TY  - BOOK
AU  - 
TI  - A manual for tephrochronology: collection, preparation, petrographic description and approximate dating of tephra (Volcanic Ash)
PY  - 1977///
CY  - Colo
PB  - Virginia Steen-McIntyre : Idaho Springs
KW  - Volcanic ash, tuff, etc
N1  - Bibliography: p. 130-142
ER  -