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Lone Cone District

Producer in Dolores county in Colorado, United States with commodities Silver, Gold, Copper, Lead, Coal, Zinc, Antimony, Manganese, Sulfur, Tellurium
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Sections on this page
  1. Identification information
  2. Geographic coordinates
  3. Site location context
  4. Geographic areas
  5. Public Land Survey System information
  6. Commodities
  7. Materials information
  8. Alteration
  9. Mineral occurrence model information
  10. Host and associated rocks
  11. Nearby scientific data
  12. Geologic structures
  13. Controls for ore emplacement
  14. Economic information about the deposit and operations
  15. Mining district
  16. Land status
  17. Ownership information
  18. Links to other databases
  19. Bibliographic references
  20. General comments
  21. Reporter information

Geologic information

Identification information

Deposit ID 10087921
MRDS ID D010908
Record type District
Current site name Lone Cone District
Alternate or previous names Dunton District, Patented Claims: Little Wounder, MS 1516, Great Bear, MS 12930, Lion, MS 12930, Sirius, MS 12931, Little Emma, MS 12951a, Dunton Mill Site, MS 12951b, Orion, MS 12953a, Orion Mill Site, MS 12953b, Otsego Estension, MS 15746a, Otsego Mill Site, MS 15746b, Otsego, MS 15747a, Otsego Extension Mill Site, MS 15747b, Gold Nugget, MS 16240a, Gold Nugget Mill Site, MS 16240b, Como, MS 16246a, Como Mill Site, MS 16246b, Horlick, MS 17235a, Almont, MS 17235a, Yule, MS 17235a, Priest, MS 17235a, Heddle, MS 17235a, Smuggler, MS 17235a, Lombard, MS 17235a, Dick, MS 17235a, Lombard Mill Site, MS 17235b, Columbia, MS 18486a, America, MS 18486a, Nil Desperandum, MS 18486a, Brooklyn MS 18498, Mayflower, Ms18499, Susie, MS 18519, Nettie, MS 18519, Little May, MS 18519, Mount Pleasant Mill Site, MS 20539

Geographic coordinates

Geographic coordinates: -108.09482, 37.77279 (WGS84)
Elevation 2694
Relative position 6.0 TO 6.7 MILES N 36 TO 50 W FROM RICO

Site location context

Political divisions (FIPS codes)

Dolores(county)

Colorado(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Dolores Peak(quadrangle 1:24,000 scale)

Dove Creek(quadrangle 1:100,000 scale)

Cortez(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Upper Dolores(hydrologic unit)

Upper Colorado-Dolores(hydrologic accounting unit)

Upper Colorado-Dolores(hydrologic subregion)

Upper Colorado(hydrologic region)

Federal lands

San Juan National Forest(National Forest)

National Forest FS(Type of land area)

FS(Federal land areas administered by FS)

Geographic areas

Country State County
United States Colorado Dolores

Public Land Survey System information

Meridian Township Range Section Fraction State
New Mexico 041N;040N;040N 011W;011W;012W 32,33;04,05,06,09;01,24 Colorado

Comments on the location information

  • MIGUEL MTNS AND NAVAJO BASIN AND UPPER WEST DOLORES RIVER VALLEY. DISTRICT ALSO EXTENDS ONTO RICO (1960) QUAD. ELEV AND LAT-LONG GIVEN ARE FOR DUNTON TOWNSITE (W2 SW SEC. 33, T41N, R11W). ; INFO FROM LAND.ST :1975
  • (LAND STATUS AND ADMINISTRATIVE AREA LOCATIONS CALCULATED USING GIS OVERLAY ANALYSIS FOR SAN JUAN N. F.). DISTRICT LIES ALONG WEST DOLORES RIVER FROM DUNTON TO ABOUT 2.5 MILES DOWNSTREAM, AND INCLUDES LOWER PARTS OF PAPOOSE, FALL, EAGLE, AND GEYSER CREEKS, AND SEVERAL UNNAMED TRIBUTARY GULCHES. ISOLATED MINE, ROSEBUD, LIES ALONG SILVER CREEK OR JOHNNY BULL CREEK NNW OF CALICO PEAK SEVERAL MILES TO SOUTH. BUT IS INCLUDED IN LONE CONE DISTRICT ON BASIS OF ORE OCCURRENCE, STRUCTURAL AND HOST ROCK SIMILARITY TO LONE CONE PROPER. DISTRICT ACCESSIBLE VIA ROAD UP WEST DOLORES RIVER FROM NEAR STONER AND VIA DUNTON ROAD ALONG MEADOW CREEK FROM DOLORES RIVER VALLEY 6 MILES NORTH OF RICO; VIA TRAIL UP FISH CREEK AND WILLOW CREEK AND DOWN TRIBUTARY OF COAL CREEK NORTH OF DUNTON; VIA ROAD AND TRAIL SOUTH FROM PLACERVILLE AND SAN MIGUEL RIVER, UP FALL CREEK, AND DOWN UPPER WEST DOLORES RIVER VALLEY; VIA ROAD AND TRAIL FROM VANADIUM AND VANCE JUNCTION ON SAN MIGUEL RIVER SOUTH AND SW OVER SAN

