MetallogenyoftheGreatBasin:Cru

Evolution,FluidFlow,andOreDepos

Open-File Report 2006 −1280

U.S. Department of the Interior

U.S. Geological Survey
Metallogeny of the Great Basin: Crustal Evolution, Fluid 

Flow, and Ore Deposits 

By Albert H. Hofstra1 and Alan R. Wallace2

1–USGS, MS-973, Box 25046, Denver, CO 80225, <ahofstra@usgs.gov> 

2–USGS, Mackay School of Earth Sciences, MS-176, Reno, NV, 89557, <alan@usgs.gov> 

Open-File Report 2006–1280 

U.S. Department of the Interior 

U.S. Geological Survey 
U.S. Department of the Interior 

DIRK KEMPTHORNE, Secretary 

U.S. Geological Survey 

P. Patrick Leahy, Acting Director 

U.S. Geological Survey, Reston, Virginia 2006 

For product and ordering information: 

World Wide Web: http://www.usgs.gov/pubprod 

Telephone: 1-888-ASK-USGS 

For more information on the USGS—the Federal source for science about the Earth, 

its natural and living resources, natural hazards, and the environment: 

World Wide Web: http://www.usgs.gov 

Telephone: 1-888-ASK-USGS 

Any use of trade, product, or firm names is for descriptive purposes only and does not imply 

endorsement by the U.S. Government. 

Although this report is in the public domain, permission must be secured from the individual 

copyright owners to reproduce any copyrighted material contained within this report. 

Suggested citation: 

Hofstra, A.H. and Wallace, A.R., 2006, Metallogeny of the Great Basin: Crustal Evolution, Fluid Flow, and Ore 

Deposits: U.S. Geological Survey Open-File Report 2006-1280, 36 p. 

ii
Contents 

Abstract................................................................................................................................................................................1 

Introduction .........................................................................................................................................................................2 

Relation to previous and current USGS projects in the region..................................................................................4 

Synergies with others........................................................................................................................................................5 

Milestones ...........................................................................................................................................................................5 

Database development......................................................................................................................................................6 

Geologic maps ....................................................................................................................................................................6 

Geophysics ..........................................................................................................................................................................7 

Geochemistry ......................................................................................................................................................................8 

Neoproterozoic to Devonian passive margin................................................................................................................8 

Late Paleozoic and Mesozoic contraction.....................................................................................................................9 

Mesozoic and Cenozoic arc magmatism and pluton-related ore deposits ...........................................................10 

Paleogene basins, magmatism, faulting, and ore deposits ......................................................................................10 

Neogene basins, magmatism, faulting, and epithermal ore deposits.....................................................................11 

Regional and district scale geologic and hydrologic models ..................................................................................13 

Metallogeny of the Great Basin Bibliography: 2002–2006 publications by USGS personnel and 

collaborators ..............................................................................................................................................................14

Figures 

1. Significant metal deposits in the Great Basin (black outline) from Hofstra (2005b). Dot size is proportional 

to the amount of metal in the deposits (t=tons, Kt= kilotons) .....................................................................29 

2. Color shaded relief map showing the location of gold deposits (see explanation, BM=base metal), state 

boundaries (dark lines), and Metallogeny of the Great Basin (MGB) project study areas: Great Basin 

(yellow dashed line), Northern Nevada (orange box), and mining districts (Carlin trend, 

Beowawe/Mule Canyon–magenta boxes). The blue box outlines the previous Department of 

Energy/Water Resources Discipline Death Valley Region 3-D Hydrogeologic Study Area around the 

Nevada Test Site.................................................................................................................................................30 

3. Example of a topical map/database product on geophysical terrains by Glen and others (2004a) that 

summarizes the attributes and inferred sources of magnetic and gravity anomalies across the Great 

Basin......................................................................................................................................................................31 

4. A revised 1:250,000 scale Nevada State Digital Geologic Map was produced by Crafford (2005; in press) 

to frame development of regional cross sections and 3-D models...........................................................32 

5. Three-dimensional perspective view of some of the regional geologic cross sections in the northern 

Nevada study area by Sweetkind and others (2005a,b) ..............................................................................33 

6. Example of a 3-D hydrogeologic model (Qal= Quaternary alluvium, Tv=Tertiary volcanic rocks, 

RMA=siliciclastic rocks of the Roberts Mountains Allochthon, Pz Ls=Paleozoic carbonate rocks) 

and grid used for flow modeling in the Beowawe geothermal area by Tilden and others (2005) .......34 

7. Examples of 2-D hydrogeologic models for the Beowawe geothermal area and Eocene Carlin trend by 

Person and others (2005; AFT=apatite fission track)....................................................................................35 

8. Diagram showing the hierarchical nature of geologic data from Yager and Hofstra (2004).........................36 

iii
Conversion Factors 

Inch/Pound to SI 

Multiply By To obtain 

Length 

inch (in.) 2.54 centimeter (cm) 

inch (in.) 25.4 millimeter (mm) 

foot (ft) 0.3048 meter (m) 

mile (mi) 1.609 kilometer (km) 

mile, nautical (nmi) 1.852 kilometer (km) 

yard (yd) 0.9144 meter (m) 

Area 

acre 4,047 square meter (m2) 

acre 0.4047 hectare (ha) 

acre 0.4047 square hectometer (hm2

) 

acre 0.004047 square kilometer (km2

) 

square foot (ft2

) 929.0 square centimeter (cm2) 

square foot (ft2

) 0.09290 square meter (m2) 

square inch (in2

) 6.452 square centimeter (cm2) 

section (640 acres or 1 square 

mile) 

259.0 square hectometer (hm2

) 

square mile (mi2

) 259.0 hectare (ha) 

square mile (mi2

) 2.590 square kilometer (km2) 

Volume 

barrel (bbl), (petroleum, 

1 barrel=42 gal) 

0.1590 cubic meter (m3) 

ounce, fluid (fl. oz) 0.02957 liter (L) 

pint (pt) 0.4732 liter (L) 

quart (qt) 0.9464 liter (L) 

gallon (gal) 3.785 liter (L) 

gallon (gal) 0.003785 cubic meter (m3

) 

gallon (gal) 3.785 cubic decimeter (dm3

) 

million gallons (Mgal) 3,785 cubic meter (m3

) 

cubic inch (in3

) 16.39 cubic centimeter (cm3) 

cubic inch (in3

) 0.01639 cubic decimeter (dm3) 

cubic inch (in3

) 0.01639 liter (L) 

cubic foot (ft3

) 28.32 cubic decimeter (dm3) 

cubic foot (ft3

) 0.02832 cubic meter (m3) 

cubic yard (yd3

) 0.7646 cubic meter (m3) 

iv
cubic mile (mi3

) 4.168 cubic kilometer (km3) 

acre-foot (acre-ft) 1,233 cubic meter (m3

) 

acre-foot (acre-ft) 0.001233 cubic hectometer (hm3

) 

Flow rate 

acre-foot per day (acre-ft/d) 0.01427 cubic meter per second (m3/s) 

acre-foot per year (acre-ft/yr) 1,233 cubic meter per year (m3/yr) 

acre-foot per year (acre-ft/yr) 0.001233 cubic hectometer per year 

(hm3

/yr) 

foot per second (ft/s) 0.3048 meter per second (m/s) 

foot per minute (ft/min) 0.3048 meter per minute (m/min) 

foot per hour (ft/hr) 0.3048 meter per hour (m/hr) 

foot per day (ft/d) 0.3048 meter per day (m/d) 

foot per year (ft/yr) 0.3048 meter per year (m/yr) 

cubic foot per second (ft3

/s) 0.02832 cubic meter per second (m3/s) 

cubic foot per second per square 

mile [(ft3

/s)/mi2] 

 0.01093 cubic meter per second per 

square kilometer [(m3

/s)/km2] 

cubic foot per day (ft3

/d) 0.02832 cubic meter per day (m3/d) 

gallon per minute (gal/min) 0.06309 liter per second (L/s) 

gallon per day (gal/d) 0.003785 cubic meter per day (m3

/d) 

gallon per day per square mile 

 [(gal/d)/mi2

] 

 0.001461 cubic meter per day per square 

kilometer [(m3

/d)/km2] 

million gallons per day 

(Mgal/d) 

 0.04381 cubic meter per second (m3

/s) 

million gallons per day per 

square mile [(Mgal/d)/mi2

] 

1,461 cubic meter per day per square 

kilometer [(m3

/d)/km2] 

inch per hour (in/h) 0 .0254 meter per hour (m/h) 

inch per year (in/yr) 25.4 millimeter per year (mm/yr) 

mile per hour (mi/h) 1.609 kilometer per hour (km/h) 

Mass 

ounce, avoirdupois (oz) 28.35 gram (g) 

pound, avoirdupois (lb) 0.4536 kilogram (kg) 

ton, short (2,000 lb) 0.9072 megagram (Mg) 

ton, long (2,240 lb) 1.016 megagram (Mg) 

ton per day (ton/d) 0.9072 metric ton per day 

ton per day (ton/d) 0.9072 megagram per day (Mg/d) 

ton per day per square mile 

[(ton/d)/mi2

] 

 0.3503 megagram per day per square 

kilometer [(Mg/d)/km2

] 

ton per year (ton/yr) 0.9072 megagram per year (Mg/yr) 

ton per year (ton/yr) 0.9072 metric ton per year 

Pressure 

v
atmosphere, standard (atm) 101.3 kilopascal (kPa) 

bar 100 kilopascal (kPa) 

inch of mercury at 60oF (in Hg) 3.377 kilopascal (kPa) 

pound-force per square inch 

(lbf/in2

) 

6.895 kilopascal (kPa) 

pound per square foot (lb/ft2

) 0.04788 kilopascal (kPa) 

pound per square inch (lb/in2

) 6.895 kilopascal (kPa) 

Density 

pound per cubic foot (lb/ft3) 16.02 kilogram per cubic meter 

(kg/m3

) 

pound per cubic foot (lb/ft3) 0.01602 gram per cubic centimeter 

(g/cm3

) 

Energy 

kilowatthour (kWh) 3,600,000 joule (J) 

Radioactivity 

picocurie per liter (pCi/L) 0.037 becquerel per liter (Bq/L) 

Specific capacity 

gallon per minute per foot 

[(gal/min)/ft)] 

 0.2070 liter per second per meter 

[(L/s)/m] 

Hydraulic conductivity 

foot per day (ft/d) 0.3048 meter per day (m/d) 

Hydraulic gradient 

foot per mile (ft/mi) 0.1894 meter per kilometer (m/km) 

Transmissivity* 

foot squared per day (ft2/d) 0.09290 meter squared per day (m2/d) 

Application rate 

pounds per acre per year 

[(lb/acre)/yr] 

 1.121 kilograms per hectare per year 

[(kg/ha)/yr] 

Leakance 

foot per day per foot [(ft/d)/ft] 1 meter per day per meter 

inch per year per foot [(in/yr)/ft] 83.33 millimeter per year per meter 

[(mm/yr)/m] 

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows: 

°F=(1.8×°C)+32 

Temperature in degrees Fahrenheit (°F) may be converted to degrees Celsius (°C) as follows: 

°C=(°F-32)/1.8 

Vertical coordinate information is referenced to the insert datum name (and abbreviation) here for instance, “North American 

Vertical Datum of 1988 (NAVD 88).” 

Horizontal coordinate information is referenced to the insert datum name (and abbreviation) here for instance, “North American 

Datum of 1983 (NAD 83).” 

Altitude, as used in this report, refers to distance above the vertical datum. 

vi
*Transmissivity: The standard unit for transmissivity is cubic foot per day per square foot times foot of aquifer thickness 

[(ft3

/d)/ft2]ft. In this report, the mathematically reduced form, foot squared per day (ft2/d), is used for convenience. 

Specific conductance is given in microsiemens per centimeter at 25 degrees Celsius (μS/cm at 25 °C). 

Concentrations of chemical constituents in water are given either in milligrams per liter (mg/L) or micrograms per liter (μg/L). 

