South Eureka Property

Producer in Eureka county in Nevada, United States with commodities Gold, Silver, Lead, Zinc, Arsenic, Antimony

Sections on this page

Identification information
Geographic coordinates
Site location context
Geographic areas
Public Land Survey System information
Commodities
Materials information
Alteration
Mineral occurrence model information
Host and associated rocks
Nearby scientific data
Geologic structures
Ore body information
Controls for ore emplacement
Economic information about the deposit and operations
Mining district
Land status
Ownership information
Bibliographic references
General comments
Reporter information

Geologic information

Identification information

Deposit ID	10310482
MRDS ID	M232576
Record type	Site
Current site name	South Eureka Property
Alternate or previous names	Eureka-Windfall-Rustler Mine, North Paroni pit, South Paroni pit, Lookout Pit, Lookout Mountain, Norse-Windfall Mine, Western Windfall Open Pit Mine, Windfall Venture, New Windfall Shaft, Windfall-Rustler Mine, Rustler (adjoins the property to the south)
Related records	10044935, 10222389

Comments on the site identification

This record encompasses the area described by two earlier incomplete records, M232576, and M232201. The current record includes all material from those records plus additional information.

Geographic coordinates

Geographic coordinates:	-115.97784, 39.44993 (WGS84)
Elevation	2440
Relative position	The South Eureka property/Windfall Mine is located approximately 5-7 miles south of Eureka, Nevada.

Site location context

Political divisions (FIPS codes)

Eureka(county)

Nevada(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Pinto Summit(quadrangle 1:24,000 scale)

Mount Hamilton(quadrangle 1:100,000 scale)

Ely(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Diamond-Monitor Valleys(hydrologic unit)

Central Nevada Desert Basins(hydrologic accounting unit)

Central Nevada Desert Basins(hydrologic subregion)

Great Basin(hydrologic region)

Federal lands

Bureau of Land Management(Bureau of Land Management NV)

Bureau of Land Management NV BLM(Type of land area)

BLM(Federal land areas administered by BLM)

Geographic areas

Country	State	County
United States	Nevada	Eureka

Public Land Survey System information

Meridian	Township	Range	Section	Fraction	State
Mount Diablo	018N	053E	02 11		Nevada

Comments on the location information

The old Windfall (Norse-Windfall) Mill Site is located approximately 5 miles south of Eureka, Nevada at the north end of the Fish Creek Range. The South Eureka property is another mile to 2 miles south. Access to the site is south 1.2 miles from Eureka on U.S. Highway 50 and then west 2.3 miles on Windfall Canyon Road.

Commodities

Commodity	Importance
Gold	Primary
Silver	Secondary
Lead	Secondary
Zinc Critical	Secondary
Arsenic Critical	Tertiary
Antimony Critical	Tertiary

Comments on the commodity information

Ore Materials: native gold, cerussite, smithsonite
Gangue Materials: scorodite, limonite, quartz, calcite, dolomite

Materials information

Materials	Type of material
Gold	Ore
Cerussite	Ore
Smithsonite	Ore
Scorodite	Gangue
Limonite	Gangue
Quartz	Gangue
Calcite	Gangue
Dolomite	Gangue

Alteration

(Local) Dolomite has been "sanded" due to intergranular corrosion.

Mineral occurrence model information

Model code	75
USGS model code	19c
Deposit model name	Distal disseminated Ag-Au
Mark3 model number	18
Model code	173
USGS model code	26a.1
Deposit model name	Sediment-hosted Au
Mark3 model number	17

Host and associated rocks

Host or associated

Host

Rock type

Sedimentary Rock > Carbonate > Dolomite

Rock type qualifier

?sanded?

