1. ⁴⁰Ar/³⁹Ar ages of some Challis Volcanic Group rocks and the initiation of Tertiary sedimentary basins in southwestern Montana Author/Creator: M'Gonigle, John W. Publication/Creation: Washington : U.S. G.P.O. ; Denver, CO : For sale by the U.S. Geological Survey, Information Services, 1996 Resource Type: Book Access & Availability: Loading
2. 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