Geologic units containing alkalic volcanic rock

Earth material > Volcanic rock

Alkalic volcanic rock

A volcanic rock that contains more sodium and/or potassium than is required to form feldspar with the available silica.

Subtopics:
Phonolite
Tephrite

New Mexico

felsic shallow-intrusive rocks (Phanerozoic | Cenozoic | Tertiary): Middle Tertiary felsic shallow-intrusive rocks; phonolites and trachytes of northeastern N.M.; includes the rhyolite of Ash Mountain

Wyoming

Alkalic extrusive and intrusive igneous rocks (Phanerozoic | Cenozoic | Tertiary | Eocene): ALKALIC INTRUSIVE AND EXTRUSIVE IGNEOUS ROCKS (AGE ABOUT 44 Ma)--Light- to greenish-gray porphyry.
Alkalic extrusive and intrusive igneous rocks (Phanerozoic | Cenozoic | Quaternary): ALKALIC EXTRUSIVE AND INTRUSIVE IGNEOUS ROCKS (AGE 1.25 Ma)--Leucite- and nepheline-rich flows, scoria, and necks.