TY  - RPRT
TI  - Preliminary chemical and mineralogical analyses of the major volcanic ash beds in the Oligocene Brule Formation, northwestern Nebraska
AU  - Kendell A. Dickinson
PY  - 1994
DO  - 10.3133/ofr94292
UR  - https://pubs.usgs.gov/publication/ofr94292
ID  - ofr94292
ER  -