Dunka Road

Prospect in St. Louis county in Minnesota, United States with commodities Copper, Nickel, Platinum, Palladium, Ruthenium, Rhodium, Cobalt, Gold

Sections on this page

Identification information
Geographic coordinates
Site location context
Geographic areas
Public Land Survey System information
Commodities
Materials information
Alteration
Mineral occurrence model information
Host and associated rocks
Nearby scientific data
Geologic structures
Ore body information
Controls for ore emplacement
Economic information about the deposit and operations
Mining district
Ownership information
Reserves and resources
Workings at the site
Links to other databases
Bibliographic references
General comments
Reporter information

Geologic information

Identification information

Deposit ID	10097433
MRDS ID	W018674
Record type	Site
Current site name	Dunka Road
Alternate or previous names	Dunka River Area

Geographic coordinates

Point of reference	Ore Body
Geographic coordinates:	-91.9004, 47.6656 (WGS84)
Location accuracy	10(meters)

Site location context

Political divisions (FIPS codes)

St. Louis(county)

Minnesota(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Babbitt(quadrangle 1:24,000 scale)

Ely(quadrangle 1:100,000 scale)

Two Harbors(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Rainy Headwaters(hydrologic unit)

Rainy(hydrologic accounting unit)

Rainy(hydrologic subregion)

Souris-Red-Rainy(hydrologic region)

Geographic areas

Country	State	County
United States	Minnesota	St. Louis

Public Land Survey System information

Meridian	Township	Range	Section	Fraction	State
4th Principal	059N;060N	013W;012W	01,02;31,20,10		Minnesota

Comments on the location information

T59N, R13W; T60N, R12W. Located about 10 south of the town of Babbitt, MN. Location extends into additional sections of T60N, R12W. Drainage map also extends into Great Lakes Region. DEPOSIT COVERS 4 SQUARE MILES

Commodities

Commodity	Importance
Copper	Primary
Nickel Critical	Primary
Platinum Critical	Primary
Palladium Critical	Primary
Ruthenium Critical	Tertiary
Rhodium Critical	Tertiary
Cobalt Critical	Secondary
Gold	Secondary

Comments on the commodity information

HIGH PD AND AU CONTENTS MAY BE DUE TO LATE-STAGE MINERALIZING FLUIDS. PYRRHOTITE TO CHALCOPYRITE RATIO INCREASES TOWARD CONTACT WITH A HORNFELS INCLUSION AND TOWARD THE BASAL CONTACT WITH THE VIRGINIA FORMATION. SEE GEERTS AND OTHERS (1990) FOR FURTHER PGE DATA AND STATISTICAL ANALYSES. SEE MORTON AND HAUCK (1987) AND HAUCK AND BARNES (1989) FOR FURTHER PGE DATA.

Materials information

Materials	Type of material
Bornite	Ore
Chalcopyrite	Ore
Cubanite	Ore
Gold	Ore
Pentlandite	Ore
Pyrrhotite	Ore
Sphalerite	Ore
Analcime	Gangue
Apatite	Gangue
Biotite	Gangue
Chlorite	Gangue
Ilmenite	Gangue
Kaolinite	Gangue
Magnetite	Gangue
Natrolite	Gangue
Olivine	Gangue
Plagioclase	Gangue
Sericite	Gangue

Alteration

(Local) Alteration Assemblage Of Chlorite, Bleached Plagioclase, Serpentine, And Uralite

Analytical data

Result	HIGH GRADE AREAS CONTAIN AS MUCH AS 9.4 PPM PD AND 2.0 PPM PT. CU:NI=5.1:1. MOST OF ORE IS 2-3% SULFIDE, BUT IS LOCALLY MASSIVE. PT+PD VALUES RANGE FROM 100->2400 PPB OVER 10 FT INTERVALS. HIGH GRADE INTERSECTIONS IN FIVE DRILL HOLES RAN A MAXIMUM OF 5.64% CU, 0.64% NI, 2 PPM PT, 9.4 PPM PD, 9 PPB IR, 85 PPB RH, 20 PPB RU, 2.1 PPM AU, AND 15 PPM AG. WEIGHTED AVERAGE FOR COMBINED PT AND PD=1259 PPB, OF AG=1.22 PPM, OF AU=125 PPB, OF CU=0.71%, OF NI=0.24%. MEDIAN PT+PD=1164 PPB. A 3-FT INTERSECTION OF 50% SULFIDES RAN 8.8 PPM PD, 1.35 PPM AU, 15 PPM AG. A 17-FT INTERSECTION RAN 2.8 PPM PT. CONCENTRATES CONTAINED 1176 PPB PT AND 5245 PPB PD. CU:NI=3:1
Result	PD:PT=3:1