Commodities

Commodity Importance
Silver Primary
Gold Primary
Copper Primary
Lead Primary
Coal Secondary
Zinc Critical Tertiary
Antimony Critical Tertiary
Manganese Critical Tertiary
Sulfur Tertiary
Tellurium Critical Tertiary

Materials information

Materials Type of material
Argentite Ore
Chalcocite Ore
Chalcopyrite Ore
Coal Ore
Galena Ore
Polybasite Ore
Pyrargyrite Ore
Pyrite Ore
Sphalerite Ore
Stibnite Ore
Tennantite Ore
Barite Gangue
Chalcedony Gangue
Epsomite Gangue
Gypsum Gangue
Melanterite Gangue
Quartz Gangue
Rhodochrosite Gangue
Sulfur Gangue

Alteration

  • (Local) Silicification Of Sandstone Wall Rocks Near Fissures; Some Oxidayion Of Sulfide Ores

Mineral occurrence model information

Model code 85
USGS model code 22c
Deposit model name Polymetallic veins
Mark3 model number 46

Host and associated rocks

  • Host or associated Associated
    Rock type Plutonic Rock > Mafic Intrusive Rock > Gabbro
    Rock unit name Microgabbro;Calico Peak Porphyry
    Rock description Microgabbro;Calico Peak Porphyry
    Stratigraphic age (youngest) Pliocene
  • Host or associated Associated
    Rock type Volcanic Rock (Aphanitic) > Felsic Volcanic Rock > Latite
  • Host or associated Associated
    Rock type Volcanic Rock (Aphanitic) > Mafic Volcanic Rock > Basalt
  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Shale
  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Siltstone
  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Sandstone
    Rock unit name Dolores Formation;Cutler Formation
    Rock description Dolores Formation;Cutler Formation

Nearby scientific data

(1) -108.09482, 37.77279
ListMap

Economic information

Geologic structures

Type of structure Regional
Structure description San Juan Uplift, Paradox Basin
Type of structure Local
Structure description Rico Dome, Dunton Syncline, Calico Peak Anticline, Dunton Fault, Papoose Fault, Emma Fault, Almont Fault, Unnamed Faults

Controls for ore emplacement

  • Principal Fissures Of Graben System

Economic information about the deposit and operations

Development status Producer
Commodity type Both
Deposit size Small
Significant Yes
Discovery year 1880
Discoverer John A Gilmore
Year of first production 1885
Year of last production 1980

Mining district

District name Lone Cone (Dunton) District

Land status

Ownership category Private
Area name San Juan N. F.

Ownership information

  • Type Owner-Operator
    Owner Warren E. Wright, Clifton (Rosebud Mine ; Rado Reef Resources, Stoner (Emma Mine
    First year 1981

