| Main commodities | Cu; Fe |
|---|---|
| Other commodities | Ti; platinum-group metals |
| Ore minerals | titaniferous magnetite |
| Quadrangle map, 1:250,000-scale | DI |
|---|---|
| Quadrangle map, 1:63,360-scale | C-5 |
| Latitude | 59.7203 |
| Longitude | -157.67 |
| Nearby scientific data | Find additional scientific data near this location |
| Location and accuracy | The Humble prospect is 12 miles east-northeast of the summit of Kemuk Mountain. The prospect is centered near the southwest corner of section 20, T. 5 S., R. 49 W. It is in an area of extensive surficial deposits with few conspicuous topographic features and little outcrop. The location is accurate to within 1 mile. |
Geologic descriptionThe Humble prospect is above a pronounced 4-mile-square magnetic anomaly identified in an aeromagnetic survey flown for Humble Oil and Refining Company in 1959 (Berg and Cobb, 1967). The anomaly reflects a large composite mafic and ultramafic body beneath 90 to 140 feet of unconsolidated Quaternary deposits. The pluton was explored by 16 diamond drill holes as the Kemuk prospect, some holes down to a depth of almost 2,000 feet. It is a composite, tabular, southeast-dipping body of clinopyroxenite with some olivine-bearing and hornblende-bearing rocks ((Nokleberg and others, 1987; T. Hinderman, personal communication, 2000). The country rocks cut by the drilling are hornfels and quartzite. The body contains much titaniferous magnetite that probably occurs as segregations and disseminations in the clinopyroxenite. The body was estimated to have a resource of 2.4 billion long tons that average 15 to 17 percent total iron (Nokleberg and others, 1987). A beneficiation test indicates the feasibility of producing a concentrate containing 65 percent Fe, 2 to 3 percent SiO2, 0.005 to 0.016 percent P2O5, and 2 to 3 percent TiO2. In 2010, Millrock Resources staked a large block of claims over the body, calling it the Humble prospect. Millrock with funding provided by Kinross Gold Corp., began drilling in August of 2011 (Millrock, 2012). The drilling was begun to test the idea that the body was similar to the gabbro body (IL005) peripheral to the large Pebble copper-gold porphyry deposit (IL007) which features similar geochemistry and geophysical characteristics. In September, 2011, Millrock reported that the drilling was not going well (Millrock Resources Inc., 2011). | |
| Geologic map unit | (-157.672211371216, 59.7195757955189) |
|---|---|
| Mineral deposit model | Titaniferous magnetite in clinopyroxenite; Alaska PGE? (Cox and Singer, 1986; model 9?); Porphyry Cu-Au-(Mo) (Cox and Singer, 1986; model 20c). |
| Mineral deposit model number | 9?, 20c |
| Age of mineralization | The age of the body is not known. The age of the country rocks is uncertain; from regional trends, they could be clastic sedimentary rocks of either Jurassic or Cretaceous age (Decker and others, 1994). |
| Workings or exploration | The Humble prospect is above a pronounced 4-mile-square magnetic anomaly identified in an aeromagnetic survey flown for Humble Oil and Refining Company in 1959 (Berg and Cobb, 1967). The anomaly reflects a large composite mafic and ultramafic body beneath 90 to 140 feet of unconsolidated Quaternary deposits. The pluton was explored by 16 diamond drill holes as the Kemuk prospect, some drilled to a depth of almost 2,000 feet. In 2010, Millrock Resources staked a large block of claims over the body, calling it the Humble prospect. Millrock with funding provided by Kinross Gold Corp., began drilling in August of 2011(Millrock, 2012). In September, 2011, Millrock reported that the drilling was not going well (Millrock Resources Inc., 2011). |
|---|---|
| Indication of production | None |
| Reserve estimates | The prospect was estimated to have a resource of 2.4 billion long tons that average 15 to 17 percent total iron in titaniferous magnetite (Nokleberg and others, 1987). A beneficiation test indicates the feasibility of producing a concentrate containing 65 percent Fe, 2 to 3 percent SiO2, 0.005 to 0.016 percent P2O5, and 2 to 3 percent TiO2. |