Sultana - Orleans Mine

Past Producer in Nevada county in California, United States with commodities Gold, Silver

Geologic information

Identification information

Deposit ID 10310687
Record type Site
Current site name Sultana - Orleans Mine
Alternate or previous names Electric Mine, Orleans Mine, Prescott Mine, Houston Hill Mine, Sebastopol Mine, Centennial Mine

Comments on the site identification

  • The Sultana Mine is a consolidation of the Sultana Mine (formerly called the Electric Mine), and the Orleans, Prescott , Houston Hill, Sebastopol, and Centennial mines.

Geographic coordinates

Geographic coordinates: -121.04533, 39.20299 (WGS84)
Elevation 817
Location accuracy 100(meters)
Relative position 1 mile southeast of the town of Grass Valley
(click for info)

Geographic areas

Country State County
United States California Nevada

Public Land Survey System information

Meridian Township Range Section Fraction State
Mount Diablo 015N 008E 35 SE/4 California

Comments on the location information

  • The location point selected for latitude and longitude represents the Orleans Mine shaft symbol on Lindgren?s 1896 1:14,400-scale Grass Valley Special Map (contained in Lindgren?s 1896 Nevada City Special Folio) and transcribed onto the USGS Grass Valley 7.5-minute quadrangle.


Commodity Importance
Gold Primary
Silver Secondary

Comments on the commodity information

  • Ore Materials: Free-milling fine to coarse gold in quartz. Auriferous pyrite, galena, arsenopyrite
  • Gangue Materials: Quartz, calcite, chalcopyrite, sphalerite

Materials information

Materials Type of material
Gold Ore
Pyrite Ore
Galena Ore
Arsenopyrite Ore
Quartz Gangue
Calcite Gangue
Chalcopyrite Gangue
Sphalerite Gangue


  • (Local) Ankeritic, sericitic, and pyritic replacement of wall rocks adjacent to veins

Mineral occurrence model information

Model code 273
USGS model code 36a
Deposit model name Low-sulfide Au-quartz vein
Mark3 model number 27

Host and associated rocks

  • Host or associated Host
    Rock type Plutonic Rock > Mafic Intrusive Rock > Diorite > Diabase
    Rock type qualifier porphyry
    Stratigraphic age (youngest) Early Cretaceous
  • Host or associated Host
    Rock type Plutonic Rock > Granitoid > Granodiorite
    Stratigraphic age (youngest) Mesozoic
    Stratigraphic age (oldest) Paleozoic

Nearby scientific data

(1) -121.04533, 39.20299

Geologic structures

Type of structure Regional
Structure description Wolf Creek Fault Zone, Gillis Hill Fault, Melones Fault Zone

Ore body information

  • General form Tabular

Controls for ore emplacement

  • Mineralization occurs as erratic shoots within mesothermal gold-bearing quartz deposited within fracture zones.

