Chañarcillo is a town and mine in the

Atacama Desert The Atacama Desert ( es, Desierto de Atacama) is a desert plateau in South America covering a 1,600 km (990 mi) strip of land on the Pacific coast, west of the Andes Mountains. The Atacama Desert is the driest nonpolar desert in the ...

of Copiapó Province, Atacama Region,

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the eas ...

, located near Vallenar and 60 km from Copiapó. It is noted for its silver mining. The town grew up after the Chañarcillo silver mine was discovered on May 16, 1832, by Juan Godoy. This event sparkled the Chilean silver rush. Villalobos, Sergio; Silva, Osvaldo; Silva Fernando and Estelle, Patricio. Historia de Chile. Editorial Universitaria 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 and since then until 1960, only minor amounts of silver was produced by removing pillars in mines or from the dump material. In 1870, 1570 miners worked in the Chañarcillo mines; however the mines were exhausted by 1874 and mining largely ended in 1888 after the mines 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 ...

, the Sierra de Chanarcillo, characterized by radial fractures and northwest

striking Strike may refer to: People *Strike (surname) Physical confrontation or removal *Strike (attack), attack with an inanimate object or a part of the human body intended to cause harm *Airstrike, military strike by air forces on either a suspected ...

faults. Silver ore occurs in nearly vertical veins within these fractures and faults within interbedded

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms wh ...

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 ...

s. This ore zone is an oxidized and supergene_(geology)

sulfide Sulfide (British English also sulphide) 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 chemical compounds l ...

enriched rock. Oxidized ores occur above the water table and supergene sulfide enrichment below. In the oxidized zone, ore minerals include native silver and argentite have been replaced by

cerargyrite 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 colum ...

, iodobromite,

bromyrite Bromyrite or bromargyrite is a natural mineral form of silver bromide found mainly in Mexico and Chile. Hardness is 1.5 to 2. Related are chlorargyrite and iodyrite. It was first described in 1859 for an occurrence in Plateros, Zacatecas, Me ...

, embolite,

iodyrite Iodyrite or iodargyrite is a natural mineral form of silver iodide. Related minerals are chlorargyrite and bromargyrite Bromyrite or bromargyrite is a natural mineral form of silver bromide found mainly in Mexico and Chile. Hardness is 1.5 to ...

. In the supergene sulfide enriched zone, ore minerals include pearceite, proustite, tetrahedrite, polybasite, and pyrargyrite. Magnificent groups of large crystals have been found at Chañarcillo, including proustite,

stephanite Stephanite is a silver antimony sulfosalt mineral with formula: Ag5 Sb S4. It is composed of 68.8% silver, and sometimes is of importance as an ore of this metal. History Under the name Schwarzerz it was mentioned by Georgius Agricola in 1546, ...

, chlorargyrite and adamite.

References

;Bibliography * Silver mines in Chile Populated places in Copiapó Province Mines in Atacama Region Underground mines in Chile Former mines in Chile {{Atacama-geo-stub

Geology

See also

References