Mother Lode
Encyclopedia
Mother lode is a principal vein
or zone of veins of gold
or silver
ore
. The term probably came from a literal translation of the Spanish veta madre, a term common in old Mexican mining. Veta madre, for instance, is the name given to an 11 kilometres (6.8 mi) silver vein discovered in 1548 in Guanajuato
, New Spain
(modern-day Mexico
).
In the United States
, Mother Lode is most famously the name given to the long alignment of hard-rock gold deposits stretching northwest to southeast in the Sierra Nevada of California
. The California Mother Lode is a zone from 1.5 to 6 km (0.93205910497471 to 3.7 mi) wide and 190 kilometres (118.1 mi) long, extending from Georgetown
in El Dorado County
on the north, through Amador
, Calaveras
, and Tuolumne
counties, south to Mormon Bar
in Mariposa County
. It was discovered in the early 1850s, during the California gold rush
. Following the elucidation of the theory of plate tectonics
, the Mother Lode was found to coincide with the suture line of a terrane
, the Smartville Block
. The zone contains hundreds of mines and prospects, including some of the best-known historic mines of the gold-rush era. Individual gold deposits within the Mother Lode are gold-bearing quartz
veins up to 15 metres (49.2 ft) thick and a few thousand feet long. The California Mother Lode was one of the most productive gold-producing districts in the United States. Now it is known as a destination for tourism.
The California gold rush
, as with most gold rush
es, started with the discovery of placer
gold in sands and gravels of streambeds, where the gold had eroded from the hard-rock vein deposits. Placer miners followed the gold-bearing sands upstream to discover the source in the bedrock
. This source was the "mother" of the gold in the river and so was dubbed the "mother lode
".
A popular misconception is that small veins of gold or silver ore in a mining district are necessarily branches of a single rich and massive mother lode deep in the ground. This idea is contrary to modern theories of ore deposits.
The term is also used metaphor
ically to refer to the origin of something valuable or in great abundance.
Vein (geology)
In geology, a vein is a distinct sheetlike body of crystallized minerals within a rock. Veins form when mineral constituents carried by an aqueous solution within the rock mass are deposited through precipitation...
or zone of veins of gold
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...
or silver
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...
ore
Ore
An ore is a type of rock that contains minerals with important elements including metals. The ores are extracted through mining; these are then refined to extract the valuable element....
. The term probably came from a literal translation of the Spanish veta madre, a term common in old Mexican mining. Veta madre, for instance, is the name given to an 11 kilometres (6.8 mi) silver vein discovered in 1548 in Guanajuato
Guanajuato
Guanajuato officially Estado Libre y Soberano de Guanajuato is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 46 municipalities and its capital city is Guanajuato....
, New Spain
New Spain
New Spain, formally called the Viceroyalty of New Spain , was a viceroyalty of the Spanish colonial empire, comprising primarily territories in what was known then as 'América Septentrional' or North America. Its capital was Mexico City, formerly Tenochtitlan, capital of the Aztec Empire...
(modern-day Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
).
In the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, Mother Lode is most famously the name given to the long alignment of hard-rock gold deposits stretching northwest to southeast in the Sierra Nevada of California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
. The California Mother Lode is a zone from 1.5 to 6 km (0.93205910497471 to 3.7 mi) wide and 190 kilometres (118.1 mi) long, extending from Georgetown
Georgetown, California
Georgetown is a census-designated place in El Dorado County, California. It is the northeastern-most town in the Californian Mother Lode. The population was 2,367 at the 2010 census, up from 962 at the 2000 census...
in El Dorado County
El Dorado County, California
El Dorado County is a county located in the historic Gold Country in the Sierra Nevada Mountains and foothills of the U.S. state of California. The 2010 population was 181,058. The El Dorado county seat is in Placerville....
on the north, through Amador
Amador County, California
Amador County is a county located in the Sierra Nevada of the U.S. state of California. As of the 2010 census, the population was 38,091. The county seat is Jackson.Amador County bills itself as "The Heart of the Mother Lode" and lies within the Gold Country...
, Calaveras
Calaveras County, California
Calaveras County is a county located in the Gold Country of the U.S. state of California. Calaveras is the Spanish word for skulls; the county was reportedly named for the remains of Native Americans discovered by the Spanish explorer Captain Gabriel Moraga. As of the 2010 census, the county had a...