Comments on the production information

  • PARTIAL PRODUCTION RECORD. FIGURES UNAVAILABLE BUT CONSIDERED SMALL FOR ANY PRODUCTION FROM 1880 TO 1895. AG PRODUCTION FOR 1896 TO 1903 ESTIMATED BASED ON DIFFERENCE BETWEEN REPORTED DOLORES COUNTY TOTALS AND THOSE FOR PIONEER (RICO) DISTRICT TABULATED BY MCKNIGHT (1974). AG PRODUCTION FOR 1904 TO 1930 DERIVED FROM DIFFERENCE BETWEEN REPORTED ANNUAL DOLORES COUNTY TOTALS AND PIONEER DISTRICT TOTALS. ALL ESTIMATED AU FIGURES FOR 1896 TO 1930 CALCULATED FROM REPORTED VALUES USING AVERAGE PRICE OF $20.65/OZ AU AND DIFFERENCE BETWEEN REPORTED VALUES FOR DOLORES COUNTY AND PIONEER DISTRICT; ROUNDED TO NEAREST TENTH OZ. FIRST PB AND CU PRODUCTION REPORTED IN 1908. ALL ESTIMATED PB AND CU FIGURES FOR 1908 TO 1930 CALCULATED FROM DIFFERENCES BETWEEN REPORTED VALUES FOR DOLORES COUNTY AND PIONEER DISTRICT, USING AVERAGE ANNUAL PRICES/LB FOR PB AND CU AS REPORTED BY HENDERSON FOR 1908-1923 OR USING AVERAGE METALS PRICES CALCULATED FROM YOTAL COUNTY PRODUCTION AND VALUE FOR 1924 AND 1928-1930;
  • PB ROUNDED TO NEAREST LB, CU ROUNDED TO NEAREST TENTH LB. FIGURE FOR PB IN 1919 ESTIMATED FROM REPORTED ORE TONNAGE AND GRADE FOR ROSEBUD MINE. FIGURES FOR 1937 AND FROM COLORADO DIV. MINES ANNUAL OPERATOR REPTS. FOR EMMA MINE. FIGURES FOR 1950 REPRESENT PRODUCTION FROM GEYSER GROUP. ORE TONNAGES EITHER NOT REPORTED FOR COUNTY OR NOT REPORTED SEPARATELY BY DISTRICT WITHIN COUNTY. ALL OTHER FIGURES FROM USBM MINERAL YEARBOOKS. NO PRODUCTION REPORTED IN IN DISTRICT FOR 1906, 1917, 1926-1927, 1931-1936, 1939, 1942-1949, 1951-1979, AND AFTER 1980.

Comments on the workings information

  • PRINCIPAL PROPERTIES DEVELOPED BY HILLSIDE DRIFT TUNNELS DRIVEN INTO FISSURES AND VEINS OF GRABEN SYSTEM; SOME HILLSIDE CROSSCUT TUNNELS. SMUGGLER AND EMMA MINES DEVELOPED BY AS MANY AS FIVE LEVELS ON VEIN, INTERCONNECTED BY WINZES AND SHAFTS. OPEN CUTS; MILL SITES; AERIAL TRAM FROM SMUGGLER MINE TO EMMA MILL.

Comments on development

  • ALTHOUGH PROSPECTORS HAD TRAVERSED ENTIRE AREA DURING TIME OF RICO DISCOVERIES IN 1870S, NO DISCOVERIES WERE MADE AT DUNTON, PROBABLY BECAUSE OF COVER ON HILLSIDES AND LACK OF EXPOSURES. INITIAL DISCOVERY CREDITED TO JOHN A. GILMORE WHO LOCATED EMMA LODE ON 5/15/80 AND ORIGINALLY NAMED IT LITTLE EMMA. CLAIM WAS RELOCATED ON 5/15/98 BY A. F. ADAMS, EMMA JACKSON, MILLARD GILMORE, ABBIE MESERVY,AND ADELLA TOWNSEND. SECOND DISCOVERY WAS SMUGGLER LODE, LOCATED BY P.K. SCOTT ON 4/16/83;LOCATION WAS AMENDED ON 10/20/00 TO INCLUDE INTERESTS OF RICHARD KELLAR, HORATIO AND MARY DUNTON. DISCOVERIES CAUSED RESPECTABLE BOOM IN 1883, WITH EXTABLISHMENT OF TOWN OF BOWEN ACROSS RIVER FROM EMMA AND SMUGGLER MINES. BOOM WAS SHORT LIVED, AND TOWN COLLAPSED. ALMONT EXTENSION LOCATED 6/26/89 BY A.P. ADAMS, S.W. CLEGG, AND J.P. REES, AMENDED 9/6/01 BY RICHARD KELLAR. PRODUCTION, IF ANY, FROM DISTRICT FROM 1880 TO 1895 WAS CONSIDERED SMALL. RECORDED PRODUCTION BEGAN IN 1896. HENDERSON (1926) REPORTS SMELTER
  • AND MILL UNDER CONSTRUCTION AT DUNTON IN 1897; MILL IN OPERATION IN 1898. BULK OF AG AND AU PRODUCTION TOOK PLACE FROM 1896 TO 1913, WITH PB AND CU FIRST BEING PRODUCED IN 1908. PRODUCTION DECREASED FROM 1914 THROUGH WW I, BUT REVIVED FROM 1920 TO 1925 AND 1928 TO 1930. EMMA AND SMUGGLER PRODUCED INTERMITTENTLY FROM 1937 TO 1941; GEYSER GROUP RECORDED SMALL PRODUCTION IN 1950. NO FURTHER ACTIVITY REPORTED IN INTERVENING YEARS AND UNTIL 1970S WHEN SOME EXPLORATION AND DEVELOPMENT WAS DONE BY MINING DEVELOPMENT RESOURCES AT SMUGGLER MINE (1974), WARREN WRIGHT AT ROSEBUD MINE (1981), AND RADO REEF RESOURCES AT EMMA MINE (1979-1980), THE LATTER REPORTING SOME PRODUCTION.

