Rising Sun Mine

Site Name

Primary: Rising Sun Mine

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Commodity

Primary: Gold
Secondary: Copper

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Location

State: California
County: Placer
District: Illinois District

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Land Status

Land ownership: Private
Note: the land ownership field only identifies whether the area the mine is in is generally on public lands like Forest Service or BLM land, or if it is in an area that is generally private property. It does not definitively identify property status, nor does it indicate claim status or whether an area is open to prospecting. Always respect private property.
Administrative Organization: Placer County Planning Department

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Holdings

Not available

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Workings

Not available

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Ownership

Not available

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Production

Not available

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Deposit

Record Type: Site
Operation Category: Past Producer
Deposit Type: Hydrothermal vein; hydrothermal stringer zone
Operation Type: Underground
Discovery Year: 1866
Years of Production:
Organization:
Significant: Y
Deposit Size: S

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Physiography

Not available

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Mineral Deposit Model

Model Name: Low-sulfide Au-quartz vein

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Orebody

Form: Tabular

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Structure

Type: R
Description: Gillis Hill Fault; Weimar Fault Zone

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Alterations

Alteration Type: L
Alteration Text: None reported

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Rocks

Name: Granodiorite
Role: Associated
Age Type: Associated Rock
Age Young: Mesozoic

Name: Sandstone
Role: Associated
Description: Meta-
Age Type: Associated Rock
Age Young: Late Jurassic

Name: Slate
Role: Associated
Age Type: Associated Rock
Age Young: Late Jurassic

Name: Diabase
Role: Host
Age Type: Host Rock
Age Young: Triassic

Name: Gabbro
Role: Host
Age Type: Host Rock
Age Young: Triassic

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Analytical Data

Not available

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Materials

Ore: Gold
Ore: Pyrite
Ore: Chalcopyrite
Gangue: Quartz

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Comments

Comment (Commodity): Commodity Info: Waring (1915) reported that 80% of the gold obtained was native and the remaining 20% was from sulfides ($150-200 per ton based on pre-1935 gold rates). Lindgren (1900) reported that the gold is coarse and commonly visible to the naked eye. Specimen gold was produced from a 40-foot long high-grade ore shoot.

Comment (Commodity): Ore Materials: Native gold and auriferous sulfides (pyrite, chalcopyrite)

Comment (Commodity): Gangue Materials: Quartz

Comment (Development): The Rising Sun Mine opened in 1866 and continued operation until 1884; the original mining claim was patented in 1870. Nearly all production was obtained during this period. The mine was then idle until 1919, when a period of minor sporadic mining took place until 1932. Some of this mining activity was associated with working of the adjacent Big Oak Tree Mine. Only very small tonnages of ore were produced during a few brief mining episodes over this period. The Rising Sun Mine was reportedly closed in 1935 (Chandra, 1961; Koschmann and Bergendahl, 1968). In 1933, mill tailings in several ponds and dumps at the mine site, which were estimated to comprise about 7,200 tons total, were evaluated for recovery of gold. One of the piles was partially processed with cyanidation in 1917. It is not known if the tailings were ever completely processed or if any are still present at the site. In the 1890?s, an adit was started from the canyon of the Bear River with the intention of intersecting the workings of the Rising Sun Mine. It was eventually completed in the late 1920?s or very early 1930?s. Amalgamation and cyanidation processes were used at this mine.

Comment (Economic Factors): Clark (1970) estimated production at the Rising Sun Mine to be in excess of $2 million.

