Stipek and Kotovic

Prospect in Alaska, United States with commodities Gold, Silver

Geologic information

Identification information

Deposit ID 10308954
MRDS ID A012832
Record type Site
Current site name Stipek and Kotovic
Alternate or previous names Bergstrom (Rock Creek)
Related records 10001988

Geographic coordinates

Geographic coordinates: -165.42818, 64.60808 (WGS84)
Relative position This lode prospect is on the southeast side of Rock Creek about 3,000 feet upstream of the Snake River road and 1.85 miles south-southwest of Mount Brynteson. The prospect is at surface elevations of about 200 to 225 feet. The map location is in the NW1/4 section 23, T. 10 S., R. 34 W., Kateel River Meridian, and it is accurate to within 250 feet. This is locality 43 of Cobb (1972 [MF 463], 1978 [OFR 78-93]).
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Gold Primary
Silver Secondary

Materials information

Materials Type of material
Arsenopyrite Ore
Gold Ore
Ilmenite Ore
Pyrite Ore
Albite Gangue
Calcite Gangue
Quartz Gangue

Alteration

  • Albitization; extensive sulfidization especially introduction of arsenopyrite.

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) -165.42818, 64.60808

Comments on the geologic information

  • Geologic Description = This prospect was one of two known as Stipek and Kotovic; the second, on the divide between Rock Creek and Glacier Creek, is NM235. The east side of Rock Creek was evidently being prospected by W. Stipek and J. Kotovic in 1916, when it was visited by Mertie (1918 [B 662-I, p. 432-33]). Workings at that time consisted of a 70-foot shaft and 70 feet of crosscuts. The collar of the shaft was at an elevation of about 200 feet. A mineralized zone found in the crosscut was rich in sulfides and reported to strike N 5 E. Dump material contained 0.4 ounce of gold per ton; stringer sulfide zones without quartz reportedly contained about 7 ounces of gold per ton. A 120-foot-long adit, apparently examined by Mertie (1918), was driven from near the elevation of Rock Creek through the lode. Mertie (1918) reported that a 12-foot vein of shattered white quartz yielded about 250 pounds of concentrate to the ton. Sulfides, especially arsenopyrite, were abundant from the near the vein to the face of the adit. Another adit, 40 feet long, was driven into the lode about 75 feet to the south and apparently encountered the same vein and sulfide zone as the longer adit. The prospect was inactive when visited by Cathcart in 1920 (Cathcart, 1922, p. 244-245). He reported that tunnels were driven S 75 E and S 25 E and that the quartz-albite vein had a strike of N 65 E and dipped 50 south. Ilmenite occurrs on fracture surfaces in the quartz. Wallrock was reported as chlorite-quartz schist, in general agreement with the findings of Bundtzen and others (1994), who mapped the bedrock on Rock Creek as chlorite-rich metaturbidite schist. The prospect was explored between about 1985 and 1995 by R.V. Bailey, BHP (?), Newmont Mining Company, and Kennecott Exploration Company. This exploration included northwest-trending trenches that exposed stratiform, as well as crosscutting quartz and sulfides and a fault that may cut off the deposit. The trench and drill results show that the deposit is semi-continuous over a northeasterly strike length of about 500 feet, but the grade is low and individual mineral zones are discontinuous. In general, this deposit is similar to those at Reinisch (NM213), Walsh Cut (NM214), and Goodluck Gulch (NM202).
  • Age = Mid-Cretaceous; veins cross cut regionally metamorphosed schist; see NM207.

Economic information

Economic information about the deposit and operations

Development status Prospect
Commodity type Metallic

Comments on exploration

  • Status = Probably inactive

Mining district

District name Nome

Comments on the production information

  • Production Notes = There possibly was production of minor free gold during milling tests of the ore.

Comments on the workings information

  • Workings / Exploration = The Stipek and Kotovic prospect on Rock Creek was explored by a 70-foot shaft and about 230 feet of level adit or crosscut workings before 1920. It appears to have been active when visited by Mertie in 1916 (Mertie, 1918 [B 662-I, p. 425-449]). It was inactive in 1920. The prospect was again active between about 1985 and 1995. It was drilled and trenched by several companies including BHP(?) in 1990, Newmont in 1992, and Kennecott Exploration Company in 1994. Both core and reverse circulation holes were drilled in the appraisal of the prospect.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Alaska Resource Data File ARDF NM217
USGS Mineral Resources Data System MRDS A012832
USGS Mineral Resources Data System MRDS D002594

Bibliographic references

  • Deposit

    Cathcart, S.H., 1922, Metalliferous lodes in southern Seward Peninsula: U.S. Geological Survey Bulletin 722, p. 163-261.

  • Deposit

    Hummel, C.L., 1962, Preliminary geologic map of the Nome C-1 quadrangle, Seward Peninsula, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-247, 1 sheet, scale 1:63,360.

  • Deposit

    Cobb, E.H., 1972, Metallic mineral resources map of the Nome quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-463, 2 sheets, scale 1:250,000.

  • Deposit

    Cobb, E.H., 1978, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Nome quadrangle, Alaska: U.S. Geological Survey Open-File report 78-93, 213 p.

  • Deposit

    Bundtzen, T.K., Reger, R.D., Laird, G.M., Pinney, D.S., Clautice, K.H., Liss, S.A., and Cruse, G.R., 1994, Progress report on the geology and mineral resources of the Nome mining district: Alaska Division of Geological and Geophysical Surveys, Public Data-File 94-39, 21 p., 2 sheets, scale 1:63,360.

Comments on the references

  • Primary Reference = This report

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 10-JUL-00 Hawley, C.C. and Hudson, Travis L. Hawley Resource Group