South Bullion / Trout Creek Deposit

Site Name

Primary: South Bullion / Trout Creek Deposit
Secondary: Main Zone
Secondary: North Pod Zone
Secondary: Southern Zone
Secondary: Central Zone
Secondary: Northern Zone
Secondary: part of the Railroad-Pinon property
Secondary: Cord Ranch - Pi?on Range

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Commodity

Primary: Gold
Primary: Silver
Tertiary: Mercury
Tertiary: Barium-Barite
Tertiary: Arsenic
Tertiary: Antimony

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Location

State: Nevada
County: Elko
District: Robinson Mountain District

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Land Status

Land ownership: Private
Note: the land ownership field only identifies whether the area the mine is in is generally on public lands like Forest Service or BLM land, or if it is in an area that is generally private property. It does not definitively identify property status, nor does it indicate claim status or whether an area is open to prospecting. Always respect private property.

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Holdings

Not available

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Workings

Not available

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Ownership

Owner Name: Royal Standard Minerals, Inc.
Info Year: 2006

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Production

Not available

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Deposit

Record Type: Site
Operation Category: Producer
Deposit Type: replacement
Operation Type: Surface
Discovery Year: 1979
Years of Production:
Organization:
Significant: Y
Deposit Size: S

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Physiography

Not available

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Mineral Deposit Model

Model Name: Sediment-hosted Au

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Orebody

Form: tabular

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Structure

Type: L
Description: Tertiary age faults strike NW and NNE. One set of NW-striking, south-dipping reverse faults controlled ore deposition.

Type: R
Description: The deposit lies within the Mesozoic-age, N- to NW-trending Pinon Range anticline. Tertiary age faults strike NW and NNE. One NW-striking fault set shows reverse displacement and acted as conduits for hydrothermal fluids.

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Alterations

Alteration Type: L
Alteration Text: Alteration at South Bullion consists of silicification, decalcification, and argillization. Alteration within the Trout Creek portion of the deposit consists predominantly of silicification and hematization. Gold mineralization is intimately related, both temporally and spatially, to silicification of the Webb Formation. Silicification of the Webb Formation has resulted in 1) replacement of primary calcareous material by authigenic quartz, forming the major portion of the fine grained jasperoid, 2) development of quartz overgrowths, some of which are multiple overgrowths, 3) the in-filling of fractures and vugs by coarse anhedral and euhedral quartz, and 4) pervasive silica flooding along zones of induced secondary porosity and permeability. Portions of the Webb Formation and Devils Gate Limestone are decalcified in an envelope to the jasperoid. An unsilicified portion of the Webb Formation that directly overlies the jasperoid contains numerous fine calcite veinlets; a similar zone occurs directly below the jasperoid and is characterized by massive vein- and cavity-filling sparry calcite. Weak argillic alteration is suggested by the presence of dispersed hydrothermal clays within the Webb Formation and the Chainman Shale at both the local and district scales. Due to the regional extent of the clays, as contrasted to the limited area of gold mineralization, the gold is thought to not necessarily be temporally associated with this weak argillization event.

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Rocks

Name: Siltstone
Role: Host
Description: calcareous
Age Type: Host Rock
Age Young: Early Mississippian

Name: Mudstone
Role: Host
Description: interbedded
Age Type: Host Rock
Age Young: Early Mississippian

Role: Associated
Age Type: Associated Rock Unit
Age Young: Early Pennsylvanian
Age Old: Early Mississippian

Role: Associated
Age Type: Associated Rock Unit
Age Young: Late Mississippian
Age Old: Early Mississippian

Name: Limestone
Role: Associated
Age Type: Associated Rock
Age Young: Late Devonian
Age Old: Middle Devonian

Name: Quartzite
Role: Host
Age Type: Host Rock
Age Young: Early Mississippian

Name: Sandstone
Role: Host
Age Type: Host Rock
Age Young: Early Mississippian

Name: Shale
Role: Host
Age Type: Host Rock
Age Young: Early Mississippian

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Analytical Data

Not available

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Materials

Ore: Gold
Ore: Kaolinite
Ore: Alunite
Ore: Pyrite
Ore: Stibnite
Ore: Jarosite
Ore: Hematite
Ore: Calcite
Ore: Limonite
Gangue: Barite

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Comments

Comment (Commodity): Ore Materials: native gold

Comment (Commodity): Gangue Materials: barite, calcite, hematite, jarosite, stibnite, pyrite, alunite, kaolinite, limonite