Reference information

Bibliographic references

  • Deposit

    BUSH, A.L., AND BROMFIELD, C.S., 1966, GEOLOGIC MAP OF THE DOLORES PEAK QUADRANGLE, DOLORES AND SAN MIGUEL COUNTIES, COLORADO: USGS MAP GQ-536.

  • Deposit

    PRATT, W.P., AND OTHERS, 1969, GEOLOGIC MAP OF THE RICO QUADRNAGLE, DOLORES AND NONTEZUMA COUNTIES, COLORADO: USGS MAP GQ-797.

  • Deposit

    BASTIN,E.S., 1922, SILVER ENRICHMENT IN THE SAN JUAN MOUNTAINS, COLORADO: USGS BULL. 735-D, P. 116-129.

  • Deposit

    KRANTZ, P.R., AND FREEMAN, W.H., 1923, A STUDY OF THE ORES OF DUNTON DOLORES COUNTY, COLORADO: COLORADO SCHOOL OF MINES THESIS T-503.

  • Deposit

    HENDERSON, C.W., 1926, MINING IN COLORADO, A HISTORY OF DISCOVERY, DEVELOPMENT, AND PRODUCTION: USGS PROF. PAPER 138, P. 114-117.

  • Deposit

    COLORADO DIV. MINES INF. REPTS. AND ANNUAL OPERATOR REPTS.

  • Deposit

    BLM MINERAL SURVEYS

  • Deposit

    MCKNIGHT, E.T., 1974, GEOLOGY AND ORE DEPOSITS OF THE RICO DISTRICT, COLORADO: USGS PROF. PAPER 723.

  • Production

    HENDERSON, 1926, P. 117; MCKNIGHT, 1974, P. 6; USGS/USBM MINERAL RESOURCES OF U.S.; USBM MINERAL YEARBOOKS; COLO. DIV. MINES ANN. OPERATOR REPTS.

