| Deposit ID | 10310333 |
|---|---|
| MRDS ID | M242950 |
| Record type | Site |
| Current site name | Twin Creeks Mine |
| Alternate or previous names | Chimney Creek Mine, Rabbit Creek Mine, Mega pit (the merged pit), DZ Zone, Main, Chert Zone, HGO Zone, Jackrabbit Zone, LGO Zone, Sage, Section 8, Snowshoe Zone, South Layback, Section 30, South Oxide, Upper Sill Zone, West Pit, SWS Zone |
| Related records | 10047577 |
| Geographic coordinates: | -117.15096, 41.28322 (WGS84) |
|---|---|
| Elevation | 1590 |
| Relative position | The Twin Creeks Mine is located about 40 miles NE of Winnemucca.\n\n |
Political divisions (FIPS codes)
Humboldt(county)
Nevada(state)
United States(country)
North America(continent)
Land(continent)
USGS map quadrangles
Dry Hills North(quadrangle 1:24,000 scale)
Osgood Mountains(quadrangle 1:100,000 scale)
McDermitt(quadrangle 1:250,000 scale)
Hydrologic units (watersheds)
Middle Humboldt(hydrologic unit)
Humboldt(hydrologic accounting unit)
Black Rock Desert-Humboldt(hydrologic subregion)
Great Basin(hydrologic region)
| Country | State | County |
|---|---|---|
| United States | Nevada | Humboldt |
| Meridian | Township | Range | Section | Fraction | State |
|---|---|---|---|---|---|
| Mount Diablo | 039N | 042E | 12, 13 24 | Nevada | |
| Mount Diablo | 039N | 043E | 05 06 07 08, 18, 19, 30 | Nevada |
| Commodity | Importance |
|---|---|
| Gold | Primary |
| Silver | Primary |
| Lead | Tertiary |
| Zinc Critical | Tertiary |
| Arsenic Critical | Tertiary |
| Mercury | Tertiary |
| Antimony Critical | Tertiary |
| Barium-Barite Critical | Tertiary |
| Materials | Type of material |
|---|---|
| Gold | Ore |
| Albite | Gangue |
| Chlorite | Gangue |
| Kaolinite | Gangue |
| Sericite | Gangue |
| Calcite | Gangue |
| Amphibole | Gangue |
| Quartz | Gangue |
| Pyrite | Gangue |
| Augite | Gangue |
| Epidote | Gangue |
| Limonite | Gangue |
| Leucoxene | Gangue |
| Feldspar | Gangue |
| Tourmaline | Gangue |
| Fluorite | Gangue |
| Barite | Gangue |
| Goethite | Gangue |
| Model code | 173 |
|---|---|
| USGS model code | 26a.1 |
| Deposit model name | Sediment-hosted Au |
| Mark3 model number | 17 |
| Host or associated | Host | ||||
|---|---|---|---|---|---|
| Rock type | Sedimentary Rock > Clastic Sedimentary Rock > Shale | ||||
| Rock type qualifier | interlayered calcareous | ||||
| Rock unit name | Valmy and Comus Formations | ||||
| |||||
| Host or associated | Host | ||||
|---|---|---|---|---|---|
| Rock type | Sedimentary Rock > Clastic Sedimentary Rock > Siltstone | ||||
| Rock unit name | Valmy and Comus Formations | ||||
| |||||
| Host or associated | Host | ||||
|---|---|---|---|---|---|
| Rock type | Sedimentary Rock > Chemical Sediment > Chert | ||||
| Rock unit name | Valmy and Comus Formations | ||||
| |||||
| Host or associated | Host | ||||
|---|---|---|---|---|---|
| Rock type | Volcanic Rock (Aphanitic) > Mafic Volcanic Rock | ||||
| Rock unit name | Valmy and Comus Formations | ||||
| |||||
| Host or associated | Host | ||||
|---|---|---|---|---|---|
| Rock type | Sedimentary Rock > Carbonate > Limestone | ||||
| Rock type qualifier | carbonaceous | ||||
| Rock unit name | Etchart Limestone | ||||
| |||||
| Host or associated | Associated | ||
|---|---|---|---|
| Rock type | Volcanic Rock (Aphanitic) > Pyroclastic Rock > Tuff | ||
| Rock type qualifier | basaltic hydroclastic | ||
| |||
| Host or associated | Associated | ||
|---|---|---|---|
| Rock type | Volcanic Rock (Aphanitic) > Mafic Volcanic Rock > Basalt | ||
| Rock type qualifier | basalt | ||
| |||
| Host or associated | Associated | ||
|---|---|---|---|
| Rock type | Sedimentary Rock > Mixed Clastic/Volcanic Rock | ||