NOTE TO USGS USERS: Use of hectare (ha) as an alternative name for square hectometer (hm2

) is restricted to the measurement 

of small land or water areas. Use of liter (L) as a special name for cubic decimeter (dm3

) is restricted to the measurement of 

liquids and gases. No prefix other than milli should be used with liter. Metric ton (t) as a name for megagram (Mg) should be 

restricted to commercial usage, and no prefixes should be used with it. 

vii
SI to Inch/Pound 

Multiply By To obtain 

Length 

centimeter (cm) 0.3937 inch (in.) 

millimeter (mm) 0.03937 inch (in.) 

meter (m) 3.281 foot (ft) 

kilometer (km) 0.6214 mile (mi) 

kilometer (km) 0.5400 mile, nautical (nmi) 

meter (m) 1.094 yard (yd) 

Area 

square meter (m2) 0.0002471 acre 

hectare (ha) 2.471 acre 

square hectometer (hm2

) 2.471 acre 

square kilometer (km2

) 247.1 acre 

square centimeter (cm2

) 0.001076 square foot (ft2) 

square meter (m2

) 10.76 square foot (ft2) 

square centimeter (cm2

) 0.1550 square inch (ft2) 

square hectometer (hm2

) 0.003861 section (640 acres or 1 square 

mile) 

hectare (ha) 0.003861 square mile (mi2

) 

square kilometer (km2

) 0.3861 square mile (mi2) 

Volume 

cubic meter (m3) 6.290 barrel (petroleum, 1 barrel = 42 

gal) 

liter (L) 33.82 ounce, fluid (fl. oz) 

liter (L) 2.113 pint (pt) 

liter (L) 1.057 quart (qt) 

liter (L) 0.2642 gallon (gal) 

cubic meter (m3

) 264.2 gallon (gal) 

cubic decimeter (dm3

) 0.2642 gallon (gal) 

cubic meter (m3

) 0.0002642 million gallons (Mgal) 

cubic centimeter (cm3

) 0.06102 cubic inch (in3) 

cubic decimeter (dm3

) 61.02 cubic inch (in3) 

liter (L) 61.02 cubic inch (in3

) 

cubic decimeter (dm3

) 0.03531 cubic foot (ft3) 

cubic meter (m3

) 35.31 cubic foot (ft3) 

cubic meter (m3

) 1.308 cubic yard (yd3) 

cubic kilometer (km3

) 0.2399 cubic mile (mi3) 

viii
cubic meter (m3

) 0.0008107 acre-foot (acre-ft) 

cubic hectometer (hm3

) 810.7 acre-foot (acre-ft) 

Flow rate 

cubic meter per second (m3/s) 70.07 acre-foot per day (acre-ft/d) 

cubic meter per year (m3/yr) 0.000811 acre-foot per year (acre-ft/yr) 

cubic hectometer per year 

(hm3

/yr) 

811.03 acre-foot per year (acre-ft/yr) 

meter per second (m/s) 3.281 foot per second (ft/s) 

meter per minute (m/min) 3.281 foot per minute (ft/min) 

meter per hour (m/hr) 3.281 foot per hour (ft/hr) 

meter per day (m/d) 3.281 foot per day (ft/d) 

meter per year (m/yr) 3.281 foot per year ft/yr) 

cubic meter per second (m3

/s) 35.31 cubic foot per second (ft3/s) 

cubic meter per second per 

square kilometer [(m3

/s)/km2] 

91.49 cubic foot per second per square 

 mile [(ft3

/s)/mi2] 

cubic meter per day (m3

/d) 35.31 cubic foot per day (ft3/d) 

liter per second (L/s) 15.85 gallon per minute (gal/min) 

cubic meter per day (m3

/d) 264.2 gallon per day (gal/d) 

cubic meter per day per square 

kilometer [(m3

/d)/km2] 

684.28 gallon per day per square mile 

[(gal/d)/mi2

] 

cubic meter per second (m3

/s) 22.83 million gallons per day (Mgal/d) 

cubic meter per day per square 

kilometer [(m3

/d)/km2] 

0.0006844 million gallons per day per 

square mile [(Mgal/d)/mi2

] 

cubic meter per hour (m3

/h) 39.37 inch per hour (in/h) 

millimeter per year (mm/yr) 0.03937 inch per year (in/yr) 

kilometer per hour (km/h) 0.6214 mile per hour (mi/h) 

Mass 

gram (g) 0.03527 ounce, avoirdupois (oz) 

kilogram (kg) 2.205 pound avoirdupois (lb) 

megagram (Mg) 1.102 ton, short (2,000 lb) 

megagram (Mg) 0.9842 ton, long (2,240 lb) 

metric ton per day 1.102 ton per day (ton/d) 

megagram per day (Mg/d) 1.102 ton per day (ton/d) 

megagram per day per square 

kilometer [(Mg/d)/km2

] 

2.8547 ton per day per square mile 

[(ton/d)/mi2

] 

megagram per year (Mg/yr) 1.102 ton per year (ton/yr) 

metric ton per year 1.102 ton per year (ton/yr) 

Pressure 

kilopascal (kPa) 0.009869 atmosphere, standard (atm) 

kilopascal (kPa) 0.01 bar 

ix
kilopascal (kPa) 0.2961 inch of mercury at 60°F (in Hg) 

kilopascal (kPa) 0.1450 pound-force per inch (lbf/in) 

kilopascal (kPa) 20.88 pound per square foot (lb/ft2

) 

kilopascal (kPa) 0.1450 pound per square inch (lb/ft2

) 

Density 

kilogram per cubic meter 

(kg/m3

) 

0.06242 pound per cubic foot (lb/ft3

) 

gram per cubic centimeter 

(g/cm3

) 

62.4220 pound per cubic foot (lb/ft3

) 

Energy 

joule (J) 0.0000002 kilowatthour (kWh) 

Radioactivity 

becquerel per liter (Bq/L) 27.027 picocurie per liter (pCi/L) 

Specific capacity 

liter per second per meter 

[(L/s)/m] 

4.831 gallon per minute per foot 

[(gal/min)/ft] 

Hydraulic conductivity 

meter per day (m/d) 3.281 foot per day (ft/d) 

Hydraulic gradient 

meter per kilometer (m/km) 5.27983 foot per mile (ft/mi) 

Transmissivity* 

meter squared per day (m2/d) 10.76 foot squared per day (ft2/d) 

Application rate 

kilograms per hectare per year 

[(kg/ha)/yr] 

0.8921 pounds per acre per year 

[(lb/acre)/yr] 

Leakance 

meter per day per meter 

[(m/d)/m] 

1 foot per day per foot [(ft/d)/ft] 

millimeter per year per meter 

[(mm/yr)/m] 

0.012 inch per year per foot [(in/yr)/ft] 

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows: 

°F=(1.8×°C)+32 

Temperature in degrees Fahrenheit (°F) may be converted to degrees Celsius (°C) as follows: 

°C=(°F-32)/1.8 

Vertical coordinate information is referenced to the insert datum name (and abbreviation) here, for instance, “North American 

Vertical Datum of 1988 (NAVD 88)” 

Horizontal coordinate information is referenced to the insert datum name (and abbreviation) here, for instance, “North American

Datum of 1983 (NAD 83)” 

Altitude, as used in this report, refers to distance above the vertical datum. 

*Transmissivity: The standard unit for transmissivity is cubic foot per day per square foot times foot of aquifer thickness 

[(ft3

/d)/ft2]ft. In this report, the mathematically reduced form, foot squared per day (ft2/d), is used for convenience. 

Specific conductance is given in microsiemens per centimeter at 25 degrees Celsius (μS/cm at 25°C). 

Concentrations of chemical constituents in water are given either in milligrams per liter (mg/L) or micrograms per liter (μg/L). 

x
NOTE TO USGS USERS: Use of hectare (ha) as an alternative name for square hectometer (hm2

) is restricted to the measurement 

of small land or water areas. Use of liter (L) as a special name for cubic decimeter (dm3

) is restricted to the measurement of 

liquids and gases. No prefix other than milli should be used with liter. Metric ton (t) as a name for megagram (Mg) should be 

restricted to commercial usage, and no prefixes should be used with it. 

xi
Metallogeny of the Great Basin: Crustal Evolution, 

Fluid Flow, and Ore Deposits 

By Albert H. Hofstra1 and Alan R. Wallace2

1–USGS, MS-973, Box 25046, Denver, CO 80225, <ahofstra@usgs.gov> 

2–USGS, Mackay School of Earth Sciences, MS-176, Reno, NV, 89557, <alan@usgs.gov> 

Abstract 

The Great Basin physiographic province in the Western United States contains a diverse 

assortment of world-class ore deposits. It currently (2006) is the world’s second leading producer 

of gold, contains large silver and base metal (Cu, Zn, Pb, Mo, W) deposits, a variety of other 

important metallic (Fe, Ni, Be, REE’s, Hg, PGE) and industrial mineral (diatomite, barite, perlite, 

kaolinite, gallium) resources, as well as petroleum and geothermal energy resources. Ore deposits 

are most numerous and largest in size in linear mineral belts with complex geology. 

U.S. Geological Survey (USGS) scientists are in the final year of a research project initiated 

in the fall of 2001 to increase understanding of relations between crustal evolution, fluid flow, and 

ore deposits in the Great Basin. Because of its substantial past and current mineral production, this 

region has been the focus of numerous investigations over the past century and is the site of 

ongoing research by industry, academia, and state agencies. A variety of geoinformatic tools was 

used to organize, reinterpret, and display, in space and time, the large amounts of geologic, 

geophysical, geochemical, and hydrologic information deemed pertinent to this problem. This 

information, in combination with concentrated research on (1) critical aspects of the geologic 

history, (2) an area in northern Nevada that encompasses the major mineral belts, and (3) important 

mining districts and deposits, is producing new insights about the interplay between key tectonic 

events, hydrothermal fluid flow, and ore genesis in mineral belts. 

The results suggest that the Archean to Holocene history of the Great Basin was punctuated 

by several tectonic events that caused fluids of different origins (sea water, basinal brine, meteoric 

water, metamorphic water, magmatic water) to move through the crust. Basement faults reactivated 

during these events localized deformation, sedimentation, magmatism, and hydrothermal fluid flow 

in overlying rocks to form mineral belts that contain ore deposits of different types and ages that 

are locally superimposed (demonstrating inheritance). Fluid flow in these systems also was 

influenced by the distribution of permeable lithologies and paleotopographic highs and lows. 

Hydrothermal fluids evolved from their initial chemistries towards compositions that reflect the fO2

and fS2

 buffering capacity of, and the ligands and metals present in, the rocks (±older 

mineralization) through which they moved. In northern Nevada, where gold deposits are relatively 

common, carbonaceous, pyritic strata buffered fluids of diverse origins to H2S-rich compositions so 

1
they could transport gold repeatedly over Paleozoic-Cenozoic time (convergent evolution). Ore 

formed where metal-laden fluids encountered effective physicochemical traps. Maps of Neogene 

basin fill and erosion surfaces identify areas where preexisting ore deposits have been progressively 

exposed or concealed. Comparisons with analogous terrains and deposit types in other parts of the 

world provide global context. 

The initial findings and some of the databases, geologic maps, sections, reconstructions, 

hydrogeologic models, topical syntheses, regional overviews, short courses, field guides, and 

deposit comparisons produced by project staff and associated managers, contractors, and 

collaborators have been presented in numerous abstracts, symposia, USGS publications, and 

professional journals over the last 5 years (see the extensive bibliography). Notable among these 

was the 2005 Geological Society of Nevada symposium in Reno, Nevada, and the 2005 Geological 

Society of America annual meeting in Salt Lake City, Utah, where project results were presented to 

audiences from around the nation and world. The final results of the project will be submitted for 

publication in 2007 to appropriate USGS and professional journals. A special issue of 

GEOSPHERE, scheduled for publication in 2007, will be devoted to the results of this project and 

related work. This special issue will reach an international audience and be available worldwide on 

the internet. 

Much of the research for this project has concentrated on areas that will receive the focused 

attention of the mining industry in the future. As such, the data and interpretations generated by 

this project have direct use for land-use managers in Federal, State, and local agencies. Improved 

hydrogeologic models developed by this project will considerably enhance ongoing and future 

water resource investigations in the region. The increased understanding of when, where, and how 

hydrothermal systems produce significant economic deposits has direct uses for mineral 

exploration and for future USGS mineral resource assessments in the Great Basin and other parts of 

the world. 

Introduction 

The Great Basin contains a large number of significant deposits for several commodities 

(Figure 1). It also contains some giants, such as the Carlin trend, which is the world’s third largest 

gold camp; Bingham Canyon, one of the 10 largest porphyry copper systems; and Spor Mountain, 

the world’s largest beryllium mine. Important molybdenum resources include Buckingham, Mt. 

Hope, and Pine Grove. The Great Basin is the world’s third-leading producer of barite, from 

numerous deposits, and rare-earth elements, from the Mountain Pass mine. Production of lead, 

zinc, and silver from Utah porphyry systems rivals that of important mines in the Mississippi 

Valley region. Comstock, Tonapah, and Rochester in western Nevada are some of the country’s 

largest silver mines. What is most remarkable is the large number of gold-bearing deposits of 

different types and ages that are present in this single region (Figure 2). Production from these 

deposits has made the United States the world’s second leading gold producer. There are deposits 

of Devonian sedimentary exhalative (sedex) gold; Jurassic reduced intrusion-related gold; 

Cretaceous porphyry, distal disseminated, and orogenic gold; Eocene porphyry, distal disseminated, 

and Carlin gold; and Cenozoic epithermal gold. The Great Basin also has more low-sulfidation 

epithermal gold deposits associated with bimodal magmatism and range-front faults than any other 

place in the world. 

Many of these ore deposits occur in linear belts that are thought to be underlain by crustal 

structures produced by Neoproterozoic rifting. In the major mineral belts, basement faults are 

manifested by (1) growth faults, abrupt facies changes, and syngenetic ore deposits; (2) anomalous 

fold orientations and translational fault systems; and (3) igneous intrusions of Jurassic, Cretaceous, 

2
and Tertiary age. These relations suggested that crustal structures localized deformation, 

magmatism, and hydrothermal activity repeatedly over the complex Phanerozoic tectonic history of 

the region. They also prompted the following questions: How did mineral belts in the Great Basin 

originate and evolve through time? What role did the crystalline basement, terrigenous detrital 

sequence, carbonate sequence, and magmas play in the genesis of ore fluids? How did older 

structural features in these belts influence later episodes of mineralization? Were gold and other 

elements recycled? How do the mineral belts and deposits in this metallogenic province compare to 

those in other parts of the world? 

To address these questions we needed: (1) high-quality framework information (geologic, 

geophysical, geochemical), which was readily available for the Great Basin; (2) a medium in which 

to interpret a variety of data sets (Geographic Information System [GIS] and relational databases); 

(3) 2- and 3-D geologic reconstructions for major episodes of mineral deposit formation on regional 

and/or district scales; (4) numerical models of fluid flow and mineral precipitation for areas and 

districts of interest; and (5) comparable information on important deposit types in the Great Basin 

and other parts of the world. 