Result

HIGH GRADE AREAS CONTAIN AS MUCH AS 9.4 PPM PD AND 2.0 PPM PT. CU:NI=5.1:1. MOST OF ORE IS 2-3% SULFIDE, BUT IS LOCALLY MASSIVE. PT+PD VALUES RANGE FROM 100->2400 PPB OVER 10 FT INTERVALS. HIGH GRADE INTERSECTIONS IN FIVE DRILL HOLES RAN A MAXIMUM OF 5.64% CU, 0.64% NI, 2 PPM PT, 9.4 PPM PD, 9 PPB IR, 85 PPB RH, 20 PPB RU, 2.1 PPM AU, AND 15 PPM AG. WEIGHTED AVERAGE FOR COMBINED PT AND PD=1259 PPB, OF AG=1.22 PPM, OF AU=125 PPB, OF CU=0.71%, OF NI=0.24%. MEDIAN PT+PD=1164 PPB. A 3-FT INTERSECTION OF 50% SULFIDES RAN 8.8 PPM PD, 1.35 PPM AU, 15 PPM AG. A 17-FT INTERSECTION RAN 2.8 PPM PT. CONCENTRATES CONTAINED 1176 PPB PT AND 5245 PPB PD. CU:NI=3:1

Result

PD:PT=3:1

Mineral occurrence model information

Model code	9
USGS model code	5a
Deposit model name	Duluth Cu-Ni-PGE

Host and associated rocks

Host or associated

Associated

Rock type

Sedimentary Rock > Clastic Sedimentary Rock > Argillite

Rock unit name

Virginia Formation

Stratigraphic age (youngest)	Paleoproterozoic

Host or associated

Host

Rock type

Plutonic Rock > Mafic Intrusive Rock > Gabbro > Troctolite

Rock unit name

Partridge River Intrusion

Stratigraphic age (youngest)	Mesoproterozoic

Nearby scientific data

Ore Body (1)	Gunflint (~1,878 Ma), Biwabik, and Emily Iron Formations	ListMap

Economic information

Geologic structures

Type of structure	Regional
Structure name	Faulting Related To Rift Origin Of Duluth Complex
Type of structure	Local
Structure description	Proposed Faults Offsetting Ultramafic Subunits Trend Northeast And Dip Steeply Southeast. Northwest Trending Strike-Slip Faults
Type of structure	Regional
Structure description	Several Ne-Trending Normal Faults Parallel The Midcontinent Rift System Near The Margin. These Faults Formed During The Opening Of The Rift And Controlled Emplacement Of The Troctolitic And Late Intrusions.

Ore body information

General form DISSEMINATED

Strike N45E

Dip 25E

Thickness 100M

Length 10000M

Depth to top 0M

General form	DISSEMINATED
Strike	N45E
Dip	25E
Thickness	100M
Length	10000M
Depth to top	0M

Comments on the ore body information

PYRRHOTITE AND OTHER SULFIDES MAKE UP TO 10 PERCENT OF THE ROCK. HIGH GRADE AREAS CONTAIN AS MUCH AS 9.4 PPM PD AND 2.0 PPM PT. CU:NI=5.1:1. MOST OF ORE IS 2-3% SULFIDE, BUT IS LOCALLY MASSIVE. PT+PD VALUES RANGE FROM 100->2400 PPB OVER 10 FT INTERVALS. HIGH GRADE INTERSECTIONS IN FIVE DRILL HOLES RAN A MAXIMUM OF 5.64% CU, 0.64% NI, 2 PPM PT, 9.4 PPM PD, 9 PPB IR, 85 PPB RH, 20 PPB RU, 2.1 PPM AU, AND 15 PPM AG. WEIGHTED AVERAGE FOR COMBINED PT AND PD=1259 PPB, OF AG=1.22 PPM, OF AU=125 PPB, OF CU=0.71%, OF NI=0.24%. MEDIAN PT+PD=1164 PPB. A 3-FT INTERSECTION OF 50% SULFIDES RAN 8.8 PPM PD, 1.35 PPM AU, 15 PPM AG. A 17-FT INTERSECTION RAN 2.8 PPM PT. CONCENTRATES CONTAINED 1176 PPB PT AND 5245 PPB PD. CU:NI=3:1; PD:PT=3:1. (Geerts and others, 1990; Morton and Hauck, 1989; Hauck and Barnes, 1989).