| Rock type qualifier | volcaniclastic | ||
| |||
| Host or associated | Associated | ||
|---|---|---|---|
| Rock type | Volcanic Rock (Aphanitic) > Mafic Volcanic Rock > Basalt | ||
| Rock type qualifier | basaltic sills | ||
| |||
| Host or associated | Associated | ||
|---|---|---|---|
| Rock type | Volcanic Rock (Aphanitic) > Mafic Volcanic Rock > Basalt | ||
| Rock type qualifier | lava flows | ||
| |||
| Host or associated | Associated | ||
|---|---|---|---|
| Rock type | Plutonic Rock > Ultramafic Intrusive Rock | ||
| Rock type qualifier | ultramafic (iherzolite) sills | ||
| |||
| (1) | -117.15096, 41.28322 |
|---|
| Type of structure | Local |
|---|---|
| Structure description | The Conelea overturned anticline dominates the structural picture of the early Rabbit Creek Mine area. The fold axis strikes N20-30W, dips 20-30 degrees southwest, and plunges 5 degrees northwest. The Conelea Anticline is offset by three NE-striking faults; the northernmost of the three (DZ fault) has about 2000 ft. of dextral offset. The DZ fault is interpreted as a Riedel "R" shear associated with an inferred major N-S basement suture with right lateral offset, the "Rabbit Suture". Low angle unconformity developed in the Gough's Canyon Formation. The Chimney Creek deposit occurs along a northeasterly range front lineament that is probably an extension of the Getchell Fault. Host rocks strike NE, dip 21-32 NW. |
| Type of structure | Regional |
| Structure description | Leviathan allochthon. Antler orogenic belt. major, deep seated, N-S structural zone (suture) 40 km (25 miles) long, known as the Getchell high-angle fault system bounds the eastern flank of the Osgood Mountains. N-S trending belt of gold mineralization that is at least 5.6 km (3.5 miles) long and 300 m (1000 ft) to 450m (1500ft) wide. Roberts Mountain Thrust (below) and the Golconda Thrust (above), intruded by the mid-Cretaceous Osgood Mt. granodiorite and related trachyandesite dikes. |
| General form | tabular to irregular |
|---|
| Operation type | Surface |
|---|---|
| Development status | Producer |
| Commodity type | Both |
| Significant | Yes |
| Discovery year | 1985 |
| Discoverer | Gold Fields Mining Corp./ Santa Fe Pacific Gold |
| Year of first production | 1986 |
| Year of last production | 2006 |
| Production years | 1987-present |
| District name | Potosi District |
|---|
| Ownership category | Private |
|---|---|
| Area name | Winnemucca BLM Administrative District |
| Ownership category | BLM Administrative Area |
| Type | Owner-Operator |
|---|---|
| Owner | Newmont Gold Co. |
| Year | 2006 |
Santa Fe Pacific Gold 1996 SEC Form 10K
Mining Engineering, 1/1/97
Northern Miner, 2/6/95,
Northern Miner, 6/3/96
California Mining Journal, 3/1/95
California Mining Journal, 3/1/96
Pay Dirt, 2/1/96
Pay Dirt, 3/1/96
Pay Dirt, 11/1/96
Bloomstein and others, 1991; Bonham, 1986, 1989, 1991; F. Breit, oral communication, 2000; Davis and Tingley, 1999; Gardiner, 1989, 1990
Gardiner and Giancola, 1991
Giancola, 1995, 1996, 1997, 1998, 1999, 2000
Harding, 2004m
Mason and others, 1996;
Nevada Bureau of Mines and Geology, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004; Newmont Mining Corp., 2003; Osterberg and Guilbert, 1991; Santa Fe Pacific Gold Corp., 1995a, 1995c; Schack, 2003; Tingley, 1998; United States Bureau of Land Management, 1979g, 1996e, 1996h; United States Bureau of Mines, 1995; United States Geological Survey, 1980d, 1980e.
Nevada Mining Association Bulletin, Oct-Nov., 1985.
The Mining Record, Nov. 13, 1985, P.3
Reno Gazette Journal, Nov. 11, 1985.
The Northen Miner Newspaper, Nov. 11, 1985.
