|Latitude & Longitude (WGS84):||39° 20' 39'' North , 120° 48' 4'' West|
|Latitude & Longitude (decimal):||39.34429,-120.80103|
|Köppen climate type:||Csb : Warm-summer Mediterranean climate|
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
|Jurassic - Triassic|
145 - 252.17 Ma
|Mesozoic sedimentary and volcanic rocks|
Age: Mesozoic (145 - 252.17 Ma)
Reference: Chorlton, L.B. Generalized geology of the world: bedrock domains and major faults in GIS format: a small-scale world geology map with an extended geological attribute database. doi: 10.4095/223767. Geological Survey of Canada, Open File 5529. 
|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.