Controls for ore emplacement

Sulfides Segregated In Basal Troctolites Sub-Parallel To Lower Contacts. Sulfur Derived From Country Rock. Redox Boundaries Important To Deposition Of Late-Stage Mineralization
Faults And Folds Were Responsible For Localizing Sulfide Mineralization As Well As For Providing Conduits For Later Syn- To Post-Magmatic Hydrothermal Fluids.

Comments on the geologic information

BIWABIK AND VIRGINIA FORMATIONS OVERLIE OLDER GRANITE. DULUTH GABBROS EMPLACED IN RIFT-RELATED VOIDS AND GRABENS. TROCTOLITIC LAST GABBROS FORM BASAL CONTACT. ORE IS INHOMOGENEOUS INDICATING SOME CONTAMINATION FROM COUNTRY ROCK THROUGH DEVOLATILIZATION. COUNTRY ROCK XENOLITHS ARE COMMON IN HOST ROCKS. IN DUNKA ROAD AREA INTRUSION HAS BEEN DIVIDED INTO FOUR MAJOR LITHOLOGIC UNITS AND SEVERAL SUBUNITS (GEERTS AND OTHERS, 1990).
THE DULUTH COMPLEX IS A LARGE, COMPOSITE THOLEIITIC MAFIC INTRUSION THAT WAS EMPLACED INTO COMAGMATIC FLOOD BASALTS ALONG A PORTION OF THE MIDDLE PROTEROZOIC (1.1 GA, KEWEENAWAN) MIDCONTINENT RIFT SYSTEM. THE DULUTH COMPLEX OVERLAYS METASEDIMENTS (SLATES, ARGILLITES, AND GRAYWACKES) OF THE VIRGINIA FORMATION WHICH IN TURN OVERLAYS THE BIWABIK IRON FORMATION.
SEVERAL NE-TRENDING NORMAL FAULTS PARALLEL THE MIDCONTINENT RIFT SYSTEM NEAR THE MARGIN. THESE FAULTS FORMED DURING THE OPENING OF THE RIFT AND CONTROLLED EMPLACEMENT OF THE TROCTOLITIC AND LATE INTRUSIONS.
PROPOSED FAULTS OFFSETTING ULTRAMAFIC SUBUNITS TREND NORTHEAST AND DIP STEEPLY SOUTHEAST. NORTHWEST TRENDING STRIKE-SLIP FAULTS. ALTERATION ASSEMBLAGE OF CHLORITE, BLEACHED PLAGIOCLASE, SERPENTINE, AND URALITE.

Economic information about the deposit and operations

Development status	Prospect
Commodity type	Metallic
Deposit size	Large
Significant	Yes
Discovery year	1967
Discoverer	U.S. Steel (Usx)

Mining district

District name	Western Margin Duluth Complex

Ownership information

Type Operator

Owner U.S. Steel/Fleck Resources

First year 1990
Type Owner

Owner USX Corp.

First year 1990

Type	Operator
Owner	U.S. Steel/Fleck Resources
First year	1990

Type	Owner
Owner	USX Corp.
First year	1990

Reserves and resources

Type

In-situ

Estimate year

1989

Total resources

44mt ore

Commodity	Subtype	Grade	units	Group	Importance	Year
Copper	Cu	0.77	wt-pct	Copper	Major	1989
Nickel	Ni	0.24	wt-pct	Nickel	Major	1989

Type

In-situ

Estimate year

1989

Total resources

122mt ore

Commodity	Subtype	Grade	units	Group	Importance	Year
Copper	Cu	0.5	wt-pct	Copper	Major	1989
Nickel	Ni	0.16	wt-pct	Nickel	Major	1989

Type

In-situ

Estimate year

1977

Total resources

136mt ore

Commodity	Subtype	Grade	units	Group	Importance	Year
Copper	Cu	0.5	wt-pct	Copper	Major	1977
Nickel	Ni	0.76	wt-pct	Nickel	Major	1977

