Quartzite


Quartzite
Quartzite
Swan Peak Quartzite (Ordovician) exposed just north of Tony Grove Lake, Cache County, Utah.
The quartzite of the Prospect Mountain Formation on top of Wheeler Peak, the highest peak within Nevada, United States.

Quartzite (from German Quarzit[1]) is a hard metamorphic rock which was originally sandstone.[2] Sandstone is converted into quartzite through heating and pressure usually related to tectonic compression within orogenic belts. Pure quartzite is usually white to gray, though quartzites often occur in various shades of pink and red due to varying amounts of iron oxide (Fe2O3). Other colors, such as yellow and orange, are due to other mineral impurities.

When sandstone is metamorphosed to quartzite, the individual quartz grains recrystallize along with the former cementing material to form an interlocking mosaic of quartz crystals. Most or all of the original texture and sedimentary structures of the sandstone are erased by the metamorphism. Minor amounts of former cementing materials, iron oxide, carbonate and clay, often migrate during recrystallization and metamorphosis. This causes streaks and lenses to form within the quartzite.

Orthoquartzite is a very pure quartz sandstone composed of usually well rounded quartz grains cemented by silica. Orthoquartzite is often 99% SiO2 with only very minor amounts of iron oxide and trace resistant minerals such as zircon, rutile and magnetite. Although few fossils are normally present, the original texture and sedimentary structures are preserved. The term is often misused, and should be used for only tightly-cemented metamorphic quartzites, not quartz-cemented quartz arenites.[3] The typical distinction between the two (since each is a gradation into the other) is a proper quartzite is so highly cemented, diagentically altered, and metamorphosed that it will fracture and break across grain boundaries, not around them. Quartzite is very resistant to chemical weathering and often forms ridges and resistant hilltops. The nearly pure silica content of the rock provides little to form soil from and therefore the quartzite ridges are often bare or covered only with a very thin layer of soil and little vegetation.

Contents

Uses

Abandoned quartzite mine in Kakwa Provincial Park, British Columbia, Canada
Biface in quartzite – Stellenbosch, South Africa

Because of its hardness and angular shape, crushed quartzite is often used as railway ballast.[4] Quartzite is a decorative stone and may be used to cover walls, as roofing tiles, as flooring, and stair steps. Crushed quartzite is sometimes used in road construction.[2] High purity quartzite is used to produce ferrosilicon, industrial silica sand, silicon and silicon carbide.[5] During the Stone Age quartzite was used as an (although inferior) alternative to flint.[6]

Occurrences

In the United States, formations of quartzite can be found in some parts of Pennsylvania, eastern South Dakota, Central Texas,[7] southwest Minnesota,[8] Devil's Lake State Park in the Baraboo Hills in Wisconsin,[9] the Wasatch Range in Utah,[10] near Salt Lake City, Utah and as resistant ridges in the Appalachians[11] and other mountain regions. Quartzite is also found in the Morenci Copper Mine in Arizona.[12] The town of Quartzsite in western Arizona derives its name from the quartzites in the nearby mountains in both Arizona and Southeastern California. A glassy vitreous quartzite has been described from the Belt Supergroup in the Coeur d’Alene district of northern Idaho.[13]

In the United Kingdom, a craggy ridge of quartzite called the Stiperstones (early OrdovicianArenig Epoch, 500 Ma) runs parallel with the Pontesford-Linley fault, 6 km north-west of the Long Mynd in south Shropshire. Also to be found in England are the Cambrian "Wrekin quartizite" (in Shropshire), and the Cambrian "Hartshill quartzite" (Nuneaton area).[14] In Wales, Holyhead mountain and most of Holy island off Anglesey sport excellent Precambrian quartzite crags and cliffs. In the Scottish Highlands, several mountains (e.g. Foinaven, Arkle) composed of Cambrian quartzite can be found in the far north-west Moine Thrust Belt running in a narrow band from Loch Eriboll in a south-westerly direction to Skye.[15]

In Canada, the La Cloche Mountains in Ontario are composed primarily of white quartzite.

Thin-section image of suartzite from Salangen, South Troms, Norway, showing elongate minerals associated with high strain regimes.
Normal view of quartzite, from the same sample as the thin section image above showing elongate minerals associated with high strain regimes.