Comment (Development): No exploration is known to have taken place in the area prior to 1979. The property was staked by L. L. Trease and H. D. Christianson in 1979 on the basis of mineralized jasperoid outcrops. In 1981, Amoco Minerals drilled 31 vertical reverse circulation holes on 200-400 ft. centers. The best intercept was 80 ft. grading 0.032 opt gold. A lack of continuity of mineralization over the wide spaced drilling caused Amoco to drop the lease. In 1983, Freeport Minerals Co. leased the property and drilled 8 holes. The best intercept was 40 ft. grading 0.083 opt gold, although the drilling was otherwise discouraging and Freeport dropped the lease. Teck Resources acquired the property in 1986 and conducted intensive exploration for one year. Teck then optioned its interest to Lord River Gold Mines, Ltd., who continued to fund exploration with Teck as operator. Teck/Lord River had drilled 32 holes in the area by 1989. A soil geochemical survey was donethat showed widespread arsenic anomalies, with gold occurring as isolated point concentrations. Mercury values up to 8100 ppb form thin linear anomalies that are thought to be leakage along structures from mineralization at depth. In 1995, Royal Standard Minerals acquired Cyprus Gold Exploration's position. In 1997 it was reported that Cameco Corp., through a joint venture with Royal Standard Minerals, was earning a 51% interest in the Cord Ranch property (Robinson Mountain District) through a positive feasibility study. Fourteen drill holes were completed totaling 11,425 feet. In 2003, Royal Standard Minerals Inc. reevaluated the data on its Pi?on and Railroad projects to determine the economic potential of the near surface resources. This work concentrated on the Pi?on, Main, and North Pod and the Railroad, Pod, and East Jasperoid deposits included within Royal Standard Mineral's approximately 16,000 acre property. An initial 10-hole (2,620 feet) drilling program completed on the Pi?on Main Zone deposit focused upon extending the near surface portion of the deposit toward the south, southeast and northwest into areas of thin overburden in an effort to determine the gold-silver resource tonnage and grade potentials within these areas for a proposed mine plan. The company continued with a feasibility study on the Pi?on-Railroad project, and planned to complete a draft of a development plan and the filing of the first draft mining permit application to Federal and State agencies for a 5,000-ton/day mine and heap-leach facility before the end of 2003. The overall grade of the resource included within the mine feasibility study was estimated to be 0.045 opt gold. The dimensions of the Pi?on near surface portion of the measured gold-silver oxide deposit are 1,400 feet along strike, 300 to 600 feet wide and 15 to 150 feet thick. Royal Standard's evaluation of data from more than 600 drill holes identified several potentially economic low grade (0.02-0.10 opt) bulk-mineable gold deposits including the Pod and South Bullion deposits. South Bullion includes a large gold -silver bearing system with measured, indicated and inferred tonnages of 30.6 million tons of 0.026 opt at a 0.01 opt cutoff grade. The lower grade geologic mineral inventory is in addition to several additional near surface gold deposits on the property. In 2004, RSM conducted a metallurgical column leach testing program of samples from the gold-silver near surface resource at the Pinon deposit that returned favorable test results indicating 72% gold recoveries for this deposit and 54% for silver at a nominal minus 0.25 inch size fraction. RSM also completed the open pit mine development and surface facilities plans for four (4) deposits on the Pinon and Railroad projects that includes an initial 7 million tons of near surface measured oxide gold-silver resource estimate that is part of the larger gold-silver resource

Comment (Development): RSM is currently (2006) evaluating the economic potential of the larger, near-surface deposits (Main Zone and North Pod open pit measured oxide gold-the "starter pit") in the South Bullion resource area. There is the potential for a higher grade (0.04 - 0.05 opt) open pit oxide deposit that RSM is currently evaluating for possible development. The Railroad, Pod-East Jasperoid deposits located on the northern portion of the Company's 16,000 acre land package are a high priority project to be further evaluated for their economic potential. The property was 100% controlled by Royal Standard Minerals (RSM), Inc. in 2006. RSM?s 2006 current exploration was focused on developing the Main and North Pod near-surface zones in the South Bullion resource area. South Bullion includes a large, gold-silver bearing system with measured, indicated and inferred resources of 30.6 million tons grading 0.026 opt (0.01 opt cut-off). Plans include pursuing a mining permit on this property in 2007 for an open pit heap leach operation.

Comment (Economic Factors): Trout Creek was reported in 1988 to have identified reserves of 1.5 million tons of ore grading 0.04 opt gold.In 2004, Royal Standard reports that South Bullion includes a large gold -silver bearing system with measured, indicated and inferred tonnages of 30.6 million tons of 0.026 opt gold at a 0.01 opt cutoff grade.

Comment (Environment): The deposit lies within the Pinon Range which occurs within the narrow N-S trending belt which coincides with the position of the Paleozoic continental margin.

Comment (Geology): The Au:Ag ratio of the ore is about 1: 8.

