The Peñasquito Polymetallic Mine is the fifth largest silver mine in the world and the second largest in Mexico. It is located in north-eastern corner of the State of Zacatecas and is wholly owned by

Newmont Newmont Corporation is an American gold mining company based in Greenwood Village, Colorado. It is the world's largest gold mining corporation. Incorporated in 1921, it holds ownership of gold mines in the United States, Canada, Mexico, the Do ...

. It is an

open pit Open-pit mining, also known as open-cast or open-cut mining and in larger contexts mega-mining, is a surface mining technique that extracts rock or minerals from the earth. Open-pit mines are used when deposits of commercially useful ore or ...

operation which began commercial operations in March 2010, but still managed to produce 13,952,600 ounces of

silver Silver is a chemical element; it has Symbol (chemistry), symbol Ag () and atomic number 47. A soft, whitish-gray, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. ...

that year. Estimated reserves for the Peñasquito Mine are 17.82 million oz of

gold Gold is a chemical element; it has chemical symbol Au (from Latin ) and atomic number 79. In its pure form, it is a brightness, bright, slightly orange-yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal ...

, 1,070.1 million oz of silver, 3,214 tons of

lead Lead () is a chemical element; it has Chemical symbol, symbol Pb (from Latin ) and atomic number 82. It is a Heavy metal (elements), heavy metal that is density, denser than most common materials. Lead is Mohs scale, soft and Ductility, malleabl ...

and 7,098 million tons of

zinc Zinc is a chemical element; it has symbol Zn and atomic number 30. It is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodic tabl ...

. The mine has its own radio station, XHESP-FM 98.9 "Radio Peñasco".

Geology

The

country rock Country rock is a music genre that 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 sty ...

consists of

Mesozoic The Mesozoic Era is the Era (geology), era of Earth's Geologic time scale, geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Period (geology), Periods. It is characterized by the dominance of archosaurian r ...

sediments that were deposited in the Basin of Mexico (Mexico Geosyncline). These sediments were intruded by quartz-feldspar porphyries,

quartz monzonite Quartz monzonite is an intrusive, felsic, igneous rock that has an approximately equal proportion of orthoclase and plagioclase feldspars. It is typically a light colored phaneritic (coarse-grained) to porphyritic granitic rock. The plagioclase ...

porphyries, and other feldspar-phyric intrusives in the late

Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

to the mid-

Oligocene The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...

, which form sills,

dikes Dyke or dike may refer to: General uses * Dyke (slang), a slang word meaning "lesbian" * Dike (geology), formations of magma or sediment that cut through and across the layering of adjacent rocks * Dike (mythology), ''Dikē'', the Greek goddess ...

, and

stocks Stocks are feet and hand restraining devices that were used as a form of corporal punishment and public humiliation. The use of stocks is seen as early as Ancient Greece, where they are described as being in use in Solon's law code. The law de ...

. The primary ore for the Peñasquito Polymetallic Mine is in two

diatreme A diatreme, sometimes known as a maar-diatreme volcano, is a volcanic pipe associated with a gaseous explosion. When magma rises up through a crack in Earth's crust and makes contact with a shallow body of groundwater, rapid expansion of heated ...

breccia Breccia ( , ; ) is a rock composed of large angular broken fragments of minerals or Rock (geology), rocks cementation (geology), cemented together by a fine-grained matrix (geology), matrix. The word has its origins in the Italian language ...

s, named the Peñasco and the Brecha Azul. The mineralization contains gold, silver, lead and zinc. The

s flare upward, and are filled with

ted country rock and intrusions. The rock surrounding the diatremes contain disseminated

galena Galena, also called lead glance, is the natural mineral form of lead(II) sulfide (PbS). It is the most important ore of lead and an important source of silver. Galena is one of the most abundant and widely distributed sulfide minerals. It crysta ...

sphalerite Sphalerite is a sulfide mineral with the chemical formula . It is the most important ore of zinc. Sphalerite is found in a variety of deposit types, but it is primarily in Sedimentary exhalative deposits, sedimentary exhalative, Carbonate-hoste ...

and

sulfosalt Sulfosalt minerals are sulfide minerals with the general formula , where *A represents a metal such as copper, lead, silver, iron, and rarely mercury, zinc, vanadium *B usually represents semi-metal such as arsenic, antimony, bismuth, and rarely ...

s within phyllic (

sericite Sericite is the name given to very fine, ragged grains and Aggregate (geology), aggregates of white (colourless) micas, typically made of muscovite, illite, or paragonite. Sericite is produced by the alteration of orthoclase or plagioclase feldsp ...

–

pyrite The mineral pyrite ( ), or iron pyrite, also known as fool's gold, is an iron sulfide with the chemical formula Fe S2 (iron (II) disulfide). Pyrite is the most abundant sulfide mineral. Pyrite's metallic luster and pale brass-yellow hue ...

–

quartz Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The Atom, atoms are linked in a continuous framework of SiO4 silicon–oxygen Tetrahedral molecular geometry, tetrahedra, with each oxygen being shared between two tet ...

) and proplytic (

chlorite The chlorite ion, or chlorine dioxide anion, is the halite (oxyanion), halite with the chemical formula of . A chlorite (compound) is a compound that contains this group, with chlorine in the oxidation state of +3. Chlorites are also known as s ...

–

epidote Epidote is a calcium aluminium iron sorosilicate mineral. Description Well developed crystals of epidote, Ca2Al2(Fe3+;Al)(SiO4)(Si2O7)O(OH), crystallizing in the monoclinic system, are of frequent occurrence: they are commonly prismatic in ha ...

–pyrite)

hydrothermal alteration Metasomatism (from the Greek μετά ''metá'' "change" and σῶμα ''sôma'' "body") is the chemical alteration of a Rock (geology), rock by hydrothermal and other fluids. It is traditionally defined as metamorphism which involves a change in t ...

envelopes. Where the diatremes intersect

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) ...

units manto deposits of ore mineralization occur.

History

The history of exploration of the Peñasquito project began in 1992 when Kencott recognized the area's potential for a significant mineral deposit and began exploration. The exploration was suspended in 1997 but resumed in 2002 when Western Silver took over. A significant polymetallic deposit was discovered in 2006 and construction of the mine began in 2007, the first concentrates were produced in October 2009, and commercial production began in 2010.In 2006, Western Silver sold the property to Glamis Gold Ltd. for $1.2 billion in exchange for Glamis stock. Goldcorp became the owner of the mine in 2006 when it purchased Glamis. In 2019, Newmont acquired Goldcorp, obtaining full ownership interest in Peñasquito, which consists of the Peñasco and Chile Colorado open pit mines.

2017 Protest

A week-long protest disrupted operations at the Peñasquito mine during the first week of October 2017.

Goldcorp Goldcorp Inc. was a gold production company headquartered in Vancouver, British Columbia, Canada. The company stood among the largest gold producers in the world, employed about 15,800 people worldwide, engaged in gold mining and related activit ...

had been forced to "announce a temporary suspension of operations due to a blockade by truck drivers protesting a loss of contracts at the country’s biggest gold deposit."

References

{{DEFAULTSORT:Penasquito Mine Silver mines in Mexico Gold mines in Mexico Surface mines in Mexico Geology of Mexico