| Main commodities | Cu; Zn |
|---|---|
| Ore minerals | chalcopyrite; cubanite; pyrite; pyrrhotite; sphalerite |
| Gangue minerals | quartz |
| Quadrangle map, 1:250,000-scale | SR |
|---|---|
| Quadrangle map, 1:63,360-scale | B-2 |
| Latitude | 60.3571 |
| Longitude | -147.7055 |
| Nearby scientific data | Find additional scientific data near this location |
| Location and accuracy | The prospect is located at an elevation of 350 feet on the south side of the unnamed creek that drains into the South Arm of Bay of Isles. It is in the NW1/4 section 15, T. 3 N., R. 10 E., of the Seward Meridian. This is location 20 of Condon and Cass (1958), location 100 of Cobb and Richter (1972), location 128 of MacKevett and Holloway (1977), location 210 of Cobb and Tysdal (1980), and location S-65 of Jansons and others (1984). This location is accurate to within 300 feet. |
Geologic descriptionThe prospect consists of parallel mineralized shear zones that strike N 10 E and dip 70 to 80 W (Kurtak and Jeske, 1986). Individual zones as much as 15 feet wide enclose lenses of unsheared greenstone and form an aggregate width of 90 feet. The shear zones are traceable for about 6 miles along strike. The sheared rock is chloritized greenstone schist that is locally brecciated (Kurtak and Jeske, 1986). The greenstone is mapped as Orca Group of early Tertiary age (Nelson and others, 1985). Sulfide minerals in the zone are chalcopyrite, pyrite, pyrrhotite, cubanite, and sphalerite (Cobb and Tysdal, 1980). Workings on the prospect consist of a 96-foot-deep shaft, an adit with two drifts totalling more than 150 feet, and a 100-foot-long open cut near the collar of the shaft. Poy (1926) reported that the mineralization averaged 2.2 percent copper over a width of 18 feet in the underground drifts. Samples from the surface cut contained from 38 ppm to 4.0 percent copper and from trace to 6.0 ppm silver. Some ore was shipped from the property in 1908 (Kurtak and Jeske, 1986). | |
| Geologic map unit | (-147.707512935185, 60.3565083440436) |
|---|---|
| Mineral deposit model | Cyprus massive sulfide (Cox and Singer, 1986; model 24a) |
| Mineral deposit model number | 24a |
| Age of mineralization | Tertiary or younger; the mineralization is in rocks of the Orca Group of Tertiary age. |
| Alteration of deposit | Greenstone has been chloritized. |
| Workings or exploration | The property was developed by a 96-foot-deep shaft, an adit with two drifts totalling more than 150 feet, and a 100-foot-long open cut near the collar of the shaft (Johnson, 1916; Kurtak and Jeske, 1986). Poy (1926) reported that the mineralization averaged 2.2 percent copper over a width of 18 feet in the underground drifts. The shaft is currently flooded (Kurtak and Jeske, 1986). Samples from the surface cut contained from 38 ppm to 4.0 percent copper and from trace to 6.0 ppm silver (Kurtak and Jeske, 1986). |
|---|---|
| Indication of production | Undetermined |
| Reserve estimates | Poy (1926) inferred a reserve of 85,000 tons of ore containing 1.31 percent copper and 5.4 percent iron. Rogers and Hoyt (1999) reported a reserve of 85,000 tons containing 2,040,000 pounds of copper, 425 ounces of gold and 8,500 ounces of silver. |
| Production notes | In 1908, a small but unknown amount of ore was shipped (Kurtak and Jeske, 1986). |
Additional commentsPatent was applied for in 1924. | |
ReferencesPoy, C.W., 1926, Topographic and Assay Maps of the Pandora Prospect, Knight Island, Alaska, private report for Kennecott Copper Co., held at U.S. Bureau of Land Management Alaska State Office, Anchorage, 1 v.
| |
| Reporters | Jeff A. Huber and Carol S. Huber (Anchorage) |
|---|---|
| Last report date | 12/7/2001 |