North Star Mine

The North Star Mine is a copper mine located in Jefferson county, Colorado at an elevation of 7,500 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

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Site Name

Primary: North Star Mine

Commodity

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

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

Owner Name: Brumm, A. G.
Years: 1967 -

Production

Not available

Deposit

Record Type: Site
Operation Category: Past Producer
Deposit Type: Vein
Operation Type: Unknown
Discovery Year: 1895
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: Rogers Fault Zone

Alterations

Alteration Type: L
Alteration Text: Breccia Fragments Are Reported As Being Altered

Rocks

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

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

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

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

Analytical Data

Analytical Data: ADAMS AND OTHERS' (1953) ANALYSES OF MINERALIZED BRECCIA FROM UNDERGROUND WORKINGS SHOWED 0.002 TO 0.850% U WITH ANOMALOUS CU OF 1.84 TO 5.74%. ALTHOUGH NO PB, ZN, OR AG MINERALS WERE OBSERVED, ANALYSES SHOWED 0.10% PB, 0.10 TO 0.38% ZN, AND TRACE TO 6.42 OZ/TON AG WITH ANOMALOUS VALUE OF 20.30 OZ/TON AG FROM DUMP SAMPLE.

Materials

Ore: Malachite
Ore: Bornite
Ore: Covellite
Ore: Uranophane
Ore: Chalcocite
Ore: Pitchblende

Comments

Comment (Location): 0.5 MILE NORTH OF RALSTON CREEK ; INFO FROM LAND.ST :(1975)

Comment (Commodity): OTHER SECONDARY BUT ILL-DEFINED U MINERAL TENTATIVELY CALLED HYDROPITCHBLENDE

Comment (Production): RECORD LISTED FIGURES AS CU BUT PROBABLY ARE TONS CU ORE

Comment (Development): MINE PRODUCED 4 TONS CU ORE IN 1894 AND 12 TONS IN 1916. URANIUM DISCOVERED BY USGS IN 1952

Comment (Deposit): DEPOSIT LIES IN NW-TRENDING SUBSIDIARY FRACTURES OF ROGERS FAULT SYSTEM IN MICROCLINE GNEISS COMPLEXLY INTERLAYERED WITH AMPHIBOLITE, HORNBLENDE GNEISS, BIOTITE GNEISS, AND PEGMATITE, ALL WITH NE STRIKE AND STEEP SE DIP. U AND CU MINERALS FOUND IN FRACTURE FILLINGS AND AS NONUNIFORMLY DISTRIBUTED CEMENTATION OF ALTERED BRECCIA FRAGMENTS.

Comment (Workings): SHORT UPPER LEVEL. LOWER ADIT DRIVEN GENERALLY N 20 E ABOUT 72 FT CONNECTING WITH 1894 STOPE THAT ONCE WAS OPEN TO SURFACE

Comment (Deposit): Discovery Year: 1890S

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. 193-194

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 OTHERS, 1953, URANIUM OCCURRENCES IN THE GOLDEN GATE CANYON AND RALSTON CREEK AREAS, JEFFERSON COUNTY, COLORADO: USGS CIRC. 320

Reference (Production): ORIGINAL CRIB RECORD

Colorado Mining Photos

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