TY  - BOOK
AU  - M'Gonigle,John W.
AU  - Dalrymple,G.Brent
TI  - 40Ar/39Ar ages of some Challis Volcanic Group rocks and the initiation of Tertiary sedimentary basins in southwestern Montana
T2  - Bulletin
AV  - QE75 B9 no. 2132
PY  - 1996///
CY  - Washington
PB  - U.S. Govt. Print. Off.
KW  - Rocks, Igneous
KW  - Montana
KW  - Argon-argon dating
KW  - Geology, Stratigraphic
KW  - Tertiary
ER  -