02152oam 2200577 450 991070540880332120170427072705.0(CKB)5470000002451303(OCoLC)889723472(EXLCZ)99547000000245130320140901d1996 ua 0engurn||||||||||txtrdacontentcrdamediacrrdacarrier⁴⁰Ar/³⁹Ar ages of some Challis Volcanic Group rocks and the initiation of Tertiary sedimentary basins in southwestern Montana /by John W. M'Gonigle and G. Brent DalrympleWashington :United States Government Printing Office,1996.1 online resource (iii, 17 pages) illustrations, mapsU.S. Geological Survey bulletin ;2132Title from title screen (viewed August 28, 2014).Also available online in PDF format from the U.S. Geological Survey Warehouse (http://pubs.er.usgs.gov/)."A summary of ⁴⁰Ar/³⁹Ar age analyses of eighteen samples of volcanic rocks from the Challis Volcanic Group and a summary of basin stratigraphy in southwestern Montana."Includes bibliographical references (pages 6-7).Argon-argon datingGeology, StratigraphicTertiaryIgneous rocksMontanaArgon-argon datingfastGeology, StratigraphicfastIgneous rocksfastTertiary Geologic PeriodfastMontanafastArgon-argon dating.Geology, StratigraphicIgneous rocksArgon-argon dating.Geology, Stratigraphic.Igneous rocks.Tertiary Geologic Period.M'Gonigle John W.1393061Dalrymple G. BrentGeological Survey (U.S.),COPCOPOCLCOOCLCFGPOBOOK9910705408803321⁴⁰Ar3448694UNINA