Jumbo-Morovoratz Mine

The Jumbo-Morovoratz Mine is a silver and gold mine located in La Plata county, Colorado at an elevation of 8,921 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-Morovoratz Mine
Secondary: Patented Claims: Morovoratz, MS 88
Secondary: Morovoratz, MS 91
Secondary: Jumbo, MS 19879

Commodity

Primary: Silver
Primary: Gold
Secondary: Copper
Secondary: Lead

Location

State: Colorado
County: La Plata
District: California (La Plata) 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.
Administrative Organization: San Juan N. F.

Holdings

Not available

Workings

Type: Underground

Ownership

Owner Name: Jumbo Mining Co. (Jumbo Mine)
Home Office: Durango, Co.
Years: 1934 -

Owner Name: Golden West Development Co. (Jumbo Mine)
Home Office: Ft. Worth, Tx.
Years: 1934 -

Production

Not available

Deposit

Record Type: Site
Operation Category: Past Producer
Deposit Type: Vein
Operation Type: Unknown
Year First Production: 1875
Year Last Production: 1932
Discovery Year: 1875
Discovery Method: Ore-Mineral In Place
Years of Production:
Organization:
Significant: N
Deposit Size: S

Physiography

General Physiographic Area: Intermontane Plateaus
Physiographic Province: Colorado Plateaus
Physiographic Section: Navajo Section

Mineral Deposit Model

Model Name: Polymetallic veins

Orebody

Not available

Structure

Type: R
Description: San Juan Uplift, Four Corners Platform

Type: L
Description: La Plata Dome, May Day-Idaho Fault System

Alterations

Alteration Type: L
Alteration Text: Alteration Of Cu Sulfide

Rocks

Name: Diorite
Role: Associated
Age Type: Associated Rock
Age Young: Paleocene

Name: Diorite
Role: Associated
Age Type: Associated Rock Unit
Age Young: Paleocene

Name: Diorite
Role: Associated
Age Type: Host Rock
Age Young: Late Jurassic

Analytical Data

Not available

Materials

Ore: Chalcopyrite
Ore: Gold
Gangue: Quartz

Comments

Comment (Deposit): Discovery Year: 1870S

Comment (Location): (LAND STATUS AND ADMINISTRATIVE AREA LOCATIONS CALCULATED USING GIS OVERLAY ANALYSIS FOR SAN JUAN N. F.). ON WEST SIDE OF LA PLATA RIVER BELOW BAY CITY GULCH, 3.25 MILES SSW OF LA PLATA TOWNSITE (UNSURVEYED SECTIONS). ; INFO FROM LAND.ST :1974

Comment (Deposit): COUNTRY ROCKS CONSIST OF ENTRADA AND JUNCTION CREEK SANDSTONES AND WANAKAH FM LIMESTONE AND MARL INTRUDED BY DIORITE-MONZONITE PORPHYRY SILLS AND DIKES AND COMPLEXLY FAULTED. ORE APPEARS TO HAVE BEEN DEVELOPED IN MOROVORATZ MINE ALONG 6- TO 8-INCH SHEAR ZONE BETWEEN ENTRADA SANDSTONE AND WANAKAH FM MARL MEMBER AND ALONG MOROVORATZ FAULT ALSO SEPARATING SANDSTONE AND MARL. IN NW PART OF MINE, JUMBO VEIN IS A 1- TO 2-FT-WIDE SHEAR ZONE WITH 1- TO 3-INCH GOUGY BRECCIA IN ENTRADA SANDSTONE. RUBY TUNNEL EXPLORED VEIN CUTTING JUNCTION CREEK SANDSTONE. IN CUNNINGHAM TUNNEL, JUMBO VEIN IS BROAD SHEAR ZONE CUTTING ENTRADA SANDSTONE, WANAKAH FM MARL, AND PORPHYRY DIKE.

Comment (Workings): MOROVORATZ CROSSCUT TUNNEL DRIVEN N 83 W FOR 220 FT, THENCE N 32 W FOR 110 FT, CUTTING VEINS AT 260 AND 320 FR FROM PORTAL. FIRST VEIN DEVELOPED BY 60-FT DRIFT DRIVEN S 24 W; SECOND VEIN (MOROVORATZ FAULT) DEVELOPED BY 70-FT NE DRIFT AND 700-FT DRIFT DRIVEN GENERALLY S 60 W, WITH 320 FT OF ADDITIONAL TUNNEL DEVELOPMENT AT END. SECOND CROSSCUT DRIVEN GENERALLY N 60 W FOR 200 FT FROM POINT IN SW DRIFT 40 FT FROM MAIN CROSSCUT, THENCE BRANCHING INTO 380-FT DRIFT DRIVEN GENERALLY S 50 W AND 130-FT DRIFT DRIVEN GENERALLY N 60 E, THE END OF WHICH IS BOTTOM OF WINZE FROM END OF UPPER NONA TUNNEL; IN SW DRIFT, RAISE OR WINZE AT 40 FT FROM BRANCH AND SHAFT AT 140 FT FROM BRANCH. RUBY TUNNEL LOCATED 550 FT NW OF MOROVORATZ, DRIVEN GENERALLY S 50 W FOR 280 FT. CUNNINGHAM TUNNEL LOCATED 470 FT SE OF MOROVORATZ, DRIVEN GENERALLY WESTWARD FOR 1680 FT; AT 1100 FT FROM PORTAL, JUMBO VEIN DEVELOPED BY 180-FT DRIFT DRIVEN GENERALLY N 35 E AND 230-FT DRIFT DRIVEN GENERALLY S 45 W, BOTH WITH APPROX 160

Comment (Workings): FT OF SUBSIDIARY DEVELOPMENT DRIFT.

Comment (Production): PARTIAL PRODUCTION RECORD. PRODUCTION FIGURES UNAVAILABLE FOR 1870S AND 1880S, BUT CONSIDERED SMALL. 1912 PRODUCTION CREDITED TO MOROVORATZ; 1915-1920 PRODUCTION CREDITED TO JUMBO; 1914 AND 1922-1932 PRODUCTION CREDITED TO JUMBO-MOROVORATZ.

Comment (Development): MOROVORATZ, ONE OF FIRST VEINS DISCOVERED IN DISTRICT, OPERATED FROM 1870S AT LEAST UNTIL 1883, IDLE FOR AT LEAST 20 YEARS, REVIVED IN 1907, AND PRODUCED INTERMITTENTLY FROM 1912 TO 1932.

References

Reference (Deposit): ECKEL, E.B., AND OTHERS, 1949, GEOLOGY AND ORE DEPOSITS OF THE LA PLATA DISTRICT, COLORADO: USGS PROF. PAPER 219, P. 69-70, 132, PL. 23.

Reference (Deposit): COLORADO DIV. MINES INF. REPTS.

Reference (Deposit): BLM MINERAL SURVEYS MS 88, 91, 19879

Reference (Production): ECKEL AND OTHERS, 1949, P. 132 (AS COMPILED FROM USBM RECORDS)

Colorado Mining Photos

Check out this collection of Colorado's best historic mining photos: Incredible Photos of Colorado Mining Scenes.