Type

In-situ

Estimate year

1990

Total resources

83mt ore

Commodity	Subtype	Grade	units	Group	Importance	Year
Platinum	Pt	0.1129	g/mt	PGE	Minor	1990
Palladium	Pd	0.1976	g/mt	PGE	Minor	1990

Comments on the reserve resource information

ALONG THE WESTERN MARGIN OF THE DULUTH COMPLEX, THE CU-NI SULFIDE RESOURCES ARE ESTIMATED AT 4.4 BILLION TONS OF 0.66 PERCENT CU WITH A CU:NI RATIO OF 3.3:1. PGE RESOURCE ESTIMATE INCLUDES AN ENRICHED ZONE OF 37 MILLION TONS.
PGE RESOURCE ESTIMATE INCLUDES AN ENRICHED ZONE OF 37 MILLION TONS

Workings at the site

Type of workings Surface

Area 1600HA

Overall length 9144M

Overall width 1600M

Type of workings	Surface
Area	1600HA
Overall length	9144M
Overall width	1600M

Comments on the workings information

DEPOSIT COVERS 4 SQUARE MILES

Comments on development

Prospectors first discovered copper and nickel near Ely, Minnesota about 20 miles north of NorthMet (Dunka Road) in the 1940?s. Subsequently Bear Creek Mining Company conducted a regional exploration program resulting in the discovery of the Babbitt or Minnamax deposit. US Steel (USX) started an exploration program in the Duluth Complex in the late 1960?s and over the next few years drilled 112 core holes into the NorthMet property (then called Dunka Road). In 1987 the Minnesota Natural Resources Research Institute (NRRI) published data suggesting that a large resource of platinum group minerals (PGM?s) could be contained within the base of the Duluth Complex. In 1989, PolyMet, then known as Fleck Resources, leased the NorthMet property from USX. Since 1998, PolyMet has conducted drilling and metallurgical testing to further the project and has now contracted a pre-feasibility study.

Reference information

Links to other databases

Agency	Database name	Acronym	Record ID	Notes
USGS	Mineral Resources Data System	MRDS	W018674

Bibliographic references

Commodity

BONNICHSEN, BILL, 1974, COPPER AND NICKEL RESOURCES IN THE DULUTH COMPLEX, NORTHEASTERN MINNESOTA: MINNESOTA GEOLOGICAL SURVEY INFORMATION CIRCULAR 10, 24 P.
Geology

IPLEY, E.M., 1986, ORIGIN AND CONCENTRATION MECHANISMS OF COPPER AND NICKEL IN DULUTH COMPLEX SULFIDE ZONES - A DILEMMA: ECONOMIC GEOLOGY, V. 81, P. 974-978.
Geology

RIPLEY, E.M., 1986, APPLICATION OF STABLE ISOTOPIC STUDIES TO PROBLEMS OF MAGMATIC SULFIDE ORE GENESIS WITH SPECIAL REFERENCE TO THE DULUTH COMPLEX, MINNESOTA, IN FRIEDRICH, G.H., AND OTHERS, EDS., GEOLOGY AND METALLOGENY OF COPPER DEPOSITS: NEW YORK, SPRINGER-VERLAG, P. 25-42
Geology

FOOSE, M., AND WEIBLEN, P., 1986, THE PHYSICAL AND PETROLOGIC SETTING AND TEXTURAL AND COMPOSITIONAL CHARACTERISTICS OF SULFIDES FROM THE SOUTH KAWISHIWI INTRUSION, DULUTH COMPLEX, MINNESOTA, USA, IN FRIEDRICH, G.H., AND OTHERD, EDS., GEOLOGY AND METALLOGENY OF COPPER DEPOSITS: NEW YORK, SPRINGER-VERLAG, P. 8-24.
Geology

RIPLEY, E.M., 1981, SULFUR ISOTOPIC STUDIES OF THE DUNKA ROAD CU-NI DEPOSIT, DULUTH COMPLEX, MINNESOTA: ECONOMIC GEOLOGY, V. 76, P. 610-620
Deposit

BONNICHSEN, BILL, 1972, SULFIDE MINERALS IN THE DULUTH COMPLEX, IN SIMS, P.K., AND MOREY, G.B., EDS., GEOLOGY OF MINNESOTA: A CENTENNIAL VOLUME: MINNESOTA GEOLOGICAL SURVEY, P. 388-393.
Development