The overall goals of the Metallogeny of the Great Basin (MGB) project were to improve 

understanding of the tectonic events that triggered hydrothermal fluid flow and ore formation in the 

Great Basin, and to gain a better understanding of the origins and histories of the major mineral 

belts in northern Nevada. Specific project objectives included: (1) synthesis of key information 

generated over past decades in the Great Basin by the USGS, States, academia, and the mining and 

petroleum industries into digital maps, cross sections, and relational databases; (2) augmentation 

and combination of these maps, cross sections, and databases with new information from critical 

topical or geographic areas to address fundamental problems of ore genesis for a variety of mineral 

deposit types; (3) construction of a digital 3-D geologic model in northern Nevada that 

encompasses the major mineral belts; (4) construction of one or more detailed 2- and 3-D 

hydrogeologic models for large mining districts and geothermal areas; (5) reconstructions of the 

geology for important periods of ore formation on regional and/or district scales; and (6) numerical 

models of fluid flow, metal transport, and ore deposition. The project was designed to build a 

pyramid of knowledge using currently (2006) available information technology. At the base are 

topical maps and data on Great Basin geology and mineral deposits. These products were designed 

to capture the current state of knowledge on related topics and enter it into standard GIS and 

database software. For example, to understand Neogene metallogeny we need to assemble relevant 

information on geophysics, basins, faulting, magmatism, and epithermal ore deposits. In the 

middle of the pyramid is a regional geologic model for an area in northern Nevada that 

encompasses the major gold belts. We have been constructing maps, sections, and flow models for 

this area. At the top of the pyramid are a series of geologic, fluid flow, and chemical models for 

mining districts of interest. The yellow, orange, and magenta lines on Figure 2 outline study areas 

for the Great Basin, northern Nevada gold belts, and select mining districts. Figure 3 is an example 

of a topical map database product. Figure 4 is a revised digital geologic map of Nevada. Figure 5 

shows some of the regional cross sections in the northern Nevada study area. Figure 6 is an 

example of a 3-D hydrogeologic model, and Figure 7 shows examples of 2-D flow models of fluid 

flow. 

To fulfill project objectives, a large team of experts and the full laboratory capabilities of 

the USGS collaborated on this world class metallogenic province. Survey personnel that 

contributed to the MGB project included management (Constance Nutt and Peter Vikre); emeritus 

geoscientists (Harry Cook, Anita Harris, Charles Naeser, J. Thomas Nash, F.G. “Barney” Poole, 

Ted Theodore, and Charles Thorman); USGS staff scientists (Carl Abston, William Christiansen, 

Paul Denning, Sharon Diehl, Jeff Doebrich, Edward du Bray, Julie Dumoulin, Poul Emsbo, James 

3
Evans, Robert Fleck, Jonathan Glen, Mathew Granitto, V.J.S. “Tien” Grauch, Albert Hofstra, Keith 

Howard, Alex Iriondo, David John, Michael Kunk, Gary Landis, Karen Lund, Daniel Miggins, 

Lavinia Mills-Herring, Lisa Morgan, Robert Morin, Barry Moring, Thomas Moore, Benita 

Murchey-Setnicker, David Ponce, Wayne Premo, Barnaby Rockwell, Brian Rodriguez, Robert Rye, 

Jay Sampson, Donald Shamp, Sharon Smith, Lawrence Snee, Donald Sweetkind, Janet Tilden, 

Alan Wallace, Jackie Williams, Douglas Yager, and Ross Yeoman); a Mendenhall postdoctoral 

fellow (Joseph Colgan); student employees (Logan Hackett, Carl Bern); and volunteers (Julianne 

McCabe, Katherine Fifarek). The project also recruited a number of contractors and cooperative 

researchers (Samal Abani, Robert Blodgett, Elizabeth Crafford, Richard Fifarek, Kenneth Hickey, 

Jared Morrow, Mark Person, Ning Zhang) that were critical to its success. 

We wish to acknowledge and thank the individuals listed above as well as their numerous 

collaborators and coauthors for their valuable contributions. The purpose of this report is to 

summarize the progress made towards project goals and to provide a bibliography of USGS 

research products on topics relevant to the metallogeny of the Great Basin. This project has lead to 

a vastly improved understanding of the fundamental controls on the genesis of ore deposits and the 

roles of rock packages, magmatism, crustal structures, fluid flow, and inheritance in this worldclass gold province. Additional information on past and current Mineral Resources Program 

projects is available at the http://minerals.er.usgs.gov/usgs/. 

Relation to previous and current USGS projects in the region 

 The Metallogeny of the Great Basin (MGB) project builds on the results of two previous 5-

year Mineral Resources Program projects in the Great Basin. The Western Region Gold project 

culminated in a two-part Special Issue of Economic Geology devoted to gold deposits in northern 

Nevada (John and others, 2003b; Hofstra and others, 2003 and articles therein). The Humboldt 

River Basin Assessment project published a USGS Bulletin (Wallace and others, 2004b) that 

evaluated the metallic mineral-resource potential of a large area in northern Nevada and produced 

related publications (e.g., Nash, 2004; Yager and Folger, 2005; Ludington and others, 2006). The 

current MGB project was inspired by the Department of Energy/Water Resources Discipline 

(DOE/WRD) Death Valley Hydrogeologic Models project (Figure 2) that generated 2- and 3-D 

interpretations of the geology to frame simulations of ground water flow systems (e.g., Sweetkind 

and others, 2001; Potter and others, 2002). The MGB project also has had synergies with several 

other USGS projects in the Great Basin and adjacent areas, and some investigations were jointly 

supported by two or more projects and/or involved some of the same individuals. Examples 

include: the Western Region Surveys and Analysis project that produced digital datasets on mineral 

deposits, geology, geophysics, and geochemistry (e.g., Nutt and Ludington, 2003; Ludington and 

others, 2005, 2006); the Sources of Industrial Minerals in Western States project (e.g., Bliss and 

others, 2002, Koski and Hein, 2003; Rytuba and others, 2003; Wallace, 2003d, 2004); the Metals in 

Brine and Petroleum project that evaluated the role of seafloor discharges of brine and petroleum in 

the formation of syngenetic ore deposts in sedimentary basins (e.g., Emsbo, 2004; Hofstra and 

Emsbo, 2005; Johnson and Emsbo, 2004); the Geochemical and Isotope Studies of the Evolution of 

Ore Deposits project that has characterized the stable isotope geochemistry of sulfate minerals in 

igneous and hydrothermal systems, the gas and noble gas isotope composition of magmatic 

hydrothermal alunite, and the source of salt in hydrothermal fluids from diverse hydrothermal 

systems (Rye, 2005; Landis and Rye, 2005; Hofstra and Emsbo, 2005); the Resources and Hazards 

of Hydrothermal Systems in Cascades Volcanoes project that has elucidated controls on alteration 

and metallogenesis in the Oligocene-Quaternary Cascades arcs (e.g., John and others, 2003a); a 

project that investigated the origin, tectonic relations, and manifestations of the Yellowstone 

4
hotspot track (e.g., Morgan and others, 2004; Pierce and others, 2004); a project that evaluated the 

coupling of mechanical, thermal, chemical and hydraulic phenomena in ore formation (e.g., Berger 

and others, 2005); allied investigations by our Western and Central Region Mineral Resources 

Team Chief Scientists Connie Nutt and Peter Vikre (Nutt and Hofstra, in press; Vikre and others, 

2003, 2005a,b, in press); and related investigations by colleagues on other projects (e.g., Church 

and others, 2005). The MGB project also complements two groundwater investigations in the Great 

Basin: the Hydrogeologic Framework of Aquifer Systems in the Desert Southwest project that 

addresses ground-water availability (Chuang and others, 2003; Howard and others, in press) and 

the Basin and Range Carbonate Aquifer System Study (BARCASS) project that is conducting 

research on regional ground-water flow systems in Nevada and potential impacts from future 

ground-water pumping (http://nevada.usgs.gov/barcass/index.htm). Several emeritus scientists 

(Harry Cook, Anita Harris, Charles Naeser, J. Thomas Nash, F.G. “Barney” Poole, Ted Theodore, 

and Charles Thorman) were supported by the MGB project to aid completion of their maps, reports, 

and syntheses. The project also supported the initial work of Mendenhall postdoctoral research 

fellow Joe Colgan on extensional faulting and uplift cooling histories of critical areas in the Great 

Basin. 

Synergies with others 

Related work and collaborative research with the Nevada Bureau of Mines and Geology 

(NGMB; http://www.nbmg.unr.edu/), particularly the online publication of geologic maps and data 

on wells, ore deposits/mining districts, igneous rocks, isotopic dates, and faults, has been an 

important foundation of this project. Collaborations with students and professors from several 

academic institutions and industry geologists have also been of critical importance. 

The MGB project endorsed three Mineral Resources Program External Research Proposals 

that were awarded in 2005 and 2006. James Saunders (Auburn University) is investigating the 

timing and duration of bimodal magmatism and hydrothermal activity in the vicinity of the 

bonanza-grade, low-sulfidation Sleeper Au-Ag deposit using laser 40Ar/39Ar methods. Kenneth 

Hickey and Richard Tosdal (Mineral Deposits Research Unit, University of British Columbia) are 

documenting paleothermal anomalies around Eocene Carlin-type gold districts in Nevada using 

apatite and zircon fission-track methods. Jean Cline (University of Nevada, Las Vegas) and John 

Muntean (NBMG) are tracing fluid sources and flow paths in the Getchell Trend. 

Milestones 

This project has had a number of important milestones. At the 2002 Geological Society of 

America meeting in Denver, the USGS and Society of Economic Geologists (SEG) jointly 

sponsored a topical session on “Diverse origins of sedimentary rock-hosted disseminated gold 

deposits” to gain an international perspective (Spain, Macedonia, Australia, New Zealand, 

Indonesia, China, and the United States) on the settings, attributes, fluid sources, and processes of 

ore formation. Two invited overview papers on epithermal precious and base metal deposits and 

Carlin-type gold deposits, coauthored by David John and Albert Hofstra, respectively, were 

published in the 100th Anniversary Volume of SEG (Simmons and others, 2005; Cline and others, 

2005). At the 2005 Geological Society of Nevada symposium convened in Reno every 5 years, 

project results were presented to an audience of international to local mining, exploration, and 

research geologists. Contributions by project personnel, contractors, and collaborators accounted 

for 15 of the 37 contributions on the geology of the Great Basin region that were presented at this 

meeting. At the 2005 Geological Society of America annual meeting in Salt Lake City, two USGS5
sponsored topical sessions on “Great Basin Tectonics and Metallogeny” were convened to 

familiarize a national to regional audience with project research and to gain input from regional 

experts. An outgrowth of this meeting will be the publication of final reports in a special issue of 

GEOSPHERE, edited by the project chiefs - Albert Hofstra and Alan Wallace - devoted to “Great 

Basin Tectonics and Metallogeny” in the latter part of 2006 and 2007. GEOSPHERE is an ideal 

place to publish project research because it is an electronic journal designed to handle a wide 

variety of conventional and unconventional reports, maps, sections, databases, and animations. It 

also is available worldwide on the internet, thereby ensuring that the results of the project will be 

available globally. As appropriate, other final reports will be submitted in 2007 for publication in 

USGS and professional journals. 

Database development 

One of the major challenges of this project has been to determine how to organize data in 

ways that have geologic meaning and application Figure 8 shows the hierarchical nature of 

geologic information. We are working to compile and organize information on the age, location, 

and attributes of geologic entities, that range in scale from a mineral in a sample to progressively 

larger map units, and to link these data through the various scales. For example, noble gas data on 

olivine may be from a sample of basalt collected from a dike that fed a flow that is part of a 

volcanic center in the northern Nevada rift that is part of a large igneous province related to the 

Yellowstone hotspot track. Database development has moved forward on several fronts. This effort 

benefited from concurrent work by USGS and external research groups associated with the 

CHRONOS (www.chronos.org) geoinformatic project that are developing ontologies and databases 

for geologic maps and igneous and sedimentary rocks. Initial reports include an overview on 

database design concepts and schema for the project (Yager and Hofstra, 2004), a preliminary 

hierarchical database for bimodal igneous rocks (Yager and others, 2005), an integrated National 

Aeronautics and Space Administration/Goddard Space Flight Center and USGS rock magnetic 

database (Nazrova and Glen, 2004), a conodont database for Nevada (Crafford and Harris, in 

press), and a fossil database design (N. Zhang and R. Blodgett, unpublished administrative report 

for A.H. Hofstra). An important ingredient in the igneous rock database has been geochronologic 

data compiled by C.D. Henry at the NBMG. Likewise, conodont fossil age control produced by 

USGS emeriti, Anita Harris and Charles Sandberg, has been of critical importance for sedimentary 

rocks. Database design, population, and/or implementation are continuing on a master igneous rock 

database (D. Yager and others), a fossil and sedimentary-rock database (N. Zhang and others), and 

an ore-deposit database (A. Hofstra and others). 

Geologic maps 

GeoLogic Services was contracted to produce a revised, 1:250,000-scale, digital geologic 

map of Nevada (Figure 4) to frame the development of regional cross sections and 3-D models in 

northern Nevada (Crafford, 2005, in press). Important refinements to the map include the addition 

of conodont ages and color alteration indices (CAI; Crafford and Harris, 2005, in press) and revised 

pluton ages and compositions (du Bray and Nash, 2005; du Bray and others, in press). 

