Mary Ann

Prospect in Alaska, United States with commodity Gold
Sections on this page
  1. Identification information
  2. Geographic coordinates
  3. Site location context
  4. Geographic areas
  5. Commodities
  6. Materials information
  7. Alteration
  8. Mineral occurrence model information
  9. Nearby scientific data
  10. Economic information about the deposit and operations
  11. Mining district
  12. Links to other databases
  13. Bibliographic references
  14. General comments
  15. Reporter information

Geologic information

Identification information

Deposit ID 10003476
MRDS ID A106234
Record type Site
Current site name Mary Ann

Geographic coordinates

Geographic coordinates: -149.18268, 61.81956 (WGS84)
Relative position East of Reed Creek, about 2,500 ft east-northeast of the mouth of Good Hope Creek a tributary of Reed Creek. Accurate within 2,500 ft. Locality 32 of Chapin (1921), locality 30 of Cobb (1972), and locality 22 of MacKevett and Holloway (1977).

Site location context

Political divisions (FIPS codes)

Matanuska-Susitna(Borough)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Anchorage D-6(quadrangle 1:63,360 scale)

Anchorage NW(quadrangle 1:100,000 scale)

Anchorage(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Lower Susitna River(hydrologic unit)

Susitna River(hydrologic accounting unit)

South Central Alaska(hydrologic subregion)

Alaska(hydrologic region)

Federal lands

Hatcher Pass Management Area-East(State Special Management Area)

State Special Management Area ST(Type of land area)

ST(Federal land areas administered by ST)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Gold Primary

Materials information

Materials Type of material
Gold Ore
Quartz Gangue

Alteration

  • (Local) Wall-rock alteration within a few inches of the vein is intense, but seldom extends more than 10 to 12 inches beyond the quartz filling. Sericitization and carbonate alteration predominate, but there is some pyritization and in the outer parts of the alteration zone chloritization is present (Ray, 1954).

Mineral occurrence model information

Model code 273
USGS model code 36a
Deposit model name Low-sulfide Au-quartz vein
Mark3 model number 27

Nearby scientific data

(1) -149.18268, 61.81956

Economic information

Comments on the geologic information

  • Geologic Description = Quartz vein traced along outcrop of early Paleocene and Late Cretaceous tonalite. The lithology is dominantly biotite-hornblende tonalite with lesser biotite-hornblende quartz diorite. Wall-rock alteration within a few inches of the vein is intense, but seldom extends more than 10 to 12 inches beyond the quartz filling. Sericitization and carbonate alteration predominate, but there is some pyritization and in the outer parts of the alteration zone chloritization is present (Ray, 1954). No data on possible gold content (Cobb, 1979).
  • Age = Late Cretaceous or younger; vein cut early Paleocene and Late Cretaceous tonalite.

Economic information about the deposit and operations

Development status Prospect
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Willow Creek

Comments on the workings information

  • Workings / Exploration = In 1919 a tunnel was being driven to intersect a quartz vein that had been traced along the surface (Chapin, 1921).

Reference information

Bibliographic references

  • Deposit

    Chapin, Theodore, 1921, Lode developments in the Willow Creek district: U.S. Geological Survey Bulletin 714-E, p. 201-206.

  • Deposit

    MacKevett, E.M., Jr., and Holloway, C.D., 1977, Map showing metalliferous and selected non-metalliferous mineral deposits in the eastern part of southern Alaska: U.S. Geological Survey Open-File Report 77-169-A, 99 p., 1 sheet, scale 1:1,000,000.

  • Deposit

    Cobb, E.H., 1972, Metallic mineral resources map of the Anchorage quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-409, 1 sheet, scale 1:250,000.

  • Deposit

    Cobb, E.H., 1979, Summary of references to mineral occurrences (other than mineral fuels and construction materials in the Anchorage quadrangle, Alaska: U.S. Geological Survey Open-File Report 79-1095, 184 p.

  • Deposit

    MacKevett, E.M., Jr., and Holloway, C.D., 1977, Map showing metalliferous mineral deposits in the western part of southern Alaska: U.S. Geological Survey Open-File Report 77-169-F, 38 p., 1 sheet, scale 1:1,000,000.

Comments on the references

  • Primary Reference = Chapin, 1921

General comments

Subject category Comment text
Deposit Model Name = Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a)

Reporter information

Type Date Name Affiliation Comment
Reporter 30-JUL-1998 D.P. Bickerstaff U.S. Geological Survey
Reporter 30-JUL-1998 S.W. Huss U.S. Geological Survey

Beyond USGS

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

Authoritative Alaska resources

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