MINING JOURNAL OF LONDON, 1989, FLECK AGREEMENT ON DUNKA: MINING JOURNAL OF LONDON, V. 312, NO. 8006, FEB. 10, 1989, P. 104.
Geology

GEERTS, STEPHEN, BARNES, R.J., AND HAUCK, S.A., 1990, GEOLOGY AND MINERALIZATION IN THE DUNKA ROAD COPPER-NICKEL MINERAL DEPOSIT, ST. LOUIS COUNTY, MINNESOTA: NATURAL RESOURCES RESEARCH INSTITUTE TECHNICAL REPORT NRRI/GMIN-TR-89-16, 69 P.
Deposit

MORTON, PENELOPE, AND HAUCK, S.A., 1989, PRECIOUS METALS IN THE COPPER-NICKEL DEPOSITS OF THE DULUTH COMPLEX, IN MOREY, G.B., ED., WORKSHOP ON THE APPLICABILITY OF GOLD AND PLATINUM-GROUP-ELEMENT MODELS IN MINNESOTA: MINNESOTA GEOLOGICAL SURVEY INFORMATION CIRCULAR 30, P. 47-48.
Deposit

MORTON, PENELOPE, AND HAUCK, S.A., 1987, PGE, AU AND AG CONTENTS OF CU-NI SULFIDES FOUND AT THE BASE OF THE DULUTH COMPLEX, NORTHEASTERN MINNESOTA: NATURAL RESOURCES RESEARCH INSTITUTE TECHNICAL REPORT NRRI/GMIN-TR-87-04, 81 P.
Reserve-Resource

LISTERUD, W.H., AND MEINEKE, D.G., 1977, MINERAL RESOURCES OF A PORTION OF THE DULUTH COMPLEX AND ADJACENT ROCKS IN ST. LOUIS AND LAKE COUNTIES, NORTHEASTERN MINNESOTA: MINNESOTA DEPARTMENT OF NATURAL RESOURCES, DIVISION OF MINERALS, MINERALS EXPLORATION SECTION, REPORT 93, 74 P.
Commodity

COOMBES, J.S., 1990, PLATINUM 1990: LONDON, JOHNSON MATTHEY PUBLIC LIMITED COMPANY, 64 P.
Commodity

HAUCK, S.A., AND BARNES, R.J., 1989, PRECIOUS METALS (PT-PD-AU-AG) IN THREE COPPER-NICKEL DEPOSITS IN THE DULUTH COMPLEX: NATURAL RESOURCES RESEARCH INSTITUTE, CENTER FOR APPLIED RESEARCH AND TECHNOLOGY DEVELOPMENT, TECHNICAL SUMMARY REPORT NRRI/GMIN-TSR-89-1, 19 P.
Deposit

PAGE, N. J, 1986, DESCRIPTIVE MODEL OF DULUTH CU-NI-PGE, IN COX, D.P. AND SINGER, D.A., MINERAL DEPOSIT MODELS: U.S. GEOLOGICAL SURVEY BULLETIN 1693, P. 16.
Geology

HOLLISTER, V.F., 1980, ORIGIN OF GRAPHITE IN THE DULUTH COMPLEX: ECONOMIC GEOLOGY, V. 75, P. 764-766.
Geology

HAUCK, S.A., SEVERSON, M.J., ZANKO, L., BARNES, S-J., MORTON, P., ALMINAS, H., FOORD, E.E., AND DAHLBERG, E.H., 1997, AN OVERVIEW OF THE GEOLOGY AND OXIDE, SULFIDE AND PLATINUM-GROUP ELEMENT MINERALIZATION ALONG THE WESTERN AND NORTHERN CONTACTS OF THE DULUTH COMPLEX: GEOLOGICAL SOCIETY OF AMERICA SPECIAL PAPER, V. 312, PP. 137-185.

