1. ⁴⁰Ar/³⁹Ar and K-Ar geochronology and tectonic significance of the Upper Cretaceous Adel Mountain volcanics and spatially associated Tertiary igneous rocks, northwestern Montana Publication/Creation: Reston, Va. : U.S. Dept. of the Interior, U.S. Geological Survey, 2005 Resource Type: Book Access & Availability: Loading