Several 1:24,000 scale maps of key areas also were produced by project staff (Willow 

Creek Reservoir and Willow Creek Reservoir SE Quadrangles–Wallace, 2003a,b; Verdi Peak 

Quadrangle–Howard and MacCready, 2004; Mule Canyon Quadrangle–John and Wrucke, 2003; 

Cedars Quadrangle– Moore and others, in press; Big Bald Mountain Quadrangle and part of the 

Tognini Quadrangle–Nutt and Hart, 2004; Minden Quadrangle–Ramelli and others, 2003; Vigo NE 

6
Quadrangle–Scott and Harding, in press; Beaver Peak Quadrangle– Theodore and others, 2003; 

Oxley Peak Area–Thorman and others, 2003; Unity Reservoir Quadrangle–Evans, 2003; and 

Huntsman Ranch Quadrangle–Wallace and others, in press). 

Geophysics 

A geophysical terrane map of the entire Great Basin region and adjacent areas (Glen and 

others, 2004a) outlines gravity and magnetic anomalies and provides information on their attributes 

and inferred sources (Figure 3). New gravity data have been collected to fill gaps and refine 

models of the thickness of basin fill in important mineral districts, along regional cross sections, 

and between ranges across the northern Nevada study area (e.g., Sweetkind and others, 2005a,b; 

Tilden and others, 2005; Figure 6). Variations in the thickness of basin fill provide additional 

evidence of range tilt domains across the Great Basin. The basement gravity anomaly in northcentral Nevada has been better characterized and postulated to represent either a deep crustal 

discontinuity or mid- to subcrustal mafic intrusions associated with the Northern Nevada Rift 

(Ponce and Glen, 2005). Gravity and magnetic data also have been used to map regional-scale 

fractures intruded by bimodal magmas associated with the Yellowstone hot spot in the northern 

Great Basin and adjacent areas of Washington, Oregon, and Idaho (Evans and others, 2004; Coe 

and Glen, 2004; Glen and Ponce, 2002; Glen and others, 2003, 2004b). These studies also show 

that preexisting crustal structures influenced the distribution of bimodal magmatism in the northern 

Great Basin and southeast Oregon. PRJ, Inc. was contracted to provide geophysical interpretations 

based on their proprietary (high-resolution) aeromagnetic surveys of intrusions, volcanic rocks, and 

faults along some of the regional cross sections in northern Nevada (unpublished administrative 

report for A.H. Hofstra). Geophysical data were used together with geologic evidence and 

variations in the isotopic compositions of igneous intrusions to show that deep crustal structures 

influenced Paleozoic tectonics, magmatism, and the alignment of ore deposits in some of the major 

mineral belts of northern Nevada (Crafford and Grauch, 2002; Grauch and others, 2003). Emsbo 

and others (2006) go on to suggest that the vast endowment of gold in these mineral belts results 

from the protracted interplay of orogenic, basinal, and hydrothermal processes along reactivated 

basement faults near the lithospheric boundary produced by the Neoproterozoic breakup of 

Rodinia. 

Magnetotelluric (MT) soundings acquired between 1994 and 2005 in northern Nevada were 

modeled to detect the presence, or absence, and orientations of deep penetrating faults in the 

vicinity of recognized mineral belts in northern Nevada. New MT surveys were conducted to map 

the position of the east-west suture zone between the Archean Wyoming province and the 

Paleoproterozoic Mojave province in western Utah and northeast Nevada that localized the giant 

Bingham Canyon porphyry copper deposit (Rodriguez and Williams, 2002, 2005; Rodriguez and 

others, 2005, Wannamaker and others, 2002; Williams and Rodriguez, 2003, 2004, 2005). A 

surprising result of the MT modeling in northern Nevada is that most of the crustal faults detected 

are at an oblique angle to the strike of the mineral belts. This result may be caused by the dilation 

of oblique faults that intersect, or occur within, the mineral belts and is consistent with the strike of 

some ore-controlling faults at the surface. The new MT surveys suggest that the ArcheanProterozoic suture zone veers to the north just east of Wells, Nevada. This interpretation indicates 

that only the northeastern corner of Nevada is underlain by Archean crust, and that the remainder of 

northeastern Nevada is underlain by Proterozoic crust. Supporting evidence for this interpretation 

is provided by SHRIMP U-Pb ages of inherited zircons and Sr and Nd isotopic signatures of 

Mesozoic and Cenozoic intrusions in the Northern Ruby Mountains–East Humboldt Range core 

complex (Premo and others, 2005) that indicate it is underlain by siliciclastic rocks derived from 

7
the craton and/or Proterozoic crust. Because the composition of the deep crust may have an 

important influence on magma generation and on deeply circulating fluids, this distinction between 

crusts of different ages and character may prove to be critical for developing regional ore-genesis 

models. 

Geochemistry 

Data on the Pb, Sr, and Nd isotopic composition of igneous and sedimentary rocks and ore 

deposits are being compiled to identify basement features and refine understanding of the source of 

these elements in magmas and hydrothermal systems (Grauch and others, 2003; Premo and others, 

2005). 

Major-oxide and trace-element analyses of intrusive and extrusive igneous rocks made by 

the USGS over past decades have been gathered, locations verified, and descriptions improved for 

inclusion in a master igneous-rock database currently (2006) in preparation (D. Yager and others). 

USGS data on intrusions also has been combined with data from other sources to build a 

comprehensive data set for intrusions in the northern Nevada study area (du Bray and Nash, 2005; 

du Bray and others, in press). The ability of remotely sensed multispectral thermal infrared data to 

map variations in the silica content of igneous rocks has been demonstrated in the Hiller Mountains 

(Hook and others, 2005). USGS trace-element data on variably altered and mineralized rocks have 

been gathered, enhanced, and compared to trace-element data on soil and sediment (Yager and 

Folger, 2005) to evaluate the geochemical expression of significant base- and precious-metal 

deposits in these media (Granitto and others, 2005). In this study, factor analysis was used to 

identify element associations in the data related to major rock and deposit types. 

Neoproterozoic to Devonian passive margin 

Studies are in progress on the style of extensional faulting during Rodinian rifting and the 

nature of Neoproterozoic-Middle Cambrian siliciclastic sedimentary rocks in the Great Basin (K. 

Lund). A major effort has been made to improve understanding and digital datasets pertinent to 

Paleozoic rocks because they host a large proportion of the metallic mineral resources in the Great 

Basin and in some deposits were important sources of elements in the ores. Conodont age and CAI 

maps and database of Nevada have been prepared to validate the age of map units and facilitate 

revisions and to identify thermal anomalies related to deformation, magmatism, and hydrothermal 

activity (Crafford and Harris, 2005, in press). A bibliography of paleontological data has been 

compiled (Blodgett and others, in press) and a fossil database constructed to house information on 

the fossil age and environment of sedimentary rocks in the Great Basin that can be served over the 

web (N. Zhang and R. Blodgett unpublished administrative report for A.H. Hofstra). Because so 

many syngenetic and epigenetic ore deposits occur in Devonian and Mississippian rocks, the fossil 

database is currently being populated with information on fossils of that age to aid reconstructions 

of basin architecture over that time period (e.g., Emsbo and Morrow, 2005). Data from published 

and unpublished, described, and dated sections are being transformed into a database to enable 

digital displays of unit lithology, thickness, facies, and paleogeography (e.g., McCabe and others, 

2005; F.G. Poole and others, in prep.). A sedimentary rock database is also under construction to 

integrate fossil, lithology, facies, and sequence information over a range of scales. The sedimentary 

facies and sequence stratigraphy of Paleozoic carbonate rocks have been characterized along an 

east-west profile across the Great Basin, which enables us to evaluate the influence of facies and 

unconformities on the localization of ore (Cook and Corboy, 2004; Cook, 2005, 2006). This study 

and a companion study by Crafford (2005) show that most Carlin-type gold deposits are located 

8
where crustal faults intersect slope-facies rocks near the carbonate platform margin. The vast 

majority of the gold in Carlin-type deposits is hosted in Devonian rocks. A report on the chemical 

and isotopic composition of barren and mineralized sections of the Devonian Popovich Formation 

is in preparation (W. Christiansen and A. Hofstra). Rocks of Devonian age also record episodes of 

synsedimentary faulting that produced abrupt facies changes and localized discharges of metal and 

nutrient-laden basinal brines and petroleum; these fluids formed metalliferous black shales and 

sedex gold, zinc and barite resources (Emsbo and others, 2002; Hofstra and Emsbo, 2005; Emsbo 

and Morrow, 2005; Johnson and Emsbo, 2004). A number of smaller sedex barite and Carlin-type 

gold deposits occur in the overlying Carboniferous foreland basin sequence. Basinal brines also 

produced small Mississippi Valley-type (MVT) lead-zinc deposits and occurrences, such as those 

hosted in Mississippian rocks in the Good Springs district. Brine migration pathways through 

permeable carbonate strata and faults are marked by the formation of hydrothermal zebra dolomite 

(Diehl and others, 2005a,b). Brines were produced by the evaporation of seawater (Hofstra and 

Emsbo, 2005) in silled basins when the Great Basin was at equatorial paleolatitudes (Berger and 

Theodore, 2005a,b) and evolved to become hot ore fluids as they circulated through underlying 

sedimentary and crystalline rocks (Church and others, 2005). The distribution and field relations 

between zebra dolomite, sedex, and MVT deposits in the Great Basin suggest that brine migration 

was widespread and occurred in response to two tectonic events: Devonian extensional faulting and 

Mississippian contraction associated with the Antler orogeny (Diehl and others, 2005a,b). A global 

context for sedex barite is provided by a comparison of deposits in the world’s three largest barite 

producing regions in the Great Basin, China, and India (Clark and others, 2004). 

Late Paleozoic and Mesozoic contraction 

An important improvement of the new Nevada State digital geologic map over earlier maps 

is a revised grouping of colloquial formations and units into coherent tectono-stratigraphic terranes 

and foreland-basin sequences associated with major orogenies in the Great Basin (Crafford, 2005, 

in press). A digital map of large-scale folds produced by these orogenic events in northern Nevada 

is currently (2006) in preparation (T. Moore). Important manifestations of these tectonic events 

have been documented by several studies. Recognition of Late Devonian and Mississippian arkose 

derived from an unidentified granitic source terrane adds a new dimension to the Antler orogeny 

(Ketner and others, 2005). Thermal metamorphism of carbonaceous material in sedex horizons in 

the Carlin trend during the Antler orogeny generated petroleum containing elevated levels of gold 

(Emsbo and Koenig, 2005). Field relations indicate that a post-Antler episode of thrust faulting in 

the Carlin trend was synchronous with deposition of the Pennsylvanian and Permian Strathearn 

Formation (Theodore and others, 2004). Identification of a new chonetoidean brachipod fossil in 

the southern Shoshone range improves stratigraphic correlations in the Permian overlap assemblage 

(Rachebouf and others, 2004). The time and space distribution of deformation and sedimentation 

associated with the Jurassic Elko orogeny is described by Thorman and Peterson (2003). The 

importance of Late Paleozoic and Mesozoic structural inversion along reactivated basement faults 

and its role in the formation of the antiforms that focused fluid flow and large concentrations of 

Carlin-type gold deposits is shown by Hofstra (2005b) and Emsbo and others (2006). Related work 

by J.L. Muntean at the NBMG and his colleagues demonstrates that Carlin-type gold deposits are 

localized along inverted Paleozoic normal faults. The influence of low-angle and bedding-parallel 

faults produced by these orogenic events on lateral fluid flow and the localization of ore in Carlintype deposits was described by Nutt and Thorman (2005). 

9
Mesozoic and Cenozoic arc magmatism and pluton-related ore deposits 

The space-time-compositional evolution of intrusive rocks in the Great Basin is being 

synthesized to clarify the roles of magma evolution and episodes of magma emplacement in the 

formation of a variety of pluton-related mineral deposits and to improve digital geologic maps of 

Utah and Nevada (Nutt and Ludington, 2003; du Bray and Nash, 2005; du Bray and others, in 

press; Crafford, in press). This work also has contributed to the development of a metamorphic 

map of California (Day and others, 2003). Detailed studies of Cretaceous and Tertiary intrusions in 

the Ruby Mountains-East Humboldt Range have enhanced understanding of magma petrogenesis, 

crustal contamination, and emplacement mechanisms at mid-crustal levels during contraction and 

extension (Howard and others, 2004a,b; Lee and others, 2003; Snoke and others, 2004; Premo and 

others, 2005). Complementary studies of Eocene intrusions in the Carlin trend and adjacent areas 

in north central Nevada have been conducted by C. Henry and M. Ressel at the NBMG and 

University of Nevada, Reno. Studies of Jurassic intrusions and ore deposits in the Bald Mountain 

district indicate it is the first reduced intrusion-related gold deposit to be recognized in the Great 

Basin (Nutt and Hofstra, in press; E. du Bray and T. Nash, in prep.). The role of magmatic versus 

non-magmatic fluids in the formation of Jurassic reduced intrusion-related gold deposits (Nutt and 

Hofstra, in press), Eocene porphyry, skarn, vein, replacement, and distal disseminated deposits 

(Battle Mountain–McGibbon and Theodore, 2002; Park City–John, in press; Bingham Canyon–

Cunningham and others, 2002, 2003, 2005), Eocene Carlin-type gold deposits and younger 

epithermal deposits (see below) have been addressed on a district-by-district basis and for different 

deposit types in several publications. 

