Unnamed (southwest of Mt. Parker)

Occurrence in Alaska, United States with commodities Gold, Silver, Arsenic, Zinc

Geologic information

Identification information

Deposit ID 10002249
MRDS ID A013151
Record type Site
Current site name Unnamed (southwest of Mt. Parker)
Related records 10113126

Geographic coordinates

Geographic coordinates: -136.88601, 58.86 (WGS84)
Relative position This occurrence consists of a locally mineralized fault or shear zone which can be traced for more than 4000-feet. The fault crosses the ridge about 0.2 mile southeast of Mt. Parker at an elevation of about 2900 feet. The coordinates, accurate within 0.1 mile, mark the point where the vein-fault crosses the ridge south of Mt. Parker. The fault continues southwesterly to Lamplugh Glacier and northeasterly into Ptarmigan Creek. Rossman (1959, B 1058-B, pl. 4, p. 55-56) reported two hydrothermally altered segments in the vein-fault, one to the northeast in Ptarmigan Creek; the second is about 2000 feet southwest of the ridge and 1000 feet east of Lamplugh Glacier.
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Gold Primary
Silver Secondary
Arsenic Secondary
Zinc Secondary

Materials information

Materials Type of material
Arsenopyrite Ore
Pyrite Ore
Sphalerite Ore
Quartz Gangue

Alteration

  • (Local) Rossman (1959, B 1058-B, p. 56) reported alteration along the 4500-foot length of the structure. In general veins of the area are altered for as much as 10-15 feet on each side of the controlling fault structures; the alteration products include ankerite.

Mineral occurrence model information

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

Host and associated rocks

  • Host or associated Associated
    Rock type Plutonic Rock > Granitoid > Granite
    Stratigraphic age (youngest) Late Cretaceous
  • Host or associated Host
    Rock type Plutonic Rock > Granitoid > Granite

Nearby scientific data

(1) -136.88601, 58.86

Comments on the geologic information

  • Geologic Description = A prominent locally mineralized fault cuts granodiorite of Cretaceous age on the ridge south of Mt. Parker, and enters the major cataclasite schist zone of the Ptarmigan basin to the northeast (Rossman, 1959, B 1058-B, pl. 4; Brew and others, 1978, pl. 1A). A 200-foot long quartz-bearing segment exposed on the west side of the Ptarmigan Creek basin is in schistose (cataclasite); a hydrothermally altered segment mapped by Rossman above Lamplugh Glacier is in granodiorite.? the vein-fault is traceable for 4500 feet. It is one of the strongest mineralized structures in the Reid Inlet gold area (Kimball and others, 1978). In addition to quartz, mineralized segments contain arsenopyrite, pyrite and black sphalerite.
  • Age = Late Cretaceous or younger.

Economic information

Economic information about the deposit and operations

Development status Occurrence
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Juneau

Comments on the workings information

  • Workings / Exploration = The vein-fault has only been traced on the surface. Prospectors who examined mineralized segments of the vein thought it contained ferberite, but Rossman identified the dark mineral as iron-rich sphalerite (Rossman, 1959, p. 55-56). No assays are given, probably owing to the absence of visible free gold in the vein-fault structure.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A013151
USGS Alaska Resource Data File ARDF MF025

Bibliographic references

  • Deposit

    Rossman, Darwin, 1959, Geology and ore deposits in the Reid Inlet area, Glacier Bay, Alaska: U.S. Geological Survey Bulletin 1058-B, p. 33-58.

  • Deposit

    Brew, D.A., Johnson, B.R., Grybeck, D., Griscom, A., Barnes, D.F., Kimball, A.L., Still, J.C., and Rataj, J.L., 1978, Mineral resources of the Glacier Bay National Monument Wilderness Study Area, Alaska: U.S. Geological Survey Open-File Report 78-494, 670 p.

Comments on the references

  • Primary Reference = Rossman, 1959 (B 1058-B)

General comments

Subject category Comment text
Deposit Model Name = Low-sulfide gold-quartz vein (Cox and Singer, 1986; model 36a).
Deposit Other Comments = the occurrence is of interest because of the strength and continuous nature of the vein-fault structure. Possibly, gold-bearing veins could occur in subsidiary tensional structures or at vein intersections. Rossman's main map (B 1058-B) suggests that the northeast vein-fault will intersect the projection of the northwest striking Ptarmigan Creek fault under cover in Ptarmigan Creek basin. (The Ptarmigan Creek fault appears to be the fundamental control of the Highland Chief prospect--MF030) No near term exploration is expected because the occurrence is in Glacier Bay National Park and Preserve.

Reporter information

Type Date Name Affiliation Comment
Reporter 08-APR-99 Hawley, C.C. Hawley Resource Group