Comments on the geologic information

  • REGIONAL GEOLOGY The Sultana-Orleans Mine is within the Grass Valley District, home to California's two largest underground gold mines, the Empire and the Idaho-Maryland. The district is located 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 range. The Foothills Gold Belt roughly coincides with the Foothills Metamorphic Belt, which can be subdivided into four major lithotectonic belts: Western Belt, Central Metamorphic Belt, Feather River Peridotite Belt, and Eastern Belt. The Grass Valley District lies within the Central Belt, where in the Grass Valley area it is marked by an 8-mile-wide north-trending assemblage of two accreted terranes that range from Late Triassic to Late Jurassic in age. The Central Belt is bounded on the east and west by regional-scale tectonic suture zones; the Wolf Creek Fault Zone on the west and the Gills Hill Fault/Melones Fault Zone on the east. The oldest rocks in the area are those of the Carboniferous-Triassic metasedimentary Calaveras Complex. Originally clastics, these rocks were converted to schistose or slaty rocks during the Late Paleozoic orogeny and locally into a contact-metamorphic biotite gneiss by intruded granodiorite during Late Mesozoic time. The slates of the Jurassic Mariposa Formation, which outcrop in a small part of the area, are relatively unaltered. Igneous rocks in the district include granodiorite, diabase, porphyrite, amphibolite schist, serpentinite, gabbro, diorite, quartz porphyry, and various dike rocks (Johnston, 1940). The veins of the Grass Valley and neighboring Nevada City districts are not connected with or continuations of the famous Mother Lode vein system to the south. The last veins of the Mother Lode end about 20 miles to the south. Also, the Grass Valley veins differ in general character from those of the Mother Lode. Generally, the Grass Valley veins are narrower and produce a higher-grade ore than those of the Mother Lode. The veins trend in two primary directions. One set trends N-S (dipping E or W), and the other trends E-W (dipping N or S). The major feature of the Grass Valley District is a body of Lower Cretaceous granodiorite and diabase five miles long from north to south and half a mile to two miles wide (probably the apex of a larger batholitic mass). It which is intruded into older sedimentary and igneous rocks, including diabase of the Mesozoic-Paleozoic Lake Combie Complex, and is itself cut by various dike rocks. Gold-quartz veins cut the granodiorite and diabase (and in some cases, serpentinite) throughout the district. Most of the veins strike generally north, parallel to the intrusive body, and display gentle dips averaging 35?. Others strike northwest, parallel to a diabase contact with the granodiorite. The veins fill minor thrust faults that occur within fracture zones of various width and degree of fracturing. The maximum measured reverse displacement is 20 feet (Johnston, 1940). In all veins, quartz is the principal vein material and occurs in four textural types: 1) Comb quartz that forms crustifications and lines vugs, 2) massive milky quartz with a granular texture that displays many sharp crystal faces and has not undergone deformation, 3) sheared quartz developed with little or no dilation of the vein fracture and commonly showing ribbon or shear-banding structures, and 4) brecciated quartz formed where vein movement dilated the interwall space (Johnston, 1940). Gold occurs in quartz and in sulfides, principally pyrite. Although specimen ore has been found, most ore from the district occurs as fine and coarse free-milling gold in ores averaging between 0.25 to 0.5 ounces per ton.
  • An important structural feature in the district is a group of "crossing" vertical or steeply dipping fractures that strike northeast, about normal to the long axis of the granodiorite body. In places they are simple fractures; elsewhere they form sheeted fracture zones several feet wide. Some are tight, some are open and form watercourses, and few contain any quartz. Two main stages of primary or hypogene mineralization are recognized - 1) a hypothermal stage represented by one vein and one mineralized crossing, in which magnetite, pyrrhotite, pyrite, and specularite were deposited, and 2) a mesothermal stage, in which the gold quartz veins were formed. The mesothermal stage is further divided into two sub-stages - an older one, in which quartz is the principal gangue mineral, and a younger one, marked by the deposition of carbonates. Pyrite and arsenopyrite, deposited in the quartz stage, are the earliest sulfides of the gold-quartz veins. Sphalerite, chalcopyrite, and galena are somewhat later. No secondary or supergene minerals have been noted except limonite, calcite, and gypsum, which are being deposited in the oxidized zone. The distribution of gold in the ore shoots is extremely erratic and assays of adjacent vein samples commonly differ widely. Some ore shoots have a pitch length of several thousand feet, but most are much smaller. Adjacent to veins and crossing fractures, the wall rocks are generally highly altered. Ankerite, sericite, and pyrite have replaced the original rock-forming minerals. Lesser amounts of chlorite and epidote have been found. The wall rock has not been replaced by quartz. LOCAL GEOLOGY The Sultana Mine veins are the southern continuation of the Empire-Ophir Hill vein system, which produces in the Empire Mine to the north. The Empire Mine was the most productive underground mine in California history. All of the veins in the Sultana property are in diabase porphyry with the single exception of the lower workings (1750') of the Prescott Hill shaft, which penetrated granodiorite. Veins include the Rich Hill vein and the Ophir (Orleans) vein before they pass onto Empire Mine property. In the Orleans shaft, the Ophir vein strikes N 30? W and dips from 12? to 52? W (averages 40? W), with a width of 2 feet between walls and 8 inches of quartz. The ore contained 3% sulfides, primarily pyrite, galena, and arsenopyrite, which averaged 3.5 ounces of gold and 0.7 ounces of silver per ton. The Prescott Hill vein has an average dip of 25? W and strikes north to northwest. The vein was small, averaging 12 inches, and all the ore came from above the 700-foot level. The Sebastopol Electric vein lies 700 feet east of the south end and parallel to the Orleans and Prescott Hill veins. The Houston vein lies north of the Sebastopol and several hundred feet east of the Ophir-Prescott Hill vein, strikes N 45? W and dips 45? SW. Ore produced from this small 8 inch vein was very rich yielding as high as $160 per ton. Gold was 790 fine.

Economic information

Economic information about the deposit and operations

Operation type Underground
Development status Past Producer
Commodity type Metallic
Significant Yes
Discovery year >1850

Mining district

District name Grass Valley

Land status

Ownership category Private
Area name Nevada County Planning Dept.