Paleogene basins, magmatism, faulting, and ore deposits 

Information on Paleogene topography, faulting, and extension-related folds is provided by 

studies of Eocene basins in the northern Independence Range and exposures of fluvial and 

lacustrine rocks in the Alligator Ridge district and other areas in the eastern Great Basin (e.g., 

Howard and Nutt, 2005; Nutt and Howard, 2003; Nutt, 2002). Related investigations on the 

Eocene Elko basin and adjacent topographic highs in the vicinity of the Carlin trend and Jerritt 

Canyon district by S.R. Haynes, K.A. Hickey, and R.M. Tosdal at the University of British 

Columbia have identified a pulse of Eocene extensional faulting that is coeval with Carlin-type 

gold mineralization. Information on Late Cretaceous-Paleogene exhumation and development of an 

Eocene erosion surface, provided by apatite fission-track dating and the distribution of Eocene 

basins, is currently (2006) being assembled (K. Hickey and others, in prep.). These studies 

influence hydrogeologic models developed for the Carlin trend (e.g., Person and others, 2005). 

Subsequent large-magnitude extension in the Ruby Mountains and development of several 

other metamorphic core complexes and tilted slabs provide important exposures of the upper and 

middle crust (Howard, 2002, 2003, 2005). These rocks place constraints on the attributes of older 

thrust faults and folds, igneous intrusions, and Neogene extension that frame development of 

regional cross sections (e.g., Sweetkind and others, 2005a,b) and constrain hydrogeologic models 

for neighboring districts, such as the Carlin trend mentioned above. 

Understanding of the distribution, composition, and age of calc-alkaline volcanic centers, 

calderas, and ash-flow tuffs has been improved by a number of the 1:24,000 scale maps listed 

earlier. A study of the widespread late Eocene Caetano Tuff has defined the age and attributes of 

two distinct eruptive units and the location of a source caldera in an east-west volcano-tectonic 

trough (John and Henry, 2005). Related investigations of calderas and ash-flow tuffs by C. Henry 

and J. Faulds at the NBMG and M. Best and E. Christiansen at Brigham Young University are 

10
enhancing understanding of regional volcanology, topographic relief, and the distribution of 

paleovalleys across the Great Basin, as well as understanding of the style of subsequent faulting 

within and east of the Walker Lane in the western Great Basin. The paucity of epithermal ore 

deposits associated with the southward-sweeping patterns of Eocene-Miocene calc-alkaline 

volcanism in the Great Basin and the abundance of deposits associated with the ancestral Cascades 

magmatic arc have been described in a number of overviews (Ludington and John, 2002; John, 

2003, 2005; and John and others, 2005) and deposit/district studies mentioned below. 

Preliminary syntheses (Cline and others, 2004; Hofstra, 2002a, 2004, 2005a; Thorman, 

2002) and an invited overview paper on the role of older geologic features, Eocene geologic 

setting, and origin of Carlin-type gold deposits in northern Nevada, with a comprehensive database 

on the geology and attributes of deposits in every district/trend, was published in the 100th 

Anniversary Volume of Economic Geology (Cline and others, 2005). A related overview on 

stratabound ore bodies in several Carlin-type districts suggests these may be of Paleozoic age and 

syngenetic origin (Berger and Theodore, 2005a,b). Another important overview suggests that 

successive reactivation of faults and superposition of hydrothermal systems in mineral belts above 

a lithospheric boundary explains the huge endowment of gold in northern Nevada (Emsbo and 

others, 2006). Detailed studies of the attributes and origin of the Devonian Rodeo sedex gold 

deposit in the Carlin trend (Emsbo and others, 2002), Jurassic reduced intrusion-related gold 

deposits in the Bald Mountain district (Nutt and Hofstra, 2002, in press), and Eocene Carlin-type 

gold deposits in the Alligator Ridge, Getchell, and Gold Bar districts (Nutt and Hofstra, 2002; Cline 

and others, 2002a,b, 2003a,b; Yigit and others, 2006) were critical to development of these 

interpretations. 

Complementary studies of the other types of sedimentary rock-hosted disseminated gold 

(SRHDG) deposits in the Great Basin (Samal and others, 2005; Cunningham and others, 2002, 

2003, 2005; Emsbo and others, 2002, 2005; McGibbon and Theodore, 2002; Theodore and Kotlyar, 

2002; Nutt and Hofstra, 2002, in press) and elsewhere in the world (Christiansen and others, 2002; 

Daliran and others, 2002; Percival and Hofstra, 2002a,b; Turner and others, 2002) together with 

research on the large number of Carlin-type and other sedimentary rock-hosted gold deposits in 

China (Goldfarb and others, 2004; Hofstra and others, 2005a,b,c; Zhang and others, 2005) provide 

global context and show the ability of reduced, carbonaceous, pyritic sedimentary rocks to buffer 

fluids from different sources to H2S-rich compositions that facilitate the transport and deposition of 

gold (convergent evolution). Preliminary overviews on the diverse origins of sedimentary rockhosted disseminated gold deposits around the world (Hofstra, 2002b, 2004) contributed to the 

model developed for Nevada Carlin-type deposits cited above, and a thorough overview paper on 

these deposits is currently (2006) in preparation (A. Hofstra and P. Emsbo). 

Neogene basins, magmatism, faulting, and epithermal ore deposits 

Neogene basin and lake development, bimodal magmatism associated with crustal 

extension and mantle upwelling (such as the Yellowstone hot spot), Basin and Range block 

faulting, and climate evolution resulted in the formation of numerous low-sulfidation gold, silver, 

and mercury deposits, the world’s largest beryllium deposit (Spar Mountain), significant 

molybdenum, uranium, and gallium resources, large diatomite deposits, numerous geothermal 

areas, and important ground water resources (e.g., Rytuba and others, 2003; Wallace 2005a,b; 

Wallace and others, 2004a). These processes also led to the present configuration, exposure, and 

concealment of both pre-Neogene and Neogene mineral deposits. Evaluating and "stripping away" 

the effects of processes that took place during the Neogene is the first step in reconstructing the 

early Tertiary and older mineralizing environments and metallogenesis. 

11
Detailed studies of the Miocene Humboldt Formation and younger fluvial and lacustrine 

deposits constrain the timing of Basin and Range faulting and reveal changing patterns of basin 

accumulation and erosion between 16 Ma and the Present related to the formation and removal of 

volcanic and tectonic dams (Wallace, 2002, 2005a,b; Wallace and others, 2004b). As a 

consequence, mineral deposits in northeastern Nevada are being exhumed while those in 

northwestern Nevada are being concealed. Resulting exposure levels and basin attributes influence 

the supergene oxidation of sulfide ores, estimates of the depth of cover over concealed deposits, 

and evaluations of ground-water resources. 

The origin, processes, and patterns of volcanism and tectonism that were inherited from preexisting structures and caused by the Yellowstone hot spot track, and their geophysical expressions 

have been mapped and described (Glen and Ponce, 2002; Glen and others, 2003, 2004b, Morgan 

and others, 2004; Pierce and others, 2004; Rytuba and others, 2004). The distribution, age, and 

geochemistry of bimodal volcanic rocks in the Miocene northern Nevada rift and other volcanic 

centers in northern Nevada have been assembled into a database, facilitating studies of their 

petrogenesis and their relation to basement features and low sulfidation Au-Ag deposits (John, 

2005; John and others, 2002, 2005; Ponce and Glen, 2005; Yager and others, 2005). Studies of the 

mid-Miocene Steens Mountain volcanic field document the early magmatic evolution of the hot 

spot and provide a detailed record of magnetic reversals of wide applicability (Jarboe and others, 

2003, 2004). The neighboring intermediate composition Santa Rosa-Calico eruptive products of 

about the same age are inferred to result from interactions between mantle- and crustal-derived 

materials (Brueseke and others, 2003). The origin of paleomagnetic fabics in igneous rocks also has 

been assessed (Plenier and Glen, 2004). Studies of the Pliocene Coso volcanic field in southeastern 

California document the age, compositional evolution, and kinematics of subsequent block 

rotations along the western side of the Great Basin (Pluhar and others, 2003a,b, 2004). 

Studies of the geology, age, and attributes of low-sulfidation gold-silver deposits in northern 

Nevada document the similarities and differences among such deposits that formed during the past 

16 million years. Deposits studied in detail included Mule Canyon (John and Hofstra, 2002), 

Midas (Leavitt and others, 2003), Ivanhoe (Wallace, 2003c), Seven Troughs (Hudson and others, 

2005, 2006) and other deposits in the Lovelock area (John and Muntean, 2006), and Florida 

Canyon (Samal and others, 2005). Some of these are located along or near the northern Nevada rift 

or subparallel magnetic anomalies farther west; ages differ, in places significantly, but the deposits 

have many features in common, indicating that many ore-forming processes were independent of 

time. 

In the western part of the Great Basin, volcanic centers along the ancestral Cascades 

magmatic arc and the Walker Lane dextral shear zone controlled the localization of several 

Miocene porphyry-epithermal systems analogous to those being studied in the present Cascades arc 

(Ludington and John, 2002; John and others, 2003a). In the Virginia Range, multiple episodes of 

magmatism, acid-sulfate alteration, and low-sulfidation precious-metal mineralization were 

documented (Vikre and others, 2003), and, at Goldfield, the age and composition of magmatic 

hydrothermal alunites were characterized (Vikre and others, 2005a,b). The attributes of these and 

many other epithermal systems in the area suggest they are the shallow manifestations of porphyry 

systems. 

The Cedars Au-Ag prospect in the southern Shoshone Range is one of a small number of 

epithermal systems associated with the southward sweep of calc-alkaline magmatism (e.g., Round 

Mountain). However, this system formed 19 million years ago, after the main sweep of volcanism 

and during the very early onset of Basin and Range extensional faulting (Moore and O’Sullivan, 

2005). 

12
Such studies of the attributes, magmatic affiliations, and relation to deformation of 

epithermal deposits in the Great Basin have been a foundation of regional syntheses (John and 

others, 2002, 2005; John, 2003, 2005). These studies comprised an important part of an invited 

paper for the 100th Anniversary Volume of Economic Geology (Simmons and others, 2005) that 

refined classifications and origins of epithermal gold-silver deposits around the world. It also 

provided a database on the geology and characteristics of the epithermal deposits in the Great Basin 

that are of international economic or scientific importance. 

Regional and district scale geologic and hydrologic models 

The relations between geologic data, models, interpretations and their inherent uncertainties 

were evaluated by Sweetkind and others (2002). A regional geologic model that encompasses the 

major mineral belts in northern Nevada (Carlin trend, Battle Mountain-Eureka trend, Getchell 

trend, Jerritt Canyon district, Alligator Ridge district, northern Nevada rift) is being constructed 

from a digital elevation model, the revised 1:250,000–scale geologic map of Nevada, deep drill 

holes, a series of geologic cross-sections, interpretations of geophysical data, and fossil/isotopic age 

information (Sweetkind and others, 2005a,b). A summary 3-D display of this information and a 

discussion of its relevance to the origin and evolutionary history of the mineral belts in northern 

Nevada is currently (2006) in preparation by D. Sweetkind and others. 

To meet the needs of the project, the hydrologic modeling task had to develop new 

computer code that could handle high-permeability fault zones in 2-D simulations of crustal scale 

ground-water flow, heat, stable isotope, noble gases, and silica transport (Person and others, in 

press) and in 3-D simulations of fluid flow and heat transport. This task also used a “present is the 

key to the past” approach to calibrate the hydrologic parameters of rock units and structures. The 

district and deposit studies mentioned above show that convection of meteoric fluids in response to 

magmatism and/or extensional faulting can produce significant ore deposits. Hence, our initial 

modeling efforts only involve meteoric ground water and rocks. Two cross-sectional models were 

used to evaluate the importance of regional topography-driven fluid flow on present-day 

geothermal (Beowawe) and Miocene (Mule Canyon) hydrothermal systems located in the northern 

Nevada rift (Gao and others, 2003). These models suggest that fault dislocations are too numerous 

and rock permeabilities are too low for such regional flow systems to develop in Tertiary time. 

Rather, the modeling suggests that convection cells with restricted lateral and vertical extents are 

the norm. 

Preliminary hydrogeologic models of the Dixie Valley and Beowawe geothermal areas, 

Miocene Mule Canyon low-sulfidation gold-silver system, and the Eocene Carlin gold trend 

evaluated the role of high-permeability fault zones. The results suggest that there are two endmember types of meteoric hydrothermal systems in the Great Basin (Hofstra, 2005b; Person and 

others, 2005). At one end are barren geothermal systems where convection is restricted to fault 

planes. The fluids interact little with wall rocks, have the smallest oxygen isotope shifts, and 

contain little gold. At the other end are Carlin systems where there was wholesale fluid convection 

through reduced sedimentary rocks enriched in gold. These mineralizing systems have the largest 

oxygen shifts and world-class endowments of gold. The Mule Canyon low-sulfidation system is 

intermediate in character. The 2- and 3-D geologic models for these systems are currently (2006) 

being refined and gridded (e.g., Tilden and others, 2005) for a final round of modeling. Some of 

these models will be used to evaluate the influence of magmatic heat and fluids. Manuscript(s) on 

the results of these hydrogeologic models are currently (2006) in preparation. 

13
Metallogeny of the Great Basin Bibliography: 

2002-2006 publications by USGS personnel and collaborators 

Berger, B.B., Anderson, R.E., Phillips, J.D., and Tingley, J.V., 2005, Plate-boundary transverse 

deformation zones and their structural roles in localizing mineralization in the Virginia City, 

Goldfield, and Silver Star mining districts, Nevada, in Rhoden, H.N., Steininger, R.C., and Vikre, 

P.G., eds., Geological Society of Nevada Symposium 2005: Window to the World, Reno, 

Nevada, May 2005, p. 269–281. 

Berger, V.I., and Theodore, T.G., 2005a, Implications of stratabound Carlin-type gold deposits in 

Paleozoic rocks of north-central Nevada; slide presentation: U. S. Geological Survey Open-File 

Report 2005-1156, 37 p. 

