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 . It is an open pit operation which began operations in March 2010, but still managed to produce 13,952,600 ounces of silver that year. Estimated reserves for the Peñasquito Mine are 17.82 million oz of gold , 1,070.1 million oz of silver, 3,214 tons of lead and 7,098 million tons of zinc . The mine has its own radio station, XHESP-FM 98.9 "Radio Peñasco".
13-561: The country rock consists of Mesozoic sediments that were deposited in the Basin of Mexico (Mexico Geosyncline). These sediments were intruded by quartz-feldspar porphyries, quartz monzonite porphyries, and other feldspar-phyric intrusives in the late Eocene to the mid- Oligocene , which form sills , dikes , and stocks . The primary ore for the Peñasquito Polymetallic Mine is in two diatreme breccias , named
26-621: A cognate inclusion. Xenoliths and xenocrysts provide important information about the composition of the otherwise inaccessible mantle . Basalts , kimberlites , lamproites and lamprophyres , which have their source in the upper mantle , often contain fragments and crystals assumed to be a part of the originating mantle mineralogy. Xenoliths of dunite , peridotite and spinel lherzolite in basaltic lava flows are one example. Kimberlites contain, in addition to diamond xenocrysts, fragments of lherzolites of varying composition. The aluminium -bearing minerals of these fragments provide clues to
39-507: A location in the Mexican state of Zacatecas is a stub . You can help Misplaced Pages by expanding it . This article about a specific mine is a stub . You can help Misplaced Pages by expanding it . Country rock (geology) In geology , country rock is the rock native to an area, in contrast to any intrusion of viscous geologic material, commonly magma , or perhaps rock salt (in salt domes ) or unconsolidated sediments . Magma
52-458: Is a rock fragment ( country rock ) that becomes enveloped in a larger rock during the latter's development and solidification. In geology , the term xenolith is almost exclusively used to describe inclusions in igneous rock entrained during magma ascent, emplacement and eruption. Xenoliths may be engulfed along the margins of a magma chamber , torn loose from the walls of an erupting lava conduit or explosive diatreme or picked up along
65-411: Is intruded by an igneous body of rock which formed when magma forced upward through fractures , or melted through overlying rock . Magma then cooled into solid rock, different from the surrounding country rock. Sometimes, a fragment of country rock will break off and become incorporated into the intrusion, and is called a xenolith , from Greek , ξένος , xenos , "strange,", and λίθος , lithos ,
78-417: Is typically less dense than the rock it intrudes, widening and filling existing cracks, sometimes melting the already-existing country rock. The term "country rock" is similar to, and in many cases interchangeable with, the terms basement and wall rocks . Country rock can denote the widespread lithology of a region in relation to the rock which is being discussed or observed. Settings in geology when
91-529: The Peñasco and the Brecha Azul. The mineralization contains gold, silver, lead and zinc. The diatremes flare upward, and are filled with brecciated country rock and intrusions. The rock surrounding the diatremes contain disseminated galena , sphalerite and sulfosalts within phyllic ( sericite – pyrite – quartz ) and proplytic ( chlorite – epidote –pyrite) hydrothermal alteration envelopes. Where
104-408: The ancient Greek word for "stone." The heat of the intrusions usually changes the country rock, often to contact metamorphic rock . Commonly, hornfels is produced, or skarn . When describing recent alluvium , the material that has arrived through volcanic , glacial or fluvial action can be described as a veneer on the (older) country rock. Xenolith A xenolith ("foreign rock")
117-627: The base of a flowing body of lava on the Earth's surface. A xenocryst is an individual foreign crystal included within an igneous body. Examples of xenocrysts are quartz crystals in a silica -deficient lava and diamonds within kimberlite diatremes. Xenoliths can be non-uniform within individual locations, even in areas which are spatially limited, e.g. rhyolite -dominated lava of Niijima volcano ( Japan ) contains two types of gabbroic xenoliths which are of different origin - they were formed in different temperature and pressure conditions. Although
130-457: The depth of origin. Calcic plagioclase is stable to a depth of 25 km (16 mi). Between 25 km (16 mi) and about 60 km (37 mi), spinel is the stable aluminium phase. At depths greater than about 60 km, dense garnet becomes the aluminium-bearing mineral. Some kimberlites contain xenoliths of eclogite , which is considered to be the high-pressure metamorphic product of basaltic oceanic crust , as it descends into
143-596: The diatremes intersect limestone units manto deposits of ore mineralization occur. A week-long protest disrupted operations at the Peñasquito mine during the first week of October 2017. Goldcorp 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." 24°39′18.27″N 101°41′49.455″W / 24.6550750°N 101.69707083°W / 24.6550750; -101.69707083 This article about
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#1732773277769156-495: The term country rock is used include: When describing a pluton or dike , the igneous rock can be described as intruding the surrounding country rock , the rock into which the pluton has intruded. When country rock is intruded by a dike, perpendicular to the bedding plane , it is called discordant intrusion, while a parallel intrusion by a sill indicates a sub-parallel or concordant intrusion . Most intrusions into country rock are via magma . Usually, country rock
169-419: The term xenolith is most commonly associated with inclusions in igneous rocks, a broad definition could also include rock fragments which have become encased in sedimentary rock . Xenoliths have been found in some meteorites . To be considered a true xenolith, the included rock must be identifiably different from the rock in which it is enveloped; an included rock of similar type is called an autolith or
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