Incline series veins on Bodie Bluff, and of vein samples from the Noonday Mine near Silver Hill, Bodie Mining District .....................................................................................87 41. Secondary electron images of samples representative of Burgess series veins on Standard Hill, Bodie Mining District ...................................................................................89 42. Secondary electron images of samples representative of Silver Hill series veins on and near Oro Mine dump, Silver Hill, Bodie Mining District ..........................................91 43. Secondary electron images of samples representative of Silver Hill series veins on and near Addenda Mine, Silver Hill, Bodie Mining District ...........................................92 44. Secondary electron images of samples representative of Silver Hill series veins on and near Red Cloud mine dump, Silver Hill, Bodie Mining District ...............................93 45. Secondary electron images of samples representative of Silver Hill series veins on and near Red Cloud, Contention, and Maybelle Mine dumps, Silver Hill, Bodie Mining District .............................................................................................................................94 46. Image showing oriented consecutive sections, graphs showing relative element concentrations, and bulk sample element concentrations of sinter from Bodie Bluff summit, Bodie Mining District ..................................................................................................96 47. Graph of Ag, As, Sr concentrations versus Au, Sb, Rb concentrations in sinter from the dismembered sinter terrace, sinter fragments in volcaniclastic deposits, and Incline series veins, Bodie Mining District, Bodie Bluff summit .................................97 48. Geologic map of the Spring Peak sinter, Mineral County, Nevada, and image showing nearly intact sinter beds from the northern margin of the terrace ....................99 49. Image of sample, and graphs showing relative element concentrations and bulk sample element concentrations of Spring Peak sinter from the Hg prospect in the sinter terrace, Spring Peak alteration zone .........................................................................101 50. Image showing sample, and graphs showing relative element concentrations and bulk sample element concentrations of Spring Peak sinter from the Hg prospect in the sinter terrace, Spring Peak alteration zone ...................................................................102