Berger, V.I., and Theodore, T.G., 2005b, Implications of stratabound Carlin-type gold deposits in 

Paleozoic rocks of north-central Nevada, in Rhoden, H.N., Steininger, R.C., and Vikre, P.G., 

eds., Geological Society of Nevada Symposium 2005: Window to the World, Reno, Nevada, May 

2005, p. 43–78. 

Bliss, J.D., Moyle, P.R., and Long, K.R., eds., 2002, Contributions to Industrial-Minerals Research: 

U.S. Geological Survey Bulletin 2209, Version 1.0, URL http://pubs.usgs.gov/bul/b2209/. 

Blodgett, R.B., Zhang, N., Hofstra, A.H., and Morrow, J.R., in press, Great Basin Paleontological 

Bibliography: U.S. Geological Survey Open-File Report, 171 manuscript pages. 

Brueseke, M.E., Hart, W.K., Wallace, A.R., Heizler, M.T., and Fleck, R.J., 2003, Mid-Miocene 

volcanic field development in northern Nevada—New age constraints on the timing of Santa 

Rosa-Calico volcanism [abs.]: Geological Society of America, Abstracts with Programs, v. 35, 

no. 4, p. 63. 

Christiansen, W.D., Premo, W.R., Hofstra, A.H., Emsbo, P., and Lange, I.M., 2002, Stratabound 

SRHDG resource in Middle Proterozoic rocks of the Big Belt Mountains near York, Montana 

[abs.]: Geological Society of America, Abstracts with Programs, v. 34, no. 6, p. 143. 

Chuang, F.C., McKee, E.H., Howard, K.A., 2003, Hydrogeologic factors that influence ground 

water movement in the desert southwest United States: U.S. Geological Survey Open-File Report 

03-0294, 38 p., 21 sheets. 

Church, S.E., Cox, D.P., Wooden, J.L., Tingley, J.V., and Vaughn, R.B., 2005, Base- and preciousmetal deposits in the Basin and Range of southern California and southern Nevada—

Metallogenic implication of lead isotope studies: Earth Science Reviews, v. 73, p. 323–346. 

Clark, S.H.B., Poole, F.G., and Wang, Z., 2004, Comparison of some sediment-hosted, stratiform 

barite deposits in China, the United States, and India: Ore Geology Reviews, v. 24, nos.1–2, p. 

85-101. 

14
Cline, J.S., Hofstra, A.H., Muntean, J., Tosdal, R.M., and Hickey, K.A., 2004, Characteristics and 

genesis of Carlin-type gold deposits, Nevada, USA: Special Publication, Centre for Ore Deposit 

and Exploration Studies (CODES), v. 5, p. 133–139. 

Cline, J.S., Hofstra, A.H., Muntean, J.L., Tosdal, R.M., and Hickey, K.A., 2005, Carlin-type gold 

deposits in Nevada—Critical geologic characteristics and viable models: Economic Geology, 

100th Anniversary Volume, p. 451–484. 

Cline, J.S., Shields, J.S., Riciputi, L., Fayek, M., Copp, M., Muntean, T.L., and Hoftstra, A.H., 

2003b, Trace element and isotope microanalyses support a deep ore fluid source at the Getchell 

Carlin-type gold deposit, northern Nevada [abs.]: Geological Society of America, Abstracts with 

Programs, v. 35, no. 6, p. 358. 

Cline, J.S., Stuart, F.M., Hofstra, A.H., Premo, W.R., Riciputi, L., Tosdal, R.M., and Tretbar, D.R., 

2003a, Multiple sources of ore-fluid components at the Getchell Carlin-type gold deposit, 

Nevada, USA: 7th Biennial SGA-SEG Meeting, Athens, Greece, Aug. 24–28, 2003, 4 p. 

Cline, J.S., Stuart, F.M., Hofstra, A.H., and Tretbar, D.R., 2002a, Helium and stable isotopic 

constraints on the source of ore fluid components at the Getchell Carlin-type gold deposit, northcentral Nevada, USA [abs.]: Eighth Biennial Pan-American Current Research on Fluid 

Inclusions, Halifax, Canada, Program with Abstracts, p. 23–24. 

Cline, J.S., Stuart, F.M., Hofstra, A.H., Tretbar, D.R., Riciputi, L., and Premo, W.R., 2002b, He, 

Nd, and stable isotope constraints on Carlin-type ore fluid components, Getchell, NV, USA 

[abs.]: Geological Society of America, Abstracts with Programs v. 34, no. 6, p. 141. 

Coe, R.S., and Glen, J.M.G., 2004, The complexity of reversals, in Channell, J.E.T., Lowrie, W., 

and Meert, J., eds., Timescales of the internal geomagnetic field: American Geophysical Union, 

Geophysical Monograph. 

Cook, H.E., 2005, Carbonate sequence stratigraphy: An exploration tool for sediment-hosted, 

disseminated gold deposits in the Great Basin, in Rhoden, H.N., Steininger, R.C., and Vikre, 

P.G., eds., Geological Society of Nevada Symposium 2005: Window to the World, Reno, 

Nevada, May 2005, p. 19–24. 

Cook, H.E., 2006, Great Basin Paleozoic carbonate platform—Facies, facies transitions, 

depositional models, platform architecture, sequence stratigraphy, and predictive oil and gas 

reservoir and mineral host models: Nevada Petroleum Society Field Trip Guidebook, July 18–24. 

Cook, H.E., and Corboy, J.J., 2004, Great Basin Paleozoic carbonate platform—Facies, facies 

transitions, depositional models, platform architecture, sequence stratigraphy, and predictive 

mineral host models: U.S. Geological Survey Open-File Report 2004-1078, 129 p., 

http://pubs.usgs.gov/of/2004/1078/ 

Crafford, E.J., 2005, Nevada tectonic history and ore deposits—Constraints provided by a new 

Nevada state digital geologic map [abs.], in Rhoden, H.N., Steininger, R.C., and Vikre, P.G., 

eds., Geological Society of Nevada Symposium 2005: Window to the World, Reno, Nevada, May 

2005, p. 1308. 

15
Crafford, E., in press, Nevada State Digital Geologic Map: U.S. Geological Survey Open-File 

Report. 

Crafford, A.E.J., and Grauch, V.J.S., 2002, Geologic and geophysical evidence for the influence of 

deep crustal structures on Paleozoic tectonics and the alignment of world class gold deposits, 

north-central Nevada, USA: Ore Geology Reviews, v. 21, p. 157–184. 

Crafford, A.E.J., and Harris, A.G., 2005, New digital Conodont Alteration Index (CAI) maps of 

Nevada [abs.]: Geological Society of America, Abstracts with Programs, v. 37, no. 7, p. 379. 

Crafford, E. and Harris, A.G., in press, Digital Conodont Database of Nevada: U.S. Geological 

Survey Open-File Report. 

Cunningham, C.G., Austin, G.W., Naeser, C.W., Rye, R.O., Ballantyne, G.H., and Barker, C.E., 

2002, Carlin-type gold deposits related to the Bingham Canyon, Utah, porphyry Cu deposit; 

thermal and isotopic constraints [abs.]: Geological Society of America, Abstracts with Programs 

v. 34, no. 6, p. 143. 

Cunningham, C.G., Austin, G.W., Naeser, C.W., Rye, R.O., Ballantyne, G.H., Stamm, R.G., and 

Barker, C.E., 2003, Formation of a paleothermal anomaly and disseminated gold deposits 

associated with the Bingham Canyon porphyry Cu-Au-Mo system, Utah: Economic Geology, v. 

99, p. 789–806. 

Cunningham, C.G., Austin, G.W., Naeser, C.W., Rye, R.O., Balantyne, G.H., Stamm, R.G., and 

Barker, C.E., 2005, Formation of a paleothermal anomaly and disseminated gold deposits 

associated with the Bingham Canyon porphyry Cu-Au-Mo system, Utah; Reply: Economic 

Geology, v. 100, p. 594–595. 

Daliran, F., Hofstra, A., Walther, J., and Stuben, D., 2002, Agdarreh & Zarshuran SRHDG 

Deposits, Takab Region, NW-Iran [abs.]: Geological Society of America Abstracts with 

Programs, v. 34, no. 6, p. 141. 

Day, H.W., Blake, M. C., Ernst, W. G., Hacker, B. R., Howard, K., Jacobson, C., Springer, R. K., 

Todd, V., and Wentworth, C., 2003, A preliminary metamorphic map of California [abs.]: 

Geological Society of America, Abstracts with Programs, v. 35, no. 6, p. 96. 

Diehl, S.F., Hofstra, A.H., Emsbo, P., Koenig, A., Vikre, P., and Lufkin, J., 2005a, Distribution of 

hydrothermal zebra dolomite and its relation to base and precious metal deposits in the Great 

Basin, in Rhoden, H.N., Steininger, R.C., and Vikre, P.G., eds., Geological Society of Nevada 

Symposium 2005: Window to the World, Reno, Nevada, May 2005, p. 187–208. 

Diehl, S.F., Hofstra, A.H., Koenig, A., Lufkin, J., Emsbo, P., and Vikre, P., 2005b, Paleozoic 

tectonics, brine migration, and formation of hydrothermal zebra dolomite, sedex, and MVT 

deposits along the carbonate platform in the Great Basin [abs.]: Geological Society of America, 

Abstracts with Programs, v. 37, no. 7, p. 379. 

16
du Bray, E.A., Ressel, M.W., and Barnes, C.G., in press, Geochemical database for intrusive rocks 

of northeast Nevada: U.S. Geological Survey Data Series Report. 

du Bray, E.A., and Nash, J.T., 2005, A new whole-rock major and trace element geochemical 

database for intrusive rocks of northern Nevada—Implications for petrogenesis and metallogeny 

[abs.]: Geological Society of America, Abstracts with Programs, v. 37, no. 7, p. 379. 

Emsbo, P., 2004, Genetic links among syngenetic metal accumulations in sedimentary basins; giant 

sediment-hosted metal deposits to metalliferous black shales: Geological Society of America, 

Abstracts with Programs, v. 36, no. 5, p. 199. 

Emsbo, P., Griffin, G.L., and Hofstra, A.H., 2002, Geology, geochemistry, and genesis of SEDEX 

Au ores on the Carlin Trend, Nevada [abs.]: Geological Society of America, Abstracts with 

Programs v. 34, no. 6, p. 140. 

Emsbo, P., Groves, D.I., Hofstra, A.H., and Bierlein, F.P., 2006, The giant Carlin gold province—

A protracted interplay of orogenic, basinal, and hydrothermal processes above a lithospheric 

boundary: Mineralium Deposita, v. 41, p. 517–525. 

Emsbo, P., and Koenig, 2005, Discovery and significance of gold-rich bitumen in the Rodeo 

deposit, northern Carlin trend, Nevada [abs.]: Geochimica et Cosmochimica Acta, v. 69, p. 123. 

Emsbo, P., and Morrow, J. R., 2005, Links between Devonian basin architecture and gold 

mineralization, north-central Nevada—An undervalued tectonic control? [abs.]: Geological 

Society of America, Abstracts with Programs, v. 37, no. 7, p. 418. 

Emsbo, P., Zhang, X-C., Hofstra, A.H., Hu, R-Z., Johnson, C.A., Su, W-C., Pi, D-H., Koenig, A., 

and Grauch, R., 2005, Lower Cambrian metallogenesis of south China—Interplay between 

diverse basinal hydrothermal fluids and marine chemistry, in Mao, J. and Bierlein, F.P., eds., 

Mineral Deposit Research: Meeting the Global Challenge, Proceedings of the 8th Biennial SGA 

Meeting, Beijing, China, 18–21 August 2005, p. 115–118. 

Evans, J.G., 2003, Preliminary geologic map of the Unity Reservoir quadrangle, Baker County, 

Oregon: U.S. Geological Survey Miscellaneous Field Studies Map, scale 1:24,000. 

Evans, J.G., Griscom, A., Halvorson, P.F., and Cummings, M.L., 2004, Tracking the western 

margin of the North American Craton beneath southeastern Oregon—A multidisciplinary 

approach: Idaho Geological Survey Bulletin 30, p. 35–58. 

Gao, Yongli, Person, M. A., Dahlstrom, D., Hofstra, A., Sweetkind, D., Howard, K., John, D., 

Prudic, D., and Wallace, A., 2003, The role of faults in the plumbing of the Great Basin 

geothermal systems and gold mineralization [abs.]: Geological Society of America, Abstracts 

with Programs, v. 35, no. 6, p. 617. 

Glen, J.M.G., and Ponce, D.A , 2002, Large-scale fractures related to inception of the Yellowstone 

Hotspot: Geology, v. 30, no.7, p. 647–650. 

17
Glen, J.M.G., McKee, E. H., Ludington, S., Ponce, D.A., Hildenbrand, T.G., and Hopkins, M.J., 

2004a, Geophysical terranes of the Great Basin and parts of surrounding provinces: U.S. 

Geological Survey Open-File Report 2004-1008, 303 p. 

Glen, J.M.G., Ponce, D.A., Nomade, S., and John, D.A., 2003, Dike emplacement and the birth of 

the Yellowstone hotspot, western USA [abs.]: EGS-AGU-EUG joint assembly, Nice, France, 

April 2003. 

Glen, J.M.G., Ponce, D.A., and Sepulveda, E., 2004b, Yellowstone hotspot melting and its relation 

to pre-existing crustal structures and Great Basin extension: Eos, Transactions, American 

Geophysical Union, 85(47), Fall Meeting Supplement, Abstract V51B–0555. 