General comments

Subject category Comment text
Deposit DISTRICT LIES BETWEEN INTRUSIVE CENTERS OF SAN MIGUEL MTNS AND THOSE OF PIONEER (RICO) DISTRICT. SEDIMENTARY ROCKS DIP GENERALLY NORTH AND NE, WITH PERMIAN CUTLER FM EXPOSED ON LOWER SLOPES ALONG WEST DOLORES RIVER AND CRETACEOUS DAKOTA SANDSTONE CAPPING MESAS. PROMINENT STRUCTURAL FEATURE IS NNW-SSE-TRENDING ASYMMETRICAL GRABEN EXTENDING FROM SOUTH SIDE OF DUNN PEAK-DOLORES PEAK INTRUSIVE CENTER SE TO NW FLANK OF RICO DOME. DUNTON FAULT BOUNDS GRABEN ON NE AND SPLITS INTO PAPOOSE FAULT EAST OF DUNTON. EMMA FAULT BOUNDS GRABEN ON SW. SEVERAL OTHER FAULTS OR ONE OF TWO FAULTS WITH SPLITS LIE WITHIN GRABEN BUT TOWARD SW SIDE. IN LOWEST STRUCTURAL BLOCK, DUNTON SYNCLINE PRESERVES MANCOS SHALE (UPPER CRETACEOUS) AND DAKOTA SANDSTONE INTRUDED BY LAMPROPHYRE SILL. TOWARD SE, FAULTS DIE OUT IN TRIASSIC SEDIMENTS JUST BEYOND AREA OF HORNBLENDE LATITE SILLS OF RICO DISTRICT. CROSS FAULTS TRENDING NEARLY AT RIGHT ANGLES TO GRABEN SLIGHTLY OFFSET GRABEN FAULTS. PORPHYRITIC LATITE DIKE FOLLOWS
Deposit PORTION OF PAPOOSE FAULT; MICROGABBRO DIKES TREND GENERALLY PARALLEL TO EMMA FAULT BOTH INSIDE AND OUTSIDE GRABEN. ALMONT FAULT SPLIT FORMS TRIANGLE WITH EMMA AND CROSS FAULT. THERMAL, FE-BEARING, AND H2S-BEARING SPRINGS ARE ASSOCIATED WITH GRABEN AND CROSS FAULTS. KRANTZ AND FREEMAN (1923) DESCRIBE ORE DEPOSITS AS VEINS AVERAGING 2 FT WIDE AND OLLOWING GRABEN FAULTS, DIPPING STEEPLY SW TO VERTICAL. BUSH AND BROMFIELD (1966) SHOW VERTICAL TO SW DIPS ON ALMONT AND OTHER SUBPARALLEL FAULTS TO SW BUT 80 TO 85 NE DIP ON EMMA VEIN. KRANTZ AND FREEMAN IDENTIFIED TWO PERIODS OF PRIMARY ORE DEPOSITION: (1) SPHALERITE, PYRITE, ARGENTITE (AS INCLUSIONS IN SPHALERITE), AND QUARTZ, FOLLOWED BY SHEARING AND FRACTURING, AND (2) GALENA, CHALCOPYRITE, PYRITE, AND QUARTZ, WITH GALENA DEPOSITED IN FRACTURES AND REPLACING SPHALERITE, FOLLOWED BY SECOND PERIOD OF SHATTERING. NEAR-SURFACE AG ENRICHMENT CAUSED BY SECONDARY DEPOSITION OF PYRARGYRITE, PROUSTITE, ARGENTITE, AND CHALCOPYRITE. IN FRACTURES
Deposit CUTTING PRIMARY ORE. STIBNITE FOUND IN FRACTURES AND AS RADIATING CRYSTAL CLUSTERS ON QUARTZ IN VUG LININGS, BUT PARAGENETIC POSITION UNCERTAIN. UNVERIFIED REPORTS CITE NATIVE SULFUR OF POSSIBLE FUMAROLIC ORIGIN OCCURRING AT SOME MINES. BASTIN (1922) OBSERVED HOT MINE WATERS EVOLVING CO2 AND H2S AND DEPOSITING FERRUGINOUS CALCITE AND SULFATES OF CA, MG, AND AL-FE. ALTHOUGH SECONDARY AG ENRICHMENT NOTED, BASTIN BELIEVED MOST OF AG SULFOSALTS TO BE OF PRIMARY ORIGIN. DEPTH OF OXIDATION AND ENRICHMENT MAY NOT BE FAR DUE TO INHIBITING EFFECT OF HOT, ASCENDING, H2S-BEARING SOLUTIONS. EMMA AND SMUGGLER MINES USED COAL FROM DAKOTA FM ON WEST LIMB OF DUNTON SYNCLINE WHERE IT MAY HAVE BEEN LOCALLY UPGRADED BY LAMPROPHYRE SILL.
Deposit DISTRICTKNOWN MOST COMMONLY BY POPULAR NAME OF "DUNTON," BUT BLM CLAIM RECORDS ASSIGN DISTRICT NAME OF "LONE CONE." LITTLE WOUNDER CLAIM (MS 1516) ORIGINALLY ASIGNED TO PIONEER (RICO) DISTRICT, BUT IS INCLUDED IN LONE CONE ON BASIS OF ACTUALLOCATION NEAR DUNTON. OTHER CLAIMS ASSIGNED TO LONE CONE DISTRICT LIE FARTHER NORTH IN NAVAJO BASIN BUT ARE INCLUDED IN MOUNT WILSON DISTRICT ON BASIS OF DIFFERENT ORE OCCURENCES, HOST ROCKS, AND STRUCTURE. INDIVIDUAL RECORDS PREPARED FOR PRINCIPAL MINES AND PROPERTIES FOR WHICH SOME DESCRIPTIONS AVAILABLE: AMERICA, EMMA, FREE COINAGE, GEYSER, ROSEBUD, AND SMUGGLER. OTHER NAMED PROPERTIES (METAL AND THOSE WITH REPORTED OCCURENCES OF NATIVE S) FOR WHICH NO DESCRIPTIONS AVAILABLE AND NO RECORDS PREPARED INCLUDED B AND M, COMO, CORKSCREW, LITTLE SWAN, MOUNT PLEASANT, POOR BOY, SULFUR KING, TROY, AND YELLOW BEE. ; INFO.SRC : 1 PUB LIT; 2 UNPUB REPT

Reporter information

Type Date Name Affiliation Comment
Reporter 01-OCT-1983 Schwochow, Stephen D. Colorado Geological Survey

Beyond USGS

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

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