Rock unit name

Hamburg Dolomite

Stratigraphic age (youngest)	Middle Cambrian
Stratigraphic age (oldest)	Late Cambrian

Host or associated Host

Rock type

Rock unit name Secret Canyon Shale

Stratigraphic age (youngest) Middle Cambrian
Host or associated Host

Rock type

Rock unit name Dunderberg Shale

Stratigraphic age (youngest) Late Cambrian

Host or associated	Associated
Rock type	Volcanic Rock (Aphanitic) > Intermediate Volcanic Rock > Andesite
Rock type qualifier	intensely altered hornblende andesite dikelike masses

Host or associated

Associated

Rock type

Volcanic Rock (Aphanitic) > Felsic Volcanic Rock > Rhyodacite

Rock type qualifier

intrusive

Rock unit name

Ratto Spring Rhyodacite

Stratigraphic age (youngest)	Oligocene
Stratigraphic age (oldest)	Eocene

Host or associated Associated

Rock type Sedimentary Rock > Clastic Sedimentary Rock > Shale

Nearby scientific data

(1)	-115.97784, 39.44993	ListMap

Economic information

Geologic structures

Type of structure	Regional
Structure description	The deposit is situated at the southern end of Dunderberg-Windfall belt.
Type of structure	Local
Structure description	northeast-striking fissures

Ore body information

General form tabular

General form	tabular

Controls for ore emplacement

Fractured permeable zones and capping shale have localized ore formation, as well as the intersection of northeast-striking fissures and faults with the upper Hamburg Dolomite.

Comments on the geologic information

Gold occurs as disseminated low-grade ore in Hamburg Dolomite. The ore forms a number of shoots, that were controlled by the intersection of northeast striking fissures on faults w/the upper Hamburg Dolomite. The mineralization here is unique in regards to the rest of the district, by the absence of the lead and silver

Economic information about the deposit and operations

Operation type	Surface-Underground
Development status	Producer
Commodity type	Metallic
Deposit size	Medium
Significant	Yes
Discovery year	1904
Year of first production	1908
Year of last production	1989
Production years	1908-1940?, 1975-1989

Mining district

District name	Eureka District

Land status

Ownership category	BLM Administrative Area
Area name	Battle Mountain BLM Administrative District

Ownership information

Type Owner-Operator

Owner Staccato Gold Resources, Ltd.

Year 2006

Type	Owner-Operator
Owner	Staccato Gold Resources, Ltd.
Year	2006

Comments on the workings information

In 1981, the open pit was irregular in shape, very deep and narrow. Geologists visiting the operation said it looked like more mining was probably being carried out farther up (south) in the canyon, but the entire operation was not visible from the road. There was a heap leach recovery plant on site. Early work was underground.

Comments on other economic factors

From 1908 to 1916, reported production was 24,000 ounces of gold from 65,320 tons of ore valued at $349,428. From 1975-84 and 1988 reported production was 96,380 ounces of gold. Also, 59 ounces of silver were produced in 1988.
In 1986, drill inferred reserves for the South Rustler Zone were reported at 584 kilotonnes of material grading 0.02 ounces of gold per ton. In 1988 there was a reported 3 million tons of material grading 0.03 ounces of gold per ton at the Windfall-Rustler deposit.
Mine Development Associates of Reno, Nevada has estimated a total resource of over 445,000 ounces of gold on the Lookout Mountain portion of the property as follows:
Measured Mineral Resource of 4.753 million tons at 0.020 ounces per ton gold. (95,070 oz.)
Indicated Mineral Resource of 8.269 million tons at 0.021 ounces per ton gold. (173,649 oz.)
Inferred Mineral Resource of 9.309 million tons at 0.019 ounces per ton gold. (176,871 oz.)

As a result of drilling in 2006, these numbers were upgraded to 5,490,000 tons at 0.044 ounces per ton gold

