Silicic to intermediate volcanic rocks

Rhyolite and dacite flows with associated minor tuffs. Commonly interbedded with Santa Fe or Gila Group sedimentary units. Dacitic lavas in northern Jemez Mountains are Pliocene.
State New Mexico
Name Silicic to intermediate volcanic rocks
Geologic age Neogene, mostly Miocene
Lithologic constituents
Igneous > Volcanic > Felsic-volcanic > Rhyolite (Flow, Pyroclastic-tuff)
Igneous > Volcanic > Felsic-volcanic > Dacite (Flow, Pyroclastic-tuff)
NGMDB product
Counties Bernalillo - Catron - Cibola - Colfax - Grant - Los Alamos - Rio Arriba - Sandoval - Sierra - Socorro - Taos