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Move details in top-heavy lead into main body of article. Correct material that is out of date with latest definitions. The Encyclopedia Britannica 1911 stuff is wonderfully detailed, elegantly worded, 110 years out of date, and not really about schist per se; replace.
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[[Image:Schist detail.jpg|thumb|Schist specimen showing the characteristic "scaly" schistose texture, caused by platy micas]]
[[Image:Schist detail.jpg|thumb|Schist specimen showing the characteristic "scaly" schistose texture, caused by platy micas]]


'''Schist''' ({{IPAc-en|ʃ|ɪ|s|t}} {{respell|shist}}) is a medium-grained [[metamorphic rock]] showing pronounced '''''schistosity'''''. This means that the rock is composed of [[mineral]] grains easily seen with a low-power [[hand lens]], oriented in such a way that the rock is easily split into thin flakes or plates. This [[Texture (geology)|texture]] reflects a high content of platy minerals, such as [[mica]]s, [[talc]], [[chlorite]], or [[graphite]]. These are often interleaved with more granular minerals, such as [[feldspar]] or [[quartz]].
'''Schist''' ({{IPAc-en|ʃ|ɪ|s|t}} {{respell|shist}}) is a medium-[[Metamorphism#Metamorphic grades|grade]] [[metamorphic rock]] formed from [[mudstone]] or [[shale]].<ref name="GeologyDictionary">{{cite web |url=http://www.theodora.com/geology/glossarys.html#schist |title=Schist definition |work=Dictionary of Geology |access-date=2013-07-12}}</ref> Schist has medium to large, flat, sheet-like grains in a preferred orientation (nearby grains are roughly parallel). It is defined by having more than 50% [[Crystal habit#List of crystal habits|platy]] and elongated minerals (such as micas or talc),<ref name="Glossary">{{cite book | url=https://books.google.com/books?id=SfnSesBc-RgC&q=schist+definition+50%25+platy+-study&pg=PA577 | title=Glossary of Geology | publisher=Springer |last1=Jackson |first1=J.A. |last2=Mehl |first2=J.P. |last3=Neuendorf |first3=K.K.E. | year=2005 | page=577 | isbn=9780922152766}}</ref> often finely interleaved with [[quartz]] and [[feldspar]].<ref name="Cambridge Guide">{{cite book | url=https://books.google.com/books?id=SnianWtB5WgC&q=schist+quartz+feldspar+interleaved&pg=PA153 | title=Cambridge Guide to Minerals, Rocks and Fossils | publisher=[[Cambridge University Press]] |last1=Bishop |first1=A.C. |last2=Woolley |first2=A.R. |last3=Hamilton |first3=W.R. | year=1999 | page=153 | isbn=9780521778817}}</ref> These lamellar (flat, planar) [[mineral]]s include [[mica]]s, [[Chlorite group|chlorite]], [[talc]], [[hornblende]], [[graphite]], and others. Quartz often occurs in drawn-out grains to such an extent that a particular form called quartz schist is produced. Schist is often [[garnet]]iferous. Schist forms at a higher temperature and has larger grains than [[phyllite]].<ref name=EG/> Geological [[Foliation (geology)|foliation]] (metamorphic arrangement in layers) with medium to large grained flakes in a preferred sheetlike orientation is called ''schistosity''.<ref name=EG>{{cite book |first1=Stephen |last1=Marshak |first2=M. Scott |last2=Wilkerson |first3=M. Bett |last3=Wilkerson |title=Essentials of Geology |url=https://books.google.com/books?id=Ya9pQgAACAAJ |date=2009 |publisher=W. W. Norton |isbn=978-0-393-19656-6 |edition=3rd}}</ref>


Schist typically forms during [[regional metamorphism]] accompanying the process of mountain building (''[[orogeny]]'') and usually reflects a medium [[Metamorphism#Metamorphic grades|grade]] of metamorphism. It can form from many different kinds of rocks, including [[sedimentary rock]]s such as [[mudstone]]s and [[igneous rock]]s such as [[tuff]]s. Schist metamorphosed from mudstone is particularly common and is often very rich in mica (a ''mica schist'').
The names of various schists are derived from their mineral constituents. For example, schists primarily composed of [[biotite]] and [[muscovite]] are called mica schists.<ref name="GeologyDictionary"/><ref>{{Cite book|title=Earth science |last=Tarbuck |first=Edward J. |date=2012|publisher=Prentice Hall/Pearson|others=Lutgens, Frederick K.|isbn=978-0321688507|edition=13th|location=Upper Saddle River, N.J.|oclc=693684089}}</ref> Most schists are mica schists, but graphite and chlorite schists are also common. Schists are also named for their prominent or perhaps unusual mineral constituents, as in the case of garnet schist, [[tourmaline]] schist, and [[glaucophane]] schist.