Comments on development

Mineralization was discovered in the Windfall area in1904, and an underground mine and cyanide vat leach recovery facility produced and treated 65,132 tons of ore valued at $349,428 from 1908 to 1916. Production continued intermittently until about 1940. The property was acquired by Idaho Mining Corp. in 1968, which developed and tested it from 1972 to1974, built a plant in 1975 and began production in 1976, mining the same ore body via open pit methods. Between 1975 and 1978 the Windfall Pit, and associated cyanide heap-leach piles, waste dumps, mill process building, office and laboratory were constructed. Because the ore body contains anomalous amounts of mercury, a retort was constructed to recover mercury as a by-product.
The Windfall Venture group conducted the bulk of exploration during the period 1970-1980 in an attempt to expand on their Windfall Mine reserves. Work on the immediate Hoosac property consisted of soil and rock chip sampling, limited geologic mapping, and drilling 63 shallow rotary drill holes. Six of the holes intersected shallow mineralization in excess of 700 ppb Au. Amselco Exploration leased the claims in the mid-1980s and drilled eight holes on the east side of the property
Windfall Ventures continued mining until about 1989, employing 35-46 workers. The last operator of the site was Norse Windfall Mines, Inc. in 1990, after which the site was abandoned with little or no reclamation.
In 1994 and 1995, the Nevada Division of Environmental Protection and subcontractors conducted several inspections and evaluations of the Windfall Mine site and noted that unmaintained process components and materials left on the property had the potential to degrade waters which constituted part of the water supply for the town of Eureka. In 2001, two underground storage tanks and over 300 mostly empty chemical drums were removedfrom the site. Periodic sampling and monitoring of the water in existing wells was begun, and two monitoring wells were drilled, mercury and arsenic contaminated soil around the old mercury retort and mill building were removed.
Tenneco Minerals drilled the property in 1989-1991. Pathfinder Exploration explored the property in 1992 and 1993. Activities by Pathfinder consisted of collection of BLEG samples, geologic mapping, collection of rock and soil samples, ground magnetics/VLF surveys, and completion of 18 reverse circulation holes for a total of 3,284 m drilled. Six of the holes intercepted thick intervals of anomalous gold mineralization ranging upwards of 24 m of 822 ppb Au. The property was joint ventured to Cambior Exploration in 1994. Cambior mapped approximately 2,071 ha, collected rock chip and soil samples, and completed 26 reverse circulation drill holes for a total of 5848 m drilled. Intercepts in the 1995 program consisted of 13.7 m of 445 ppb Au, 7.6 m of 692 ppb Au, and 51.8 m of 450 ppb Au. The fourteen-hole 1996 drilling program encountered widespread alteration and anomalous trace element geochemistry, but little gold (10.6 m of 0.116 g/t Au). Detailed mapping and sampling identified ore controlling structures and Archimedes-type host rocks on the west side of Hoosac Mountain as drill targets.

By 2006, Staccato Gold Resources, Ltd. had consolidated several earlier mined adjacent producing properties over 17,600 acres (27 square miles) into their "South Eureka property" which includes the Windfall Mine, the Rustler pit, North and South Paroni pits and the Lookout Pit as well as five claim blocks: Lookout Mountain, Hiero/Syracuse, Windfall Patents, South Ratto and Hoosac, as well as a separate bloc at New York Canyon. Staccato increased its gold resource for the combined property to 545,000 ozs Au measured and indicated, and 336,000 ozs Au inferred, including a coherent high-grade deposit of more than 200,000 ozs, averaging .24 ozs per ton.

Reference information

Bibliographic references

Deposit

Roberts R.J.,et al., 1967,Geology and Mineral Resources of Eureka Co., Nev; Nev. Bureau of Mines Bull 64
Deposit

USBM (Ely) Mils No.111, Reference No 3201100142
Deposit

Nolan T.B., 1962,The Eureka Mining District, Nev., USGS PP.406
Deposit

Vanderberg W.O., 1938, Reconnaissance of Mining Districts in Eureka Co., USBM IC.7022.
Deposit

NBMG Spec Pub. MI-1980 through NBMG MI-84; NBMG MI-86 through MI-95, NBMG MI-99, NBMG MI-00.
Deposit

NBMG Map 91, 1st, 2nd, 3rd
Deposit

Bentz, J.and Garside, L. J., 1981, Field Examination Report, Aug 31, 1981.
Deposit

Division of Mine Inspection, 1983, Directory of Nevada Mine Operations active During Calendar Year 1983.
Deposit

Couch, B. F. and Carpenter, J., 1943, NBMG Bull 37, no. 4, Ser. 38, p. 64.
Deposit

Long, K.R., DeYoung, J.H., Jr., and Ludington, S.D., 1998, Database of significant deposits of gold, silver, copper, lead, and zinc in the United States; Part A, Database description and analysis; part B, Digital database: U.S. Geological Survey Open-File Report 98-206, 33 p., one 3.5 inch diskette
Deposit