, and Tuolumne
Tuolumne County, California
Tuolumne County is a county in the Sierra Nevada of the U.S. state of California. The northern half of Yosemite National Park is located in the eastern part of the county. As of the 2010 census, the population was 55,365, up from 54,501 at the 2000 census...
counties, south to Mormon Bar
Mormon Bar, California
Mormon Bar is an unincorporated community in Mariposa County, California. It is located south-southeast of Mariposa, at an elevation of 1772 feet . Mormon Bar is located near State Route 49....
in Mariposa County
Mariposa County, California
Mariposa County is a county in the U.S. state of California, located in the western foothills of the Sierra Nevada mountains. It lies north of Fresno, east of Merced, and southeast of Stockton. As of the 2010 census, the population was 18,251 up from 17,130 at the 2000 census...
. It was discovered in the early 1850s, during the California gold rush
California Gold Rush
The California Gold Rush began on January 24, 1848, when gold was found by James W. Marshall at Sutter's Mill in Coloma, California. The first to hear confirmed information of the gold rush were the people in Oregon, the Sandwich Islands , and Latin America, who were the first to start flocking to...
. Following the elucidation of the theory of plate tectonics
Plate tectonics
Plate tectonics is a scientific theory that describes the large scale motions of Earth's lithosphere...
, the Mother Lode was found to coincide with the suture line of a terrane
Terrane
A terrane in geology is short-hand term for a tectonostratigraphic terrane, which is a fragment of crustal material formed on, or broken off from, one tectonic plate and accreted or "sutured" to crust lying on another plate...
, the Smartville Block
Smartville Block
The Smartville Block, also called the Smartville Complex or Smartville Intrusive Complex, is a geologic zone in the foothills of the Sierra Nevada mountain range, in the historic Gold Country in eastern California.-Gold:...
. The zone contains hundreds of mines and prospects, including some of the best-known historic mines of the gold-rush era. Individual gold deposits within the Mother Lode are gold-bearing quartz
Quartz
Quartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. There are many different varieties of quartz,...
veins up to 15 metres (49.2 ft) thick and a few thousand feet long. The California Mother Lode was one of the most productive gold-producing districts in the United States. Now it is known as a destination for tourism.
The California gold rush
California Gold Rush
The California Gold Rush began on January 24, 1848, when gold was found by James W. Marshall at Sutter's Mill in Coloma, California. The first to hear confirmed information of the gold rush were the people in Oregon, the Sandwich Islands , and Latin America, who were the first to start flocking to...
, as with most gold rush
Gold rush
A gold rush is a period of feverish migration of workers to an area that has had a dramatic discovery of gold. Major gold rushes took place in the 19th century in Australia, Brazil, Canada, South Africa, and the United States, while smaller gold rushes took place elsewhere.In the 19th and early...
es, started with the discovery of placer
Placer mining
Placer mining is the mining of alluvial deposits for minerals. This may be done by open-pit or by various surface excavating equipment or tunneling equipment....
gold in sands and gravels of streambeds, where the gold had eroded from the hard-rock vein deposits. Placer miners followed the gold-bearing sands upstream to discover the source in the bedrock
Bedrock
In stratigraphy, bedrock is the native consolidated rock underlying the surface of a terrestrial planet, usually the Earth. Above the bedrock is usually an area of broken and weathered unconsolidated rock in the basal subsoil...
. This source was the "mother" of the gold in the river and so was dubbed the "mother lode
Lode
In geology, a lode is a deposit of metalliferous ore that fills or is embedded in a fissure in a rock formation or a vein of ore that is deposited or embedded between layers of rock....
".
A popular misconception is that small veins of gold or silver ore in a mining district are necessarily branches of a single rich and massive mother lode deep in the ground. This idea is contrary to modern theories of ore deposits.
The term is also used metaphor
Metaphor
A metaphor is a literary figure of speech that uses an image, story or tangible thing to represent a less tangible thing or some intangible quality or idea; e.g., "Her eyes were glistening jewels." Metaphor may also be used for any rhetorical figures of speech that achieve their effects via...
ically to refer to the origin of something valuable or in great abundance.
See also
- Alaska Gold Rush
- California Gold RushCalifornia Gold RushThe California Gold Rush began on January 24, 1848, when gold was found by James W. Marshall at Sutter's Mill in Coloma, California. The first to hear confirmed information of the gold rush were the people in Oregon, the Sandwich Islands , and Latin America, who were the first to start flocking to...
- Gold CountryGold CountryGold Country is a region in the central and northeastern part of California, United States. It is famed for the mineral deposits and gold mines that attracted waves of immigrants, known as the 49ers, during the 1849 California Gold Rush.-Geography:State Route 49 was built through the Gold Country,...
- Placer miningPlacer miningPlacer mining is the mining of alluvial deposits for minerals. This may be done by open-pit or by various surface excavating equipment or tunneling equipment....