Where the type of the original rock (the ''[[protolith]]'') is discernible, the schist is usually given a name reflecting its protolith, such as ''schistose metasandstone''. Otherwise, the names of the consitutent minerals will be included in the rock name, such as ''quartz-felspar-biotite schist''.
⚫
The individual [[mineral]] grains in schist, drawn out into flaky scales by heat and pressure, can be seen with the naked eye. Schist is characteristically ''foliated'', meaning that the individual mineral grains split off easily into flakes or slabs. The word schist is derived ultimately from the [[Greek language|Greek]] word ''σχίζειν'' (''schízein'') meaning "to split",<ref name="OD">{{cite web | url=http://www.oxforddictionaries.com/definition/english/schist | title=Schist | publisher=[[Oxford University Press]] | work=English Dictionary | access-date=10 February 2014}}</ref> which is a reference to the ease with which schists can be split along the plane in which the platy minerals lie.


⚫
The word schist is derived ultimately from the [[Greek language|Greek]] word ''σχίζειν'' (''schízein'') meaning "to split",<ref name="OD">{{cite web | url=http://www.oxforddictionaries.com/definition/english/schist | title=Schist | publisher=[[Oxford University Press]] | work=English Dictionary | access-date=10 February 2014}}</ref> which is a reference to the ease with which schists can be split along the plane in which the platy minerals lie.
Most schists are derived from [[clay]]s and [[mud]]s that have passed through a series of metamorphic processes involving the production of shales, [[slate]]s and phyllites as intermediate steps. Certain schists are derived from fine-grained [[igneous rock]]s such as [[basalt]]s and [[tuff]]s.


== Definition ==
⚫
==Historical mining terminology==
Geologists define schist as medium-grained [[metamorphic rock]] that shows well-developed schistosity.{{sfn|British Geological Survey|1999 |p=3}} Schistosity is a thin layering of the rock produced by [[metamorphism]] (a ''[[foliation (geology)|foliation]]'') that permits the rock to easily be split into flakes or slabs less than {{convert|5 to 10|mm|1|sp=us}} thick.<ref name="schid-etal=2007">{{cite book |last1=Schmid |first1=R. |last2=Fettes |first2=D. |last3=Harte |first3=B. |last4=Davis |first4=E. |last5=Desmons |first5=J. |year=2007 |chapter=How to name a metamorphic rock. |title=Metamorphic Rocks: A Classification and Glossary of Terms: Recommendations of the International Union of Geological Sciences Subcommission on the Systematics of Metamorphic Rocks |publisher=Cambridge University Press |location=Cambridge |page=7 |url=https://stuff.mit.edu/afs/athena.mit.edu/course/12/12.115/www/12.114%20Papers/BGS/Metamorphic/DetailedMetamorphic/1%20How%20to%20name%20a%20metamorphic%20rock.pdf |access-date=28 February 2021}}</ref><ref name="BGS">{{cite journal |last1=Robertson |first1=S. |title=BGS Rock Classification Scheme, Volume 2: Classification of metamorphic rocks |journal=British Geological Survey Research Report |date=1999 |volume=RR 99-02 |url=http://nora.nerc.ac.uk/id/eprint/3226/1/RR99002.pdf |access-date=27 February 2021 |ref={{harvid|British Geological Survey|1999}} |p=5}}</ref> The mineral grains in a schist are typically from {{convert|0.25 to 2|mm|2|sp=us}} in size{{sfn|British Geological Survey|1999 |p=24}} and so are easily seen with a 10× [[hand lens]].<ref>{{cite book |last1=Blatt |first1=Harvey |last2=Tracy |first2=Robert J. |title=Petrology : igneous, sedimentary, and metamorphic. |date=1996 |publisher=W.H. Freeman |location=New York |isbn=0716724383 |edition=2nd |p=360}}</ref> Typically, over half the mineral grains in a schist show a preferred orientation. Schists make up one of the three divisions of metamorphic rock by [[Texture (geology)|texture]], with the other two divisions being [[gneiss]], which has poorly developed schistosity and thicker layering, and [[granofels]], which has no discernible schistosity.<ref name="schid-etal=2007"/>{{sfn|British Geological Survey|1999 |pp=5-6}}

