Leviathan Mine, Leviathan Peak, Monitor - Mogul Mining District, Alpine County, California, USAi

Regional Level Types
Leviathan Mine	Mine
Leviathan Peak	Peak
Monitor - Mogul Mining District	Mining District
Alpine County	County
California	State
USA	Country

A Cu-Au-Ag-S-Se-Hg-Fe mine located in the S½ secs. 14 & 15, in the N½ secs. 22 & 23 & in sec. 26, T10N, R21E (MD), 4.8 km (3.0 miles) NW of Leviathan Peak and 5.8 km (3.6 miles) NE of Loope, along Leviathan Canyon, near the Nevada state line, on National Forest land. Discovered in 1863 and was first worked for Cu & Au. The first S production was in 1933. Produced in 1894. Purchased by Anaconda Co. in 1952. MRDS database stated accuracy for this location is 100 meters. This locality is evidenced on the topo map by a large area of indicated tailings/excavation.

Mineralization is hosted in Pliocene andesite. The ore body is 41.15 meters thick, and is generally elliptical lens-like in form at a thickness of 27.43 meters, and with a depth-to-top of 60.96 meters. Alteration is local (silicification). Local rocks include Tertiary volcanic flow rocks, unit 17 (Cascade Range) and/or Plio-Pleistocene and Pliocene loosely consolidated deposits.

Sulfur was first discovered while prospecting for chalcanthite. The sulfur occurs in masses, stringers and veins, in a gray, altered porphyritic andesite with a maximum thickness of 135 feet. It is coarsely crystalline and glossy in porous tuff & evenly distributed. The sulfur in andesite (?), or opalized tuff, is less evenly distributed and fills fracture planes rather than pores. Mineralized tuff contains up to 70% S, but averages 35%. Rare masses or veins occur in both rock types. The mineralized andesite averages 25% but varies widely.

The S ore body occurs as a flat, faulted, elliptical lens at least 2,400 feet long. The S has impregnated the lower part of a lake-deposited (?) tuff bed and part of the underlying andesite (?). The tuff is white to yellowish. Contacts between non-mineralized and mineralized tuff are sharp, but in the andesite they are gradational over distances of 10 to 15 feet. Locally, the tuff is replaced by highly irregular areas of gray, opaline material several feet in length. Part of the tuff contains fine-grained crystals of kaolinized feldspar. The andesite (?) is remarkably similar to these replacement areas. An agglomerate unit about 120 feet in maximum thickness overlies the tuff. Rounded to angular brown to black porphyritic volcanic clasts from 1 foot to a fraction of an inch, are set in a gray tuffaceous sandstone matrix. Overlying the agglomerate is an unmineralized white tuff of about 100 foot maximum thickness, which thins rapidly and pinches out. Prior to pit development, a silicified "cap rock" rested on the tuff, which was as much as 160 feet thick, thinning away from the ore body.

Workings include surface and underground openings.

It was mined in an open pit. The ore averages 28% S with traces of cinnabar. It also occurs as a replacement in tuff. Thin beds of S interfinger with tuff one mile S and one mile W of the pit.

Workings include surface openings comprised of a 600 foot by 1,500 foot open pit (overall depth = 121.92 meters; overall length = 609.6 meters; and, an overall width of 304.8 meters). The pit mine had 35 foot benches for stripping and 15 foot benches for mining ore. The waste to ore ratio was generally 11:1.

Production information: This mine produced nearly all the S mined in California, averaging about 250,000 tons annually. Copper production was between 100,000 and 1,000,000 (pounds ??) of Cu. The output was sent to Yerington, Nevada, and used to make H2SO4.

Total annual values of production from 1953 through 1962 were: $757,740 ( 1953), $1,150,429, $1,167,573, $1,561,595, $1,492,464, $1,428,852, $1,365,600, $1,670,647, $1,673,609, and $1,413,223. Total long tons of ore for the period were 1,668,349; total long tons S were 465,616, and estimated total value produced was $14,542,732. Once a high-grade Cu ore mine, it became generally unproductive after the 1860's.

Anaconda supplied data from a typical sample (date = ?) from a truckload of mineralized tuff. It was: insoluble (mostly SiO2), 49%; Fe at 6%, S at 33%, soluble salts at 12%, and traces of Al2O3, MgO, and CaO. Sulfates such as romerite may be forming on the pit floor today.

Other Databases

Link to USGS MRDS:	10028007

Other Regions, Features and Areas containing this locality

References