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

Host or associated	Host
Rock type	Plutonic Rock > Granitoid > Granite

Nearby scientific data

(1)	-136.88601, 58.86	ListMap

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.

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