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Dixie Comstock mine, Dixie Valley Mining District, Churchill Co., Nevada, USAi
Regional Level Types
Dixie Comstock mineMine
Dixie Valley Mining DistrictMining District
Churchill Co.County
NevadaState
USACountry

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Key
Latitude & Longitude (WGS84):
39° 51' 56'' North , 118° 1' 2'' West
Latitude & Longitude (decimal):
Locality type:
Köppen climate type:


Silver Gold
Structure: Mineralization occurs adjacent to an igneous contact. A roughly N-S-trending high-angle range-front fault cuts the host rocks near the mine area.

Alteration: Intense multiple phase silicification has occurred with minor adularization of the host rocks.

Commodity: Ore Materials: electrum; native silver; copper and lead sulfides Gangue Materials: Quartz, adularia, chloritoid

Deposit: Mineralization at the mine consists of well-developed stockworks transitional to hydrothermal breccias developed in the Stillwater Gabbro of Jurassic age. Mineralization is associated with intense multiple phase silicification with minor adularization, and consists of variable amounts of sulfides and gold. Mineralization may be genetically related to an adjacent igneous contact. Gold occurs as free grains of electrum ranging in size from 5-100 microns or larger. Minor amounts of native silver have also been reported. Sulfides occur as minor accessory minerals, but gold shows no strong correlation with such accessory sulfides and often appears to be very late in the paragenetic sequence. Assignment of USGS model based on mineralogy and stockwork nature of veining and ignoring the mafic intrusive host rock type.

Deposit type: Hot-spring Au-Ag

Development: Clyde Garrett discovered gold at Dixie Comstock in April 1934. Underground mining at that time was hindered by the intense heat and large volume of hot water intersected in the mine workings at less than 75 ft. depth. Through 1938, 8000 tons of gold ore had been treated with recovery of over $145,000. By 1940, a total of 1500 ft. of underground workings had been developed. Production continued to October 8, 1942 when the War Production Board issued its limitation order L-208. Cumulative production totaled 17,880 tons of Au-Ag ore for a combined value of $293,304. The Au:Ag ratio was 2:3 with a gold equivalent grade of 0.793 opt gold. During the period 1955-1970, various operators conducted trenching, drilling, and soil sampling programs. In 1970, the Mexican Gold and Silver Mining Company began open pit mining and removed 5000 yards of gravel overburden by year?s end. In September 1975, the first ore was shipped from this open pit operation. Approximately 86 short tons grading 2.26 opt Au and 2.43 opt Ag were trucked to the Southern Pacific railhead at Luning. Asarco Inc. leased the property 1983-1984 but dropped the lease because of the small size of the deposit and the strip ratio. Santa Fe Mining, Inc. leased the property in 1986 and completed 65 reverse circulation drill holes which largely defined the present orebody. In 1990, Horizon Gold Corporation purchased the Dixie Comstock lease agreement from Santa Fe Mining, Inc. and began feasibility studies for an open pit operation. Plans for this pit include a strip ratio of 2.4:1 and a production rate of 8000 tons of ore per day. Dore product was expected to consist of approx. 50% Au and 50% Ag. In 1995, Atlas entered into an option on the Dixie Comstock project with Horizon Resources Corp. No new production has resulted from the deposit since its delineation in 1990.

Geology: Mineralization at the mine consists of well-developed stockworks transitional to hydrothermal breccias in the Stillwater Gabbro of Jurassic age. The host rock has been subjected to intense multiple phase silicification with minor adularization, and contains variable amounts of sulfides and gold.

Ore(s): Mineralization occurs adjacent to an igneous contact to which it may be genetically related.

Select Mineral List Type

Standard Detailed Strunz Dana Chemical Elements

Commodity List

This is a list of exploitable or exploited mineral commodities recorded at this locality.


Mineral List


15 valid minerals.

Rock Types Recorded

Note: this is a very new system on mindat.org and data is currently VERY limited. Please bear with us while we work towards adding this information!

Select Rock List Type

Alphabetical List Tree Diagram

Detailed Mineral List:

Calcite
Formula: CaCO3
Reference: Econ Geol (1994) 89:707-719
Chalcopyrite
Formula: CuFeS2
Reference: NBMG Spec. Pub. 31 Minerals of Nevada; Econ Geol (1994) 89:707-719
Chloritoid
Formula: (Fe2+,Mg,Mn2+)Al2(SiO4)O(OH)2
Reference: U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Cinnabar
Formula: HgS
Reference: Econ Geol (1994) 89:707-719
Copper
Formula: Cu
Reference: U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
'Electrum'
Formula: (Au, Ag)
Reference: NBMG Spec. Pub. 31 Minerals of Nevada; Econ Geol (1994) 89:707-719; U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Gold
Formula: Au
Reference: NBMG Spec. Pub. 31 Minerals of Nevada; Econ Geol (1994) 89:707-719
Kaolinite
Formula: Al2(Si2O5)(OH)4
Reference: Econ Geol (1994) 89:707-719
'K Feldspar'
Reference: U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
'K Feldspar var: Adularia'
Formula: KAlSi3O8
Reference: U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
'Limonite'
Formula: (Fe,O,OH,H2O)
Reference: Econ Geol (1994) 89:707-719
Magnetite
Formula: Fe2+Fe3+2O4
Reference: Econ Geol (1994) 89:707-719
Molybdenite
Formula: MoS2
Reference: Econ Geol (1994) 89:707-719
Montmorillonite
Formula: (Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O
Reference: Econ Geol (1994) 89:707-719
Muscovite
Formula: KAl2(AlSi3O10)(OH)2
Reference: Econ Geol (1994) 89:707-719
Muscovite var: Sericite
Formula: KAl2(AlSi3O10)(OH)2
Reference: Econ Geol (1994) 89:707-719
Opal
Formula: SiO2 · nH2O
Reference: Econ Geol (1994) 89:707-719
Pyrite
Formula: FeS2
Reference: Econ Geol (1994) 89:707-719
Quartz
Formula: SiO2
Reference: NBMG Bull 83 Geology and Mineral Deposits of Churchill County, Nevada; Econ Geol (1994) 89:707-719; U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Silver
Formula: Ag
Reference: U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.

List of minerals arranged by Strunz 10th Edition classification

Group 1 - Elements
Copper1.AA.05Cu
'Electrum'1.AA.05(Au, Ag)
Gold1.AA.05Au
Silver1.AA.05Ag
Group 2 - Sulphides and Sulfosalts
Chalcopyrite2.CB.10aCuFeS2
Cinnabar2.CD.15aHgS
Molybdenite2.EA.30MoS2
Pyrite2.EB.05aFeS2
Group 4 - Oxides and Hydroxides
Magnetite4.BB.05Fe2+Fe3+2O4
Opal4.DA.10SiO2 · nH2O
Quartz4.DA.05SiO2
Group 5 - Nitrates and Carbonates
Calcite5.AB.05CaCO3
Group 9 - Silicates
Chloritoid9.AF.85(Fe2+,Mg,Mn2+)Al2(SiO4)O(OH)2
Kaolinite9.ED.05Al2(Si2O5)(OH)4
Montmorillonite9.EC.40(Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O
Muscovite9.EC.15KAl2(AlSi3O10)(OH)2
var: Sericite9.EC.15KAl2(AlSi3O10)(OH)2
Unclassified Minerals, Rocks, etc.
'K Feldspar'-
'var: Adularia'-KAlSi3O8
'Limonite'-(Fe,O,OH,H2O)

List of minerals arranged by Dana 8th Edition classification

Group 1 - NATIVE ELEMENTS AND ALLOYS
Metals, other than the Platinum Group
Copper1.1.1.3Cu
Gold1.1.1.1Au
Silver1.1.1.2Ag
Group 2 - SULFIDES
AmXp, with m:p = 1:1
Cinnabar2.8.14.1HgS
AmBnXp, with (m+n):p = 1:1
Chalcopyrite2.9.1.1CuFeS2
AmBnXp, with (m+n):p = 1:2
Molybdenite2.12.10.1MoS2
Pyrite2.12.1.1FeS2
Group 7 - MULTIPLE OXIDES
AB2X4
Magnetite7.2.2.3Fe2+Fe3+2O4
Group 14 - ANHYDROUS NORMAL CARBONATES
A(XO3)
Calcite14.1.1.1CaCO3
Group 52 - NESOSILICATES Insular SiO4 Groups and O,OH,F,H2O
Insular SiO4 Groups and O, OH, F, and H2O with cations in [6] coordination only
Chloritoid52.3.3.1(Fe2+,Mg,Mn2+)Al2(SiO4)O(OH)2
Group 71 - PHYLLOSILICATES Sheets of Six-Membered Rings
Sheets of 6-membered rings with 2:1 layers
Muscovite71.2.2a.1KAl2(AlSi3O10)(OH)2
Sheets of 6-membered rings with 2:1 clays
Montmorillonite71.3.1a.2(Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O
Group 75 - TECTOSILICATES Si Tetrahedral Frameworks
Si Tetrahedral Frameworks - SiO2 with [4] coordinated Si
Quartz75.1.3.1SiO2
Si Tetrahedral Frameworks - SiO2 with H2O and organics
Opal75.2.1.1SiO2 · nH2O
Unclassified Minerals, Mixtures, etc.
'Electrum'-(Au, Ag)
'K Feldspar'-
'var: Adularia'-KAlSi3O8
Kaolinite-Al2(Si2O5)(OH)4
'Limonite'-(Fe,O,OH,H2O)
Muscovite
var: Sericite
-KAl2(AlSi3O10)(OH)2