Comment (Deposit): Three areas of mineralization have been identified within the Trout Creek portion of the deposit: the Southern, Central, and Northern zones. Only the Central and Southern zones are known to contain significant thicknesses of ore-grade gold mineralization. Narrow felsic dikes of unknown age outcrop west and south of the deposit but are not found within it. The South Bullion resource area contains the Main zone and North Pod zone. Jasperoid is developed along the controlling faults and along the contact between the Webb Formation and the Devils Gate Limestone. Jasperoid within the fault hosts small veinlets of calcite, quartz, and barite and shows multiple periods of brecciation and silicification. Gold and associated elements are closely correlated with the degree of silicification. Hematite occurs with jasperoid and in the Devils Gate limestone immediately below the contact with the Webb Formation. The Pinon project deposit occurs in siltstone beds within a graben faulted area. Mineralized oxide zones occur along a 1,300 feet strike length less than 90 feet below the surface. Gold mineralization in the South Bullion portion of the deposit is intimately related, both temporally and spatially, to silicification of the Webb Formation. Silicification of the Webb Formation has resulted in 1) replacement of primary calcareous material by authigenic quartz, forming the major portion of the fine grained jasperoid, 2) development of quartz overgrowths, some of which are multiple overgrowths, 3) the in-filling of fractures and vugs by coarse anhedral and euhedral quartz, and 4) pervasive silica flooding along zones of induced secondary porosity and permeability. Portions of the Webb Formation and Devils Gate limestone are decalcified in an envelope to the jasperoid. An unsilicified portion of the Webb Formation that directly overlies the jasperoid contains numerous fine calcite veinlets; a similar zone occurs directly below the jasperoid and is characterized by massive vein- and cavity-filling sparry calcite. Weak argillic alteration is suggested by the presence of dispersed hydrothermal clays within the Webb Formation and the Chainman Shale at both the local and district scales. Due to the regional extent of the clays, as contrasted to the limited area of gold mineralization, the gold is thought to not necessarily be temporally associated with this weak argillization event.

Comment (Identification): This record encompasses all material contained in MRDS records RE00044 and RE00045. The Trout Creek and South Bullion deposits are two parts of the same deposit which have been claimed by different owners in the past and have thus been described under different names in the literature. UTM is to near center of the main project area. Dark Star is a nearby adjacent property about 2 miles or so east of the main Trout Creek/South Bullion/Pi?on deposit and it has its own MRDS record. The Pod (and East Jasperoid) deposit area is also controlled by Royal Standard Minerals and included in their Pi?on-Railroad property descriptions, is located about a mile south of Trout Creek and is described in a separate MRDS record.

Comment (Location): The deposit is located on the west flank of the Pinon Range. The Trout Creek deposit is the northern portion of a single hydrothermal system, the southern portion of which is the South Bullion deposit (record #RE00045). The property boundary between Trout Creek and South Bullion deposits is the section line between sections 22 and 27, T30N, R53E.

Comment (Workings): small open pit, advanced exploration workings; drillholes.

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References

Reference (Deposit): Thoreson, R., 1991, Geology and gold deposits of the Rain subdistrict, Elko County, Nevada, in Raines, G.L., et al., eds., Geology and Ore Deposits of the Great Basin, The Geological Society of Nevada, Reno, p. 635-643.

Reference (Deposit): NBMG MI-88 thru MI-02

Reference (Deposit): NBMG Bull. 106

Reference (Deposit): Elko Land Status Map 1978

Reference (Deposit): Amer. Mines (1996), 1995

Reference (Deposit): Thoreson, R., 1990, Geology and Ore Deposits of the Rain Subdistrict, Elko County, Nevada, Oral Presentation at Great Basin Symposium, The Geological Society of Nevada, Reno/Sparks, April 4.

Reference (Deposit): Nevada Dept.of Minerals, 1994

Reference (Deposit): Newmont Gold 1993 Sec Form 10k.

Reference (Deposit): Jackson, P.R., and Ruetz, J.W., 1991, Geology of the Trout Creek disseminated gold deposit, Elko County, Nevada, in Raines, G.L., et al, eds., Geology and Ore Deposits of the Great Basin, the Geological Society of Nevada, Reno, p. 729-734.

Reference (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.

Reference (Deposit): 2004 Royal Standard Minerals website.

Reference (Deposit): Putnam, B. R., and Henriques, E. Q. B., 1991, Geology and Mineralization at the South Bullion Deposit, Pinon Range, Elko County, Nevada: Implications for Western United States Cenozoic Tectonics, in Raines, G. L., et al., Eds., Geology and Ore Deposits of the Great Basin, Geological Society of Nevada, Reno, p. 713-728.

Reference (Deposit): Royal Standard Minerals Inc. press releases, 4/21/2003; 11/3/2003; 11/5/2003.

Reference (Deposit): Thompson, 1999

Reference (Deposit): Newmont Ann. Rept. 1988

Reference (Deposit): Jackson, P., 1992, Geology and mineralization of the Emigrant Springs Project, Elko County, Nevada, in Buffa, R. and Coyner, A., eds., The Geology and Ore Deposits of the Great Basin-Field Trip Guidebook Compendium, The Geological Society of Nevada, Reno, p. 125-130.

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Nevada Gold

Nevada has a total of 368 distinct gold districts. Of the of those, just 36 are major producers with production and/or reserves of over 1,000,000 ounces, 49 have production and/or reserves of over 100,000 ounces, with the rest having less than 100,000 ounces. Read more: Gold Districts of Nevada.