References

  1. ^ German Loan Words in English. German.about.com (2010-06-22). Retrieved on 2011-06-05.
  2. ^ a b Powell, Darryl. "Quartzite". Mineral Information Institute. http://www.mii.org/Minerals/photoquartzite.html. Retrieved 2009-09-09. 
  3. ^ Ireland, H. A. (1974). "Query: Orthoquartzite????". Journal of Sedimentary Petrology 44 (1): 264–265. doi:10.1306/74D729F0-2B21-11D7-8648000102C1865D. 
  4. ^ Railroad Ballast
  5. ^ Krukowski, Stanley T. (2006). "Specialty Silica Materials". In Jessica Elzea Kogel, Nikhil C. Trivedi, James M. Barker, Stanley T. Krukowski. Industrial minerals & rocks: commodities, markets, and uses (7 ed.). Society for Mining, Metallurgy, and Exploration (U.S.). p. 842. ISBN 0873352335. http://books.google.com/books?id=zNicdkuulE4C&pg=PA842. 
  6. ^ Raw material. Stone Age Reference Collection, Institute for archeology, University of Oslo, Norway
  7. ^ [1][dead link]
  8. ^ Natural history – Minnesota's geology – SNAs: Minnesota DNR. Dnr.state.mn.us (2000-02-17). Retrieved on 2011-06-05.
  9. ^ Geology by Lightplane. Geology.wisc.edu (1923-07-13). Retrieved on 2011-06-05.
  10. ^ John W Gottman, Wasatch quartzite: A guide to climbing in the Wasatch Mountains, Wasatch Mountain Club (1979) ISBN 0915272237
  11. ^ Quartzite
  12. ^ Kennedy, B. A. (ed.). Surface Mining, Chapter 9.4: Case Studies: Morenci/Metcalf Society for Mining, Metallurgy, and Exploration, Undated Accessed May 28, 2007
  13. ^ White, B.G. and Winston, D., 1982, The Revett/St Regis “transition zone” near the Bunker Hill mine, Coeur d’Alene district, Idaho: Idaho Bureau of Mines and Geology Bulletin 24
  14. ^ Veena. Understanding Geology. Discovery Publishing House. pp. 145–. ISBN 9788183564618. http://books.google.com/books?id=9dYw6kHptcQC&pg=PA145. Retrieved 5 June 2011. 
  15. ^ John Blunden, (1975), The mineral resources of Britain: a study in exploitation and planning, p. 281.

External links


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Synonyms:

Look at other dictionaries:

  • Quartzite — Quartzite. Le quartzite est une roche siliceuse massive, constituée de cristaux de quartz soudés. Il présente une cassure conchoïdale. Sa couleur est généralement claire. Il existe deux types de quartzite : le quartzite métamorphique (ou… …   Wikipédia en Français

  • quartzite — [ kwartsit ] n. m. • 1823; de quartz ♦ Minér. Roche massive constituée de quartz en agrégats. Le quartzite résulte du métamorphisme des grès. ● quartzite nom masculin Roche siliceuse compacte, très dure, d origine sédimentaire ou métamorphique,… …   Encyclopédie Universelle

  • Quartzite — Quartz ite, n. [Cf. F. quartzite.] (Min.) Massive quartz occurring as a rock; a metamorphosed sandstone; called also {quartz rock}. [1913 Webster] …   The Collaborative International Dictionary of English

  • quartzite — s. f. O mesmo que quartzito.   ♦ Grafia no Brasil: quartzita …   Dicionário da Língua Portuguesa

  • quartzite — [kwôrt′sīt΄] n. [ QUARTZ + ITE1] 1. a very hard, metamorphic sandstone so firmly cemented that breakage occurs through grains rather than between them 2. any sandstone tightly cemented with quartz …   English World dictionary

  • quartzite — quartzitic /kwawrt sit ik/, adj. /kwawrt suyt/, n. a granular metamorphic rock consisting essentially of quartz in interlocking grains. [1840 50; QUARTZ + ITE1] * * * Sandstone that has been converted into a solid quartz rock. Quartzites are… …   Universalium

  • quartzite — kvarcitas statusas T sritis chemija apibrėžtis Įvairios spalvos, kieta, stiklo blizgesio, grūdėta metamorfinė kvarco uoliena. atitikmenys: angl. quartzite rus. кварцит …   Chemijos terminų aiškinamasis žodynas

  • quartzite — noun Etymology: International Scientific Vocabulary Date: circa 1847 a compact granular rock composed of quartz and derived from sandstone by metamorphism • quartzitic adjective …   New Collegiate Dictionary

  • quartzite — noun a metamorphic rock consisting of interlocking grains of quartz …   Wiktionary

  • quartzite — (kouar tsi t ) s. f. Quartz hyalin grenu, ou en roche …   Dictionnaire de la Langue Française d'Émile Littré


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