Editing Tonalite (section)

{{Short description|Igneous rock}}
[[File:Tonalite.png|thumb|A piece of tonalite on red granite [[gneiss]] from Tjörn,  Sweden]]
[[File:Qapf tonalite.png|thumb|[[QAPF diagram]] with tonalite field highlighted]]
'''Tonalite''' is an [[igneous rock|igneous]], [[pluton]]ic ([[Intrusive rock|intrusive]]) [[rock (geology)|rock]], of [[felsic]] composition, with [[phaneritic]] (coarse-grained) texture. [[Feldspar]] is present as [[plagioclase]] (typically [[oligoclase]] or [[andesine]]) with [[alkali feldspar]] making up less than 10% of the total feldspar content. [[Quartz]] (SiO<sub>2</sub>) is present as more than 20% of the total quartz-alkali feldspar-plagioclase-feldspathoid ([[QAPF classification|QAPF]]) content of the rock.<ref name="lebas-streckeisen-1991">{{Cite journal|last1=Le Bas|first1=M. J.|last2=Streckeisen|first2=A. L.|title=The IUGS systematics of igneous rocks|journal=Journal of the Geological Society|volume=148|issue=5|pages=825–833|doi=10.1144/gsjgs.148.5.0825|bibcode=1991JGSoc.148..825L|year=1991|citeseerx=10.1.1.692.4446|s2cid=28548230}}</ref><ref name="bgs">{{Cite journal|date=1999|title=Rock Classification Scheme - Vol 1 - Igneous|url=http://nora.nerc.ac.uk/id/eprint/3223/1/RR99006.pdf|journal=British Geological Survey: Rock Classification Scheme|volume=1|pages=1–52}}</ref> [[Amphibole]]s and [[biotite]] are common in lesser quantities, while accessory [[mineral]]s include [[apatite]], [[magnetite]] and [[zircon]].<ref>https://geologyscience.com/rocks/igneous-rocks/intrusive-igneous-rocks/tonalite/ Tonalite Page in Geology Science</ref><ref>{{cite book |last1=Allaby |first1=Michael |title=A dictionary of geology and earth sciences |date=2013 |publisher=Oxford University Press |location=Oxford |isbn=9780199653065 |edition=Fourth |chapter=tonalite}}</ref>

In older references tonalite is sometimes used as a synonym for [[quartz diorite]]. However the current [[IUGS]] [[QAPF diagram|classification]] defines tonalite as having greater than 20% quartz, while [[quartz diorite]] varies its quartz content from 5 to 20%.<ref name="lebas-streckeisen-1991"/>

The name is derived from the type locality of tonalites, adjacent to the Tonale Line, a major structural [[lineament]] and mountain pass, [[Tonale Pass]], in the [[Italy|Italian]] and [[Austria]]n [[Alps]]. The name was first applied by [[Gerhard vom Rath]] in 1864.<ref>{{cite book |editor1-last=Jackson |editor1-first=Julia A. |title=Glossary of geology. |date=1997 |publisher=American Geological Institute |location=Alexandria, Virginia |isbn=0922152349 |edition=Fourth |chapter=tonalite}}</ref> The term ''adamellite'' was originally applied by A. Cathrein in 1890 to [[orthoclase]]-bearing tonalite (likely a [[granodiorite]]) at Monte Adamello, Italy, in 1890, but later came to refer to [[quartz monzonite]], and is now a deprecated term.<ref>{{cite journal |last1=Streckeisen |first1=A. |title=To each plutonic rock its proper name |journal=Earth-Science Reviews |date=1 March 1976 |volume=12 |issue=1 |pages=1–33 |doi=10.1016/0012-8252(76)90052-0}}</ref>

[[Trondhjemite]] is an [[orthoclase]]-deficient variety of [[sodium]]-rich tonalite with minor [[biotite]] as the only [[mafic]] mineral, named after [[Norway]]'s third largest city, [[Trondheim]].{{sfn|Jackson|1997|loc="trondhjemhite"}}

Tonalites, together with [[granodiorite]]s, are characteristic of [[calc-alkaline]] [[batholith]]s formed above [[subduction zones]].<ref>{{cite journal |last1=Castro |first1=Antonio |title=Tonalite–granodiorite suites as cotectic systems: A review of experimental studies with applications to granitoid petrogenesis |journal=Earth-Science Reviews |date=September 2013 |volume=124 |pages=68–95 |doi=10.1016/j.earscirev.2013.05.006}}</ref>

[[File:Roc de la Calme.jpg|thumb|Roc de la Calme (or Calma), a tonalite tor in the Mont-Louis-Andorra granite pluton (Variscan Pyrenees).<ref>[https://sigesocc.brgm.fr/?page=ficheMaCommune&codeCommune=66124 ''SIGES Occitanie (Font-Romeu-Odeillo-Via)''], at  sigesocc.brgm.fr; section "Carte géologique"; "Paléozoïque - Cycle hercynien... Tonalite à biotite et hornblende".</ref><ref>[https://www.geoportail.gouv.fr/carte?c=2.015,42.535&z=0.0002&l0=GEOGRAPHICALGRIDSYSTEMS.MAPS::GEOPORTAIL:OGC:WMTS%281%29&permalink=yes Topographical map extract] (in [[Géoportail]]).</ref>]]