Alaska Resource Data File 

This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards or with the North American Stratigraphic code. Any use 

of trade, product, or firm names is for descriptive purposes only and does not imply 

endorsement by the U.S. Government. 

OPEN-FILE REPORT 00-121 

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 Distribution of mineral occurrences in the Simeonof Island

1:250,000-scale quadrangle, Aleutian Islands, Alaska

 This and related reports are accessible through the USGS World Wide Web site 

http://ardf.wr.usgs.gov. Comments or information regarding corrections or missing 

data, or requests for digital retrievals should be directed to: Frederic Wilson, USGS, 4200 

University Dr., Anchorage, AK 99508-4667, e-mail fwilson@usgs.gov, telephone (907) 

786-7448. This compilation is authored by:

 Steven H. Pilcher

 Anchorage, AK

Simeonof Island quadrangle

 Descriptions of the mineral occurrences shown on the accompanying figure follow. 

See U.S. Geological Survey (1996) for a description of the information content of each field 

in the records. The data presented here are maintained as part of a statewide database 

on mines, prospects and mineral occurrences throughout Alaska.
Alaska Resource Data File 

Page 2 

Site name(s): Unnamed (on southeast coast of Nagai Island) 

Site type: Occurrence 

ARDF no.: SN001 

Latitude: 54.975 Quadrangle: SN D-4 

Longitude: 160.115 

Location description and accuracy:

 This site is on the southeast coast of Nagai Island approximately 2 miles northeast of 

Saddler Peak and includes mineral showings at sea level and in the adjacent sea-cliffs. 

Location is accurate to within a few hundred feet. 

Commodities: 

 Main: Au 

 Other: As 

Ore minerals: Arsenopyrite, gold, pyrite 

Gangue minerals: Quartz 

Geologic description:

 At this mineral occurrence two Tertiary quartz diorite sills intrude siltstone and sandstone of the Cretaceous Shumagin Formation (Ellis and Apel, 1989). The strata strike 

northwest and dip 20-50 degrees to the southwest. They are silicified and pyritic adjacent 

to the contact. The sills crop out along the sea cliffs and beach for approximately 1600 

feet. 

 Gold is present in the sills in quartz-arsenopyrite veins and stockworks thought to be 

associated with northwest-trending faults and shear zones. Gold also occurs in the altered 

rocks adjacent to the sills and in a 100-foot wide hydrothermal breccia zone. 

 In 1989 Battle Mountain Exploration Company collected 61 rock-chip samples, 22 of 

which contained >100 ppb gold (Ellis and Apel, 1989). Fifteen samples contained 100 to 

499 ppb gold, 5 contained 500 to 999 ppb gold, and 2 had >1ppm ppm gold (up to 6.55 

ppm). Elsewhere on the island they also obtained scattered pan concentrate and rock samples anomalous in arsenic, gold, and mercury. Free gold was also noted on the beach at 

Saddlers Mistake and in several streams draining the area. Anomalous gold was also 

found over a 1/2 mile area associated with a color anomaly located in steep cliffs approximately 3 miles north of this site. Numerous gold anomalies were detected on the north 

part of the island by the U.S. Geological Survey (Frisken and Kelly, 1992). 

Alteration:

SN001 
Alaska Resource Data File 

Page 3 

 Sedimentary country rocks are silicified and pyritic adjacent to the sills. Hydrothermal 

breccia zone in sills. Color anomaly about 3 miles north of site. 

Age of mineralization:

Tertiary. 

Deposit model:

 

Deposit model number (After Cox and Singer, 1986 or Bliss, 1992):

 

Production Status: None 

Site Status: Inactive 

Workings/exploration:

 In 1989 Battle Mountain Exploration mapped and sampled this mineral occurrence. Of 

61 rock-chip samples collected 22 contained >100 ppb gold. The highest value obtained 

was 6.55 ppm gold (Ellis and Apel, 1989). 

 The U.S. Geological Survey mapped and geochemically sampled in the Simeonof Island quadrangle in the late 1980's (Wilson and others, 1991; Frisken, 1992). 

Production notes:

 

Reserves:

 

Additional comments:

 This site is located on land selected by the Aleut Native Corporation. 

References:

Ellis and Apel, 1989; Wilson and others, 1991; Frisken, 1992; Frisken and Kelly, 1992. 

Primary reference: Ellis and Apel, 1989 

Reporter(s): S.H. Pilcher (Anchorage) 

Last report date: 1/24/00 

SN001 
Alaska Resource Data File 

Page 4 

 References 

Alaska Division of Natural Resources, 1997, State of Alaska General Land Status with Mineral Resources and 

Mining Claims, Alaska Peninsula, 1 map sheet, scale 1:1,000,000. 

Arbogast, B.F., Bailey, E.A., and Frisken, J.G. 1987, Analytical results and sample locality maps of stream sediments, heavy mineral concentrates, and rock samples from Port Moller, Stepovak Bay, and Simeonof 

Island quadrangles, Alaska: U.S. Geological Survey Open-File Report 87-502, 122 p., 2 map sheets, 

scale 1:250,000. 

Ellis, W.T., and Apel, R.A., 1989, Unga/Alaska Peninsula 1989 Alaska final report: Battle Mountain Exploration 

Company, Alaska District, vol. 1, 41 p., 3 map sheets, scale 500 feet and 1⁄2 mile to the inch. 

Frisken, J.G., 1992, Interpretation of reconnaissance geochemical data from the Port Moller, Stepovak Bay, and 

Simeonof Island quadrangles, Alaska Peninsula, Alaska: U.S. Geological Survey Bulletin 1968, 47 p. 3 

map sheets, scale 1:250,000. 

Frisken, J.G., and Kelly, D.L., 1992, Maps showing the distribution of gold determined in various sample media 

collected from Port Moller, Stepovak Bay, and Simeonof Island quadrangles, Alaska Peninsula, Alaska: 

U.S. Geological Survey Map MF-2155D, 2 map sheets, scale 1:250,000. 

Ransome, A.L., and Kerns, W.H, 1954, Names and definitions of regions, districts, and subdistricts in Alaska: U.

S. Bureau of Mines Information Circular 7679, 91 p. 

Wilson, F.H., Detterman, R.L., and Harris, D.E., 1991, Generalized geologic map of the Port Moller, Stepovak 

Bay, and Simeonof Island quadrangles, Alaska Peninsula, Alaska: U.S. Geological Survey Map MF2155A, 1 map sheet, scale 1:250,000. 

References