Analytical method: UNKNOWN
| Technique | UNKNOWN |
|---|---|
| Material | WHOLE ROCK |
| Institution | USGS DENVER, DENVER, CO, USA |
| Reference | Noble, D C; Rigot, W L; Bowman, H R (1979) Rare-earth-element content of some highly differentiated ash-flow tuffs and lavas. Special Paper - Geological Society of America, no.180, pp.77-85, 1979 |