Schists are defined by their texture, without reference to their composition,<ref>{{cite book |editor1-last=Jackson |editor1-first=Julia A. |title=Glossary of geology. |date=1997 |publisher=American Geological Institute |location=Alexandria, Viriginia |isbn=0922152349 |edition=Fourth |chapter=schist}}</ref><ref name="schid-etal=2007"/> and while most are a result of medium-grade metamorphism, they can vary greatly in mineral makeup.{{sfn|British Geological Survey|1999 |p=5}} However, schistosity normally develops only when that the rock contains abundant platy minerals, such as [[mica]]s or [[chlorite]]. Grains of these minerals are strongly oriented in a preferred direction in schist, often also forming very thin parallel layers. The ease which which the rock splits along the aligned grains accounts for the schistosity.<ref name="schid-etal=2007"/> Though not a defining characteristic, schists very often contain ''[[porphyroblast]]s'' (individual crystals of unusual size) of distinctive minerals, such as [[garnet]], [[staurolite]], [[kyanite]], [[sillimanite]], or [[cordierite]].{{sfn|Blatt|Tracy|1996|p=365}}

{{anchor|Paraschist}}{{anchor|Orthoschist}}
Because schists are a very large class of metamorphic rock, geologists will formally describe a rock as a schist only when the original type of the rock prior to [[metamorphism]] (the [[protolith]]) is unknown and its mineral content is not yet determined. Otherwise, the modifier ''schistose'' will be applied to a more precise type name, such as ''schistose [[semipelite]]'' (when the rock is known to contain moderate amounts of [[mica]]) or a ''schistose metasandstone'' (if the protolith is known to have been a [[sandstone]]).{{sfn|British Geological Survey|1999 |pp=3-4}} If all that is known is that the protolith was a sedimentary rock, the schist will be described as a '''paraschist''', while if the protolith was an igneous rock, the schist will be described as an '''orthoschist'''.{{sfn|British Geological Survey|1999 |pp=5-7}} Mineral qualifiers are important when naming a schist. For example, a quartz-feldspar-biotite schist is a schist of uncertain protolith that contains [[biotite]] mica, [[feldspar]], and [[quartz]] in order of apparent decreasing abundance.{{sfn|British Geological Survey|1999 |p=8}}

''Lineated schist'' has a strong linear fabric in a rock which otherwise has well-developed schistosity.{{sfn|British Geological Survey|1999 |p=5}}

⚫
===Historical mining terminology===
Before the mid-19th century, the terms slate, shale and schist were not sharply differentiated by those involved with mining.<ref>{{cite book |first=R. W. |last=Raymond |chapter=Slate |url=https://books.google.com/books?id=FpqFAAAAIAAJ&pg=PA78 |title=A Glossary of Mining and Metallurigical Terms |publisher=American Institute of Mining Engineers |year=1881 |page=78}}</ref>
Before the mid-19th century, the terms slate, shale and schist were not sharply differentiated by those involved with mining.<ref>{{cite book |first=R. W. |last=Raymond |chapter=Slate |url=https://books.google.com/books?id=FpqFAAAAIAAJ&pg=PA78 |title=A Glossary of Mining and Metallurigical Terms |publisher=American Institute of Mining Engineers |year=1881 |page=78}}</ref>


