Surcease Mine (Bunker Hill Mine; Treasure Hill Mine), Big Bend, Butte County, California, USAi

Regional Level Types
Surcease Mine (Bunker Hill Mine; Treasure Hill Mine)	Mine
Big Bend	- not defined -
Butte County	County
California	State
USA	Country

A former lode Cu-Pb-Au-Ag-Zn-Sb mine located in secs. 4, 5, 6 & 7, T21N, R4E and sec. 25, T21N, R5E, MDM, 1.1 km (3,500 feet) SSW of Big Bend (hamlet) and 5.0 km (3.1 miles) ESE of Yankee Hill and about 3 miles NE of Las Plumas, on National Forest land. Owned by the Hoefling Brothers, Sacramento, California. MRDS database stated accuracy for this location is 500 meters.

Mineralization is a Cu-Pb-Au deposit hosted in schist. The ore body is ribbon-shaped, strikes NW and dips 20-40NE & 55-70NE, at a thickness of 6.1 meters. Controls for ore emplacement included a fault zone that strikes N70E and dips 65-70N. An associated rock is granite. Local rocks include Mesozoic volcanic rocks, unit 2 (Western Sierra Foothills and Western Klamath Mountains).

Local geologic structures include a trondjemite intrusion, that is exposed 2 Miles to the SE.

Workings include underground openings comprised of an incline of 24 degrees to a depth of 450 feet. It then steepens to 40 degrees, for a total depth of 610 feet. The principal adit is on the 210 foot level, entering from Shields Gulch near the mill, and running NW on the vein 1,000 or more feet, crossing the shaft and extending to North fault. The level above it runs 420 feet SE and 560 feet NW. Below the adit, a level runs both ways with raises to prospect the downwards extension of the ore shoots. The 600 foot level was also run 450 feet SE and 600 feet NW without finding and ore body. A millsite is present. More detailed descriptions are found in O'Brien.

Production data are found in: Logan (1930); O'Brien (1949); and in Goodwin (1957).

Production information: About 27,000 tons of ore were treated in the mill. No specific dates are available. Operated in 1914-1916 and reported to have produced $17,000 (period values) from ore that yielded $7 a ton in free gold (period values). Total production has been over $200,000 (period values) to date. The larger part of ore mined averaged $9 a ton (period values). Large Au-Ag production occurred during the period 1924-1943.

A few thousand tons of ore remained in sight in May, 1928.

Analytical data results: Assayed 0.2 top 0.06 ounces Au/ton.

Operating cost for mining, milling, treatment and marketing bullion was $5.03/ton (period values).

Other Databases

Link to USGS MRDS:	10035946

Other Regions, Features and Areas containing this locality

References