Cordilleran Volcanism, Plutonism, and Magma Generation at Various Crustal Levels, Montana and Idaho : Western Montana and Central Idaho, July 20 - 25, 1989 (Volume T337)

Published by the American Geophysical Union as part of the Field Trip Guidebooks Series, Volume 337.This six-day field trip examines emplacement of late Cretaceous to Eocene felsic magmas at various crustal levels, from deep continental crust to the earth's surface.

The trip is in three parts, each approximately two days long.

Idaho batholith: deep plutonic, with no preserved volcanic rocks that are known to be related.Boulder batholith - Elkhorn Mountains Volcanics: shallow plutons, with some preserved volcanic rocks erupted from them.Challis Volcanics: broad volcanic field erupted from calderas, with some exposure of magma-chamber plutons.