Jumbo Group

The Jumbo Group is a gold mine located in Esmeralda county, Nevada at an elevation of 5,699 feet.

About the MRDS Data:

All mine locations were obtained from the USGS Mineral Resources Data System. The locations and other information in this database have not been verified for accuracy. It should be assumed that all mines are on private property.

Mine Info

Satelite View

MRDS mine locations are often very general, and in some cases are incorrect. Some mine remains have been covered or removed by modern industrial activity or by development of things like housing. The satellite view offers a quick glimpse as to whether the MRDS location corresponds to visible mine remains.

Site Name

Primary: Jumbo Group
Secondary: Part of Goldfield Consolidated Mines Co. After 1906-7. Jumbo
Secondary: Clermont
Secondary: Lucky Boy
Secondary: Grizzly Bear Claims

Commodity

Primary: Gold
Secondary: Silver
Secondary: Copper
Tertiary: Tin
Tertiary: Zinc

Location

State: Nevada
County: Esmeralda
District: Goldfield District

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.

Holdings

Not available

Workings

Type: Underground

Ownership

Not available

Production

Year: 1918
Time Period: 1917-1918
Material type: AUCUAGORE
Description: Cp_Grade: ^Avg 0.31oz/T Au, 1.13% Cu (Grizzly Bear Claim)
Year: 1915
Time Period: 1913-1915
Material type: AUCUAGORE
Description: Cp_Grade: ^Avg. 1.07 Oz/T Au, 5.58oz/T Ag, 4.21% Cu (Grizzly Bear)

Deposit

Record Type: Site
Operation Category: Occurrence
Operation Type: Unknown
Discovery Year: 1903
Years of Production:
Organization:
Significant: N
Deposit Size: S

Physiography

Not available

Mineral Deposit Model

Model Name: Epithermal quartz-alunite Au

Orebody

Form: TABULAR TO IRREGULAR

Structure

Not available

Alterations

Alteration Type: L
Alteration Text: Alunitization, Pyritization

Rocks

Name: Dacite
Role: Host
Age Type: Associated Rock
Age in Years: 21.500000+-
Age Young: Miocene

Name: Dacite
Role: Associated
Age Type: Associated Rock
Age in Years: 21.500000+-
Age Young: Miocene

Analytical Data

Analytical Data: SPECTROSCOPIC ANALYSES IN 1939-40 REVEALED PRESENCE OF SMALL AMOUNTS OF TIN IN THIS ORE.

Materials

Ore: Sphalerite
Ore: Famatinite
Ore: Wurtzite
Gangue: Pyrite
Gangue: Limonite
Gangue: Gypsum
Gangue: Alunite
Gangue: Kaolinite
Gangue: Quartz

Comments

Comment (Geology): GRIZZLY BEAR CLAIM DIFFERED FROM MOST IN GOLDFIELD DISTRICT IN THAT IT YIELDED ORE HIGH IN SILVER AND COPPER AS WELL AS GOLD (22,500 TONS AVERAGED 1.07 OZ/T AU, 5.58 OZ/T AG, 4.21% CU) WHICH CAME FROM IMMEDIATELY ABOVE THE CAMBRIAN BASEMENT.

Comment (Workings): MORE THAN 6 LEASES WERE WORKED ON THE JUMBO IN THE EARLY YEARS, EACH THROUGH A DIFFERENT SHAFT AND NOT ALL CONNECTING. MAIN SHAFT IN 1905WAS SUNK TO 450 FT. MANY LEVEL WORKINGS, ALSO. CLERMONT SHAFT WAS SUNK TO 1050 FT BY 1909 UNDER GOLDFIELD CONS. OPERATION

Comment (Location): BETWEEN COMBINATION FRACTION AND GOLDFIELD MERGER PROPERTIES. . UTM IS TO SHAFT NEAR CENTER OF NORTH END OF CLAIM GROUP. ; INFO FROM LAND.ST :1982

Comment (Production): PRODUCTION FIGURES ARE PROBABLY LOWER THAN ACTUAL ORE REMOVED. PRODUCTION WAS PRIMARILY BY LESSEES

Comment (Development): 50-FT SHAFT WAS SUNK IN-1903. OWNERS LET OUT 11 LEASES ON THE JUMBO IN 1904, FOR 8 MONTHS. IN THE 8 MONTHS ORE WITH GROSS VALUE OF $1,690,000 WAS REMOVED FROM THE CLAIM. JUMBO MINING CO. WAS INCORPORATED IN 1904. LITIGATION AMONG PARTNERS IN 1904 HALTED MINING AT THE JUMBO THROUGH 1905. THE JUMBO WAS ACQUIRED BY GEORGE WINGFIELD FOR GOLDFIELD CONSOLIDATED MINES CO, IN 1906. CALUMET AND HECLA CONSOLIDATED COPPER CO. IN IN 1935-38 DISCOVERED A MODERATE-SIZED ORE BODY IN THE SHALLOW LEVELS OF THE CLERMONT VEIN

Comment (Deposit): DISTINCT ZONE OF PARALLEL SHEETING. HIGH-GRADE ORE IS WITHIN OXIDIZED ZONE

References

Reference (Deposit): TOLMAN AND AMBROSE, 1934, ECON GEOL VOL. 29, P. 255-279.

Reference (Deposit): UNPUBLISHED MAPS OF CLERMONT MINE FROM CALUMET & HECLA'S OPERATIONS IN 1930'S: NBMG FILE 91, ITEMS 25, 26, 27, 28

Reference (Production): SHAMBERGER, 1982, P. 199; GSA MEMOIR 131, 1974; NBMG BULL 48, P. 17.

Reference (Deposit): SHAMBERGER, H.A., 1982, THE STORY OF GOLDFIELD, NEVADA HISTORICAL PRESS, CARSON CITY, NEV. 240 P.

Reference (Deposit): COLLINS, E.A., 1907 MINING AND SCIENTIFIC PRESS

Reference (Deposit): NBMG REPORT 33, P. 77-86.

Reference (Deposit): RIDGE, J.D., 1974, GSA MEM 131.

Reference (Deposit): SEARLS, F., 1948, NBMG BULL 48, P.18.

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.