In
geology
Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Ear ...
, a lode is a deposit of
metalliferous ore
Ore is natural rock or sediment that contains one or more valuable minerals, typically containing metals, that can be mined, treated and sold at a profit.Encyclopædia Britannica. "Ore". Encyclopædia Britannica Online. Retrieved 7 April 2 ...
that fills or is embedded in a
fissure
A fissure is a long, narrow crack opening along the surface of Earth. The term is derived from the Latin word , which means 'cleft' or 'crack'. Fissures emerge in Earth's crust, on ice sheets and glaciers, and on volcanoes.
Ground fissure
A ...
(or crack) in a
rock
Rock most often refers to:
* Rock (geology), a naturally occurring solid aggregate of minerals or mineraloids
* Rock music, a genre of popular music
Rock or Rocks may also refer to:
Places United Kingdom
* Rock, Caerphilly, a location in Wales ...
formation or a
vein
Veins are blood vessels in humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated b ...
of ore that is deposited or embedded between layers of rock.
The current meaning (ore vein) dates from the 17th century, being an
expansion of an earlier sense of a "channel, watercourse" in
late Middle English, which in turn is from the 11th-century meaning of ''lode'' as a ‘course, way’.
The generally accepted
hydrothermal model of lode deposition posits that metals dissolved in hydrothermal solutions (hot spring fluids) deposit the gold or other metallic minerals inside the fissures in the pre-existing rocks. Lode deposits are distinguished primarily from
placer deposits, where the ore has been eroded out from its original
depositional environment and redeposited by
sedimentation. A third process for ore deposition is as an
evaporite.
A stringer lode is one in which the rock is so permeated by small veinlets that rather than mining the veins, the entire mass of ore and the enveined
country rock
Country rock is a genre of music which fuses rock and country. It was developed by rock musicians who began to record country-flavored records in the late 1960s and early 1970s. These musicians recorded rock records using country themes, vocal s ...
is mined. It is so named because of the irregular branching of the veins into many
anastomosis
An anastomosis (, plural anastomoses) is a connection or opening between two things (especially cavities or passages) that are normally diverging or branching, such as between blood vessels, leaf#Veins, leaf veins, or streams. Such a connection m ...
stringers, so that the ore is not separable from the country rock.
One of largest silver lodes was the
Comstock Lode in Nevada, although it is overshadowed by the more recently discovered
Cannington Lode in Queensland, Australia. The largest gold lode in the United States was the
Homestake Lode. The
Broken Hill Lode in South Australia is the largest lead-zinc lode ever discovered.
See also
*
Lodestone known just as ''lode'' in the 16th and 17th centuries.
[The '' New Oxford American Dictionary'' (''NOAD''), 3rd edition.][
* Mother lode, the principal vein
* Ore genesis
* Thickness
*]General Mining Act of 1872
The General Mining Act of 1872 is a United States federal law that authorizes and governs prospecting and mining for economic minerals, such as gold, platinum, and silver, on federal public lands. This law, approved on May 10, 1872, codified the in ...
* Land patent
* Binger Hermann
*Surveying
Surveying or land surveying is the technique, profession, art, and science of determining the terrestrial two-dimensional or three-dimensional positions of points and the distances and angles between them. A land surveying professional is ca ...
*Geographic information system
A geographic information system (GIS) is a type of database containing Geographic data and information, geographic data (that is, descriptions of phenomena for which location is relevant), combined with Geographic information system software, sof ...
Notes
Ore deposits
Mineralogy
Economic geology
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