Chañarcillo is a town and mine in the

Atacama Desert The Atacama Desert () is a desert plateau located on the Pacific Ocean, Pacific coast of South America, in the north of Chile. Stretching over a strip of land west of the Andes Mountains, it covers an area of , which increases to if the barre ...

of Copiapó Province, Atacama Region,

Chile Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Paci ...

, located near

Vallenar Vallenar is a city and commune in Atacama Region, Chile. It is the capital of the Huasco Province and is located in the valley of the Huasco River. Vallenar has 52,000 inhabitants. Its main activities are farming and mining. It was founded as ...

and 60 km from

Copiapó Copiapó () is a List of cities in Chile, city and communes of Chile, commune in northern Chile, located about 65 kilometers east of the coastal List of towns in Chile, town of Caldera, Chile, Caldera. Founded on December 8, 1744, it is the capi ...

. It is noted for its

silver mining Silver mining is the extraction of silver by mining. Silver is a precious metal and holds high economic value. Because silver is often found in intimate combination with other metals, its extraction requires the use of complex technologies. In ...

. The town grew after the Chañarcillo silver mine, discovered on May 16, 1832, by Juan Godoy, sparked the

Chilean silver rush Between 1830 and 1850, Chilean silver mining grew at an unprecedented pace which transformed mining into one of the country's principal sources of wealth. The rush caused rapid demographic, infrastructural, and economic expansion in the semi-arid ...

. Villalobos, Sergio; Silva, Osvaldo; Silva Fernando and Estelle, Patricio. ''Historia de Chile''.

Editorial Universitaria Editorial Universitaria is Chilean university press based in Santiago. It was established in 1947 with funds from private people and from the University of Chile. During its existence, it has published the works of generations influential Chilean sc ...

1995. First Edition: 1974. p. 469-472. It grew in prominence in the second half of the nineteenth century and became important in the Atacama mining industry and one of the most important mines to the Chilean economy. It was connected by railway before 1862. Today the settlement is largely in ruins. The Chanarcillo District produced at least $100 million in silver before abandonment. This production from up to 20 mines was limited to a third of a square mile. From 1860 until 1885, 2,500,000 kg of silver was produced. Most production occurred before 1930. From then until 1960, only minor amounts of silver were produced by removing pillars in mines or from the dump material. In 1870, 1,570 miners worked in the Chañarcillo mines. However, the mines were exhausted by 1874 and mining largely ended in 1888 after they were accidentally flooded.Cortés 2017, p. 23. Despite this, Chañarcillo was the most productive mining district in 19th century Chile.

Geology

Chanarcillo is on the south flank of a

dome A dome () is an architectural element similar to the hollow upper half of a sphere. There is significant overlap with the term cupola, which may also refer to a dome or a structure on top of a dome. The precise definition of a dome has been a m ...

, the Sierra de Chanarcillo, characterized by radial

fractures Fracture is the appearance of a crack or complete separation of an object or material into two or more pieces under the action of stress (mechanics), stress. The fracture of a solid usually occurs due to the development of certain displacemen ...

and northwest striking faults. Silver

ore Ore is natural rock or sediment that contains one or more valuable minerals, typically including metals, concentrated above background levels, and that is economically viable to mine and process. The grade of ore refers to the concentration ...

occurs in nearly vertical

veins Veins () are blood vessels in the circulatory system of 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 those of the pulmonary and fetal c ...

within these fractures and faults within interbedded

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

s and

tuff Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. Rock that contains greater than 75% ash is considered tuff, while rock co ...

s. This ore zone is an oxidized and

supergene A supergene is a chromosomal region encompassing multiple neighboring genes that are inherited together because of close genetic linkage, i.e. much less recombination than would normally be expected. This mode of inheritance can be due to genomic ...

sulfide Sulfide (also sulphide in British English) is an inorganic anion of sulfur with the chemical formula S2− or a compound containing one or more S2− ions. Solutions of sulfide salts are corrosive. ''Sulfide'' also refers to large families o ...

enriched rock. Oxidized ores occur above the

water table The water table is the upper surface of the phreatic zone or zone of saturation. The zone of saturation is where the pores and fractures of the ground are saturated with groundwater, which may be fresh, saline, or brackish, depending on the loc ...

and supergene sulfide enrichment below. In the oxidized zone, ore minerals include native silver and

argentite In mineralogy, argentite () is cubic silver sulfide (Ag2S), which can only exist at temperatures above , , or . When it cools to ordinary temperatures it turns into its monoclinic polymorph, acanthite. The International Mineralogical Associatio ...

have been replaced by cerargyrite, iodobromite, bromyrite, embolite, and iodyrite. In the supergene sulfide enriched zone, ore minerals include pearceite,

proustite Proustite is a sulfosalt mineral consisting of silver sulfarsenide, Ag3 As S3, known also as ruby blende, light red silver, arsenic-silver blende or ruby silver ore, and an important source of the metal. It is closely allied to the corresponding ...

, tetrahedrite, polybasite, and

pyrargyrite Pyrargyrite is a Sulfosalt minerals, sulfosalt mineral consisting of silver sulfantimonite, Ag3SbS3. Known also as ''dark red silver ore'', ''ruby blende'', ''garnete blende'' or ''ruby silver'', it is an important source of the metal. It is clo ...

. Groups of large crystals have been found at Chañarcillo, including

, stephanite,

chlorargyrite Chlorargyrite is the mineral form of silver chloride (AgCl). Chlorargyrite occurs as a secondary mineral phase in the oxidation of silver mineral deposits. It crystallizes in the isometric–hexoctahedral crystal class. Typically massive to column ...

and

adamite Adamite is a zinc arsenate hydroxide mineral, Zn2 As O4O H. It is a mineral that typically occurs in the oxidized or weathered zone above zinc ore occurrences. Pure adamite is colorless, but usually it possess yellow color due to Fe compoun ...

References

;Bibliography * Silver mines in Chile Populated places in Copiapó Province Mines in Atacama Region Underground mines in Chile Former mines in Chile Mineral deposits discovered in the 1830s {{Atacama-geo-stub

Geology

See also

References