Red Ledge Mine, Washington, Washington District (Omega District), Nevada Co., California, USA
|Latitude & Longitude (WGS84):||39° 20' 39'' North , 120° 48' 4'' West|
|Latitude & Longitude (decimal):||39.34429, -120.80103|
A former Au-Cr-Fe mine located in sec. 12 & in the NW¼NE¼ sec. 13, T17N, R10E, MDM, about 2 miles SW of Washington, on National Forest land. MRDS database stated accuracy for this location is 10 meters.
Note: not to be confused with Red Ledge mine in Sierra Co.
Gold-bearing quartz lode occurs along a major fault between serpentinized ultramafic rocks and amphibole schist of the Tightner Formation. The 10 to 30 foot lode extends about 8,000 feet. The gold occurs as leaves and plates in quartz, often accompanied by mariposite and ankerite gangue. Local rocks include ultramafic rocks, chiefly Mesozoic, unit 2 (Western Sierra Nevada and Klamath Mountains).
Gold Mine: The gold/quartz veins occur in the sedimentary rocks close to the contact with serpentinite. Mariposite is often in association with the serpentine, and in close proximity to the gold.
Chromite Mine: The Chromite occurs in lenses and pods in the serpentine, close to the contact with the sedimentary rocks. Chromite was produced from the Red Ledge in the 1918-19 time period. The ore grade was 45%.
18 valid minerals. 1 (TL) - type locality of valid minerals.
This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.
Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org
|Early Jurassic - Neoproterozoic|
174.1 - 1000 Ma
|Ultramafic rocks, chiefly Mesozoic, unit 2 (Western Sierra Nevada and Klamath Mountains)|
Comments: Feather River peridotite, Kings River ophiolite, Kings-Kaweah ophiolite melange. Tectonized ultramafic complexes in western Sierra Nevada and western Klamath Mts., primarily of Ordovician to Early Jurassic age. Characterized in large part by serpentinite-matrix melanges containing blocks and slabs of ultramafic and other rocks
Reference: Horton, J.D., C.A. San Juan, and D.B. Stoeser. The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States. doi: 10.3133/ds1052. U.S. Geological Survey Data Series 1052. 
Hanks, Henry Garber (1884), Fourth report of the State Mineralogist: California Mining Bureau. Report 4, 410 pp. (includes catalog of minerals of California pp. 63-410), and miscellaneous observations on mineral products): 137.
Bradley, W.W., Huguenin, Emile, Logan, C.A., Tucker, W.B., and Waring, C.A. (1918), Manganese and chromium in California: California Mining Bureau. Bulletin 76, 248 pp.: 158.
Logan, Clarence August (1918), Unpublished Field Report, Nevada County No. 203, Red Ledge.
MacBoyle, Errol (1919), Mines and mineral resources of Nevada County: California Mining Bureau. Report 16, 270 pp. (published as separate chapter): 63, 67, 77.
Gordon, Samuel G. & E.V. Shannon (1928), Chromrutile a new mineral from California: American Mineralogist: 13: 69.
Melhase, John (1935c), Some garnet localities of California: Mineralogist: 3(11): 23.
Rocks & Minerals (1939): 14: 337.
Bradley, W.W. (1940), Thirty-sixth report of the State Mineralogist: California Division Mines Report 36: 69.
Palache, Charles, Harry Berman & Clifford Frondel (1944), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana Yale University 1837-1892, Seventh edition, Volume I, John Wiley & Sons, New York: 559-560.
Rynearson, Garn Arthur (1953), Geological investigations of chromite in California: Chromite deposits in the northern Sierra Nevada, California. California Division of Mines and Geology Bulletin 134, part 3 chapter 5: 239.
Anonymous (1957), World news on mineral occurrences: Rocks & Minerals: 32: 12.
Strunz, Hugo (1961), “Chromrutil” von der Red Ledge mine ist kein rutil. Redledgeite: Neues Jahrb. Mineral., Monatsh.: 107-111.
Strunz, Hugo (1963), Redledgeite, eine TiO2-einlagerungestruktur analog kryptomelan: Neues. Jahrb. Min. mh. 5: 116-119.
McCulloch, W.C., Oesterling, W.A., Spurck, W.H., & Tischler, M.S. (1964), Minerals for Industry, Northern California, Southern Pacific Company: Vol. II: 31.
Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 118, 136, 137, 141, 143, 194, 203, 256, 319, 350.
Bancroft, Peter (1973) The World's Finest Minerals and Crystals. Viking Press: 154.
Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 130, 174, 434, 497.
Bancroft, Peter (1984) Gem and Crystal Treasures. Western Enterprises, Mineralogical Record: 15: 89.
USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10031922 & 10163996.
U.S. Bureau of Mines, Minerals Availability System (MAS) file #0060570726.