1. Mineral Resources
  2. Online Spatial Data
  3. Mineral Resource Data System (MRDS)

Big Boulder Prospect

Past Producer in Larimer county in Colorado, United States with commodities Mica, Uranium, Beryllium, Feldspar, Lithium
Map
XML
JSON
KML
B
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. Production statistics
  17. Workings at the site
  18. Links to other databases
  19. Bibliographic references
  20. General comments
  21. Reporter information

Geologic information

Identification information

Deposit ID 10087851
MRDS ID D010315
Record type Site
Current site name Big Boulder Prospect
Related records 10117934

Geographic coordinates

Geographic coordinates: -105.40809, 40.52109 (WGS84)
Elevation 2646
Relative position 11.1 MILES N 27 E FROM ESTES PARK

Site location context

Political divisions (FIPS codes)

Larimer(county)

Colorado(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Crystal Mountain(quadrangle 1:24,000 scale)

Fort Collins(quadrangle 1:100,000 scale)

Greeley(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Big Thompson(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 007N 072W 36 S2 OF SE Colorado

Comments on the location information

  • ON DIVIDE BETWEEN SHEEP CREEK AND FISH CREEK SW OF BOILER HILL, 1.8 MILES SE OF CRYSTAL MOUNTAIN. ; INFO FROM LAND.ST :(1980)

Commodities

Commodity Importance
Mica Primary
Uranium Secondary
Beryllium Critical Tertiary
Feldspar Tertiary
Lithium Critical Tertiary

Materials information

Materials Type of material
Beryl Ore
Microcline Ore
Muscovite Ore
Apatite Gangue
Garnet Gangue
Spodumene Gangue
Torbernite Gangue
Tourmaline Gangue

Analytical data

Result PROSPECT AVERAGES 0.5 % BERYL. WALL ZONE CONTAINS 0.75 % BERYL, LOWER INTERMEDIATE CONTAINS 0.37 % BERYL, UPPER INTERMEDIATE ZONE CONTAINS 0.07 % BERYL, AND CORE CONTAINS 0.06 % BERYL.

Host and associated rocks

  • Host or associated Associated
    Rock type Plutonic Rock > Granitoid > Tonalite
    Stratigraphic age (youngest) Neoproterozoic
    Stratigraphic age (youngest) Neoproterozoic
  • Host or associated Associated
    Rock type Plutonic Rock > Pegmatite
    Rock unit name Pegmatite;Tonalite (Quartz Diorite)
    Rock description Pegmatite;Tonalite (Quartz Diorite)
  • Host or associated Host
    Rock type Metamorphic Rock > Schist
    Rock unit name Metasedimentary Rocks-Quartz-Biotite Schist;Pegmatite
    Rock description Metasedimentary Rocks-Quartz-Biotite Schist;Pegmatite

Nearby scientific data

(1) -105.40809, 40.52109
ListMap

Economic information

Geologic structures

Type of structure Regional
Structure description Front Range Uplift
Type of structure Local
Structure description Thompson Canyon Fault, Mt Olympus Batholith, Ne-Trending Folds

Ore body information

  • General form LENTICULAR
    Length 79.25M
    Width 30.48M
  • General form LENTICULAR

Economic information about the deposit and operations

Development status Past Producer
Commodity type Both
Deposit size Small
Significant No
Year of first production 1936
Year of last production 1961

Mining district

District name Crystal Mountain (Storm Mountain) Pegmatite District

Land status

Ownership category State

Ownership information

  • Type Operator
    Owner Helen Allphin
    Home office Jamestown
    First year 1964
  • Type Owner
    Owner State Of Colorado
    Home office Colorado
    First year 1964

Production statistics

  • Year 1941
    Material BE ACC
    Description Ap_Grade: ^0.10% U308
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    U3O8 Uranium Uranium 0wt-pct

Comments on the reserve resource information

  • HANLEY AND OTHERS, 1950

Workings at the site

  • Type of workings Surface/Underground
    Overall depth 3.05M

Comments on the workings information

  • FOUR SMALL OPEN CUTS; 10-FT SHAFT

Reference information

Bibliographic references

General comments

Subject category Comment text
Deposit ZONED PEGMATITE CONSISTS OF OUTER ZONE OF QUARTZ-ALBITE-MICROCLINE-MUSCOVITE PEGMATITE WITH ONE-INCH AVERAGE GRAIN SIZE AND ACCESSORY BERYL, TOURMALINE, AND APATITE. CORE CONSISTS OF MILKY QUARTZ AND GIANT MICROCLINE CRYSTALS WITH MINOR "ROTTEN" SPODUMENE AND SMALL AMOUNTS OF AUTUNITE AND GUMMITE. LENTICULAR BODY PROBABLY PINCHES OUT AT APPROX 125-FT DEPTH.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-MAR-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.