| Deposit ID | 10131061 |
|---|---|
| MAS/MILS ID | 0530330087 |
| Record type | Deposit |
| Current site name | Middle Fork Property |
| Alternate or previous names | Porter Zone - 0530331239, Clipper Zone, Clipper Adit, Snoqualmie River, Condor Zone - 0530331241, Hemlock Zone - 0530331240 |
| Point of reference | Main Entrance |
|---|---|
| Geographic coordinates: | -121.3498, 47.51152 (WGS84) |
| Elevation | 926 |
| Location accuracy | 100(meters) |
Political divisions (FIPS codes)
King(county)
Washington(state)
United States(country)
North America(continent)
Land(continent)
USGS map quadrangles
Big Snow Mountain(quadrangle 1:24,000 scale)
Skykomish River(quadrangle 1:100,000 scale)
Wenatchee(quadrangle 1:250,000 scale)
Hydrologic units (watersheds)
Snoqualmie(hydrologic unit)
Puget Sound(hydrologic accounting unit)
Puget Sound(hydrologic subregion)
Pacific Northwest(hydrologic region)
Federal lands
Mt. Baker-Snoqualmie National Forest(National Forest)
National Forest FS(Type of land area)
FS(Federal land areas administered by FS)
| Country | State | County |
|---|---|---|
| United States | Washington | King |
| Meridian | Township | Range | Section | Fraction | State |
|---|---|---|---|---|---|
| Willamette | 023 N | 011 E | 01 | Washington |
| Commodity | Importance |
|---|---|
| Copper | Primary |
| Molybdenum | Secondary |
| Gold | Secondary |
| Silver | Secondary |
| Materials | Type of material |
|---|---|
| Chalcopyrite | Ore |
| Gold | Ore |
| Molybdenite | Ore |
| Silver | Trace |
| Model code | 53 |
|---|---|
| USGS model code | 17 |
| Deposit model name | Porphyry Cu |
| Mark3 model number | 4 |
| Main Entrance (1) | -121.3498, 47.51152 |
|---|
| Strike | N20E | ||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dip | 60N | ||||||||||||||||||||||||||||||||||
| Thickness | 35M | ||||||||||||||||||||||||||||||||||
| Length | 9656M | ||||||||||||||||||||||||||||||||||
| Width | 441M | ||||||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||||||
| Operation type | Underground |
|---|---|
| Development status | Past Producer |
| Commodity type | Metallic |
| Significant | No |
| Discovery year | 1894 |
| District name | Snoqualmie |
|---|
| Type of mineral rights | Located Claim |
|---|---|
| Type of mineral rights | Patented |
| Type of mineral rights | Private Lease |
| Ownership category | National Forest |
|---|
| Type | Owner |
|---|---|
| Owner | National Resources Development Corp. |
| Interest | 100 |
| Home office | Washington |
| Year | 1977 |
| Agency | Database name | Acronym | Record ID | Notes |
|---|---|---|---|---|
| U.S. Bureau of Mines | Minerals Availability System | MAS | 0530330087 |
HUNTTING, M. T., 1956, INVENTORY OF WASHINGTON MINERALS-PART II, METALLIC MINERALS: WASHINGTON DIVISION OF MINES AND GEOLOGY BULLETIN 37, V. 1, 428 P., (P. 58).
LIVINGSTON, V.E., JR., 1971, GEOLOGY AND MINERAL RESOURCES OF KING COUNTY, WASHINGTON: WASHINGTON DIVISION OF MINES AND GEOLOGY BULLETIN 63, 200 P., 8 PL., (P. 152-153.)
H. K. THURBER, MICHAEL S. MILLER, AREL B. MCMAHAN, and FRANK E. FEDERSPIEL, 1989, ECONOMIC APPRAISAL OF THE ALPINE LAKES STUDY AREA AND ADDITIONS, WASHINGTON, in U.S. GEOLOGICAL SURVEY and U.S. BUREAU OF MINES, Mineral Resources of the Alpine Lakes Study Area and Additions, Chelan, King, and Kittitas Counties, Washington: U.S. GEOLOGICAL SURVEY BULLETIN 1542-E, P. 94-97.