==Formation==
==Formation==
Schistosity is developed at elevated temperature when the rock is more strongly compressed in one direction than in other directions (''nonhydrostatic stress''). The schistosity develop perpendicular to the direction of greatest compression, also called the shortening direction, as platy minerals are rotated or recrystallized into parallel layers.{{sfn|Blatt|Tracy|1996|p=359}} The composition of the rock must permit formation of abundant platy minerals. For example, the [[clay minerals]] in mudstone are metamorphosed to mica, producing a mica schist.<ref>{{cite book |last1=Potter |first1=Paul Edwin |last2=Maynard |first2=J. Barry |last3=Pryor |first3=Wayne A. |title=Sedimentology of shale : study guide and reference source |date=1980 |publisher=Springer-Verlag |location=New York |isbn=0387904301 |p=17}}</ref> Early stages of metamorphosis convert mudstone to a fine-grained metamorphic rock called ''[[slate]]'', which with further metamorphosis becomes fine-grained ''[[phyllite]]''. Further recrystallization produces mica schist.{{sfn|Blatt|Tracy|1996|p=365}}
During metamorphism, rocks which were originally sedimentary, igneous or metamorphic are converted into schists and [[gneiss]]es. If the composition of the rocks was originally similar, they may be very difficult to distinguish from one another if the metamorphism has been great. A [[quartz-porphyry]], for example, and a fine grained feldspathic sandstone, may both be converted into a grey or pink mica-schist. Usually, however, it is possible to distinguish between sedimentary and igneous schists and gneisses. If, for example, the whole district occupied by these rocks has traces of bedding, [[clastic]] structure, or [[Unconformity|unconformability]], then it may be a sign that the original rock was sedimentary. In other cases [[Intrusive rock|intrusive]] junctions, chilled edges, contact alteration or porphyritic structure may prove that in its original condition a metamorphic gneiss was an igneous rock. The last appeal is often to the chemistry, for there are certain rock types which occur only as sediments, while others are found only among igneous masses, and however advanced the metamorphism may be, it rarely modifies the chemical composition of the mass very greatly. Such rocks as [[limestone]]s, [[Dolomite (rock)|dolomite]]s, [[quartzite]]s, and aluminous shales have very definite chemical characteristics that distinguish them even when completely recrystallized.<ref name=EB1911>{{EB1911|wstitle=Petrology |volume=21 |page=333 |inline=1 |first=John Smith |last=Flett}}</ref>

Other platy minerals found in schists include chlorite, talc, and graphite. Chlorite schist is typically formed by metamorphosis of [[ultramafic]] igneous rocks,<ref>{{cite journal |last1=Nokleberg |first1=Warren J. |last2=Jones |first2=David L. |last3=Silberling |first3=Norman J. |title=Origin and tectonic evolution of the Maclaren and Wrangellia terranes, eastern Alaska Range, Alaska |journal=GSA Bulletin |date=1 October 1985 |volume=96 |issue=10 |pages=1251–1270 |doi=10.1130/0016-7606(1985)96<1251:OATEOT>2.0.CO;2}}</ref><ref>{{cite journal |last1=Esteban |first1=J.J. |last2=Cuevas |first2=J. |last3=Tubía |first3=J.M. |last4=Liati |first4=A. |last5=Seward |first5=D. |last6=Gebauer |first6=D. |title=Timing and origin of zircon-bearing chlorite schists in the Ronda peridotites (Betic Cordilleras, Southern Spain) |journal=Lithos |date=November 2007 |volume=99 |issue=1-2 |pages=121–135 |doi=10.1016/j.lithos.2007.06.006}}</ref> as is talc schist.<ref>{{cite journal |last1=Woguia |first1=D.L. |last2=Fagel |first2=N. |last3=Pirard |first3=E. |last4=Gourfi |first4=A. |last5=Ngo bidjeck |first5=L.M. |last6=El ouahabi |first6=M. |title=Talc schist deposits from central Cameroon: Mineralogical and physico-chemical characterization |journal=Journal of African Earth Sciences |date=June 2021 |volume=178 |pages=104182 |doi=10.1016/j.jafrearsci.2021.104182}}</ref> Talc schist also forms from metamorphosis of talc-bearing carbonate rocks formed by [[hydrothermal alteration]].<ref>{{cite journal |last1=Prochaska |first1=W. |title=Geochemistry and genesis of Austrian talc deposits |journal=Applied Geochemistry |date=September 1989 |volume=4 |issue=5 |pages=511–525 |doi=10.1016/0883-2927(89)90008-5}}</ref> Graphite schist is uncommon, but can form from metamorphosis of sedimentary beds containing abundant organic carbon.<ref>{{cite journal |last1=Ukar |first1=E. |last2=Cloos |first2=M. |title=Graphite-schist blocks in the Franciscan Mélange, San Simeon, California: Evidence of high- P metamorphism |journal=Journal of Metamorphic Geology |date=April 2016 |volume=34 |issue=3 |pages=191–208 |doi=10.1111/jmg.12174}}</ref> This may be of algal origin.<ref>{{cite book |last1=Lumpkin |first1=B. |last2=Stoddard |first2=E. |last3=Blake |first3=D. |year=1994 |chapter=The Raleigh graphite schist |title=Geology and Field Trip Guide, Western Flank of the Raleigh Metamorphic Belt, North Carolina. Carolina Geological Society Field Trip Guidebook |publisher=North Carolina Geological Survey |location=Raleigh, NC |pp=19-24 |url=https://carolinageologicalsociety.org/1990s_files/gb%201994.pdf#page=25 |access-date=22 July 2021}}</ref>