Goldfarb, Richard J., Hart, Craig, J.R., Mao, J., and Hofstra, A.H., 2004, Gold in China—The 

present understanding of emerging world-class resources [abs.]: Geological Society of Australia 

Abstracts, v. 73, p. 82. 

Granitto, M., Yager, D., and Hofstra, A.H., 2005, Geochemical data for the Great Basin—A subset 

of the USGS new National Geochemical Database [abs.]: Geological Society of America, 

Abstracts with Programs, v. 37, no. 7, p. 380. 

Grauch, V.J.S., Rodriguez, B.D., Bankey, V., and Wooden, J.L., 2003, Evidence for a Battle 

Mountain-Eureka crustal fault zone, north-central Nevada, and its relation to NeoproterozoicEarly Paleozoic continental breakup: Journal of Geophysical Research, v. 108, no. B3, 18 p. 

Hofstra, A.H., 2002a, Distinguishing characteristics and models for Carlin-type gold deposits, in

Thorman, C., ed., SEG Carlin-type deposits of northern Nevada and their regional setting field 

trip, April 17–21, 2002, Guidebook and CD ROM. 

Hofstra, A.H., 2002b, Diverse origins of sedimentary rock-hosted disseminated gold deposits 

worldwide—Overview [abs.]: Geological Society of America, Abstracts with Programs v. 34, no. 

6, p. 140. 

Hofstra, A.H., 2004, Diverse origins of sedimentary rock-hosted disseminated gold deposits—A 

global perspective, in Irish Association for Economic Geology (IAEG) Weekend Course on 

Sediment-Hosted Gold Deposits, May 15–16, Bundoran, Ireland, 5 p. 

Hofstra, A.H., 2005a, Carlin-type gold deposits, in Scott, S., Mo, X., and Yang, K., organizers, 

SGA Short Course SHC-3, Metallogeny: Current theory and exploration models, associated with 

the 8th Biennial SGA Meeting, Beijing, China, 15–17 August, 2005, p. 79–109. 

Hofstra, A.H., 2005b, Great Basin metallogeny—Interplay of tectonic events, basement faults, 

permeability, diverse fluids, rock buffers, & physicochemical traps [abs.]: Geological Society of 

America, Abstracts with Programs, v. 37, no. 7, p. 418. 

Hofstra, A.H., and Emsbo, P., 2005, Source of salt in hydrothermal fluids based on Na-Cl-Br of 

fluid inclusions [abs.]: Geochimica et Cosmochmica Acta, v. 69, 1 p. 

18
Hofstra, A.H., Emsbo, P., Hu, R., Zhang, X., and Su, W., 2005a, Origin and potential for 

significant Carlin-like gold deposits in China—Synthesis of new observations and data with 

published information [abs.]: 2005 SME Annual Meeting and Exhibition, Feb. 28–Mar. 2, Salt 

Lake City, Utah, Technical Program, p. 50. 

Hofstra, A.H., Emsbo, P., Hu, R., Zhang, X., Su, W., Nutt, C.J., and Fifarek, R.H., 2005b, Diverse 

origins of sedimentary rock-hosted disseminated gold deposits in the Great Basin and southern 

China [abs.], in Rhoden, H.N., Steininger, R.C., and Vikre, P.G., eds., Geological Society of 

Nevada Symposium 2005: Window to the World, Reno, Nevada, May 2005, p. 1315–1316. 

Hofstra, A.H., John, D.A., and Theodore, T.G., 2003, A special issue devoted to gold deposits in 

northern Nevada–Part 2. Carlin-type deposits: Economic Geology, v. 98, p. 1063–1067. 

Hofstra, A.H., Zhang, X-C, Emsbo, P., Hu, R-H, Su,W-C, Christiansen, W.D., Fu, S-H, and 

Theodorakos, P., 2005c, Source of ore fluids in Carlin-type gold deposits in the Dian-Qian-Gui 

area and West Qinling belt, P.R. China—Implications for genetic models, in Mao, J. and 

Bierlein, F.P., eds., Mineral Deposit Research: Meeting the Global Challenge, Proceedings of the 

8th Biennial SGA Meeting, Beijing, China, 18–21 August 2005, p. 533–536. 

Hook, S.J., Dmochowski, J.E., Howard, K.A., Rowan, L.C., Karlstrom, K.E., and Stock, J.M., 

2005, Variations in weight percent silica measured from remotely acquired multispectral thermal 

infrared data—Examples from the Hiller Mountains, Nevada, USA and Tres Virgenes-La 

Reforma, Baja California Sur, Mexico: Remote Sensing of Environment. 

Howard, K.A., 2002, Ruby Mountains core complex as a guide to Eocene deep crustal structure in 

the Elko-Carlin region, Nevada [abs.]: Geological Society of America, Abstracts with Programs, 

v. 34, no. 6, p. 83. 

Howard, K.A., 2003, Crustal structure in the Elko-Carlin region, Nevada, during Eocene gold 

mineralization—Ruby-East Humboldt metamorphic core complex as a guide to the deep crust: 

Economic Geology, v. 98, no. 2, p. 249–268. 

Howard, K.A., 2005, The upper crust laid on its side—Tectonic implications of steeply tilted 

crustal slabs for extension in the Basin and Range [abs.]: Geological Society of America, 

Abstracts with Programs, v. 37, no. 7, p. 419. 

Howard, K.A., Barnes, C.B., Snoke, A.W., Wright, J.E., and Lee, S., 2004a, Style of intrusion of 

crustal melts into middle crust in the Cretaceous back-arc—Ruby Mountains core complex, 

Nevada [abs.]: Geological Society of America, Abstracts with Programs, v. 36, no. 4, p. 71. 

Howard, K.A., Barnes, C.G., Snoke, A.W., Wright, J.E., and Lee, S.., 2004b, Incremental assembly 

of a batholith from crustal melts on the continental fringe of a Cretaceous arc—Ruby Mountains, 

Nevada, U.S.A [abs.]: Pucon, Chile, International Association of Volcanology and Chemistry of 

the Earth's Interior (IAVCEI), Abstracts for session 9c. 

Howard, K.A., Jachens, R.C., Chuang, F.C., and McKee, E.H., in press, Geohydrologic factors that 

influence the movement of ground-water in the Great Basin—Preliminary report: U.S. 

Geological Survey Open-File Report, 80 manuscript p. 

19
Howard, K.A. and MacCready, T., 2004, Geologic map of the Verdi Peak Quadrangle, Elko 

County, Nevada: Nevada Bureau of Mines and Geology Map 147, scale 1:24,000, also available 

at.http://www.nbmg.unr.edu/dox/m147text.pdf and http://www.nbmg.unr.edu/dox/m147plate.pdf. 

Howard, K.A., and Nutt, C.J., 2005, Extension-related folds in Eocene rocks, northeastern Nevada 

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Hudson, D.M., John, D.A., and Fleck, R.J., 2005, Geologic setting, geochemistry, and 

geochronology of epithermal gold-silver deposits in the Seven Troughs district, northwest 

Nevada [abs.]: Geological Society of America, Abstracts with Programs, v. 37, no. 7, p. 380. 

Hudson, D.M., John, D.A., and Fleck, R.J., 2006, Geology, geochemistry, and geochronology of 

epithermal gold-silver deposits in the Seven Troughs district, Pershing County, Nevada: 

Geological Society of Nevada Special Publication 42, p. 110–126. 

Jarboe, N., Coe, R.S., Glen, J.M.G., and Renne, P.R., 2003, A study of mid-Miocene Yellowstone 

hotspot volcanics and the search for the Steens Mountain Reversal [abs.]: Eos, Transactions, 

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Jarboe, N., Coe, R.S., Glen, J.M.G., and Renne, P.R., 2004, Investigating the timing and extent of 

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Camps of Utah: Utah Geological Association Guidebook, 41 manuscript p., 4 tables, 9 figs., 4 

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John, D.A., 2003, New perspectives on the origin and distribution of Cenozoic epithermal goldsilver deposits in the northern Great Basin and surrounding environs [abs.]: Spokane, 

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John, D.A., Breit, G.N., Rye, R.O., Sisson, T.W., and Vallance, J.W., 2003a, Hypogene 

hydrothermal alteration of Quaternary volcanic rocks from Mount Rainier, Washington: 

Geological Society of America, Abstracts with Programs, v. 35, no. 6, p. 553. 

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source and preliminary geochronology and geochemistry [abs.]: Geological Society of America, 

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20
John, D.A., and Hofstra, A.H., 2002, Hydrothermal alteration and stable isotope constraints on 

formation of the Mule Canyon low-sulfidation Au-Ag deposit, north-central Nevada [abs]: 

Geological Society of America, Abstracts with Programs, v. 34, no. 5, p. A-15. 

John, D.A., Hofstra, A.H., and Theodore, T.G., 2003b, Preface to special issues devoted to gold 

deposits in northern Nevada–Part 1, regional studies and epithermal deposits: Economic 

Geology, v. 98, no. 2, p. 225–234. 

John, D., and Muntean, J., 2006, Summary of characteristics of Tertiary metallic mineral deposits 

in the Lovelock area, northwestern Nevada: Geological Society of Nevada Special Publication 

42, p. 60–69. 

John, D.A., Wallace, A.R., and Hofstra, A.H., 2002, Middle Miocene epithermal Au-Ag deposits 

related to continental tholeiitic basalt magmatism, northern Great Basin, western USA [abs]: 

Geological Society of America, Abstracts with Programs, v. 34, no. 6, p. 185. 

John, D.A., Wallace, A.R., and Coolbaugh, M.F., 2005, Epithermal gold-silver deposits associated 

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America, Abstracts with Programs, v. 37, no. 7, p. 419. 

John, D.A., and Wrucke, C.T., 2003, Geologic map of the Mule Canyon quadrangle, Lander 

County, Nevada: Nevada Bureau of Mines and Geology Map 144, scale 1:24,000, 16 p. 

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Devonian to Mississippian arkosic rock derived from a granitic terrane in northwestern Nevada 

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eds., Geological Society of Nevada Symposium 2005: Window to the World, Reno, Nevada, May 

2005, p. 135–146. 

Koski, R.A., and Hein, J.R., 2003, Stratiform barite deposits in the Roberts Mountains Allochthon, 

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Landis, G.P., and Rye, R.O., 2005, Characterization of gas chemistry and noble-gas isotope ratios 

of inclusion fluids in magmatic-hydrothermal and magmatic-steam alunite: Chemical Geology, v. 

215, nos. 1–4, p. 155–184. 

Leavitt, E., Spell, T.L., Wallace, A.R., Goldstrand, P., and Arehart, G.B., 2003, Volcano-tectonic 

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America, Abstracts with Programs, v. 35, no. 4, p. 61. 

Lee, S.-Y., Barnes, C.G., Snoke, A.W., Howard, K.A., and Frost, C.D., 2003, Petrogenesis of 

Mesozoic peraluminous granites in the Lamoille Canyon area, Ruby Mountains, Nevada, USA: 

Journal of Petrology, v. 44, p. 713–732. 

21
Ludington, S., and John, D., 2002, Magmatic and metallogenic specialization of volcanic rocks 

related to epithermal gold mineralization, Great Basin, USA [abs], in Interaction between mafic 

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Ludington, S., Folger, H., Kotlyar, B.B., Mossotti, V.G., Coombs, M.J., and Hildenbrand, T.G., 

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Ludington, S., Moring, B.C., Miller, R.J., Flynn, K., Hopkins, M.J., Stone, P., Bedford, D.R., and 

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states; California, Nevada, Arizona, and Washington, version 1.0: U. S. Geological Survey OpenFile Report 2005-1305. 

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data from measured sections in the northern Great Basin [abs.]: Geological Society of America, 

Abstracts with Programs, v. 37, no. 7, p. 378–379. 

McGibbon, D.H., and Theodore, T.G., 2002, Magmatic affiliations for enigmatic gold deposits in 

the northern Battle Mountain mining district, Nevada [abs.]: Geological Society of America, 

Abstracts with Programs, v. 34, no. 6, p. 142. 

Moore, T.E., Murchey, B.L., Moring, B.C., Harris, A.G., Blodgett, R.B., O'Sullivan, P.G., and 

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of Mines and Geology Map, 42 manuscript p., 1 sheet, scale 1:24,000. 

Moore, T.E., and O'Sullivan, P.B., 2005, Miocene gold mineralization and exhumation of the 

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Morgan, L.A., Pierce, K.L., and McIntosh, W.C., 2004, Patterns of volcanic and tectonic events in 

the wake of the Yellowstone Hot Spot: Geological Society of America, Abstracts with Programs, 

v. 36, no. 5, p. 546. 

Nash, J.T., 2004, Hydrogeochemcial studies of historical mining areas in the Humboldt River Basin 

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Nazarova, K., and Glen, J.M.G., 2004, Integration of NASA/GSFC and USGS Rock Magnetic 

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85(17), Abstract GP21A-04. 

Nutt, C.J., 2002, Paleogene deformation, sedimentation, and magmatism in northeast Nevada, in

Thorman, C., ed., SEG Carlin-type deposits of northern Nevada and their regional setting, field 

trip, April 17–21, 2002, Guidebook and CD ROM. 

22
Nutt, C.J., and Hart, K.S., 2004, Geologic map of the Big Bald Mountain Quadrangle and part of 

the Tognini Spring Quadrangle, White Pine County, Nevada: Nevada Bureau of Mines and 

Geology Map 145, 8 p., 1 sheet. 

