Intrusive and extrusive igneous rocks

Composition ranges from hornblende monzonite to basalt. In Yellowstone area includes andesite and basalt of Emerald Lake (age about 2 Ma), rhyolite of Broad Creek, Pliocene Junction Butte Basalt, and gravel of Mount Everts. Age of basalt on Crescent Mountain 3.6 Ma.
State Wyoming
Name Intrusive and extrusive igneous rocks
Geologic age Miocene-Pliocene
Lithologic constituents
Major
Igneous > Volcanic > Mafic-volcanic > Basalt
Igneous > Volcanic > Mafic-volcanic > Andesite
Igneous > Plutonic > Syenitic > Monzonitehornblende monzonite
Minor
Igneous > Volcanic > Felsic-volcanic > Rhyolite
References
NGMDB product
Counties Lincoln - Park - Teton