Tephriphonolite Explained

Tephriphonolite or tephri-phonolite is a mafic to intermediate extrusive igneous rock in composition between phonotephrite and phonolite.^[1] It contains 9 to 14% alkali content and 48 to 57% silica content (see TAS diagram).^[2] Tephriphonolite is roughly equivalent to tephritic phonolite of the QAPF classification.^[3]

Tephriphonolite has been found, for example, at Colli Albani volcano in Italy^[4] and in the Asunción Rift of Paraguay.^[5]

Notes and References

1. Web site: Unusual Lava Types. https://web.archive.org/web/20201105231754/http://sci.sdsu.edu/how_volcanoes_work/Unusual%20lava.html. 2020-11-05. Strongly Alkaline Lavas. San Diego State University. 2016-09-11.
2. Eruptive History and Chemical Evolution of the Precaldera and Postcaldera Basalt-Dacite Sequences, Long Valley, California: Implications for Magma Sources, Current Seismic Unrest, and Future Volcanism. Bailey. Roy A.. 2004. 17. United States Geological Survey.
3. Book: Igneous Rocks — A Classification and Glossary of Terms . Cambridge University Press . Le Maitre, R.W. (editor) . 2002 . Cambridge . 32 . 0-521-66215-X. 2nd .
4. Crystallization kinetics and rheology of leucite-bearing tephriphonolite magmas from the Colli Albani volcano (Italy) . S. . Campagnola . A.. Vona . C. . Romano . G. . Giordano . . . 2016 . 424 . 12–29 . 10.1016/j.chemgeo.2016.01.012. 2016ChGeo.424...12C .
5. The Cretaceous Alkaline Dyke Swarm in the Central Segment of the Asunción Rift, Eastern Paraguay: Its Regional Distribution, Mechanism of Emplacement, and Tectonic Significance . V.F. . Velázquez . C. . Riccomini . C. . de Barros Gomes . J. . Kirk . Journal of Geological Research . 2011 . 2011 . 1–18 . 10.1155/2011/946701. free .