Nutt, C.J., and Hofstra, A.H., 2002, Jurassic intrusion-related and Eocene Carlin-type gold 

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Nutt, C.J., and Howard, K.A., 2003, Eocene basins in northeastern Great Basin, Utah and Nevada, 

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Nutt, C.J., and Ludington, S., 2003, Intrusive rock database for the digital geologic map of Utah: 

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Nutt, C.J., and Thorman, C.H., 2005, Role of low-angle to bedding-parallel faults in localizing 

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Programs, v. 37, no. 7, p. 418. 

Percival, T.J., and Hofstra, A.H., 2002a, Alsar district, Macedonia—Pliocene SRHDG 

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Percival, T.J., and Hofstra, A.H., 2002b, Bau, Malaysia—SRHDG deposit associated with Miocene 

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Person, M., Gao, Y., Hofstra, A., Sweetkind, D., and Prudic, D., 2005, Numerical models of fluid 

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permeability fault zones [abs.], in Rhoden, H.N., Steininger, R.C., and Vikre, P.G., eds., 

Geological Society of Nevada Symposium 2005: Window to the World, Reno, Nevada, May 

2005, p. 1324–1325. 

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Pierce, K.L., Morgan, L.A., and Saltus, R.W., 2004, Yellowstone plume head—Postulated tectonic 

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Bulletin 30, p. 1–34. 

Plenier, G., and Glen, J.M.G., 2004, Complex magnetic fabrics in igneous rocks [abs.]: Eos, 

Transactions, American Geophysical Union, Fall Meeting Supplement, 85(47), Abstract GP23B06. 

23
Pluhar, C.J., Coe, R.S., Nomade, S., Glen, J.M.G., and Lewis, J.C., 2003a, Kinematics of the Coso 

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Pluhar, C.J., Nomade, S., Glen, J.M.G., and Coe, R.S., 2003b, Jaramillo, Cobb Mtn., or Punaruu?— 

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Transactions, American Geophysical Union, Fall Meeting Supplement, 84(46), Abstract GP31D0774. 

Pluhar, C.J., Nomade, S., Glen, J.M.G., Coe, R.S., and Renne, P.R., 2004, Magnetostratigraphy, 

geochronology and geochemical evolution of the Pliocene Coso volcanic field, CA and 

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Abstracts with Programs, v. 36, no. 5, p. 430–431. 

Ponce, D.A., and Glen, J.M.G., 2005, A prominent basement feature in north-central Nevada and 

its tectonic implications [abs.]: Geological Society of America, Abstracts with Programs, v. 37, 

no. 7, p. 378. 

Potter, C.J., Sweetkind, D.S., Dickerson, R.P., and Killgore, M.L., 2002, Hydrostructural maps of 

the Death Valley region flow system, Nevada and California: U.S. Geological Survey 

Miscellaneous Field Studies Map MF-2372, 12 p., 2 sheets. 

Premo, W.R., Howard, K.A., and Castenieras, P., 2005, New SHRIMP U-Pb zircon ages and Nd 

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Implications for the timing of Tertiary core complex formation [abs.]: Geological Society of 

America, Abstracts with Programs, v. 37, no. 7, p. 359. 

Racheboeuf, P.R., Moore, T.E., and Blodgett, R.B., 2004, A new Permian chonetoidean brachiopod 

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GEOBIOS, v. 37, p. 382–394. 

Ramelli, A.R., Yount, J.C., John, D.A., and Garside, L.J., 2003, Preliminary geologic map of the 

Minden quadrangle, Douglas County, Nevada and Alpine County, California: Nevada Bureau of 

Mines and Geology Open-File Report 03-13, scale 1:24,000. 

Rodriguez, B.D., Grauch, V.J.S., and Williams, J.M., 2005, Preliminary deep crustal investigations 

to locate the Archean/Proterozoic suture zone in the Great Basin, using magnetotellurics, in

Rhoden, H.N., Steininger, R.C., and Vikre, P.G., eds., Geological Society of Nevada Symposium 

2005: Window to the World, Reno, Nevada, May 2005, p. 13–18. 

Rodriguez, B.D., and Williams, J.M., 2002, Resistivity structure across the Humboldt River Basin, 

north-central Nevada: U.S. Geological Survey Open-File Report 02-39, 114 p. 

Rodriguez, B.D., and Williams, J.M., 2005, Major crustal fault zones trend obliquely to mineral 

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24
Rye, R.O., 2005, A review of the stable-isotope geochemistry of sulfate minerals in selected 

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Rytuba, J.J., John, D.A., Foster, A., Ludington, S.D., and Kotylar, B., 2003, Hydrothermal 

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and McDermitt ore deposits, Nevada: U.S. Geological Survey Bulletin 2209-C, 35 p. 

Rytuba, J.J., John, D.A., and McKee, E.H., 2004, The track of the Yellowstone Hot Spot–What is 

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Abstracts with Programs, v. 36, no. 4, p. 94–95. 

Samal, A.R., Fifarek, R. H., and Thomason, R.E., 2005, Steam-heated alteration at the Florida 

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Scott, R.B., and Harding, A.E., in press, Geologic map of the Vigo NE quadrangle, Lincoln 

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Simmons, S.F., White, N.C., and John, D.A., 2005, Epithermal precious and base metal deposits, in

Hedenquist, J.W., Thompson, J.F.H., Goldfarb, R.J., and Richards, J.P., eds., Economic Geology, 

One Hundredth Anniversary Volume, p. 485–522. 

Snoke, A.W., Barnes, C.B., Howard, K.A., Wright, J.E., and Copeland, P., 2004, Late Eocene and 

Oligocene intrusions in the Ruby–East Humboldt core complex, Nevada—Magmatic processes in 

the middle crust in relation to tectonic extension [abs.]: Geological Society of America, Abstracts 

with Programs, v. 36, no. 4, p. 71. 

Sweetkind, D.S., Dickerson, R.P., Blakely, R.J., and Denning, P.D., 2001, Interpretive geologic 

cross sections for the Death Valley regional flow system and surrounding areas, Nevada and 

California: U.S. Geological Survey Miscellaneous Field Studies Map MF-2370, 35 p., 3 sheets. 

Sweetkind, D.S., Faunt, C.C., and Phelps, G., 2002, Evaluation and quantification of uncertainty 

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American Geophysical Union, v. 83, p. F497. 

Sweetkind, D.S., Wallace, A.R., Nutt, C.J., John, D.A., Howard, K.A., Person, M.A., Ponce, D.A., 

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Geological Society of America, Abstracts with Programs, v. 37, no. 7, p. 379. 

Sweetkind, D.S., Wallace, A.R., Nutt, C.J., John, D.A., Howard, K.A., Ponce, D.A., Glen, J.M.G., 

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25
Theodore, T.G., Berger, V.I., Singer, D.A. Harris, A.G., and Stevens, C.H., 2004, Synthrusting 

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Theodore, T.G., and Kotlyar, B.B., 2002, Geologic setting of the Battle Mountain-Eureka mineral 

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field trip, April 17–21, 2002, Guidebook and CD ROM. 

Theodore, T.G., Moring, B.C., Harris, A.G., Armstrong, A.K., and Finney, S.C., 2003, Geologic 

map of the Beaver Peak Quadrangle, Elko and Eureka Counties, Nevada: Nevada Bureau of 

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Thorman, C.H., 2002, Regional stratigraphic and structural setting of the Carlin trend region, 

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their regional setting field trip, April 17–21, 2002, Guidebook and CD ROM. 

Thorman, C.H., Brooks, W.E., Ketner, K.B., and Dubiel, R.F., 2003, Preliminary geologic map of 

the Oxley Peak area, Elko County, Nevada: Nevada Bureau of Mines and Geology Open-File 

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Thorman, C.H., and Peterson, F., 2003, The Middle Jurassic Elko Orogeny; a major tectonic event 

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Tilden, J.E., Ponce, D.A., Glen, J.M.G., John, D.A., and Person, M.A., 2005, Three-dimensional 

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Turner, S.J., Garwin, S.A., and Hofstra, A.H., 2002, Mesel SRHDG deposit and low-sulfidation 

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America, Abstracts with Programs v. 34, no. 6, p. 141. 

Vikre, P.G., in press, Sinter-vein correlations at Buckskin Mountain, National district, Humboldt 

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Vikre, P.G., Fleck, R.J., and Rye, R.O., 2005a, Ages and geochemistry of magmatic hydrothermal 

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Vikre, P., Garside, L.J., Castor, S.B., Henry, C.D., Hudson, D.M., and McIntosh, W.C., 2003, 

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26
Wallace, A.R., 2002, Late Cenozoic evolution of the Great Basin—Applications to precious-metal, 

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Wallace, A.R., 2003a, Geologic map of the Willow Creek Reservoir quadrangle, Elko County, 

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Wallace, A.R., 2003b, Geologic map of the Willow Creek Reservoir SE Quadrangle, Elko, Eureka, 

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Wallace, A.R., 2003c, Geology of the Ivanhoe Hg-Au district, northern Nevada—Influence of 

Miocene volcanism, lakes, and active faulting on epithermal mineralization: Economic Geology, 

v. 98, no. 2, p. 409–424. 

Wallace, A.R., 2003d, Regional geologic setting of late Cenozoic lacustrine diatomite deposits, 

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Wallace, A.R., 2004, Processes related to the formation of Neogene lacustrine diatom-rich 

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Wallace, A.R., 2005a, Late Cenozoic landscape evolution in northeastern Nevada and its predictive 

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Wallace, A.R., 2005b, Sedimentation, faulting, and erosion in the Carlin basin, northeastern 

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to the World, Reno, Nevada, May 2005, p. 147–160. 

Wallace, A.R., Fleck, R.J., and Theodore, T.G., 2004a, New studies on the middle Miocene 

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with Programs, v. 36, no. 4, p. 7. 

Wallace, A.R., Ludington, S., Mihalasky, M.J., Peters, S.G., Theodore, T.G., Ponce, D.A., John, 

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metallic resources in the Humboldt River basin, northern Nevada, with a section on Platinumgroup-elements (PGE) potential of the Humboldt mafic complex: U.S. Geological Survey 

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Wallace, A.R., Perkins, M.E., and Fleck, R.J., in press, Geologic map of the Huntsman Ranch 

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27
Wannamaker, P.E., Doerner, W.M., and Rodriguez, B.D., 2002, Analysis of magnetotelluric profile 

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Williams, J.M., and Rodriguez, B.D., 2003, Magnetotelluric data release for locating the 

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Open-File Report 03-495, 119 p. (http://pubs.usgs.gov/of/2003/ofr-03-495/) 

Williams, J.M., and Rodriguez, B.D., 2004, Magnetotelluric survey to locate the 

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Report 2004-1215, 212 p. (http://pubs.usgs.gov/of/2004/1215/) 

Williams, J.M., and Rodriguez, B.D., 2005, Magnetotelluric survey to locate the 

Archean/Proterozoic suture zone in north-central Elko County, Nevada: U.S. Geological Survey 

Open-File Report 2005-1255, 183 p. 

Yager, D.B., and Folger, H.W., 2005, A data viewer for stream-sediment and surface-water 

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Geological Survey Bulletin 2210-F, 9 p. 

Yager, D.B., and Hofstra, A.H., 2004, A scaled relational database design for organizing and 

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Geological Society of America, Abstracts with Programs, v. 36, no. 5, p. 150. 

Yager, D.B., Wallace, A.R., and John, D.A., 2005, A relational database for Miocene to Holocene 

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Yigit, O., Hofstra, A.H., Hitzman, M.W., and Nelson, E.P., 2006, Geology and geochemistry of 

jasperoids from the Gold Bar district, Nevada: Mineralium Deposita, v. 41, p. 527–547. 

Zhang, X., Hofstra, A.H., Hu, R., Emsbo, P., Su,W., and Ridley, W. I., 2005, Geochemistry and 

δ34S of ores and ore stage iron sulfides in Carlin-type gold deposits, Dian-Qian-Gui area, P.R. 

China—Implications for ore genesis, in Mao, J., and Bierlein, F.P., eds., Mineral Deposit 

Research• Meeting the Global Challenge: Proceedings of the 8th Biennial SGA Meeting, 

Beijing, China, 18-21 August, 2005, p. 1107–1110.

28
Mo,

W,Be

Au t Ag t Pb Kt 

Cu Kt Zn Kt

Significant Metal Deposits of the Great Basin 

Fig. 1 

29

Mo

Be

REE

W
Fig. 2 

3

0
Geophysical Terrains of the Great Basin

Magnetic Anomalies Gravity Anomalies

31 Fig. 3
Nevada State 

Digital Geologic 

Map 

Fig. 4 

3

2
Northern Nevada Study Area: Cross Sections

Sweetkind et al.,2005 

Fig. 5 

3

3
Pz Ls. 

RMA 

Tv 

3-D Model 

Beowawe 

Geothermal Area 

Grid 

Simplified Hydrogeologic Model 

Qal 

Future: 

• 3-D flow models 

• Flow models with plutons 

• Chemical models of metal 

transport and deposition 

Tilden et al., 2005 

Person, Univ. Indiana 

Fig. 6 

3

4
Eocene Carlin trend 

SW NE 

Meters 

Recharge Discharge Recharge 

Meters 

Qal 

Tsv 

RMA 

Pz Carbonate 

Neoprot 

Siliciclastic 

SL 

Meters Meters 

Beowawe Geothermal 

200°C 

Qal 

Tsv 

RMA 

Pz Carbonate 

Temperature 

“Present key to the past” 

approach to fluid flow modeling 

Constrained by geologic model, T°C, AFT data , δ18O of rocks and fluids 

Fig. 7 

3

5

Elevation (m) Elevation (m)

Elevation (m) 
Fig. 8 

3

6