General comments

Subject category	Comment text
Deposit	THE DUNKA ROAD DEPOSIT CONSISTS OF STRATABOUND DISSEMINATED SULFIDE ZONES WITH ASSOCIATED PGE-ENRICHED ZONES. ORE HORIZON DIPS UNDERGROUND. EXTENT UNKNOWN SO WIDTH UNDETERMINED. LENGTH ALONG SURFACE ARBITRARILY LIMITED. MOST OF ORE IS NEAR BASE OF TROCTOLITE AS DISSEMINATED GRAINS INTERSTITIAL TO SILICATES. THERE ALSO ARE SOME SULFIDE-SILICATE INTERGROWTHS. SOME THIN VEINLETS AND MASSIVE ORE PRESENT. SULFIDE MINERALS ARE FOUND TO 500 M ABOVE BASE BUT ORE GRADE IS ONLY TO 100 M ABOVE BASE. HIGH GRADE ZONES RUN 1-5% SULFIDES. PRECIOUS METALS ARE ASSOCIATED WITH FRACTURED AND ALTERED HOST ROCKS; CORRELATIONS AMONG THE ELEMENTS SUGGEST THAT THE PRECIOUS METALS ARE ASSOCIATED WITH CU-RICH SULFIDES. THERE WERE TWO STAGES OF SULFIDE MINERALIZATION.
Deposit	SULFIDES ORIGINATED AS INTERCUMULATE IN LITHIFYING TROCTOLITE WHEN SULFUR WAS INTRODUCED INTO LIQUID FRACTION CREATING IMMISCIBLE SUFLIDE AND SILICATE LIQUIDS. HIGHER DENSITY OF SULFIDE AND BASAL INTRODUCTION OF SULFUR CREATED BASAL LOCALIZATION. VARIATION IN SULFUR SOURCE, PATHWAYS, AND FAULTING CREATED LOCAL VARIATION AND HIGHER HORIZONS. SEE MORTON AND HAUCK (1987) FOR DISCUSSION OF PGE MINERALIZATION AND NUMEROUS ANALYSES.
Deposit	GRAPHITE IN THE DULUTH COMPLEX MAY HAVE DEVELOPED BY REACTION OF THE HYDROCARBONS FUMED FROM SLATE IN THE UNDERLYING METASEDIMENTS WITH THE CRYSTALLIZING TROCTOLITIC MAGMA.
Deposit	FAULTS AND FOLDS WERE RESPONSIBLE FOR LOCALIZING SULFIDE MINERALIZATION AS WELL AS FOR PROVIDING CONDUITS FOR LATER SYN- TO POST-MAGMATIC HYDROTHERMAL FLUIDS. SULFIDES SEGREGATED IN BASAL TROCTOLITES SUB-PARALLEL TO LOWER CONTACTS. SULFUR DERIVED FROM COUNTRY ROCK. REDOX BOUNDARIES IMPORTANT TO DEPOSITION OF LATE-STAGE MINERALIZATION. STRIKE OF THE OREBODY IS N45E.

Reporter information

Type	Date	Name	Affiliation	Comment
Reporter	01-JAN-1984	no name	U.S. Geological Survey
Updater	01-JAN-1991	Peterson, J.A.	U.S. Geological Survey
Reporter	01-JAN-1961	Sutphin, D.M. (Cannon, W.F)	U.S. Geological Survey
Updater	01-MAR-1997	Sutphin, D.M.	U.S. Geological Survey
Editor	01-MAY-1997	Mason, Jr., G.T.	U.S. Geological Survey
Editor	25-NOV-2003	Woodruff, Laurel G.	U.S. Geological Survey	Work done in Filemaker
Editor	28-FEB-2005	Woodruff, L.G.	U.S. Geological Survey

Beyond USGS

Supplemental information added by qvyshift.com. Not part of the original USGS MRDS record.

Dunka Road

Geologic information

Identification information

Geographic coordinates

Site location context

Geographic areas

Public Land Survey System information

Comments on the location information

Commodities

Comments on the commodity information

Materials information

Alteration

Analytical data

Mineral occurrence model information

Host and associated rocks

Nearby scientific data

Economic information

Geologic structures

Ore body information

Comments on the ore body information

Controls for ore emplacement

Comments on the geologic information

Economic information about the deposit and operations

Mining district

Ownership information

Reserves and resources

Comments on the reserve resource information

Workings at the site

Comments on the workings information

Comments on development

Reference information

Links to other databases

Bibliographic references

Commodity

Geology

Geology

Geology

Geology

Deposit

Development

Geology

Deposit

Deposit

Reserve-Resource

Commodity

Commodity

Deposit

Geology

Geology

General comments

Reporter information

Beyond USGS

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