Comment (Geology): REGIONAL GEOLOGY The Rising Sun Mine is within the Colfax District, which is situated in the northern portion of the Sierra Nevada Foothills Gold Belt. This belt averages 50 miles wide and extends for about 150 miles in a north-northwest orientation along the western slope of the Sierra Nevada Mountains. The Colfax District is about 7-8 miles south of the Grass Valley District, home to California's two largest underground gold mines, the Empire and the Idaho-Maryland. It is also about 10-12 miles north-northwest of the northern end of the Mother Lode Belt of mineralization. Regionally, the Foothills Gold Belt approximately coincides with the Foothills Metamorphic Belt, which in this area can be subdivided into four major lithotectonic belts: Western Belt, Central Belt, Feather River Peridotite Belt, and Eastern Belt (Schweickert and others, 1999). The Western Belt in this area consists mainly of metamorphosed volcanic, sedimentary, and intrusive rocks of the Mesozoic Smartville Complex (Beard and Day, 1987). It is separated from the Central Belt by the Wolf Creek Fault Zone. The Central Belt consists of a complicated assemblage of Paleozoic-Mesozoic metasedimentary, metavolcanic, and metaplutonic rocks that have been intruded locally by Mesozoic plutonic rocks. The Central Belt is separated from the East Belt by the Feather River Peridotite Belt, which coincides in part with the Melones Fault Zone, a major structural boundary of the western Sierra Nevada. Rocks in this belt are largely peridotite and serpentinite, with lesser amounts of metasedimentary and metavolcanic rocks locally. The East Belt is dominantly metasedimentary and metavolcanic rocks of Paleozoic-Mesozoic age. Most of the metamorphic rocks in the belt in this area have been assigned to the Lower Paleozoic Shoo Fly Complex. The metamorphic complexes are intruded in places by Mesozoic plutonic rocks. The Rising Sun Mine lies within the Central Belt, which in the Colfax area is marked by a 15-mile-wide north-trending assemblage of accreted metamorphic terranes (Tuminas, 1983). The oldest rocks in this assemblage are the metasedimentary-metavolcanic rocks of the Paleozoic-Triassic Calaveras Complex, which is exposed in the east part of the belt. Exposed in the west part of the belt, and underlying the Rising Sun Mine, are metamorphic rocks of the Paleozoic-Mesozoic Lake Combie Complex. These include mostly metavolcanic rocks and lesser amounts of metasedimentary and metaplutonic rocks. Metamorphosed turbidites of the Jurassic Mariposa Formation are exposed as a sliver between these two complexes.

Comment (Geology): LOCAL GEOLOGY The Rising Sun deposit is situated in a complex structural block between two fault zones, the Weimar and Gillis Hill. In this block, metaigneous rocks of the late Paleozoic-early Mesozoic Lake Combie Complex are wedged between two narrow northerly trending extensions of a block of turbidite deposits of the Mariposa Formation (?Colfax sequence? of Tuminas, 1983) to the south. The deposit consists of a quartz vein, part of which has ribbon structure, and small zones of quartz stringers, both of which are in metaigneous rock of the Lake Combie Complex. The geologic environment of this deposit is more similar to that of the Grass Valley Mining District, about 7-8 miles to the northwest, than it is to the Mother Lode Belt to the south. Some earlier publications (Waring, 1915; Logan, 1936) describe the wallrock of the deposit as diabase. More-recent studies have classified the country rock as gabbro (Chandra, 1961) or a mixture of gabbro and quartz diorite (Tuminas, 1983). Chandra (1961) also mapped a small stock of granodiorite on the south edge of the mine complex. Lindgren (1900) mapped the vein complex at the mine as cutting gabbro, diabase, and serpentinite. The wallrock is reportedly very hard, with no mention in the reports reviewed of any alteration. Waring (1915), however, mentioned an assay done on ?mineralized schist? from a dump at the Rising Sun, which, if this sample was from the mine itself, might suggest hydrothermal alteration of the wallrock. The Rising Sun quartz vein strikes east-northeast and dips 85SE from the surface down to the 7th level (590-foot), where it reversed dip, over a distance of 20 feet, to 85NW. In the upper levels of the mine, the quartz vein averages 18 inches in width, but increases with depth. According to Logan (1936), below the change in dip on the 7th level, the vein widened to 4-5 feet and became softer. Waring (1915) reported the vein ranges from 6 inches to 3 feet in width. Ore was composed mostly of native gold and minor amounts of auriferous sulfides (pyrite and chalcopyrite). Ore mined during the 1930?s contained about 2% sulfides, which yielded about 2 ounces of gold per ton. Overall, ore may have averaged about 1-2% sulfides. West of the 749-foot shaft, ore was well-paying down to the 7th level where the quartz vein changed dip. Low-grade stringers were mined from a point east of this shaft. A notable 40-foot-long shoot of high-grade gold ore was discovered near a cross fault on the west side of the deposit (Logan, 1936). The fault evidently bounded the rich ore on the west side and may have influenced its deposition. Also, in the west part of the 3rd level, wallrock was locally smeared with a thin film of gold. An unpublished map prepared and submitted to Waldemar Lindgren by a mine owner in 1897 shows a series of northwest-trending quartz-vein-bearing faults that displace the Rising Sun vein in several places. The owner stated these cross veins were not auriferous, although some carried copper sulfides. In addition, a northerly trending lens of serpentinite is shown on the map a few hundred feet north of the Rising Sun vein; the lens is altered to talc where it was observed.

Comment (Identification): The Rising Sun Mine is believed to be the most productive lode-gold mine in Placer County.