Metamorphosis of [[felsic]] [[volcanic rock]], such as tuff, can produce quartz-muscovite schist.<ref>{{cite journal |last1=Bauer |first1=Paul W. |title=Proterozoic rocks of the Pilar Cliffs, Picuris Mountains, New Mexico |journal=New Mexico Geological Society Field Conference Series |date=2004 |volume=55 |pages=193–205 |url=https://nmgs.nmt.edu/publications/guidebooks/downloads/55/55_p0193_p0205.pdf |accessdate=15 April 2020}}</ref>


The schists are classified principally according to the minerals they consist of and on their chemical composition. For example, many metamorphic limestones, marbles, and calc-schists, with crystalline dolomites, contain silicate minerals such as mica, [[tremolite]], [[diopside]], [[scapolite]], quartz and [[feldspar]]. They are derived from calcareous sediments of different degrees of purity. Another group is rich in quartz (quartzites, quartz schists and quartzose gneisses), with variable amounts of white and black mica, [[garnet]], feldspar, [[zoisite]] and [[hornblende]]. These were once sandstones and arenaceous rocks. The graphitic schists may readily be believed to represent sediments once containing coal or plant remains; there are also schistose [[ironstone]]s ([[hematite]]-schists), but metamorphic beds of salt or [[gypsum]] are exceedingly uncommon. Among schists of igneous origin there are the silky calc-schists, the foliated [[Serpentine group|serpentine]]s (once [[ultramafic]] masses rich in [[olivine]]), and the white mica-schists, porphyroids and banded [[halleflinta]]s, which have been derived from [[rhyolite]]s, quartz-porphyries and felsic [[tuff]]s. The majority of mica-schists, however, are altered [[claystone]]s and shales, and pass into the normal sedimentary rocks through various types of [[phyllite]] and mica-slates. They are among the most common metamorphic rocks; some of them are [[Graphite|graphitic]] and others calcareous. The diversity in appearance and composition is very great, but they form a well-defined group not difficult to recognize, from the abundance of black and white micas and their thin, foliated, schistose character. A subgroup is the [[andalusite]]-, [[staurolite]]-, [[kyanite]]- and [[sillimanite]]-schists which usually make their appearance in the vicinity of gneissose granites, and have presumably been affected by contact metamorphism.<ref name=EB1911/>


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Revision as of 19:29, 22 July 2021

Schist specimen showing the characteristic "scaly" schistose texture, caused by platy micas

Schist (/ʃɪst/ shist) is a medium-grained metamorphic rock showing pronounced schistosity. This means that the rock is composed of mineral grains easily seen with a low-power hand lens, oriented in such a way that the rock is easily split into thin flakes or plates. This texture reflects a high content of platy minerals, such as micas, talc, chlorite, or graphite. These are often interleaved with more granular minerals, such as feldspar or quartz.

Schist typically forms during regional metamorphism accompanying the process of mountain building (orogeny) and usually reflects a medium grade of metamorphism. It can form from many different kinds of rocks, including sedimentary rocks such as mudstones and igneous rocks such as tuffs. Schist metamorphosed from mudstone is particularly common and is often very rich in mica (a mica schist).

Where the type of the original rock (the protolith) is discernible, the schist is usually given a name reflecting its protolith, such as schistose metasandstone. Otherwise, the names of the consitutent minerals will be included in the rock name, such as quartz-felspar-biotite schist.

The word schist is derived ultimately from the Greek word σχίζειν (schízein) meaning "to split",[1] which is a reference to the ease with which schists can be split along the plane in which the platy minerals lie.

