Unnamed (east of East Fork of Glen Creek) (ARDF #DN076) Ag, Zn

Unnamed (east of East Fork of Glen Creek)

Occurrence, Inactive

Commodities and mineralogy

Main commodities	Ag; Zn
Other commodities	As; Cu; Pb
Ore minerals	arsenopyrite; chalcopyrite; galena; pyrite; sphalerite
Gangue minerals	quartz

Geographic location

Quadrangle map, 1:250,000-scale	DN
Quadrangle map, 1:63,360-scale	C-2
Latitude	63.5653
Longitude	-150.7235
Nearby scientific data	Find additional scientific data near this location
Location and accuracy	This occurrence is at an elevation of about 3300 feet above the East Fork of Glen Creek. It is in the SW1/4 SW1/4 SE1/4 section 31, T. 15 S., R. 16 W, Fairbanks Meridian. The location is approximate. It corresponds to number 82 of Thornsberry, McKee, and Salisbury (1984).

Geologic setting

Geologic description The country rocks in the area of this occurrence include chloritic phyllite, metafelsite, and marble of the lower Paleozoic Spruce Creek sequence. Rock units and schistosity strike ENE and dip south, off the crest of the Kantishna antiform (DN091) (Bundtzen, 1981; Thornsberry, McKee, and Salisbury, 1984, fig. K-2). The occurrence consists of semimassive sulfides in cobbles and small boulders in scree. The sulfides occur in tan, vitreous quartzite that possibly is metachert. The sulfides form parallel bands of pyrite, sphalerite, galena, and minor chalcopyrite. The scree fragments are up to 0.5 foot across and contain as much as 20 percent sulfide. Samples assayed up to 0.47 ounce of silver per ton, 1.2 percent zinc, 0.38 percent lead, 0.05 percent copper, and 1.25 percent arsenic. Gold was not determined (Thornsberry, McKee, and Salisbury, 1984, v. 2, occurrence 82).
Geologic map unit	(, )

Geologic description

The country rocks in the area of this occurrence include chloritic phyllite, metafelsite, and marble of the lower Paleozoic Spruce Creek sequence. Rock units and schistosity strike ENE and dip south, off the crest of the Kantishna antiform (DN091) (Bundtzen, 1981; Thornsberry, McKee, and Salisbury, 1984, fig. K-2). The occurrence consists of semimassive sulfides in cobbles and small boulders in scree. The sulfides occur in tan, vitreous quartzite that possibly is metachert. The sulfides form parallel bands of pyrite, sphalerite, galena, and minor chalcopyrite. The scree fragments are up to 0.5 foot across and contain as much as 20 percent sulfide. Samples assayed up to 0.47 ounce of silver per ton, 1.2 percent zinc, 0.38 percent lead, 0.05 percent copper, and 1.25 percent arsenic. Gold was not determined (Thornsberry, McKee, and Salisbury, 1984, v. 2, occurrence 82).

Geologic map unit

(, )

Production and reserves

Indication of production	None
Additional comments The occurrence is in Denali National Park and Preserve.

References

References Bundtzen, T.K., 1981, Geology and mineral deposits of the Kantishna Hills, Mt. McKinley quadrangle, Alaska: M. S. Thesis, University of Alaska, College, Alaska, 238 p. Thornsberry, V. V., McKee, C. J., and Salisbury, W. G., eds, 1984, 1983 Mineral Resource Studies: Kantishna Hills and Dunkle Mine Areas, Denali National Park and Preserve, Alaska: U. S. Bureau of Mines Open-File Report 129-84. 3 Volumes: v. 1, Text; v. 2, Appendices; v. 3, Maps. Prepared by Salisbury & Dietz, Inc., Spokane, WA.
Reporters	C.C. Hawley
Last report date	5/3/2001