Union Pacific Shaft

The Union Pacific Shaft is a uranium and copper mine located in Jefferson county, Colorado at an elevation of 6,650 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: Union Pacific Shaft
Secondary: Union Pacific Prospect

Commodity

Primary: Uranium
Primary: Copper
Secondary: Zinc
Tertiary: Silver
Tertiary: Bismuth
Tertiary: Lead

Location

State: Colorado
County: Jefferson
District: Ralston Buttes 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

Not available

Ownership

Not available

Production

Not available

Deposit

Record Type: Site
Operation Category: Occurrence
Deposit Type: Vein
Operation Type: Unknown
Discovery Method: Ore-Mineral In Place
Years of Production:
Organization:
Significant: N
Deposit Size: S

Physiography

General Physiographic Area: Rocky Mountain System
Physiographic Province: Southern Rocky Mountains

Mineral Deposit Model

Not available

Orebody

Not available

Structure

Type: R
Description: Front Range Uplift, Denver Basin

Type: L
Description: Hurricane Hill Fault System

Alterations

Alteration Type: L
Alteration Text: Replacement Of Fragments In The Breccia By K-Feldspar Or Ankerite

Rocks

Name: Pegmatite
Role: Associated
Age Type: Associated Rock Unit
Age Young: Neoproterozoic

Name: Pegmatite
Role: Associated
Age Type: Host Rock
Age Young: Neoproterozoic

Name: Pegmatite
Role: Associated
Age Type: Associated Rock
Age Young: Neoproterozoic

Name: Pegmatite
Role: Associated
Age Type: Host Rock Unit
Age Young: Neoproterozoic

Analytical Data

Analytical Data: CHANNEL SAMPLES FROM UNDERGROUND WORKINGS CONTAINED 0.003 TO 0.810% U WITH ANOMALOUS HIGH VALUE OF 5.84% U, WITH 0.10 TO 0.49% CU, 0 TO 0.04% PB, 0.08 TO 0.95% ZN, TRACE AU, TRACE TO 0.72 OZ/TON AG, 3.3 TO 8.8% CACO3, TRACE AMTS. OF NI AND CO.

Materials

Ore: Pitchblende
Ore: Tennantite
Ore: Bornite
Ore: Sphalerite
Ore: Chalcocite
Ore: Chalcopyrite
Gangue: Chlorite
Gangue: Calcite
Gangue: Hematite
Gangue: Ankerite

Comments

Comment (Development): ORIGINALLY A COPPER PROSPECT, DEWATERED IN 1951 BY UP RAILROAD FOR SAMPLING BY USGS

Comment (Deposit): LARAMIDE RIGHT-LATERAL HOST FAULT RELATED TO HURRICANE HILL FAULT SYSTEM TRENDS N 15 TO 20 W AND DIPS 35 NE. PITCHBLENDE AND ASSOCIATED SPARSE SULFIDES OCCUR IN THIN ZONE ON HIGHLY ALTERED HANGING WALL OF CENTRAL BRECCIA. ADAMS AND STUGARD'S (1956) PARAGENESIS: 1) PROPYLITIZATION AND CHLORITIZATION OF HORNBLENDE FROM GNEISS, WITH SOME PYRITE; 2) POTASSIC ALTERATION AND CRYSTALLIZATION OF ORTHOCLASE (REPLACEMENT OF PLAGIOCLASE); 3) PITCHBLENDE DEPOSITION WITH HEMATITE; 4) SIMPLE CU AND BASE-METAL SULFIDE DEPOSITION FOLLOWED BY TENNANTITE REPLACEMENT AND CHALCOPYRITE; 5) VIGOROUS CALCITE AND ANKERITE FORMATION WITH MINOR PYRITE. FAVORABILITY OF GNEISS APPARENTLY DUE TO HIGH FE-CONTENT (HORNBLENDE) MINERALS THAT ARE READILY ATTACKED BY SOLUTIONS, SUBSEQUENTLY PRECIPITATING FE TO PROVIDE EFFECTIVE MECHANISM FOR U DEPOSITION.

Comment (Location): ALONG GOLDEN GATE CANYON ; INFO FROM LAND.ST :(1975)

Comment (Workings): SURFACE CUT AND 57-FT-DEEP INCLINED SHAFT ON HEADING OF N65E WITH SHORT DRIFTS AT 30-FT LEVEL

References

Reference (Deposit): NELSON-MOORE, J.L., COLLINS, D.B., AND HORNBAKER, A.L., 1978, RADIOACTIVE MINERAL OCCURRENCES OF COLORADO AND BIBLIOGRAPHY: COLORADO GEOLOGICAL SURVEY BULL. 40, P. 195

Reference (Deposit): SHERIDAN, DOUGLAS M. AND OTHERS, 1967, GEOLOGY AND URANIUM DEPOSITS OF THE RALSTON BUTTES DISTRICT, JEFFERSON COUNTY, COLORADO: USGS PROF. PAPER 520.

Reference (Deposit): ADAMS, J.W., AND STUGARD, FREDERICK, JR., 1956, WALL-ROCK CONTROL OF CERTAIN PITCHBLENDE DEPOSITS IN GOLDEN GATE CANYON, JEFFERSON COUNTY, COLORADO: USGS BULL. 1030-G.

Reference (Deposit): ADAMS, J.W., AND OTHERS, 1953, URANIUM OCCURRENCES IN THE GOLDEN GATE CANYON AND RALSTON CREEK AREAS, JEFFERSON COUNTY, COLORADO: USGS CIRC. 320

Colorado Mining Photos

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