List of minerals for each chemical element

HHydrogen
H Montmorillonite(Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O
H Muscovite (var: Sericite)KAl2(AlSi3O10)(OH)2
H KaoliniteAl2(Si2O5)(OH)4
H OpalSiO2 · nH2O
H Limonite(Fe,O,OH,H2O)
H MuscoviteKAl2(AlSi3O10)(OH)2
H Chloritoid(Fe2+,Mg,Mn2+)Al2(SiO4)O(OH)2
CCarbon
C CalciteCaCO3
OOxygen
O QuartzSiO2
O Montmorillonite(Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O
O Muscovite (var: Sericite)KAl2(AlSi3O10)(OH)2
O KaoliniteAl2(Si2O5)(OH)4
O CalciteCaCO3
O OpalSiO2 · nH2O
O MagnetiteFe2+Fe23+O4
O Limonite(Fe,O,OH,H2O)
O MuscoviteKAl2(AlSi3O10)(OH)2
O K Feldspar (var: Adularia)KAlSi3O8
O Chloritoid(Fe2+,Mg,Mn2+)Al2(SiO4)O(OH)2
NaSodium
Na Montmorillonite(Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O
MgMagnesium
Mg Montmorillonite(Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O
AlAluminium
Al Montmorillonite(Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O
Al Muscovite (var: Sericite)KAl2(AlSi3O10)(OH)2
Al KaoliniteAl2(Si2O5)(OH)4
Al MuscoviteKAl2(AlSi3O10)(OH)2
Al K Feldspar (var: Adularia)KAlSi3O8
Al Chloritoid(Fe2+,Mg,Mn2+)Al2(SiO4)O(OH)2
SiSilicon
Si QuartzSiO2
Si Montmorillonite(Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O
Si Muscovite (var: Sericite)KAl2(AlSi3O10)(OH)2
Si KaoliniteAl2(Si2O5)(OH)4
Si OpalSiO2 · nH2O
Si MuscoviteKAl2(AlSi3O10)(OH)2
Si K Feldspar (var: Adularia)KAlSi3O8
Si Chloritoid(Fe2+,Mg,Mn2+)Al2(SiO4)O(OH)2
SSulfur
S ChalcopyriteCuFeS2
S PyriteFeS2
S MolybdeniteMoS2
S CinnabarHgS
KPotassium
K Muscovite (var: Sericite)KAl2(AlSi3O10)(OH)2
K MuscoviteKAl2(AlSi3O10)(OH)2
K K Feldspar (var: Adularia)KAlSi3O8
CaCalcium
Ca Montmorillonite(Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O
Ca CalciteCaCO3
FeIron
Fe ChalcopyriteCuFeS2
Fe PyriteFeS2
Fe MagnetiteFe2+Fe23+O4
Fe Limonite(Fe,O,OH,H2O)
Fe Chloritoid(Fe2+,Mg,Mn2+)Al2(SiO4)O(OH)2
CuCopper
Cu ChalcopyriteCuFeS2
Cu CopperCu
MoMolybdenum
Mo MolybdeniteMoS2
AgSilver
Ag Electrum(Au, Ag)
Ag SilverAg
AuGold
Au Electrum(Au, Ag)
Au GoldAu
HgMercury
Hg CinnabarHgS

References

Sort by

Year (asc) Year (desc) Author (A-Z) Author (Z-A)
Econ Geol (1994) 89:707-719
Willden, R., and Speed, R. C., (1974), Geology and Mineral Deposits of Churchill County, Nevada, NBMG Bull. 83, p 67.
Vvanderburg, W.O., (1940), Reconnaissance of Mining Districts in Churchill County, Nev., USBM I.C. 7093, p. 48.
State Inspector of Mines, (1981), Directory of Mining Operations Active in Nevada in Calendar Year 1980.
Horizon Gold Corp., Annual Report Form 10-K for Fiscal Year Ended March 31, (1991).
Horizon Gold Corp., Annual Report Form 10-K for Fiscal Year Ended March 31, (1992).
Bureau of Land Management, (1991), Environmental Assessment of Horizon Gold Corporation's Dixie Comstock Mine and Heap Leach Project, EA# NV-030-90-70.
NBMG, (1994), MI-1993
NBMG, (1997), MI-1996
Randol, (1996), The Mines Handbook.
Long, K.R., DeYoung, J.H., Jr., and Ludington, S.D., (1998), Significant deposits of gold, silver, copper, lead, and zinc in the United States: U.S. Geological Survey Open-File Report 90-206A, 33 p.; 98-206B. one 3.5 inch diskette.

USGS MRDS Record:10310498

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