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Rockfield Mine

Past Producer in Larimer county in Colorado, United States with commodities Gold, Silver
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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. Host and associated rocks
  9. Nearby scientific data
  10. Geologic structures
  11. Ore body information
  12. Economic information about the deposit and operations
  13. Mining district
  14. Land status
  15. Ownership information
  16. Links to other databases
  17. Bibliographic references
  18. General comments
  19. Reporter information

Geologic information

Identification information

Deposit ID 10014002
MRDS ID D010597
Record type Site
Current site name Rockfield Mine
Alternate or previous names Unpatented Claims: Rodkfield, Pendergast Tunnel, Valentine Lod E, Matchless Nos. 1 and 2

Geographic coordinates

Geographic coordinates: -105.60254, 40.71165 (WGS84)
Elevation 2426
Location accuracy 500(meters)
Relative position 29.1 MILES N73W FROM FORT COLLINS

Site location context

Political divisions (FIPS codes)

Larimer(county)

Colorado(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Rustic(quadrangle 1:24,000 scale)

Fort Collins(quadrangle 1:100,000 scale)

Greeley(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Cache La Poudre(hydrologic unit)

South Platte(hydrologic accounting unit)

South Platte(hydrologic subregion)

Missouri(hydrologic region)

Federal lands

Arapaho and Roosevelt National Forests(National Forest)

National Forest FS(Type of land area)

FS(Federal land areas administered by FS)

Geographic areas

Country State County
United States Colorado Larimer

Public Land Survey System information

Meridian Township Range Section Fraction State
6th Principal 009N 073W 29 SW Colorado

Comments on the location information

  • SOUTH OF SEVENMILE CREEK BASED ON BLM RECORD OF PENDERGAST TUNNEL CLAIM RECORD. ELEV AND LAT-LONG GIVEN ARE FOR CENTER SW SEC. 29 ; INFO FROM LAND.ST :1980

Commodities

Commodity Importance
Gold Primary
Silver Primary

Materials information

Materials Type of material
Pyrite Ore

Analytical data

Result MILLING ORE FROM 1941 REPORTEDLY CONTAINED 18 OZ/TON AU AND 1.5 OZ /TON AG.

Host and associated rocks

  • Host or associated Associated
    Rock type Plutonic Rock > Granitoid > Quartz Monzonite
    Rock unit name Laramide Intrusive Rocks--Quartz Monzonite Porphyry
    Rock description Laramide Intrusive Rocks--Quartz Monzonite Porphyry
    Stratigraphic age (youngest) Pliocene
    Stratigraphic age (youngest) Neoproterozoic
    Stratigraphic age (youngest) Pliocene
  • Host or associated Host
    Rock type Metamorphic Rock > Gneiss
    Rock unit name Metamorphic Rocks--Felsic And Hornblendic Gneisses;Laramide Intrusive Rocks--Quartz Monzonite Porphyry
    Rock description Metamorphic Rocks--Felsic And Hornblendic Gneisses;Laramide Intrusive Rocks--Quartz Monzonite Porphyry

Nearby scientific data

(1) -105.60254, 40.71165
ListMap

Economic information

Geologic structures

Type of structure Regional
Structure description Front Range Uplift, Sherman Batholith
Type of structure Local
Structure description Poudre River Shear Zone, Elkhorn Creek Shear Zone

Ore body information

  • Thickness 1.22M

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic
Deposit size Small
Significant No
Discovery year 1916
Discoverer Carroll Alsbury (Pendergast Tunnel Claimant)
Year of first production 1937
Year of last production 1941

Mining district

District name Manhattan District

Land status

Ownership category National Forest

Ownership information

  • Type Owner-Operator
    Owner S. A. And W. T. Pendergast
    Home office Log Cabin
    First year 1941

Comments on the production information

  • EXPLORATION AND DEVELOPMENT FROM 1923-36; PRODUCTION IN 1937 AND 1 941; NO PRODUCTION IN 1938-40.

Comments on the workings information

  • 900-FT CROSSCUT TUNNEL AND SHORT CROSSCUTS; SURFACE TRENCHES

Reference information

Bibliographic references

  • Deposit

    LOVERING, T.S., AND GODDARD, E.N., 1950, GEOLOGY AND ORE DEPOSITS O F THE FRONT RANGE, COLORADO: USGS PROF. PAPER 223, P. 285-286

  • Deposit

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

  • Production

    COLORADO DIV. MINES ANN. OPERATOR REPTS.

General comments

Subject category Comment text
Deposit AIRPHOTOS INDICATE PROBABLE QUARTZ MONZONITE DIKE TRENDING N76 TO 82E THROUGH METAMORPHICS FROM N2 SE SEC. 30 ACROSS N EDGE OF SW SEC. 29 TO S2 S2 NE SEC. 29.

Reporter information

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

Beyond USGS

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

Maps centered on this site

Authoritative Colorado resources

These are landing pages for further research — the state agencies don't currently expose per-mine deep links.