Mine Search Annual, 1984-85, Metals Economics Group, Boulder, Co, Vol vii, p. 93-94.
Oral Communication from Jim Delong, 16 Jul. 1986, geologist formerly with Gold Fields.
Geol. Soc. Nevada, 1987, Precious Metals Symposium, lectures, abstracts.
E. I., Massengill, G.L. et. al., 1991, Discovery, geology and mineralization of the Rabbit Creek gold deposit, Humboldt Co., NV. Geology and Ore Deposits of the Great Basin, GSN Symposium Proceedings Reno, Nevada, p. 821-843.
Grauch,V.J.S., and Bankey, Viki, Preliminary results of aeromagnetic studies of the Getchell disseminated gold deposit trend, Osgood Mountains North Central Nevada. Geology and Ore Deposits of the Great Basin, GSN Symposium Proceedings Reno, Nevada, p. 781-791.
California Mining Journal, April 1990
The Humboldt Sun, Winnemucca, NV, July 27, 1990, p. 32 and 34.
Rabbit Creek Mine, Santa Fe Pacific Ld Corp. brochure.
The Nevada Mineral Industry, 1990, NBMG Spec. Pub. MI-1990.
Willden, Ronald 1964, Geology and Mineral Deposits of Humboldt County, Nv: Nbmg Bull. 59p.
NBMG, 1994, MI-1993
| Subject category | Comment text |
|---|---|
| Deposit | The original gently dipping mineralized zone containing significant gold values was found in an area about 1600 by 800 feet covered by 60m to 165 m of alluvium. It consisted of a gold-bearing tabular jasperoid body 30-50 m thick extending at least 600 m outward from the center of Chimney Creek. Seven other nearby gold mineralized zones were soon recognized. These zones were first developed as the separate Rabbit Creek and Chimney Creek open pit mines, later merged into a single ?Mega-pit?. In the Section 30 South Mega pit area, mill-grade oxide mineralization was found in both limbs of a large fold, with mineralization extending more than 1,500 feet south of the limit of the Mega pit as currently planned. All three target areas were drilled extensively in 1996 and1997, and Santa Fe Pacific Gold intersected "high-grade" in some of their drilling below the Twin Creeks pit. The Galena vein underground target is relatively high-grade (0.25-0.40 opt) mineralization within a northeast-southwest trending fault zone in the greenstones immediately beneath the Vista deposit north of the Mega pit. The target extended along strike for over 1,000 feet and about 500 feet down the structure, averaging about 10-15 feet wide, open along strike and at depth. The Zone 40 target is a fold-controlled zone of high-grade (about 0.5 opt) refractory mineralization at the bottom of the Mega pit. The Sage ore body is a northern extension of the existing Twin Creeks Mega pit, and occurs in the overturned fold axis of a NW-trending anticline at depths of 600 to 1200 feet. The carbonaceous and sulfide ore will be processed through the Sage autoclave. Most gold values are found in calcareous shales in the Ordovician sequence and in limestones in the Etchart Formation, although not all layers contain the same amount of gold. Strongest gold mineralization is not adjacent to faults but the form and distribution of mineralization suggests that gold-bearing solutions gained access to favorable layers along faults. In the Ordovician sequence, gold values are highest in shales that have undergone maximum dissolution of carbonate minerals. Petrographic study shows that some gold is associated with adularia, but deposit-scale comparisons do not show a consistent relation between K/Al ratios and gold values. The distribution of antimony is similar to that of gold, whereas mercury is more concentrated than gold, and arsenic is more widely dispersed than gold. The relation between gold, iron, and sulfide sulfur values shows that mineralization is concentrated in rocks that have gained sulfur, but not iron, to form gold-bearing arsenian pyrite. Thus, these rocks have undergone sulfidation rather than pyritization. The iron that underwent sulfidation came largely from preore, diagenetic(?) ferroan dolomite and was released into solution by decarbonation, a common form of alteration associated with Carlin-type deposits. It appears tha wall-rock iron content and decarbonation processes which liberate this iron are the most important factors controlling formation of this Carlin-type gold deposit. |
| Type | Date | Name | Affiliation | Comment |
|---|---|---|---|---|
| Reporter | 01-DEC-2006 | LaPointe, D.D. | Nevada Bureau of Mines and Geology | |
| Editor | 01-SEP-2007 | Schruben, Paul G. | U.S. Geological Survey | Converted from S&A FileMaker format to Oracle. Edit checks on rocks, units, and ages with Geolex search, and other fields. |
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