TY  - RPRT
TI  - Reports and maps of the Geological Survey released only in the open files, 1970
AU  - Betsy A. Weld
AU  - Margaret S. Griffin
AU  - George W. Brett
PY  - 1971
DO  - 10.3133/cir638
UR  - https://pubs.usgs.gov/publication/cir638
ID  - cir638
ER  -