Wilson, W.L., 1986, Geology of the Eureka-Windfall and Rustler gold deposits, Eureka County, Nevada; in Sediment-Hosted Precious Metal Deposits of Northern Nevada, NBMG Report 40, p. 81-84.
Deposit

BLM site remediation website: http://www.nv.blm.gov/AML/Future%20Projects/NorseWindfall/Norse-Windfall%20Mill.htm.
Deposit

http://www.staccatogold.com/s/SouthEureka.asp

General comments

Subject category	Comment text
Deposit	Gold occurs as disseminated, low-grade ore in Hamburg Dolomite, forming a number of shoots controlled by intersection of NE-striking fissures or faults with the Hamburg Dolomite. Ore occurs primarily in the dolomite, adjacent to the faulted contact with a rhyodacite intrusive body. Mineralization here is unique from that in the rest of district in the paucity of lead and silver. The Rustler deposit, an extension of the Windfall deposit 0.5 mile south was found and put into production. Much of the Rustler ore occurs in zones that have been thoroughly silicified and somewhat brecciated. Drilling has shown that ore grade material extends from the south end of the Windfall pit to the north end of the Rustler pit. The Windfall ore bodies differ markedly from the other mineralized bodies in the district in that they are low-grade gold ore shoots with indistinct assay walls. The shoots exhibited marked structural and stratigraphic control , localized by the intersection of NE-striking fissures or faults with the Hamburg Dolomite. Staccato completed a Phase One 3-hole core drill program on the Lookout portion of the property in November 2005. Each of the three holes intercepted high-grade gold over significant interval lengths. A nine-hole follow up core drill program was underway in 2006. The nine-hole drill program will complete each hole to a depth of at least 300 meters (1,000 feet), and is designed to follow-up the November, 2005 drill program. Using the newly identified mineral model, the nine new holes are designed to extend the high-grade breccia-hosted mineralization along strike as well as laterally to the feeder structures. The structures are part of the Ratto Ridge Fault system which has been traced for a length of more than 4 kilometers (2.5 miles) by previous drilling, mapping and sampling. The Ratto Ridge Fault system represents a small portion of Staccato's 100% owned South Eureka property, which comprises an area of over 17,600 acres (27 square miles).

Subject category

Comment text

Deposit

Gold occurs as disseminated, low-grade ore in Hamburg Dolomite, forming a number of shoots controlled by intersection of NE-striking fissures or faults with the Hamburg Dolomite. Ore occurs primarily in the dolomite, adjacent to the faulted contact with a rhyodacite intrusive body. Mineralization here is unique from that in the rest of district in the paucity of lead and silver. The Rustler deposit, an extension of the Windfall deposit 0.5 mile south was found and put into production. Much of the Rustler ore occurs in zones that have been thoroughly silicified and somewhat brecciated. Drilling has shown that ore grade material extends from the south end of the Windfall pit to the north end of the Rustler pit. The Windfall ore bodies differ markedly from the other mineralized bodies in the district in that they are low-grade gold ore shoots with indistinct assay walls. The shoots exhibited marked structural and stratigraphic control , localized by the intersection of NE-striking fissures or faults with the Hamburg Dolomite.
Staccato completed a Phase One 3-hole core drill program on the Lookout portion of the property in November 2005. Each of the three holes intercepted high-grade gold over significant interval lengths. A nine-hole follow up core drill program was underway in 2006.
The nine-hole drill program will complete each hole to a depth of at least 300 meters (1,000 feet), and is designed to follow-up the November, 2005 drill program. Using the newly identified mineral model, the nine new holes are designed to extend the high-grade breccia-hosted mineralization along strike as well as laterally to the feeder structures. The structures are part of the Ratto Ridge Fault system which has been traced for a length of more than 4 kilometers (2.5 miles) by previous drilling, mapping and sampling.
The Ratto Ridge Fault system represents a small portion of Staccato's 100% owned South Eureka property, which comprises an area of over 17,600 acres (27 square miles).

Reporter information

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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