Spring Valley Hydraulic Mine (Spring Valley Mine; Cherokee Mine; Cherokee Hydraulic Mine; Cherokee Placer Mine), Cherokee, Cherokee Mining District, Butte County, California, USAi

Regional Level Types
Spring Valley Hydraulic Mine (Spring Valley Mine; Cherokee Mine; Cherokee Hydraulic Mine; Cherokee Placer Mine)	Mine
Cherokee	- not defined -
Cherokee Mining District	Mining District
Butte County	County
California	State
USA	Country

A former placer/hydraulic Au-diamond-Pt mine located 1.0 km (3,300 feet) SW of Cherokee, on Cherokee Flat, 12 miles N of Oroville. MRDS database stated accuracy for this location is 100 meters. Discovered in 1854. The Cherokee Mine was a highly productive hydraulic mine that was also notable for its production of diamonds.

Mineralization is a placer Au-PGE deposit hosted in Tertiary gravels (Model Model code 119; USGS model code 39a; BC deposit profile C01. C02; Deposit model name: Placer Au-PGE; Mark3 model number 54). The ore body is irregular in form. Controls for ore emplacement included mechanical accumulation on irregular bedrock riffles and within river- and stream-channel lag gravels, bars, and point-bar deposits. Local rocks include Eocene nonmarine rocks, unit 1 (Northern and Central California).

Most of the output of the Cherokee Mining District came from the Cherokee Mine. First developed in 1854, this deposit was hydraulicked exclusively from 1858 to 1890, when anti-debris laws reportedly forced closure. Mine tailings were dumped into Sawmill Ravine, from which they were conveyed to Dry Creek. Mining of this deposit resumed in 1900 by means of various drifting techniques and continued sporadically at least up to 1930. Exploratory work was conducted at this mine around 1980-1981. The mine has been a source of mercury in nearby Dry Creek (Brown and Murphy, 2005).

Regional geology: The Cherokee Mine is situated at the western edge of the Sierra Nevada geologic province. This province is characterized by extremely complex lithologies and structures that were assembled through various plate-tectonic processes. Paleozoic-Mesozoic metamorphic complexes intruded by various Mesozoic plutons compose the basement of the province. This basement is overlain locally by erosional remnants of Cenozoic volcanic and sedimentary rocks, including gravels. Most of these various lithologies contain gold in places. Structurally, the metamorphic rocks and some of the plutonic rocks have been deformed by folding and faulting. The major fault zones typically trend northerly or northwesterly, although in places intrusion of the younger plutons has deformed some of the zones so as to assume other trends as well. In contrast, the overlying Cenozoic rocks are relatively undeformed.

The Cherokee Mine was developed within Tertiary gold-bearing gravels deposited along a west-trending channel that underlies the basalt of Table Mountain. At its bottom, the channel is about 700 feet wide and characterized by a very irregular bedrock surface. The materials in these deposits have been derived by erosion of the various basement and older Cenozoic rocks at higher elevations. In places, the basement rocks contain gold within quartz veins and altered rock. Erosion of the gold-bearing basement rocks provided the gold that was eventually deposited in the channel at the Cherokee Mine. Lindgren (1911) reported the following stratigraphic section, from bottom to top, at the Cherokee Mine: 5-10? Hard, cemented greenstone gravel with local streaks of black clay; very poor in gold; no gold on greenstone bedrock; diamonds and platinum also recovered 20-30? Partly cemented, very coarse blue gravel with large blocks of greenstone; rich in gold, which is concentrated mostly on the surface with the underlying greenstone gravel 2-3? Decomposed gravels of the blue gravel 50? White sand and quartzose gravel; some fine gold 200? Sandy clay 50-75? Massive basalt Lindgren (1911) interpreted the clay hoizon to be part of the Ione Formation. Creely (1965) presented another stratigraphic section measured at the Cherokee Mine.

Commodity Information: Much of the gold in the blue-gravel horizon is coarse, but there is also much fine gold. Some of the gold has a fineness of 945 (Lindgren, 1911). About 400-500 small diamonds were recovered from the gravels of this mine. Several of the stones were more than two carats in weight and of good quality, but most were small and had a pale yellow tinge. This site is the best-known diamond-bearing locality in California. Ore materials included native gold, diamond, and native platinum; gangue materials included quartz, metamorphic rock, and igneous rock.

Workings included surface and underground openings and operations. The channel was orginally developed by hydraulicking, with the highwall reaching 500 feet. About 150 acres were hydraulicked to bedrock and nearly as much was worked to within 15 feet of bedrock. The lowest material was cemented. Later, the channel was worked by minor drifting, some of which was developed in a coarse, blue gravel. This layer carries coarse gold and was considered the principal productive stratum in the original hydraulic mine.

Production data: The Cherokee Mine is estimated to have yielded about $15,000,000 in gold (period values) and about 400-500 diamonds.

Other Databases

Link to USGS MRDS:	10310601

Other Regions, Features and Areas containing this locality

References