Definition

Geologists define schist as medium-grained metamorphic rock that shows well-developed schistosity.[2] Schistosity is a thin layering of the rock produced by metamorphism (a foliation) that permits the rock to easily be split into flakes or slabs less than 5 to 10 millimeters (0.2 to 0.4 in) thick.[3][4] The mineral grains in a schist are typically from 0.25 to 2 millimeters (0.01 to 0.08 in) in size[5] and so are easily seen with a 10× hand lens.[6] Typically, over half the mineral grains in a schist show a preferred orientation. Schists make up one of the three divisions of metamorphic rock by texture, with the other two divisions being gneiss, which has poorly developed schistosity and thicker layering, and granofels, which has no discernible schistosity.[3][7]

Schists are defined by their texture, without reference to their composition,[8][3] and while most are a result of medium-grade metamorphism, they can vary greatly in mineral makeup.[9] However, schistosity normally develops only when that the rock contains abundant platy minerals, such as micas or chlorite. Grains of these minerals are strongly oriented in a preferred direction in schist, often also forming very thin parallel layers. The ease which which the rock splits along the aligned grains accounts for the schistosity.[3] Though not a defining characteristic, schists very often contain porphyroblasts (individual crystals of unusual size) of distinctive minerals, such as garnet, staurolite, kyanite, sillimanite, or cordierite.[10]

Because schists are a very large class of metamorphic rock, geologists will formally describe a rock as a schist only when the original type of the rock prior to metamorphism (the protolith) is unknown and its mineral content is not yet determined. Otherwise, the modifier schistose will be applied to a more precise type name, such as schistose semipelite (when the rock is known to contain moderate amounts of mica) or a schistose metasandstone (if the protolith is known to have been a sandstone).[11] If all that is known is that the protolith was a sedimentary rock, the schist will be described as a paraschist, while if the protolith was an igneous rock, the schist will be described as an orthoschist.[12] Mineral qualifiers are important when naming a schist. For example, a quartz-feldspar-biotite schist is a schist of uncertain protolith that contains biotite mica, feldspar, and quartz in order of apparent decreasing abundance.[13]

Lineated schist has a strong linear fabric in a rock which otherwise has well-developed schistosity.[9]

Historical mining terminology

Before the mid-19th century, the terms slate, shale and schist were not sharply differentiated by those involved with mining.[14]

Formation

Schistosity is developed at elevated temperature when the rock is more strongly compressed in one direction than in other directions (nonhydrostatic stress). The schistosity develop perpendicular to the direction of greatest compression, also called the shortening direction, as platy minerals are rotated or recrystallized into parallel layers.[15] The composition of the rock must permit formation of abundant platy minerals. For example, the clay minerals in mudstone are metamorphosed to mica, producing a mica schist.[16] Early stages of metamorphosis convert mudstone to a fine-grained metamorphic rock called slate, which with further metamorphosis becomes fine-grained phyllite. Further recrystallization produces mica schist.[10]

Other platy minerals found in schists include chlorite, talc, and graphite. Chlorite schist is typically formed by metamorphosis of ultramafic igneous rocks,[17][18] as is talc schist.[19] Talc schist also forms from metamorphosis of talc-bearing carbonate rocks formed by hydrothermal alteration.[20] Graphite schist is uncommon, but can form from metamorphosis of sedimentary beds containing abundant organic carbon.[21] This may be of algal origin.[22]

Metamorphosis of felsic volcanic rock, such as tuff, can produce quartz-muscovite schist.[23]


  • Microscopic view of garnet-mica-schist in thin section under polarized light with a large garnet crystal (black) in a matrix of quartz and feldspar (white and gray grains) and parallel strands of mica (red, purple and brown).
    Microscopic view of garnet-mica-schist in thin section under polarized light with a large garnet crystal (black) in a matrix of quartz and feldspar (white and gray grains) and parallel strands of mica (red, purple and brown).
  • View of cut garnet-mica-schist
    View of cut garnet-mica-schist
  • Manhattan schist from southeastern New York State
    Manhattan schist from southeastern New York State
  • Manhattan schist outcropping in New York City's Central Park
    Manhattan schist outcropping in New York City's Central Park
  • Talc-scist from Saint-Marcel, France
    Talc-scist from Saint-Marcel, France

Engineering considerations

In geotechnical engineering a schistosity plane often forms a discontinuity that may have a large influence on the mechanical behavior (strength, deformation, etc.) of rock masses in, for example, tunnel, foundation, or slope construction.

