Phonotephrite

File:Peridotite mantle xenoliths in vesicular phonotephrite (Peridot Mesa Flow, Middle Pleistocene, 580 ka; Peridot Mesa, San Carlos Volcanic Field, Arizona) 10 (31101103172).jpg xenoliths (green) in phonotephrite from Peridot Mesa, Arizona]]

Phonotephrite or phono-tephrite is a strongly alkaline volcanic rock with a composition between phonolite and tephrite.{{cite web|url=https://www.geology.sdsu.edu/how_volcanoes_work/Unusual%20lava.html|archive-url=https://web.archive.org/web/20201105231754/http://sci.sdsu.edu/how_volcanoes_work/Unusual%20lava.html|archive-date=2020-11-05|title=Unusual Lava Types|work=Strongly Alkaline Lavas|publisher=San Diego State University|access-date=2016-09-11}} This unusual igneous rock contains 7 to 12% alkali content and 45 to 53% silica content (see TAS diagram). It can be described as a mafic phonolite or a potassic tephrite. Phonotephrite lava flows and volcanic cones have been identified in Antarctica (e.g. Mount Erebus), Europe (e.g. Mount Vesuvius), North America (e.g. Satah Mountain volcanic field) and Africa (e.g. Jbel Saghro).{{cite journal|title=⁴⁰Ar/³⁹Ar dating of the eruptive history of Mount Erebus, Antarctica: volcano evolution|last1=P. Esser|first1=Richard|last2=R. Kyle|first2=Philip|last3=McIntosh|first3=William C.|year=2004|journal=Bulletin of Volcanology|volume=66 |issue=8 |page=671 |publisher=Springer|doi=10.1007/s00445-004-0354-x |bibcode=2004BVol...66..671E |s2cid=129118037 }}{{cite journal|title=The Satah Mountain and Baldface Mountain volcanic fields: Pleistocene hot spot volcanism in the Anahim Volcanic Belt, west-central British Columbia, Canada|last1=Kuehn|first1=Christian|last2=Guest|first2=Bernard|last3=K. Russell|first3=James|last4=A. Benowitz|first4=Jeff|year=2015|page=8|journal=Bulletin of Volcanology|publisher=Springer}}{{cite journal|title=The role of fractional crystallization and late-stage peralkaline melt segregation in the mineralogical evolution of Cenozoic nephelinites/phonolites from Saghro (SE Morocco)|last1=Berger|first1=J.|last2=Ennih|first2=N.|last3=Mercier|first3=J.-C. C.|last4=Liégeois|first4=J.-P.|last5=Demaiffe|first5=D.|year=2009|journal=Mineralogical Magazine|publisher=Mineralogical Society of Great Britain and Ireland|volume=73|number=1|page=59 |doi=10.1180/minmag.2009.073.1.59 |bibcode=2009MinM...73...59B |s2cid=54866658 |issn=1471-8022}}{{cite journal | title=Nature and Evolution of Primitive Vesuvius Magmas: an Experimental Study | first1=M. | last1=Pichavant | first2=B. | last2=Scaillet | first3=A. | last3=Pommier | first4=G. | last4=Iacono-Marziano | first5=R. |last5=Cioni | journal=Journal of Petrology | publisher = Oxford University Press | year=2014 | volume=55 | issue=11 | pages=2281–2310 | doi=10.1093/petrology/egu057| doi-access=free }}