Derkey, R.E., Joseph, N.L., and Lasmanis, Raymond, 1990, Metal mines of Washington - Preliminary report: Washington Division of Geology and Earth Resources Open File Report 90-18, p. 111-112.
| Subject category | Comment text |
|---|---|
| Deposit | From Thurber and others (1989, p. 94-97) The southwest part of the Middle Fork Snoqualmie River area, which includes the Porter, Hemlock, and Condor zones, is considered to have the greatest resource potential (fig. 9). The three zones are along or near the Copper Queen fault and the less well developed faults that intersect it. The Hemlock and Porter zones are believed to be contiguous and are discussed together. The 2380 adit is the main working level for the Hemlock zone. Surface sampling and shallow core holes in the Porter and Hemlock zones indicated areas of copper-rich rock as much as 85 ft (25.9 m) wide, mainly in northeast-trending structures. Drilling results in these zones show that the disseminated copper is mainly below the 3,200-ft (975-m) elevation. Two core drill holes, one from the surface outside the boundary of the Hemlock zone and one from underground in the 2795 adit (fig. 9), penetrated to 2,277-ft and 2,155-ft (694.0- and 656.8-m) elevations, respectively, in the downward projection of the Hemlock zone. Silicified rock and the disseminated sulfide minerals indicate that a deeper zone of copper-rich rock may exist at depth below the bottoms of the holes. Sampling and petrographic studies of rock from the 1,990-ft-long (606.7 m) 2380 arlit confirm the existence of copper there. The Hemlock breccia zone was penetrated from the portal of the adit to the 1,365-ft (416.1-m) point. From that point to the working face, another 625 ft (109.5 m), the rock becomes increasingly brecciated, altered, and mineralized, and the ratio of chalcopyrite to other sulfides becomes greater. Copper content of the wallrock averages approximately 0.44 percent from the 1,400-ft (426.7-m) point to the face and increases to 0.61 percent in the innermost 90 ft (27.4 m). Also, in the innermost 100 ft (30.5 m) of the adit, some 5-ft-long (1.5 m) samples contain as much as 1.14 percent copper. Samples from a 393-ft-Iong (119.8 m) crosscut driven (fig. 9) from the 2380 level toward the center of the Hemlock zone show an overall increase in copper values near the face. Samples taken from a 30-ft-long (9.1 m) interval between 338 and 368 ft (103.0 and 112.2 m) have a weighted average of 0.78 percent copper. The copper minerals and the rock alteration in the crosscut are similar to those in the 2380 adit. A comparison of the rocks observed on the surface of the Hemlock breccia zone with those found approximately 1,650 ft (503 m) vertically below in the workings shows a pronounced increase in intensity of alteration and in the amount of copper with depth. On the surface, intensely altered rock and copper sulfide minerals commonly occur only within or adjacent to fractures; whereas, at the 2380 level, alteration and copper mineralization have been pervasive through large volumes of the brecciated rock (fig. 10). A. R. Grant (written commun., 1971) observed that some large blocks of massive unaltered rock at the surface have graded vertically into mineralized and altered rock at the 2380 level. Further, because the eastern wall of the breccia zone dips steeply eastward, the area of the mineralized zone on the 2380 level is larger than on the surface. The core drilling program by a lessee in 1975 confirmed that the altered and copper-mineralized rock continues to lower elevations in the Hemlock breccia zone. The program explored the Hemlock zone to the 1,000-ft (305-m) elevation. |
| General | This deposit includes information from MRDS records describing the Condor-Hemlock, Clipper, and Three Brothers sites. |
| Deposit | The Middle Fork Snoqualmie contains a series of mineralized highly fractured/brecciated zone along a NNE trend that are intersected by northwesterly trending fault zones. They may be part of one porphyry Cu (Mo) mineralizing event. Each highly fractured zone has a MRDS record. The records can found by searching for "Middle Fork Property" as a Grouping name in the Browser interface Advanced search. The location used is about in the middle of this fractured zone. |
| General | From Derkey and others (1990, p. 111, Condor-Hemlock) Both patented and unpatented claims are owned (1990) by United Cascade Mining Company, Inc. The deposit was explored by Anaconda Copper Co., Howe Sound Co., Climax Molybdenum Corp., Anaconda Co., Bear Creek Mining Co., Cities Services Minerals Corp., Westland Mines Ltd., Natural Resources Development Corp., Houston Oil and Minerals, and Electras Resources. |
| Type | Date | Name | Affiliation | Comment |
|---|---|---|---|---|
| Reporter | 22-FEB-94 | Thurber, H.K. | U.S. Bureau of Mines | |
| Updater | 18-MAY-09 | Causey, J. Douglas | U.S. Geological Survey |
Supplemental information added by qvyshift.com. Not part of the original USGS MRDS record.