See also

References

  1. ^ "Schist". English Dictionary. Oxford University Press. Retrieved 10 February 2014.
  2. ^ British Geological Survey 1999, p. 3.
  3. ^ a b c d Schmid, R.; Fettes, D.; Harte, B.; Davis, E.; Desmons, J. (2007). "How to name a metamorphic rock.". Metamorphic Rocks: A Classification and Glossary of Terms: Recommendations of the International Union of Geological Sciences Subcommission on the Systematics of Metamorphic Rocks (PDF). Cambridge: Cambridge University Press. p. 7. Retrieved 28 February 2021.
  4. ^ Robertson, S. (1999). "BGS Rock Classification Scheme, Volume 2: Classification of metamorphic rocks" (PDF). British Geological Survey Research Report. RR 99-02: 5. Retrieved 27 February 2021.
  5. ^ British Geological Survey 1999, p. 24.
  6. ^ Blatt, Harvey; Tracy, Robert J. (1996). Petrology : igneous, sedimentary, and metamorphic (2nd ed.). New York: W.H. Freeman. p. 360. ISBN 0716724383.
  7. ^ British Geological Survey 1999, pp. 5–6.
  8. ^ Jackson, Julia A., ed. (1997). "schist". Glossary of geology (Fourth ed.). Alexandria, Viriginia: American Geological Institute. ISBN 0922152349.
  9. ^ a b British Geological Survey 1999, p. 5.
  10. ^ a b Blatt & Tracy 1996, p. 365.
  11. ^ British Geological Survey 1999, pp. 3–4.
  12. ^ British Geological Survey 1999, pp. 5–7.
  13. ^ British Geological Survey 1999, p. 8.
  14. ^ Raymond, R. W. (1881). "Slate". A Glossary of Mining and Metallurigical Terms. American Institute of Mining Engineers. p. 78.
  15. ^ Blatt & Tracy 1996, p. 359.
  16. ^ Potter, Paul Edwin; Maynard, J. Barry; Pryor, Wayne A. (1980). Sedimentology of shale : study guide and reference source. New York: Springer-Verlag. p. 17. ISBN 0387904301.
  17. ^ Nokleberg, Warren J.; Jones, David L.; Silberling, Norman J. (1 October 1985). "Origin and tectonic evolution of the Maclaren and Wrangellia terranes, eastern Alaska Range, Alaska". GSA Bulletin. 96 (10): 1251–1270. doi:10.1130/0016-7606(1985)96<1251:OATEOT>2.0.CO;2.
  18. ^ Esteban, J.J.; Cuevas, J.; Tubía, J.M.; Liati, A.; Seward, D.; Gebauer, D. (November 2007). "Timing and origin of zircon-bearing chlorite schists in the Ronda peridotites (Betic Cordilleras, Southern Spain)". Lithos. 99 (1–2): 121–135. doi:10.1016/j.lithos.2007.06.006.
  19. ^ Woguia, D.L.; Fagel, N.; Pirard, E.; Gourfi, A.; Ngo bidjeck, L.M.; El ouahabi, M. (June 2021). "Talc schist deposits from central Cameroon: Mineralogical and physico-chemical characterization". Journal of African Earth Sciences. 178: 104182. doi:10.1016/j.jafrearsci.2021.104182.
  20. ^ Prochaska, W. (September 1989). "Geochemistry and genesis of Austrian talc deposits". Applied Geochemistry. 4 (5): 511–525. doi:10.1016/0883-2927(89)90008-5.
  21. ^ Ukar, E.; Cloos, M. (April 2016). "Graphite-schist blocks in the Franciscan Mélange, San Simeon, California: Evidence of high- P metamorphism". Journal of Metamorphic Geology. 34 (3): 191–208. doi:10.1111/jmg.12174.
  22. ^ Lumpkin, B.; Stoddard, E.; Blake, D. (1994). "The Raleigh graphite schist". Geology and Field Trip Guide, Western Flank of the Raleigh Metamorphic Belt, North Carolina. Carolina Geological Society Field Trip Guidebook (PDF). Raleigh, NC: North Carolina Geological Survey. pp. 19–24. Retrieved 22 July 2021.
  23. ^ Bauer, Paul W. (2004). "Proterozoic rocks of the Pilar Cliffs, Picuris Mountains, New Mexico" (PDF). New Mexico Geological Society Field Conference Series. 55: 193–205. Retrieved 15 April 2020.
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