Friant District

Producer in Fresno county in California, United States with commodities Gold, Silver
Sections on this page
  1. Identification information
  2. Geographic coordinates
  3. Site location context
  4. Geographic areas
  5. Public Land Survey System information
  6. Commodities
  7. Materials information
  8. Mineral occurrence model information
  9. Host and associated rocks
  10. Nearby scientific data
  11. Ore body information
  12. Controls for ore emplacement
  13. Economic information about the deposit and operations
  14. Mining district
  15. Bibliographic references
  16. General comments
  17. Reporter information

Geologic information

Identification information

Deposit ID 10310617
Record type District
Current site name Friant District

Comments on the site identification

  • The district encompasses an approximately 24-mile stretch of the San Joaquin River between Millerton Lake and Herndon.

Geographic coordinates

Geographic coordinates: -119.71136, 36.99027 (WGS84)
Location accuracy 100(meters)
Relative position Friant is about 18 miles north-northeast of the city of Fresno.

Site location context

Political divisions (FIPS codes)

Fresno(county)

California(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Friant(quadrangle 1:24,000 scale)

Fresno(quadrangle 1:100,000 scale)

Fresno(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Middle San Joaquin-Lower Chowchilla(hydrologic unit)

San Joaquin(hydrologic accounting unit)

San Joaquin(hydrologic subregion)

California(hydrologic region)

Geographic areas

Country State County
United States California Fresno

Public Land Survey System information

Meridian Township Range Section Fraction State
Mount Diablo 011S 021E 07 California

Comments on the location information

  • Location selected for latitude and longitude is the settlement of Friant on the USGS 7.5-minute Friant quadrangle. This locality is near the historic mining area that is now covered by Millerton Lake.

Commodities

Commodity Importance
Gold Primary
Silver Secondary

Comments on the commodity information

  • Commodity Info: the gold is fine and flaky.
  • Ore Materials: Native gold
  • Gangue Materials: Metamorphic rocks, igneous rocks, quartz (as clasts)

Materials information

Materials Type of material
Gold Ore
Quartz Gangue

Mineral occurrence model information

Model code 119
USGS model code 39a
Deposit model name Placer Au-PGE
Mark3 model number 54

Host and associated rocks

  • Host or associated Host
    Rock type Unconsolidated Deposit > Sand and Gravel
    Stratigraphic age (youngest) Quaternary

Nearby scientific data

(1) -119.71136, 36.99027

Economic information

Ore body information

  • General form Irregular

Controls for ore emplacement

  • Mechanical accumulation within stream-channel lag gravels, bars, and point-bar deposits.

Comments on the geologic information

  • REGIONAL GEOLOGY

    The Friant District is situated at the westernmost edge of the Sierra Nevada geologic province and within the adjacent Great Valley geologic province, which is here represented by the San Joaquin Valley. The Sierra Nevada province is characterized by complex lithologies and structures that were assembled through various plate-tectonic processes.

    In this region, the Sierra Nevada province is composed of isolated roof pendants of Paleozoic-Mesozoic metamorphic rocks that are suspended in widespread Mesozoic plutonic rock of the Sierra Nevada Batholith. Together, these rocks compose the basement of the province. This basement is overlain in places by erosional remnants of Cenozoic sedimentary and volcanic rocks, including glacial materials. Structurally, the metamorphic rocks and some of the plutonic rocks of the basement have been deformed by folding and faulting. The basement rocks contain gold in places.

    The Great Valley province is characterized largely by relatively undeformed Cenozoic sedimentary deposits, which overlie the basement of the Sierra Nevada where it extends westward underneath the San Joaquin Valley.

    LOCAL GEOLOGY

    The Friant District is associated with modern alluvial deposits of the main drainage of the San Joaquin River where it discharges into the San Joaquin Valley after passing through the Sierra Nevada basement terranes. 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 modern placer deposits along the San Joaquin River.

Economic information about the deposit and operations

Operation type Surface
Development status Producer
Commodity type Metallic
Deposit size Small
Significant Yes
Discovery year 1850

Mining district

District name Friant District

Comments on the workings information

  • Initially, gold was recovered by standard surface placering methods. Later, placer workings were developed by small-scale dredging and by aggregate-mining techniques.

Comments on other economic factors

  • Tooker and Vercoutere (1986) estimated the production of this region to be about 131,000 ounces through 1981. Clark (1970) estimated that from 1946 to the late 1960?s about $5,000-$25,000 worth of gold was produced annually as a by-product from the aggregate mines along the river.

Comments on development

  • Placer mining was conducted originally at a location now inundated by Millerton Lake, which is just upstream from the settlement of Friant. As published information about this district is sparse, it is assumed that this mining activity began during the gold rush, although an exact year is uncertain.

    At least since the 1940?s, gold has been produced as part of aggregate mining along the San Joaquin River. From 1940-1942, about $200,000 worth of gold was recovered from the sand and gravel excavated near Friant and used in construction of Friant Dam, which impounds Millerton Lake.

    Gold is still being produced as a by-product of aggregate mining along the San Joaquin River.

Reference information

Bibliographic references

  • Deposit

    Clark, W.B., 1970, Gold districts of California: California Division of Mines and Geology Bulletin 193, p. 50.

  • Deposit

    Logan, C.A., Braun, L.T. and Vernon, J.W., 1951, Fresno County: California Journal of Mines and Geology, v. 47, no. 3, p. 503-504.

  • Deposit

    Matthews, R.A. and Burnett, J.L., 1965, Fresno Sheet: California Division of Mines and Geology, Geologic Map of California, scale 1:250,000.

  • Deposit

    Tooker, E.W. and Vercoutere, T.L., 1986, Gold in the conterminous United States, Perspective of 1986 - Preliminary map of selected geographic, economic, and geologic attributes of productive (>10,000 oz) gold districts: U.S. Geological Survey Open-File Report 86-209, 32 p.

General comments

Subject category Comment text
Deposit The gold is present in the river gravels and small terrace deposits adjacent to the San Joaquin River, which receives eroded material from a large drainage basin within the Sierra Nevada to the east.

Reporter information

Type Date Name Affiliation Comment
Reporter 03-AUG-2006 Higgins, Chris T. 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.

Beyond USGS

Supplemental information added by qvyshift.com. Not part of the original USGS MRDS record.

Authoritative California resources

These are landing pages for further research — the state agencies don't currently expose per-mine deep links.