Phonotephrite or phono-tephrite is a strongly alkaline volcanic rock with a composition between phonolite and tephrite. This unusual igneous rock contains...

silica-undersaturated volcanic rock; essentially similar to nepheline syenite Phonotephrite – strongly alkaline volcanic rock with a composition between phonolite...

mafic to intermediate extrusive igneous rock in composition between phonotephrite and phonolite. It contains 9 to 14% alkali content and 48 to 57% silica...

low broad platform shield of Erebus. Slightly younger basanite and phonotephrite lavas crop out on Fang Ridge – an eroded remnant of an early Erebus...

open for travelers now. Pico do Fogo consists of basanite, tephrite, phonotephrite, clinopyroxene, amphibole, magnetite, olivine, melilite and leucite...

exposes intrusions of syenite. Kibo has five main lava formations: Phonotephrites and tephriphonolites of the Lava Tower group, on a dyke cropping out...

(Picrobasalt) U1 (Basanite or Tephrite)—Use normative mineralogy to decide. U2 (Phonotephrite) U3 (Tephriphonolite) F (Foidite)—When possible, classify/name according...

laterally discontinuous volcaniclastics, basaltic trachyandesite, phonotephrite, and trachyte Argentina Spring Tuff (36 Ma) Taylor Windmill Member:...

the northwest of Kattothyrst, has basanite lavas with an intervening phonotephrite flow on the northeast side. The Obelisk has a south end of trachybasalt...

124°34′W / 52.3750°N 124.567°W / 52.3750; -124.567 - Eroded cone Phonotephrite - 52°26.4′N 124°37.3′W / 52.4400°N 124.6217°W / 52.4400; -124.6217...