Help mindat.org|Log In|Register|
Home PageMindat NewsThe Mindat ManualHistory of MindatCopyright StatusManagement TeamContact UsAdvertise on Mindat
Donate to MindatSponsor a PageSponsored PagesTop Available PagesMindat AdvertisersAdvertise on MindatThe Mindat Store
Minerals by PropertiesMinerals by ChemistryRandom MineralSearch by minIDLocalities Near MeSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
Keyword(s):
 
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportAdd Glossary Item
StatisticsMember ListBooks & MagazinesMineral Shows & EventsThe Mindat DirectoryHow to Link to MindatDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day Gallery

Mother Lode Belt, Tuolumne Co., California, USA

This page is currently not sponsored. Click here to sponsor this page.
 
 
The Mother Lode gold belt carries the most productive and best-known mining districts in California's gold country. Although the entire foothill region of the Sierra Nevada is sometimes loosely termed the "Mother Lode Country," technically the Mother Lode is a 120-mile-Iong system of linked or en echelon gold-quartz veins and mineralized schist and greenstone that extends from the town of Mariposa, north and
northwest to northern El Dorado County.


The most productive portion of the Mother Lode has been the 1 mile segment between Plymouth and Jackson in Amador County. Other major sources of gold in the Mother Lode have been the Angels Camp, Bagby, Carson Hill, Coulterville, Georgetown, Greenwood, Jacksonville, Jamestown, Kelsey, Mount Bullion, Nashville, and Placerville districts.

The northwest-trending Mother Lode Belt traverses western Tuolumne County and is associated with the Melones Fault Zone. The rocks of this belt are typically metavolcanic, metasedimentary, and ultramafic, some of which have been hydrothermally altered to assemblages as described below. Mother Lode Belt mineralization is characterized by steeply dipping gold-bearing quartz veins and bodies of mineralized country rock adjacent to veins. Mother Lode veins are characteristically enclosed in Mariposa Formation slate with associated greenstone. The Mother Lode belt vein system ranges from a few hundred feet to a mile or more in width. Within the zone are numerous discontinuous or linked veins, which may be parallel, convergent, or en echelon. The veins commonly pinch and swell. Few can be traced more than a few thousand feet. Mother Lode type veins fill voids created within faults and fracture zones and consist of quartz, gold and associated sulfides, ankerite, calcite, chlorite, limonite, talc, chromium-bearing mica, and sericite. Stringer veins are commonly found in both adjacent footwall and hanging walls. Mother Lode ores are generally low- to moderate-grade (1/3 ounce of gold or less per ton), but ore bodies can be large. Ore shoots are generally short, 200-300 feet being the average stope length. However, they persist at depth, some having been mined to several thousand feet (Clark and Lydon, 1962). Ore shoots are commonly localized at bulges in veins, shear zones, vein intersections, or near abrupt changes in strike or dip.

Mineral List

Mineral list contains entries from the region specified including sub-localities


99 entries listed. 77 valid minerals. 1 type locality (valid mineral).

Localities in this Region

USA
USA

The above list contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders for access and that you are aware of all safety precautions necessary.

References

Savage, K.S., Tingle, T.N., O'Day, P.A., Waychunas, G.A., and Bird, D.K. (2000) Arsenic speciation in pyrite and secondary weathering phases, Mother Lode gold district, Tuolumne County, California. Applied Geochemistry: 15: 1219-1244.

USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10310603.

External Links


Mineral and/or Locality  
Mindat.org is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2015, except where stated. Mindat.org relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: August 2, 2015 09:25:44 Page generated: January 11, 2015 15:46:21