Comment (Environment): The Rising Sun Mine is in a hilly area covered with mixed oak-conifer woodland. A high school and residential areas are immediately adjacent to the mine site on the east and north.

Comment (Location): Location selected for latitude and longitude is a shaft symbol just above the word ?Rising? on the USGS 7.5-minute Colfax quadrangle.

Comment (Workings): The Rising Sun Mine was developed mainly by three shafts and associated drifting along ten levels. The three shafts were sunk to 187 feet, 350 feet, and 749 feet. Drifting reached lengths of 150 feet to the west (cut off by fault) and 400 feet to the east (property line) in the 1800?s. In 1920, stopes were 150 to 350 feet long. The wallrock is hard, and timbering was generally not required. The mine map described above in the Geology Comments shows that extensive stoping was already accomplished by the 1890?s. The map also shows a 2,000-foot long north-northwest-trending adit that was being driven from the Bear River canyon, which is northwest of the mine. The intention was to intersect the Rising Sun vein at about 500 feet below the ground surface. Logan (1936) stated that the adit was eventually completed, either in the late 1920?s or early 1930?s. The adit intersected the workings about 30 feet above the 6th level.

Comment (Deposit): The Rising Sun deposit is situated between the north end of the Mother Lode Belt of gold mineralization and the extensive lode-gold mineralization of the Grass Valley and Nevada City districts to the northwest. The geologic setting of the deposit is more similar to the deposits at Grass Valley and Nevada City. At the Rising Sun Mine, a nearly vertical east-northeast-trending main quartz vein and minor zones of stringers cut metamorphosed mafic igneous rocks; the vein ranges in thickness from 6 inches to 5 feet, and part of it exhibits ribbon structure. The vein and stringers contain native gold and minor amounts of auriferous sulfides (pyrite, chalcopyrite). Ore is higher grade in the upper 500-600 feet of the deposit, but appears to become lower grade below that depth perhaps because of a change in dip of the vein system.

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References

Reference (Deposit): Koschmann, A.H., and Bergendahl, M.H., 1968, Principal gold-producing districts of the United States: U.S. Geological Survey Professional Paper 610, 283 p.

Reference (Deposit): Schweickert, R.A., Hanson, R.E., and Girty, G.H., 1999, Accretionary tectonics of the Western Sierra Nevada Metamorphic Belt, in Wagner, D.L. and Graham, S.A., editors, Geologic field trips in northern California: California Division of Mines and Geology Special Publication 119, p. 33-79.

Reference (Deposit): Tuminas, A., 1983, Structural and stratigraphic relations in the Grass Valley-Colfax area of the northern Sierra Nevada, California: Ph.D. dissertation, University of California, Davis, 415 p.

Reference (Deposit): Waring, C.A., 1915, Placer County: 15th Annual Report of the State Mineralogist, California State Mining Bureau, p. 349.

Reference (Deposit): Saucedo, G.J. and Wagner, D.L., 1992, Geologic map of the Chico Quadrangle, California: California Department of Conservation, Division of Mines and Geology Regional Geologic Map Series, Map No. 7A, scale 1:250,000.

Reference (Deposit): Lindgren, W., 1900, Colfax folio, California: U.S. Geological Survey Atlas of the U.S., Folio 66, 10 p.

Reference (Deposit): Logan, C.A., 1921, Placer County: 17th Annual Report of the State Mineralogist, California State Mining Bureau, p. 446-447.

Reference (Deposit): Logan, C.A., 1927, Placer County: 23rd Annual Report of the State Mineralogist, California State Mining Bureau, p. 252.

Reference (Deposit): Logan, C.A., 1936, Gold mines of Placer County: 32nd Annual Report of the State Mineralogist, California Journal of Mines and Geology, p. 34-35.

Reference (Deposit): Beard, J. S. and Day, H. W., 1987, The Smartville intrusive complex, Sierra Nevada, California: The core of a rifted volcanic arc: Geological Society of America Bulletin, v. 99, no. 6, p. 779-791.

Reference (Deposit): Chandra, D.K., 1961, Geology and mineral deposits of the Colfax and Foresthill quadrangles, California: California Division of Mines Special Report 67, 50 p.

Reference (Deposit): Clark, W.B., 1970, Gold districts of California: California Division of Mines and Geology Bulletin 193, p. 38.

Reference (Deposit): Irelan, W., Jr., 1888, Placer County: Eighth Annual Report of the State Mineralogist, California State Mining Bureau, p. 462-463.

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California Gold

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