Comments on the workings information

  • Underground workings of the Sultana and Orleans mines as of 1940 are described by Johnston (1940, pl. 38).

Comments on development

  • The Sultana Mine (formerly called the Electric Mine) is a consolidation of the former Electric, Orleans, Prescott Hill, Electric, Houston Hill, Sebastopol, and Centennial mines located in the Osborne Hill area southeast of Grass Valley and south of the Empire - Star Mine. Portions of this property (in the individual mines) were worked in the early days. The old Orleans shaft was sunk to a depth of 100 feet and the Houston Hill vein was worked from 1861-1870 to a depth of 300 feet and produced between 1864 and 1867 a total of $500,000. The Sebastopol workings on the north end of the Sultana vein produced $200,000 between 1856 and 1858 from a depth of 180 feet on the incline. Between 1876 and 1883, the Centennial Mine is reported to have produced $600,000, and between 1903 and 1918, Sultana Mining Company had driven 12,000 feet of drifts and 3000 feet of crosscuts and taken out an additional. $750,000 (MacBoyle, 1919). The name was changed from the Electric Mine to the Sultana Mine in 1903 when the Sultana Mining Co. acquired the property and extended the shaft to the 800-foot level, at a vertical depth of 300 feet. South of the shaft, an inclined winze was sunk from the 800- to the 1600-foot level, about 800 feet vertically beneath the surface. Most of the ore produced by the Sultana Mining Co. came from the 800-foot level and above. The Electric, or Sultana shaft, on the Sebastopol Electric vein, prior to 1896, had reached a depth of 400 feet on the vein and later this shaft was deepened to 600 feet. From a point 1500 feet south of the shaft on the 600-foot level, a winze was sunk on the vein for a distance of 1100 feet. Drifts were driven on the vein on the 6th, 8th, and 12th levels, 800 north and 1000 south, and on the 16th level 250 feet north. Crosscuts were also driven into the hanging wall 100 feet on the 8th level, 300 feet on the 12th level, and 86 feet on the 16th level. The shaft on the Prescott hill vein, worked to a depth of 300 feet on the incline prior to 1867, was reopened by the Sultana Mining Co. in 1906 and by September 1909 had reached a depth of 1750 feet on an average dip of 25? W. Drifts were run on the vein as follows: 4th level (2000 feet south); 7th (1200 feet south); 12th (500 feet north and 1500 feet south). On the 17th level, a crosscut was driven 800 feet eastward into the footwall and on the 7th level 1200 feet in the same direction. In 1916, the Orleans shaft was dewatered and reached a depth of 800 feet with drifts on various levels both north and south and on the 700-foot level crosscuts were extended 250 feet into the hanging wall and 300 feet into the footwall to intersect the Houston Hill vein. As of 1940 the mine was closed.

Reference information

Bibliographic references

  • Deposit

    Clark, W.B., 1970, Gold districts of California: California Division of Mines and Geology Bulletin 191, p. 53.

  • Deposit

    Johnston, W.G., Jr., 1940, The gold quartz veins of Grass Valley, California: U.S. Geological Survey Professional Paper 194, 101 p.

  • Deposit

    Koschmann, A.H., and Bergendahl, M.H., 1968, Gold-producing districts of the United States: U.S. Geological Survey Professional Paper 610, 283 p.

  • Deposit

    Lindgren, W., 1896a, Geologic atlas of the United States - Nevada City Special Folio: U.S. Geological Survey Folio 29.

  • Deposit

    Lindgren, W., 1896b, Gold-quartz veins of Nevada City and Grass Valley: Seventeenth Annual Report of the U.S. Geological Survey, Part 2, p. 1-262

  • Deposit

    MacBoyle, E.M., 1919, Mines and mineral resources of Nevada County: Sixteenth Annual Report of the State Mineralogist, California State Mining Bureau, p. 1-270.

  • Deposit

    Additional information on the Sultana-Orleans Mines is contained in File Nos. 331-9089 and 339-5929 (CGS Mineral Resources Files, Sacramento)

Reporter information

Type Date Name Affiliation Comment
Reporter 25-MAR-2004 Downey, Cameron California Geological Survey CGS (Formerly CDMG)
Editor 01-SEP-2007 Schruben, Paul G. U.S. Geological Survey Converted from S&A FileMaker format to Oracle. Edit checks on rocks, units, and ages with Geolex search, and other fields.